How to count pipes, fittings and clips for plumbing
Updated October 16, 2026
Plumbing is ordered from the lengths of the runs. The bars follow from the length and the waste, the fittings and clips from the rates the plumber or the maker gives. This guide counts quantities; it does not size pipes or check pressures.
1. Measure the runs
Measure, on the plan, the cold-water run, the hot-water run and the drain run, following the route of the pipes and not a straight line.
2. Pipe bars, with waste
Add the cold and hot runs, increase them by the waste for cuts, divide by the length of a bar and round up to a whole bar.
3. Fittings, clips and valves
Fittings are counted per metre of pipe at a rate chosen from experience, clips by dividing the length by their spacing, and one isolation valve is counted per fixture. The hot pipe also takes an insulation sleeve.
Worked example: a supply with 8 fixtures
Cold 40 m, hot 25 m, bars of 4 m, clips every 0.8 m, 0.6 fitting per metre, 10 % waste:
Cold pipe 40 × 1.10 = 44.00 m, hot pipe 25 × 1.10 = 27.50 m.
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