Roof Pitch Calculator (UK): Find Your Roof Angle in Degrees
By the Professional Roofers team
Updated 2026 · Independent cost guide
Your roof pitch is the angle of the slope, and it decides which coverings will actually keep the water out. Enter two measurements and this works out the pitch in degrees, as a ratio and as a percentage, then tells you which roof coverings are rated for that angle.
Work out your roof pitch
For a clean lean-to or single slope this is exact. On a duo-pitch roof, measure the run as half the total span. Coverings list a minimum pitch from the manufacturer, so always confirm against the fixing data for your exact tile or slate.
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