{"id":108,"date":"2022-07-19T08:00:00","date_gmt":"2022-07-19T06:00:00","guid":{"rendered":"https:\/\/measureall.app\/nouvelle-application-pour-calculer-une-pente\/"},"modified":"2026-10-16T13:05:55","modified_gmt":"2026-10-16T11:05:55","slug":"new-application-for-calculating-a-slope","status":"publish","type":"post","link":"https:\/\/measureall.app\/en\/nouvelle-application-pour-calculer-une-pente\/","title":{"rendered":"App to calculate a slope: roof, terrain and staircase, from the formula in PDF format"},"content":{"rendered":"<div class=\"wp-block-rank-math-toc-block\" id=\"rank-math-toc\"><nav><ul><li class=\"\"><a href=\"#calculer-une-pente-formule-et-conversions\">Calculating a slope: formula and conversions<\/a><\/li><li class=\"\"><a href=\"#application-pente-de-toit-linclinaison-dun-versant\">Roof slope application: the inclination of a slope<\/a><ul><li class=\"\"><a href=\"#calcul-rampant-toiture-la-longueur-reelle-du-versant\">Calculating the roof slope: the actual length of the slope<\/a><\/li><\/ul><\/li><li class=\"\"><a href=\"#calcul-pente-terrain-denivele-distance-et-methodes-de-releve\">Calculation of terrain slope: elevation, distance and methods of measurement<\/a><\/li><li class=\"\"><a href=\"#calcul-pente-escalier-hauteur-de-marche-et-giron\">Calculation of stair slope: step height and step angle<\/a><\/li><li class=\"\"><a href=\"#calculateur-inclinometre-ou-plan-pdf-quelle-application-pour-calculer-une-pente\">Calculator, inclinometer or PDF plan: which application to use to calculate a slope?<\/a><\/li><li class=\"\"><a href=\"#measureall-relever-une-pente-sur-un-plan-pdf\">MeasureAll: measuring a slope on a PDF plan<\/a><\/li><li class=\"\"><a href=\"#application-pour-calculer-une-pente-ce-quil-faut-retenir\">Application for calculating a slope: what you need to remember<\/a><ul><li class=\"\"><a href=\"#faq-question-1\">How to calculate a slope?<\/a><\/li><li class=\"\"><a href=\"#faq-question-2\">Is there an app to calculate a free slope?<\/a><\/li><li class=\"\"><a href=\"#faq-question-3\">How to calculate terrain slope using cartes.gouv.fr?<\/a><\/li><li class=\"\"><a href=\"#faq-question-4\">Does Blondel's relationship replace a stair-step calculation?<\/a><\/li><li class=\"\"><a href=\"#faq-question-5\">How to calculate the length of a roof ridge?<\/a><\/li><\/ul><\/li><\/ul><\/nav><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">An application for calculating a slope meets one of three needs: obtaining a slope in percentage or degrees from already known coordinates, measuring the actual inclination of a surface with a sensor, or measuring a slope on a plan. MeasureAll meets the third need: the application uses your PDF plans on iPhone, iPad, or Android and, when the plan is reliable, the measurement can be taken at the office, without having to climb onto a roof for the only point measurement. In all cases, the calculation is based on the same formula.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This page details it with its conversions, then applies it to three concrete cases: the roof and the length of its ramp, the terrain, and the staircase. It finally helps to choose the right tool and shows how to plot these values on a PDF.<\/p>\n\n\n\n<h2 id=\"calculer-une-pente-formule-et-conversions\" class=\"wp-block-heading\">Calculating a slope: formula and conversions<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Slope compares a vertical ascent, the gradient, to the horizontal distance traveled. Expressed as a percentage, it is equal to:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Slope (%) = 100 \u00d7 elevation \u00f7 horizontal distance<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The two lengths must be in the same unit, and the distance must be horizontal, not measured along the slope. A climb of 0.20 m on 2.00 m of horizontal ground gives 100 \u00d7 0.20 \u00f7 2.00 = 10%. This is the same slope as 0.10 m on 1.00 m: doubling the two lengths does not change their ratio. This <a rel=\"noopener noreferrer\" target=\"_blank\" href=\"https:\/\/media.eduscol.education.fr\/file\/Programmes\/16\/9\/doc_acc_clg_grandeurs_109169.pdf\">Definition of the slope<\/a>, recalled by \u00c9duscol, applies to a roof as well as to a plot of land.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">To convert to degrees, take the arctangent of the ratio: angle = arctan(slope \u00f7 100). In reverse, slope = 100 \u00d7 tan(angle). A slope of 100% therefore does not correspond to 90\u00b0, but to 45\u00b0: the elevation then equals the horizontal distance.