Roof measuring area estimator

Roof Area Calculator

Convert roof length, horizontal run, pitch, and plane count into sloped roof area, roof squares, waste, and rough material cost. Use it for roof measuring searches before choosing shingles, underlayment, or metal panels.

Units

Roof length along ridge/eave (ft)Horizontal run per plane (ft)Roof pitch (x/12)Roof planes Waste / cut allowance (%)Cost per roof square or m² ($)

Roof area to order

Roof squares / measured area

Pitch multiplier

Rough cost

Roof area is a planning estimate

Dormers, hips, valleys, waste pattern, skylights, chimneys, tear-off, starter, ridge, and product coverage can change the final order. Use field measurements when the roof is not a simple plane.

Android App

Need roof area and roof square takeoffs hands-free?

Use the Android app when you need voice input, offline use, material lists, or PDF export. Free, no ads, no accounts.

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Roof Shingle Calculator

Turn roof area into bundles and shingle waste.

Roof Underlayment Calculator

Estimate roll coverage from roof area.

Roof Length Calculator

Check sloped roof length from run, pitch, and overhang.

View all

Roof area formula

Pitch multiplier = √(1 + (pitch ÷ 12)²)

Measured area = roof length × horizontal run × roof planes × pitch multiplier

Order area = measured area × (1 + waste %)

Roof squares = order area ÷ 100

Sample takeoff

A 40 ft roof length, 12 ft run, 6/12 pitch, two planes, and 10% waste needs about 1,181 ft² to order, or 11.8 roof squares.A 12 m roof length, 3.6 m run, 6/12 pitch, two planes, and 10% waste needs about 106.2 m² to order.