Roof Pitch Calculator

LIVE RESULT

Rise — vertical height

Run — horizontal distance

Standard run = 1000 mm

Building footprint area — optional, for surface area

Your Results

PITCH · ANGLE · SLOPE

Roof Pitch6:12

Angle (degrees)26.57°

Slope (percentage)50%

Pitch Multiplier1.1180

Roof Surface Area—

Conventional / standard slope

Interactive Diagram

Drag the orange apex to change both rise and run, or the blue handles to adjust one at a time. The boxes above stay in sync.

Free Online Tool · India · Metric & Imperial

Roof Pitch Calculator India — Pitch, Angle & Slope

Built for Indian builders, contractors and homeowners. Enter the rise and run of your roof in millimetres or inches and get the pitch ratio, the angle in degrees, the slope percentage and the roof pitch multiplier instantly.

Pitch ratio (X:12), angle in degrees, slope % and multiplier — all at once
Works in millimetres or inches for metric and imperial jobs
Add a footprint area to estimate the true sloped roof surface
Drag the diagram or type exact values — both stay in sync

Batch Roof Pitch Calculator

Working across several roof sections? Enter one rise, run pair per line (for example 500, 1000) and calculate the pitch, angle, slope and multiplier for every row at once.

Open batch calculator

What Is Roof Pitch?

Roof pitch describes how steep a roof is, written as rise over run — the vertical height the roof gains over a fixed horizontal distance. In India both metric (mm and metres) and the traditional X:12 ratio are used, so this roof pitch calculator supports both.

Pitch vs. Slope

The terms pitch and slope are now used interchangeably and both are based on rise over run. A flatter slope is common on RCC roofs, while sloped tile and Mangalore-tile roofs use steeper pitches to shed monsoon rain quickly.

How to Calculate Roof Pitch

The Basic Pitch Formula

Pitch = Rise ÷ Run

Roof Pitch in Degrees

Angle = arctan( Rise ÷ Run )

Example: a roof rising 500 mm over a 1000 mm run has an angle of arctan(0.5) = 26.57°.

Roof Pitch Multiplier

Multiplier = √( Rise² + Run² ) ÷ Run

Multiply the plan (flat) area of the building by the multiplier to estimate the sloped roof surface area for ordering tiles or sheets.

Roof Pitch Chart

Pitch (X:12)	Angle	Slope %	Multiplier
1:12	4.76°	8.3%	1.0035
2:12	9.46°	16.7%	1.0138
4:12	18.43°	33.3%	1.0541
6:12	26.57°	50%	1.1180
12:12	45.00°	100%	1.4142

Frequently Asked Questions

What roof pitch is common in India?

Sloped tile and metal-sheet roofs are often between 2:12 and 6:12. Steeper pitches drain heavy monsoon rain faster.

How do I convert 5 degrees to a roof pitch?

A 5 degree pitch rises about 9 mm per 100 mm of run, roughly 87 mm per metre — close to a 1:11.4 ratio.

Is pitch the same as roof angle?

They are the same slope shown differently — pitch as a ratio, angle in degrees via the arctangent function.

More Roof Pitch Calculators

Purpose-built tools for every roofing measurement — pick the one that matches your job.