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><thead><tr><th>Slope<\/th><th>Lecture<\/th><th>Angle<\/th><\/tr><\/thead><tbody><tr><td>1\u00a0%<\/td><td>1 cm per meter horizontally<\/td><td>0,57\u00b0<\/td><\/tr><tr><td>5\u00a0%<\/td><td>5 cm per meter horizontally<\/td><td>2,86\u00b0<\/td><\/tr><tr><td>10\u00a0%<\/td><td>10 cm per meter horizontally<\/td><td>5,71\u00b0<\/td><\/tr><tr><td>30\u00a0%<\/td><td>30 cm per horizontal meter<\/td><td>16,70\u00b0<\/td><\/tr><tr><td>50\u00a0%<\/td><td>50 cm per meter horizontally<\/td><td>26,57\u00b0<\/td><\/tr><tr><td>100\u00a0%<\/td><td>1 m per horizontal meter<\/td><td>45,00\u00b0<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Three mistakes often occur: dividing centimeters by meters, putting the inclined length as the denominator instead of the horizontal distance, and reading a result in degrees as radians given by the calculator. In the latter case, multiply by 180 and divide by \u03c0, once only.<\/p>\n\n\n\n<h2 id=\"application-pente-de-toit-linclinaison-dun-versant\" class=\"wp-block-heading\">Roof slope application: the inclination of a slope<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">For a two-slope roof, the slope is read on a cut perpendicular to the eaves. The elevation is the height of the slope, between the gutter, its low edge, and the eaves, its high line, and not the total height of the building. The horizontal distance is the projection of the slope, from the gutter to the eaves: it is only half the width of the roof, including the gutter overflow, if the eaves are centered. Always measure in the direction of the steeper slope, because a rafter has not the same inclination as the slopes it separates.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">On a slope, for example, the rise is 2.50 m for a horizontal projection of 4.00 m: 100 \u00d7 2.50 \u00f7 4.00 = 62.5%, i.e., arctan(0.625) = 32.01\u00b0. A roof pitch application does this calculation for you, but it does not choose the correct angles for you. As explained by the <a rel=\"noopener noreferrer\" target=\"_blank\" href=\"https:\/\/www.velux.fr\/magazine\/comment-calculer-pente-de-toit\">VELUX guide on the roof pitch<\/a>, Everything starts from properly measured horizontal height and distance.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The obtained slope is then used to verify that the planned coverage suits it. <a href=\"https:\/\/measureall.app\/en\/calculation-of-roof-slope\/\">Minimum laying slope<\/a> It depends on the material, the geographical area and the exposure of the site, as is recalled <a rel=\"noopener noreferrer\" target=\"_blank\" href=\"https:\/\/www.wienerberger.fr\/nos-atouts\/toit-intelligent\/tout-savoir-sur-la-pente-minimale-pour-une-toiture-en-tuiles.html\">wienerberger for tiled roofs<\/a>&nbsp;; Manufacturers' drawings also include the horizontal projection of the eaves. Therefore, no single value applies to all roofs.<\/p>\n\n\n\n<h3 id=\"calcul-rampant-toiture-la-longueur-reelle-du-versant\" class=\"wp-block-heading\">Calculating the roof slope: the actual length of the slope<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The slope is the inclined length of the slope, from the gutter to the eaves. It is derived from the gradient and the projection: slope = \u221a(gradient\u00b2 + projection\u00b2) For the previous slope, \u221a(2.50\u00b2 + 4.00\u00b2) = 4.72 m. Do not confuse the two lengths: 4.00 m is a horizontal distance, readable on a roof plan viewed from above, whereas 4.72 m is the inclined length, revealed by a section, a gable fa\u00e7ade or calculation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For a rectangular roof, the calculated pitch allows us to move on to the actual surface: pitch \u00d7 length of the roof, measured parallel to the eaves. A single elevation view is not enough, because of the height difference. For a complete two- or four-slope roof, our page on the <a href=\"https:\/\/measureall.app\/en\/roofer\/\">calculation of the roof surface<\/a> details the method.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Do you have the PDF of the cut? Measure the slope of the slope directly on the plan with MeasureAll: a complete file is provided.