Free tools for your septic tank
Calculators that show their working: size the tank, size the drainage field, check what emptying should cost and find out which regulator you answer to. Nothing to sell.
📏What size septic tank do I need? (Approved Document H)The size Building Control actually checks — and why three different formulas are doing the rounds.→💧Percolation test and drainage field size (Vp calculator)Work out your Vp, check it is inside the legal band, and size the drainage field with the official formula.→