Calculate minimum pipe gradients for foul and surface water drainage using UK Building Regulations Part H. Determine required falls, check gradient compliance, and calculate flow capacity. Free drainage design calculator for UK projects.
For educational purposes only. Not a substitute for professional engineering judgment.
Choose whether to calculate required gradient or flow capacity
Select foul or surface water drainage for appropriate Building Regs minimum
Select pipe size in millimetres
Select material to determine Manning's roughness coefficient
Leave blank to use default for selected material
Expected flow at the pipe section in litres per second