<\/strong><\/p>\n\n\n\n<h2 id=\"calcul-pente-terrain-denivele-distance-et-methodes-de-releve\" class=\"wp-block-heading\">Calculation of terrain slope: elevation, distance and methods of measurement<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">For a terrain, there must be two points A and B, their elevation in the same reference system and the horizontal distance separating them:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Slope (%) = 100 \u00d7 (altitude of B \u2212 altitude of A) \u00f7 horizontal distance<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The sign indicates the direction: positive when going up, negative when going down from A to B. If you have only measured the inclined length L, first find the horizontal distance: D = \u221a(L\u00b2 \u2212 d\u00e9nivel\u00e9\u00b2).<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Let\u2019s take a rectangular plot of 20 \u00d7 30 m, with a vertical difference of 2.50 m between two opposite corners. The horizontal diagonal measures \u221a(20\u00b2 + 30\u00b2) = 36.06 m, giving an average slope of 100 \u00d7 2.50 \u00f7 36.06 = 6.93%. This figure remains an average over a single direction: the terrain may be steeper elsewhere, or present a break in the slope. For useful results, measure several directions and note the direction of each measurement.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><thead><tr><th>Method<\/th><th>Principle<\/th><th>Limit<\/th><\/tr><\/thead><tbody><tr><td>Rule and level in bubble<\/td><td>Horizontal rule held, vertical gap measured to the ground, by sections<\/td><td>Local survey; the elevations of each section are added together<\/td><\/tr><tr><td>Optical or laser level, with sight<\/td><td>Reading the mire, a graduated rule, in A then in B, without moving the device<\/td><td>Stable station and common reference indispensable<\/td><\/tr><tr><td>Topographic plan PDF<\/td><td>Heights shown on the plan, distance measured between the points shown<\/td><td>No points marked or level curves, no elevation gain<\/td><\/tr><tr><td>Altimetry profile online<\/td><td>Profile traced on a map between two points<\/td><td>Indicative result, according to the altimetric data used<\/td><\/tr><tr><td>Left of the surveyor<\/td><td>Contour points, slope breaks and terrain profiles<\/td><td>Mission and precision to be specified in the quote<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">With an optical level, or a laser whose beam remains horizontal, the ruler holds in a line: altitude of B = altitude of A + reading in A \u2212 reading in B, from the same station, that is to say without moving the device. If you read 0.725 m on the aiming device in A and 1.465 m in B, at a horizontal distance of 12.40 m, the elevation is 0.725 \u2212 1.465 = \u22120.74 m. The slope is therefore 100 \u00d7 (\u22120.74) \u00f7 12.40 = \u22125.97%: the terrain slopes from A to B. <a rel=\"noopener noreferrer\" target=\"_blank\" href=\"https:\/\/leica-geosystems.com\/-\/media\/files\/leicageosystems\/products\/manuals%20quickguides\/leica_na2_nak2_um.pdf?hash=0893DF795495D188A829839C2C3EF8A9&amp;rev=4b03f9d9eeb441b981e00fa49daff0a5&amp;sc_lang=fr-be\">Leica NA2 level manual<\/a>, An optical level describes this reading principle.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Online, the former G\u00e9oportail has given way to cartes.gouv.fr. Its tool for <a rel=\"noopener noreferrer\" target=\"_blank\" href=\"https:\/\/cartes.gouv.fr\/aide\/fr\/guides-utilisateur\/visualiseur-cartographique\/calculer-un-profil-altimetrique\/\">altimetric profile<\/a> gives an overview of the relief, but the result depends on the <a rel=\"noopener noreferrer\" target=\"_blank\" href=\"https:\/\/cartes.gouv.fr\/aide\/fr\/guides-utilisateur\/utiliser-les-services-de-la-geoplateforme\/calcul-altimetrique\/\">given altimetric value used<\/a>, of its resolution and precision. For an altitude read on a map at 1\/25,000, the <a rel=\"noopener noreferrer\" target=\"_blank\" href=\"https:\/\/geodesie.ign.fr\/faq\">IGN geodetic FAQ<\/a> indicates a precision of only a few meters: at a distance of 20 m, an error of one meter in elevation changes the slope by 5 percentage points. Finally, the\u2019<a rel=\"noopener noreferrer\" target=\"_blank\" href=\"https:\/\/cartes.gouv.fr\/aide\/fr\/guides-utilisateur\/visualiseur-cartographique\/utiliser-les-outils-de-mesure\/\">angle measuring tool<\/a> The map gives an angle relative to the North, an azimuth, and not a slope.