Construction & Materials
Roof Pitch & Rafter Length Calculator
Calculate roof pitch angle and rafter length from run and rise.
Your inputs
Change any value to update the result instantly.
Rafter length
17.8885 ft
Roof pitch angle
26.6 °
Pitch ratio
6 /12
Total run incl. overhang
16 ft
Formula and working
rafter = √(run² + rise²); angle = atan(rise/run)
- 1
Collect the inputs
Rise per 12 in of run = 6 in; Total horizontal run = 15 ft; Overhang = 1 ft
- 2
Apply the formula
rafter = √(run² + rise²); angle = atan(rise/run)
- 3
Result
Rafter length = 17.8885 ft
Frequently asked questions
Important limitation
This is an educational estimate based only on the values and formula shown. Verify current rates, rules, units, and professional standards before relying on the result. It is not personalized financial or investment advice.
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