# Roof Area Calculator

Estimate flat or pitched roof surface from a footprint.

[Open this tool](https://whatson.pk/roof-area-calculator/)

Category: Construction

A pitched roof has more surface than its horizontal footprint. Using the footprint alone can understate the material requirement.

Enter the simple roof geometry, pitch and horizontal overhang. Use a measured layout for roofs with valleys, dormers or several intersecting planes.

## Inputs and controls

* Roof type: Flat; Symmetric gable; Single slope
* Measurement unit: Feet; Metres; Inches; Centimetres; Millimetres
* Building length. Allowed range: 0.001 to 100000
* Building width. Allowed range: 0.001 to 100000
* Horizontal overhang each edge. Allowed range: 0 to 1000
* Pitch angle (degrees). Allowed range: 0 to 75
* Ordering allowance (%). Allowed range: 0 to 100. Added once to the measured requirement.
* Covering quote (PKR / sq ft). Allowed range: 0 to 1000000000. Optional. Enter your own supplier quote.

## How to use

* Choose roof type and measurement unit. Enter building length, building width and horizontal overhang each edge.

* Enter pitch angle, ordering allowance and covering quote.

* Select Calculate estimate. Read the returned values alongside the assumptions below before copying, exporting or acting on the result.


## Why use this tool

The calculation makes the effect of pitch visible before you compare roofing coverage or coating quantities.


## Before relying on the result

Assumes simple planes with no dormers, valleys or roof openings. Enter horizontal overhang.


## Tool limitations

Assumes simple planes with no dormers, valleys or roof openings. Enter horizontal overhang.

## Questions

### Can it handle every roof shape?

No. It assumes simple planes. Treat openings, valleys and complicated junctions through a measured roof schedule rather than a single footprint.

### What should I check before using Roof Area Calculator?

Check Roof type, Measurement unit, Building length and Building width. Use the exact units shown beside the controls and replace any example values with your own inputs.

Source page last modified (UTC): 2026-10-01T14:08:57+00:00

This profile describes the tool. It does not execute it or supply a professional certification.