How do I find pitch factor?

Use a pitch chart: e.g., 4/12 ≈ 1.12, 6/12 ≈ 1.27, 8/12 ≈ 1.41, 10/12 ≈ 1.54, 12/12 ≈ 1.73.

Do I need separate squares for starter and ridge?

This is a combined estimate. Add extra if you want distinct counts for starter/ridge vs field shingles.

10–15% is common; increase for hips/valleys or complex roofs.

Input footprint area; the pitch factor converts it to roof surface area.

Squares give surface coverage; apply product coverage specs for underlayments separately.

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Convert roof area plus pitch and waste into roofing squares for ordering materials.

Roof area: Footprint area; multiply by pitch factor to get roof surface area.
Pitch factor: Multiplier based on roof pitch (e.g., ~1.12 for 4/12, ~1.27 for 6/12).
Waste allowance: Starter, ridge/hip, and cut waste allowance (10–15% common).

Pitch-adjusted area = roof area × pitch factor. Adjusted area adds waste.

Squares = adjusted area ÷ 100.

Pitch-adjusted area = Roof area × Pitch factor
Adjusted area = Pitch-adjusted area × (1 + Waste%)
Squares = Adjusted area ÷ 100

Use appropriate pitch factor for your roof slope; steeper roofs need higher multipliers.
Increase waste for complex roofs with many cuts; reduce for simple gables.
Pair this with roof replacement cost calculators to budget materials and labor.
Assumes a single pitch factor; complex roofs may need section-by-section pitch factors.
Waste is a single percentage; complex shapes may need higher waste.
Does not account for separate square counts for starter/ridge/shingles—this is a combined estimate.

This roof squares calculator multiplies footprint area by a pitch factor and waste to convert to roofing squares for material estimates.

Use it to size shingle and underlayment orders quickly when you know roof area and slope.

How do I find pitch factor?: Use a pitch chart: e.g., 4/12 ≈ 1.12, 6/12 ≈ 1.27, 8/12 ≈ 1.41, 10/12 ≈ 1.54, 12/12 ≈ 1.73.
Do I need separate squares for starter and ridge?: This is a combined estimate. Add extra if you want distinct counts for starter/ridge vs field shingles.
What waste % should I use?: 10–15% is common; increase for hips/valleys or complex roofs.
Is area footprint or roof surface?: Input footprint area; the pitch factor converts it to roof surface area.
Does this include underlayment/ice & water?: Squares give surface coverage; apply product coverage specs for underlayments separately.

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Roof Replacement Cost Calculator

Estimate roof replacement cost with material, labor, tear-off, and waste allowance.

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Shingle Bundles Calculator

Convert roof area into squares and shingle bundles with a waste factor.

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Roof Pitch Calculator

Find roof pitch, slope percent, and angle from rise and run.

Estimate only. Complex roofs may need section-by-section calculations. Confirm measurements on site before ordering materials.