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A slope alone does not say whether a project is feasible. <a rel=\"noopener noreferrer\" target=\"_blank\" href=\"https:\/\/www.service-public.gouv.fr\/particuliers\/vosdroits\/F1633?lang=fr\">Operational urban planning certificate<\/a> Indicates whether the proposed operation is feasible in the field. The accessibility thresholds depend on the applicable text, such as the current slope of 5% for a new ERP access path. For a garage descent, no universal maximum is established, and the average can mask a steep part: a 1.80 m elevation difference over 12 m gives an average of 15%. If the first 4 meters are limited to 5%, they only recover 0.20 m: there remains 1.60 m over 8 m, or 20%, not counting the connections at the top and bottom.<\/p>\n\n\n\n<h2 id=\"calcul-pente-escalier-hauteur-de-marche-et-giron\" class=\"wp-block-heading\">Calculation of stair slope: step height and step angle<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">For a straight line with regular steps, the slope is calculated using two quantities: the step height h and the angle g, that is, the horizontal distance between two successive steps. Angle = arctan(h \u00f7 g) and slope = 100 \u00d7 h \u00f7 g. The angle is not necessarily the total depth of the step: measure it between the steps.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For example, a staircase has 2.72 m of steps in 16 steps, i.e., h = 2.72 \u00f7 16 = 0.17 m. With a step height of 0.28 m, the angle is arctan(0.17 \u00f7 0.28) = 31.26\u00b0, or a slope of 60.71%.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The slope of a staircase says nothing about comfort or conformity. Comfort is appreciated with the Blondel relationship, 2h + g, which here is 2 \u00d7 0.17 + 0.28 = 0.62 m. The recommended ranges vary according to the sources: from 60 to 66 cm in the <a rel=\"noopener noreferrer\" target=\"_blank\" href=\"https:\/\/www.inrs.fr\/dam\/inrs\/CataloguePapier\/ED\/TI-ED-950.pdf\">Design guide from the INRS<\/a> for workplaces, from 62 to 65 cm in the <a rel=\"noopener noreferrer\" target=\"_blank\" href=\"https:\/\/www.les-caue-occitanie.fr\/sites\/default\/files\/fichiers\/ressource\/field_fichiers\/31_escalier_maconne.pdf\">CAUE sheet for Occitanie<\/a> on the masonry staircase. The INRS reminds that this relationship alone does not guarantee a safe staircase.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The regulations depend on the building. For a staircase open to the public in a new ERP, the\u2019<a rel=\"noopener noreferrer\" target=\"_blank\" href=\"https:\/\/www.legifrance.gouv.fr\/loda\/id\/JORFTEXT000034485459\/\">Order of April 20, 2017<\/a> Limits the step height to 16 cm and imposes a step height of at least 28 cm. A staircase with a step height of 17 cm and a step width of 29 cm gives a step length of 2 \u00d7 17 + 29 = 63 cm, within the ranges cited, and an angle of 30.38\u00b0, i.e., arctan(17 \u00f7 29). However, its step height exceeds this limit. An application calculates the geometry; it does not validate a staircase.<\/p>\n\n\n\n<h2 id=\"calculateur-inclinometre-ou-plan-pdf-quelle-application-pour-calculer-une-pente\" class=\"wp-block-heading\">Calculator, inclinometer or PDF plan: which application to use to calculate a slope?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Before choosing an application to calculate a slope, identify the data you have at your disposal: the right tool depends on it.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><thead><tr><th>Tool<\/th><th>What he gives<\/th><th>What he asks for<\/th><th>Limit<\/th><\/tr><\/thead><tbody><tr><td>Online calculator<\/td><td>The slope starting from two lengths<\/td><td>Gradient and horizontal distance already known<\/td><td>Does not measure anything itself<\/td><\/tr><tr><td>Electronic level or inclinometer<\/td><td>The angle of the support on which it rests<\/td><td>Physical access to the surface<\/td><td>Local measurement, based on support and calibration<\/td><\/tr><tr><td>Smartphone level<\/td><td>An indicative inclination<\/td><td>The phone placed on the surface<\/td><td>Measure presented as approximate by Apple<\/td><\/tr><tr><td>Measured on a PDF plan<\/td><td>Lengths, angles and slopes shown on the drawing<\/td><td>A plan on a scale, with a reliable rating<\/td><td>Depends on the plan and the calibration<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">An electronic level like the <a rel=\"noopener noreferrer\" target=\"_blank\" href=\"https:\/\/www.bosch-professional.com\/fr\/fr\/products\/gim-120-0601076800\">GIM 