Roof Slope Calculator

Convert roof slope between pitch, ratio, percent, angle and rise/run — instant conversion for builders.

Roof Slope Calculator

Convert roof slope between pitch, ratio, percent, angle and rise/run — instant conversion for builders.

Rise

Run

Enter values above and click Calculate — results will appear here with the formula explained.

Slope = rise/run; Percent = slope×100; Angle = atan(slope) in degrees; Pitch = rise:run

How does this work?

Roof slope can be expressed as ratio (6:12), decimal (0.5), percent (50%), or angle (26.57°). They are all the same geometry, just different units.

Percent is slope×100. Angle uses arctangent. Pitch is rise:run normalized to 12.

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What is Roof Slope?

Roof slope can be expressed as ratio (6:12), decimal (0.5), percent (50%), or angle (26.57°). They are all the same geometry, just different units. Formula: Slope = rise/run; Percent = slope×100; Angle = atan(slope) in degrees; Pitch = rise:run

Quick Answer

Roof Slope Calculator: Convert roof slope between pitch, ratio, percent, angle and rise/run — instant conversion for builders. Formula: Slope = rise/run. Example: 6 rise, 12 run = 0.

What it does: Convert roof slope between pitch, ratio, percent, angle and rise/run — instant conversion for builders.
Formula: Slope = rise/run; Percent = slope×100; Angle = atan(slope) in degrees; Pitch = rise:run
Inputs: Rise · Run
Example: 6 rise, 12 run = 0.

Calculator Inputs at a Glance

Field	What to enter
Rise	e.g. 6
Run	e.g. 12

All fields use the exact formulas shown below — results include step-by-step breakdowns you can verify by hand.

How to Use This Calculator

1Enter rise and run.
2See slope, percent, angle and pitch instantly.
3Use to convert architect drawings (angle) to builder pitch (X:12).

Formula Used

Slope = rise/run; Percent = slope×100; Angle = atan(slope) in degrees; Pitch = rise:run

Roof slope can be expressed as ratio (6:12), decimal (0.5), percent (50%), or angle (26.57°). They are all the same geometry, just different units.

Percent is slope×100. Angle uses arctangent. Pitch is rise:run normalized to 12.

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Worked Example

6 rise, 12 run = 0.5 slope = 50% = 26.57° = 6:12 pitch.

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Frequently Asked Questions

QWhat is 50% slope?

0.5 slope, 26.57°, 6:12 pitch — rise is half of run.

QIs 100% slope 45°?

Yes, 12:12 pitch is 1.0 slope, 100%, 45°.

QHow to measure on roof?

Use a level and tape: 12-inch run, measure rise.

Quick Answer

Roof Slope Calculator: Convert roof slope between pitch, ratio, percent, angle and rise/run — instant conversion for builders. Formula: Slope = rise/run. Example: 6 rise, 12 run = 0.

What it does: Convert roof slope between pitch, ratio, percent, angle and rise/run — instant conversion for builders.

Formula: Slope = rise/run; Percent = slope×100; Angle = atan(slope) in degrees; Pitch = rise:run

Inputs: Rise · Run

Example: 6 rise, 12 run = 0.

Field

What to enter

Rise

e.g. 6

Run

e.g. 12

Formula Used

Slope = rise/run; Percent = slope×100; Angle = atan(slope) in degrees; Pitch = rise:run

Roof slope can be expressed as ratio (6:12), decimal (0.5), percent (50%), or angle (26.57°). They are all the same geometry, just different units.

Percent is slope×100. Angle uses arctangent. Pitch is rise:run normalized to 12.