Glossary: Rafter Length
**Rafter Length** is the diagonal length of a structural roof rafter board, calculated from rise and run dimensions using the Pythagorean theorem, including structural eave overhang extensions.
Rafter Geometry Calculations
Rafter length is computed as: Rafter = √(Rise² + Run²) + Overhang. Carpenters cut plumb cuts at the ridge and bird's mouths at the wall plates using these layout measurements.