120 from Bosch<\/a> displays the inclination in degrees, percentages or mm\/m, with a declared accuracy of \u00b10.2\u00b0 between 1\u00b0 and 89\u00b0: this is the characteristic of this instrument, not that of a telephone. Apple also presents the <a rel=\"noopener noreferrer\" target=\"_blank\" href=\"https:\/\/support.apple.com\/fr-lu\/guide\/iphone\/iphbd435673d\/ios\">iPhone level<\/a> As an approximate measure. A photo of the roof does not replace a drawing: perspective distorts angles and lengths. For a building whose plans are available, or a project that has yet to be drawn, the PDF measurement gives the dimensions without access to the site.<\/p>\n\n\n\n<h2 id=\"measureall-relever-une-pente-sur-un-plan-pdf\" class=\"wp-block-heading\">MeasureAll: measuring a slope on a PDF plan<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">MeasureAll is a PDF plan measurement app for iPhone, iPad and Android that also serves as an application for calculating a slope from a drawing. It measures on the drawing, not on the actual surface. The path follows the steps below, which can be adapted to the document you have at hand:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Import and calibrate.<\/strong> You import the plot, elevation, or topographic plan, calibrate it to a known elevation, and then check a second elevation.<\/li>\n\n\n\n<li><strong>Lift the lengths.<\/strong> On a map, you measure the elevation and the horizontal projection of the slope; for a flight, the walking height and the ridge, or the difference between two walking noses; on a topographic map, the distance between two points on the side.<\/li>\n\n\n\n<li><strong>Measure the angle.<\/strong> Using the angle tool, mark on the drawing the angle between the slope, or the line of the walking noses, and the horizontal line, provided that the section has the same scale in both horizontal and vertical directions.<\/li>\n\n\n\n<li><strong>Apply the slope.<\/strong> For a roof, the specified slope is used to calculate the inclined surface of the slope.<\/li>\n\n\n\n<li><strong>Classify and export.<\/strong> You name the measures, you group them by project, and you export them in a spreadsheet-readable format.<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">On a long profile, the horizontal and vertical scales often differ: the drawn angle is not then the actual slope. Instead, read the quoted altitudes and distances, then apply the formula. Once the plans are loaded, the survey also works offline. The accuracy depends on the plan, its scale and the care taken in the calibration: always check a second reference point before relying on the result.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Measure the slopes of your PDF plan: a complete file is provided.<\/strong> MeasureAll is available on the\u2019<a rel=\"noopener noreferrer\" target=\"_blank\" href=\"https:\/\/apps.apple.com\/fr\/app\/measureall\/id1537547786?ct=website&amp;mt=8\">App Store<\/a> for iPhone and iPad, and on <a rel=\"noopener noreferrer\" target=\"_blank\" href=\"https:\/\/play.google.com\/store\/apps\/details?id=com.measureall.app&amp;referrer=utm_source%3Dwebsite%26utm_medium%3Dbadge\">Google Play<\/a> for Android smartphones and tablets. After this first subscription, the subscription is purchased in the app.<\/p>\n\n\n\n<h2 id=\"application-pour-calculer-une-pente-ce-quil-faut-retenir\" class=\"wp-block-heading\">Application for calculating a slope: what you need to remember<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Slope (%) = 100 \u00d7 elevation \u00f7 horizontal distance, and angle = arctan(slope \u00f7 100): a slope of 100% makes 45\u00b0, not 90\u00b0.<\/li>\n\n\n\n<li>For a roof, measure the height of the slope and its projection on a section; the slope is equal to \u221a(slope\u00b2 + projection\u00b2).<\/li>\n\n\n\n<li>For a terrain, start with two altitudes and a horizontal distance, and remember that the slope changes depending on the direction.<\/li>\n\n\n\n<li>For a staircase, calculate the height of the steps and the landings: neither the angle nor the Blondel ratio are valid for compliance.<\/li>\n\n\n\n<li>Choose the tool according to your data: <a href=\"https:\/\/measureall.app\/en\/roof-calculation-software\/\">calculator<\/a>, instrument on site or measured on a PDF plan.