Slope calculator
Convert a slope between percentage, ratio and degrees, and work out the fall over a given distance.
Percentage-
Ratio-
Degrees-
Fall over that run-
For reference
- Surface water drainage typically falls between 1:80 and 1:40.
- Level access routes are generally kept at 1:20 or shallower along their length.
- Gravel starts to migrate downhill on slopes steeper than about 1:12 unless it is confined in a grid.
- Always check the figures required by your own scheme, drainage design or building control officer.
These figures are a guide for ordering. Site conditions, compaction and wastage vary, so check against your own measurements before placing a large order.