Plumbing Cost Calculator
Work out a plumbing job's cost — pipes, fittings, fixtures and labour — with contingency and tax, from your own prices.
Plumbing costs are materials plus labour plus the surprises — and the surprises are why the contingency is there. This calculator adds them up from your own prices.
All prices are entered by you. This site publishes no construction prices, and results are estimates, not guaranteed quotes.
Your results
Enter your measurements and press Calculate.
Quantities are rounded up to whole tiles, planks, boxes or bags, after the wastage allowance. Cost appears only when you enter a price.
Formula
All lengths are converted to a single unit before the calculation: 1 ft = 0.3048 m, 1 in = 25.4 mm, 1 ft² = 0.09290304 m², 1 yd² = 9 ft². Material quantities are rounded up — you cannot buy part of a tile, plank or bag.
How to use this calculator
- Enter your cost for pipes, fittings and fixtures.
- Enter the labour hours and hourly rate.
- Add any other costs, then set the contingency and tax.
- Read the subtotal, contingency, tax and total.
Worked example
| Materials | Pipes $500 + Fittings $200 + Fixtures $1,500 = $2,200 |
|---|---|
| Labour | 20 h × $45 = $900 |
| Subtotal | $2,200 + $900 + $100 other = $3,200 |
| Contingency (10%) | $320 |
| Tax (8%) | ($3,200 + $320) × 0.08 = $281.60 |
| Total | $3,200 + $320 + $281.60 = $3,801.60 |
Check it by hand: every step above uses the formula in the box. If your numbers match the example inputs but the calculator gives a different answer, please report it via the contact page.
Frequently asked questions
What counts as a plumbing fixture?
Taps, toilets, showers, baths, basins and water heaters — the things you see and touch. Pipes and fittings are the hidden work behind them.
How much contingency should I allow for plumbing?
10–20%. Plumbing hides surprises — old pipes, hidden leaks, access problems — and the contingency is what pays for them.
How do I estimate labour hours?
From the plumber's quote, or by timing a similar job. A bathroom rough-in is typically 1–3 days; a full re-pipe is a week or more. Enter your own figure.
Is this a quote?
No. It is an estimate built from your own prices — not a guaranteed quote. Get a written quote from a licensed plumber for the real price.
Related calculators
Estimates only. Results are for planning. Measure twice, confirm box coverage and tile sizes on the packaging you buy, and follow the manufacturer's instructions. See the disclaimer.