Veystrum › Tools › Roof pitch calculator
Roof Pitch Calculator and Chart
Convert rise and run to a roof angle and slope multiplier. Rise and run can use any matching unit.
Turn this into a job estimate
Carry the pitch into a Veystrum Free workspace and add measured areas, covering and labour.
Create my free workspaceRoof pitch chart
| Pitch | Angle | Multiplier |
|---|---|---|
| 2:12 | 9.46° | 1.014 |
| 4:12 | 18.43° | 1.054 |
| 6:12 | 26.57° | 1.118 |
| 8:12 | 33.69° | 1.202 |
| 10:12 | 39.81° | 1.302 |
| 12:12 | 45.00° | 1.414 |
How to calculate roof pitch
Divide rise by run. The angle is arctan(rise ÷ run). The slope multiplier is √(rise² + run²) ÷ run.
Frequently asked questions
Must the run be 12 inches?
No. A 12-unit run is a common notation, but any matching measurement units work.
Can multiplier calculate total roof materials?
It estimates simple sloped surface area. Valleys, hips, laps, openings and waste still need project-specific allowances.
Is roof pitch the same as roof angle?
No. Pitch is a rise-to-run ratio; angle is the slope in degrees.
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