Construction/ CALCULATOR

Roof pitch and slope length

Convert a measured rise and horizontal run into pitch angle, slope percentage and sloping length.

Vertical risemVertical difference between the two measured level points.

Horizontal runmHorizontal—not sloping—distance corresponding to the rise.

Pitch angle

30.96 °

Slope

60.00 %

Rise per 1 unit of run

0.600 m/m

Sloped-area factor

1.166 ×

Sloping length for entered run

4.66 m

One straight planar slope and level horizontal reference. Eaves, ridge thickness, overhangs, sag, curved surfaces and structural rafter design are excluded. Verify dimensions from drawings, safe ground-based methods or a competent survey; do not climb an unprotected roof to obtain inputs.

FROM ESTIMATE TO ACTION

Use the result, not just the number.

Verify the inputs

Measure or document each input. If a value is only an estimate, record its source and test a conservative alternative.

Keep the calculation traceable

Save the input link or copied result together with the date, units and assumptions. A number without its inputs cannot be checked later.

Confirm the decision

Compare the estimate with the related guide, current product data and requirements that apply at your location before buying or building.

Inputs to verify

Vertical rise (m): Vertical difference between the two measured level points.
Horizontal run (m): Horizontal—not sloping—distance corresponding to the rise.

Continue your calculation

Construction

Roof covering area and pack estimate

Convert a simple horizontal roof footprint and pitch into sloping area, order area and whole packs.