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🏠Roofing Calculator

Calculate Your Roofing Needs

Calculate roofing materials needed for your project including shingles, squares, and bundles. Our free roofing calculator considers roof pitch to give accurate measurements.

Input Dimensions

Roof Size Presets

ft
ft
%
$

Results

Footprint Area

1200.00 sq ft

Pitch Factor

1.05

True Roof Area

1264.91 sq ft

Squares Needed

14 sq

Bundles Needed

42

Estimated Total Cost

$4900.00

💡 Pro Tip

1 square = 100 sq ft. Standard shingles come 3 bundles per square. 10% waste is recommended. It's better to have extra material than to run out mid-project!

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Quick Answer

Roofing estimates usually start with the project area or volume, then add a waste factor before converting the result into bags, pieces, bundles, panels, or gallons. Use this calculator when you need a fast material estimate before ordering supplies, comparing costs, or planning a construction project.

Best for

Contractors, builders, remodelers, and DIY homeowners who need a practical jobsite estimate.

Inputs needed

Start with the dimensions of the project, then choose material settings, price, and waste percentage.

How to estimate

The basic workflow is to calculate roof area, convert to squares, add starter shingles, then round up so you do not run short during installation.

What is a roofing square?

A roofing square is 100 square feet of roof area. It's the standard unit of measurement for roofing materials.

Roofing Squares Formula

Squares = Roof Area ÷ 100

One roofing square equals 100 square feet. Calculate total roof area, divide by 100, add for starter shingles and waste.

Step-by-Step Guide

1

Calculate Roof Area

Measure each plane: length × width. Sum all planes. Consider pitch for accurate area.

2

Convert to Squares

Divide total square footage by 100 to get squares.

3

Add Starter Shingles

Add 1 square of starter shingles for the roof edges.

4

Calculate Ridge/Hip

Measure ridge and hip length for cap shingles - typically 1 bundle covers ~25 linear feet.

5

Add Waste

Add 10-15% extra for waste, valleys, and mistakes.

Pro Tips

  • Always measure from the roof, not just ground estimates.
  • Consider the roof pitch - steeper roofs have more area.
  • Buy extra shingles for future repairs - they'll fade differently over time.
  • Don't forget flashing, drip edge, and underlayment.
  • Consider roof ventilation when doing a re-roof.

Frequently Asked Questions

What is a roofing square?
A roofing square is 100 square feet of roof area. It's the standard unit of measurement for roofing materials.
How many bundles of shingles in a square?
Most three-tab shingles are 3 bundles per square. Architectural shingles may be 4 or 5 bundles per square.
How do I calculate roof pitch?
Roof pitch is rise over 12 inches. Measure rise over 12 inches of run - e.g., 4/12 pitch means 4 inches rise per 12 inches run.
Should I tear off old shingles or overlay?
Building codes typically allow 2 layers. Tearing off provides a better base, but overlay is faster. Check local codes.
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