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🏗️ Guide · Building

How to calculate the cost price of a job

Materials, hours, all-in hourly rate, expenses, margin: the full method for pricing a job without working at a loss — with an example from start to finish.

By Gaetano Gallo Updated 24 July 2026 7 min read

In short

The cost price of a job is the sum of four items: the materials actually installed, offcuts included; the planned hours multiplied by your all-in hourly rate; the job's direct costs (equipment hire, skip, fuel, consumables); and a share of your company's fixed costs, already built in if your hourly rate is worked out properly. The selling price then follows: price excl. VAT = cost price × (1 + target margin).

Example: 300 € of materials + 280 € of labour (8 h at 35 €/h all-in) + 20 € of expenses = 600 € cost price. With a 30% margin, the quote goes out at 780 € excl. VAT, i.e. 858 € incl. VAT at 10% VAT. The decisive figure remains the all-in hourly rate: the company's annual overheads ÷ genuinely billable hours, i.e. commonly 1 300 to 1 500 hours a year per worker.

The four items of a cost price

Materialsquantities actually installed × purchase price excl. VAT, offcuts and breakage included

Labourplanned hours × all-in hourly rate

Direct costshire, skip and waste removal, consumables, fuel, site parking

Cost pricematerials + labour + direct costs

Selling price excl. VATcost price × (1 + target margin ÷ 100)

The share of the company's fixed costs — ten-year structural and public-liability insurance, vehicle, premises, tooling, accountant, admin time — doesn't show up as a separate line: it's already inside the all-in hourly rate, provided that rate was worked out on genuinely billable hours. That's the whole point of the next step.

Step 1: calculating your all-in hourly rate

It's the figure that decides everything else, and the one most tradespeople underestimate. The formula fits on one line:

All-in hourly ratethe company's total annual overheads ÷ genuinely billable hours in the year

The annual overheads are all your running costs: loaded pay (yours included), vehicle and fuel, ten-year structural and public-liability insurance, tooling and depreciation, premises, accountant, phone and software, training.

The billable hours are the hours spent at the client's. Not the theoretical 1 800 hours of a full-time year: you have to take out measuring up, quotes, travel, trips to the merchant, callbacks, admin, holidays and bad weather. Count 1 300 to 1 500 billable hours a year per worker.

Effect of billable hours on the hourly rate, for 48 000 € of annual overheads
Billable hours/yearFloor hourly rateDifference over an 8 h day
1 300 h36,90 €/h+ 39 € vs 1 500 h
1 400 h34,30 €/h+ 18 € vs 1 500 h
1 500 h32,00 €/hreference
1 800 h (theoretical)26,70 €/h− 42 € : the trap

Pricing on 1 800 hours instead of 1 400 is like giving yourself a 22% discount on every hour sold, without anyone asking for it. The same calculation exists online: the hourly rate calculator was written for the car workshop, but its method applies to the building trade unchanged.

Step by step: from measuring up to the selling price

  1. Price the materials, offcuts includedFor straight-laid tiling, count 5 to 10% for breakage and cutting; up to 15% for diagonal laying or an awkwardly shaped room. The calculation is done on the quantity bought, not the area on the drawing.
  2. Estimate the hours honestlyTake your real time on a comparable job, not your best memory. Add protecting the area, setting up, cleaning and clearing away: these are site hours, even if they don't lay a single tile.
  3. Apply your all-in hourly rateHours × the hourly rate from step 1. It's a cost, not a selling price: the margin comes after.
  4. Add the direct costsEquipment hire, skip, consumables, fuel, parking. These amounts are small taken one by one, and often add up to a job's whole margin once combined.
  5. Add the marginPrice excl. VAT = cost price × (1 + margin). Mind the trap: a 30% margin on the cost price is not 30% of the selling price, but 23%.
  6. Apply the right VAT rateIn France: 20% for new build, 10% for maintenance and renovation of a home completed more than two years ago, 5,5% for energy-improvement work and associated works. The reduced rates require a declaration signed by the client.

All six steps fit into the free building quote calculator: materials, hours, hourly rate, expenses and margin on one side, price excl. and incl. VAT on the other, recalculated at every keystroke.

