calcs.homes
calcs.homes
Enter rise and run in any matching unit to get the angle in degrees, percent grade, and a simplified ratio — works for stairs, roof pitch, ramps, or any incline.
Rise and run must be in the same unit — the result is unit-independent.
Angle = arctan(rise ÷ run). Percent grade = (rise ÷ run) × 100 — the same number used for road grades and roof pitch call-outs. Ratio simplifies rise:run to its lowest terms, the format carpenters use for roof pitch (like "4:12") and civil engineers use for site grading.
Enter the pitch's rise (first number) and run (always 12 for standard roof pitch notation, like "4 in 12") — the angle in degrees appears as the primary result.
Percent grade is rise divided by run as a percentage — a straightforward ratio. Degrees measure the actual angle from horizontal. They track together but aren't proportional: a 100% grade is a 45° angle, not 90°.