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">For a roofing, landscaping or general contracting company, MeasureAll offers annual subscriptions for teams, with company code activation, a single invoice and transferable licenses. <strong>Equip your construction teams: request a company quote.<\/strong><\/p>\n\n\n<div id=\"rank-math-faq\" class=\"rank-math-block\">\n<div class=\"rank-math-list\">\n<div id=\"faq-question-1\" class=\"rank-math-list-item\">\n<h3 class=\"rank-math-question\">How to calculate a slope?<\/h3>\n<div class=\"rank-math-answer\">\n\n<p>Divide the elevation by the horizontal distance between the two same points, then multiply by 100. The two lengths must be in the same unit, and the distance must be horizontal, not measured along the slope. A climb of 0.20 m on 2.00 m of horizontal ground thus gives 10%, the same slope as 0.10 m on 1.00 m.<\/p>\n\n<\/div>\n<\/div>\n<div id=\"faq-question-2\" class=\"rank-math-list-item\">\n<h3 class=\"rank-math-question\">Is there an app to calculate a free slope?<\/h3>\n<div class=\"rank-math-answer\">\n\n<p>Yes, as needed. The calculation itself requires only a formula, which many online calculators apply, and the iPhone app \"Mesures\" includes a level that provides an approximate slope. To measure a slope on a PDF, MeasureAll offers a complete package; the subscription is then purchased in the app. Choose according to the data you have available.<\/p>\n\n<\/div>\n<\/div>\n<div id=\"faq-question-3\" class=\"rank-math-list-item\">\n<h3 class=\"rank-math-question\">How to calculate terrain slope using cartes.gouv.fr?<\/h3>\n<div class=\"rank-math-answer\">\n\n<p>On cartes.gouv.fr, which replaces the old G\u00e9oportail, draw an altimetric profile between the two points: it displays the altitudes along the line. Divide the elevation by the horizontal distance, then multiply by 100. The result remains indicative, as it depends on the altimetric data used. The map\u2019s angle tool measures an azimuth, not a slope.<\/p>\n\n<\/div>\n<\/div>\n<div id=\"faq-question-4\" class=\"rank-math-list-item\">\n<h3 class=\"rank-math-question\">Does Blondel's relationship replace a stair-step calculation?<\/h3>\n<div class=\"rank-math-answer\">\n\n<p>No. Blondel's relation, 2h + g, takes into account the comfort of the step by adding two walking heights and a giron. The stair slope calculation gives the angle of the climb, arctan(h \u00f7 g). Neither of the two is sufficient to establish conformity: the required dimensions depend on the type of building and the applicable text.<\/p>\n\n<\/div>\n<\/div>\n<div id=\"faq-question-5\" class=\"rank-math-list-item\">\n<h3 class=\"rank-math-question\">How to calculate the length of a roof ridge?<\/h3>\n<div class=\"rank-math-answer\">\n\n<p>The ramp is the inclined length of the slope, from the gutter to the eaves. On a section, measure the elevation of the slope and its horizontal projection; then apply Pythagoras: ramp = \u221a(elevation\u00b2 + projection\u00b2) For a slope of 2.50 m and a projection of 4.00 m, the roof ramp calculation gives 4.72 m. Do not confuse this ramp with the horizontal distance.<\/p>\n\n<\/div>\n<\/div>\n<\/div>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>Slope formula and its conversions, three practical cases (roof and ramp, terrain, staircase), choice between calculator, inclinometer and PDF plan, and elevation of slopes on a plan with MeasureAll.<\/p>","protected":false},"author":0,"featured_media":428,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_gspb_post_css":"","footnotes":""},"categories":[1],"tags":[],"class_list":["post-108","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-general"],"_links":{"self":[{"href":"https:\/\/measureall.app\/en\/wp-json\/wp\/v2\/posts\/108","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/measureall.app\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/measureall.app\/en\/wp-json\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/measureall.app\/en\/wp-json\/wp\/v2\/comments?post=108"}],"version-history":[{"count":0,"href":"https:\/\/measureall.app\/en\/wp-json\/wp\/v2\/posts\/108\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/measureall.app\/en\/wp-json\/wp\/v2\/media\/428"}],"wp:attachment":[{"href":"https:\/\/measureall.app\/en\/wp-json\/wp\/v2\/media?parent=108"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/measureall.app\/en\/wp-json\/wp\/v2\/categories?post=108"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/measureall.app\/en\/wp-json\/wp\/v2\/tags?post=108"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}