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Roof pitch calculator

Find the pitch from a rise and a run you measure.

Unit

One unit for the rise, the run, and the plan area.

in

How far the roof goes up. Use 0 for a flat run.

in

How far the roof goes across. Must be more than 0.

sq in

A flat area to multiply by the slope factor. Leave blank to skip it.

Result

Roof pitch calculator

Unit
Inches

Pitch per 12

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Enter a rise and a run in the same unit.

Ballpark estimate, check before you buy or quote.

Verify with your local code or a professional.

Estimate for planning only. This is not tax, legal, accounting or financial advice. Results depend on the figures you enter. Check all numbers, rates and rules with the official source or a qualified professional before relying on them.

How this works and common questions

About this tool

Pitch per 12, degrees, slope percent, and a length multiplier come from the rise and run. An optional plan area is multiplied for a sloped area.

How it works

Pitch per 12 is rise divided by run, times 12. A rise of 6 and a run of 12 is 6.00 in 12.

Rules

Use the same unit for rise and run. The multiplier is the sloped length divided by the run, rounded half up to 3 decimals. Check the numbers before you buy.

Questions

What is a 6 in 12 pitch?

A rise of 6 and a run of 12. That is 26.57 degrees, a 50.00% slope, and a multiplier of 1.118.

Can I use millimetres?

Yes. Choose millimetres. A rise of 150 and a run of 300 is the same 6.00 pitch.

What does the plan area do?

If you type one, it is multiplied by the slope factor. 200 square inches at 1.118 is 223.60 square inches.

Do I need an account?

No. The tools work without one. You only need to sign in to save your work.

Is what I type saved?

No. Nothing is saved unless you sign in and choose Save. Otherwise it stays on the page.

Do you show ads or sell my information?

No. We show no ads and we do not sell your information.

Is this tax or legal advice?

No. Results are estimates for planning. Check rates and rules with the official source or a qualified professional.

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Estimate for planning only. This is not tax, legal, accounting or financial advice. Results depend on the figures you enter. Check all numbers, rates and rules with the official source or a qualified professional before relying on them.