Roof Pitch Calculator
Roof Pitch Calculator lets you roof pitch angle is atan(rise/run) and slope percentage is 100 × rise/run. Enter your own values or load the worked example.
- Copy or download the computed result
- Adjust rise
- See the processing method and limits
Method and calculation
Roof pitch angle is atan(rise/run) and slope percentage is 100 × rise/run.
Inputs and settings
Roof Pitch Calculator accepts Rise (minimum 0.000001); Horizontal run (minimum 0.000001).
Worked example
Roof Pitch Calculator example — Rise: 4; Horizontal run: 12. Computed output: { "degrees": 18.43494882292201, "percent": 33.333333333333336, "risePer12": 4 }
Output and limitations
Roof Pitch Calculator: Use finite inputs. Results use double-precision arithmetic.
Technical references: JavaScript numerical operations
Roof Pitch Calculator FAQs
Roof Pitch Calculator applies the following rule to your input: Roof pitch angle is atan(rise/run) and slope percentage is 100 × rise/run. The worked example on this page uses the same processor as the result button.
Roof Pitch Calculator has these boundaries: Use finite inputs. Results use double-precision arithmetic. Start by checking the rise field against the units or format shown.
Roof Pitch Calculator provides this sample: { "degrees": 18.43494882292201, "percent": 33.333333333333336, "risePer12": 4 }. Use the sample button to reproduce it, then replace the inputs with your own values.