A full worked example: 10 m² of tiling

A bathroom to tile, supply and fit included.

  1. Tiles: 10 m² at 15 €/m²10 × 15 = 150 €
  2. Adhesive, spacers, grout= 150 €
  3. Total materials150 + 150 = 300 €
  4. Labour: 8 h at 35 €/h all-in8 × 35 = 280 €
  5. Miscellaneous costs (cutting, waste removal)= 20 €
  6. Job cost price300 + 280 + 20 = 600 €
  7. Target margin of 30%600 × 1,30 = 780 € excl. VAT, of which 180 € margin
  8. VAT 10% (renovation)780 × 1,10 = 858 € incl. VAT

780 € excl. VAT, i.e. 78 € per m² supplied and fitted — 858 € incl. VAT for the client.

The real test comes after the job. If the tiling took 10 hours instead of 8, the cost price rises to 670 € and the margin falls from 180 € to 110 €, i.e. 16% instead of 30% — without a single price moving. Two hours too many eat 39% of the margin: that's why noting your real hours pays more than haggling with your merchant.

Redo the calculation at the end of every job with the real figures. After ten jobs, you know your own times better than any rate card, and your next quotes are right first time.

Benchmark table: margins and multipliers

In practice, many tradespeople aim for a 20 to 35% margin on the cost price, plus a 10 to 30% mark-up on the materials they supply. The right figure depends on your trade, your order book and the risk of the job.

Margin on cost price, margin on selling price and resulting price (base 600 € of cost)
Margin on costMultiplierMargin on selling pricePrice excl. VAT
15%× 1,1513,0%690 €
20%× 1,2016,7%720 €
25%× 1,2520,0%750 €
30%× 1,3023,1%780 €
35%× 1,3525,9%810 €
40%× 1,4028,6%840 €
The other benchmarks to keep in mind
BenchmarkBallpark
Billable hours per year per worker1 300 to 1 500 h
Offcuts and breakage (tiles, straight laying)5 to 10% — up to 15% on the diagonal
Mark-up on supplied materials10 to 30%
VAT, renovation of a home over 2 years old10%
VAT, energy-efficiency improvement5,5%
VAT, new build and out-of-scope work20%

These VAT rates apply to France and require a client's declaration for the reduced rates; if in doubt about your situation, your accountant decides.

The mistakes that eat the margin

  • Starting from the next guy's priceHis overheads aren't yours, nor is his equipment, still less his productivity. A per-m² price picked up from a fellow tradesman can be profitable for him and suicidal for you. The price is derived from your cost, never from the market alone.
  • Counting 1 800 billable hours a yearIt's the most costly mistake in the trade. Quotes, measuring up, travel, callbacks and admin aren't billed: they're funded by the hours that are.
  • Confusing margin and multiplierA 30% margin on the cost price is a multiplier of 1,30 and 23% of the selling price. Many tradespeople think they're making 30% of turnover when they're making 23%: on 200 000 € of work, the gap is 14 000 €.
  • Forgetting offcuts and breakageOn tiling, 10% of offcuts left out of the quote means 10% of the materials line comes straight out of your margin, job after job.
  • Never comparing planned versus actualA quote is only a hypothesis. Without feedback on the hours actually spent, the same pricing mistakes repeat endlessly — and always in the same direction.
  • Forgetting to pay yourselfA sole trader who leaves their own pay out of the annual overheads gets an artificially low hourly rate. They then sell hours that don't pay them, and call it competitiveness.

Frequently asked questions

Should you include your own wage in the cost price of a job?

Yes, always. A sole trader must include their loaded pay in the annual overheads used to calculate the hourly rate. Without it, the rate you get only covers structural costs and every hour sold makes you a little poorer, even when the job looks profitable. The rule is simple: if you don't pay yourself in the calculation, no one will in the quote.

How do you allocate fixed costs across jobs?

The simplest and most reliable way is to build them into the all-in hourly rate: total annual overheads — insurance, vehicle, premises, tooling, accountant, admin — divided by genuinely billable hours. Each hour sold then carries its share of fixed costs automatically, with no arbitrary allocation key per job. It's also what makes the pricing reproducible from one quote to the next.

Margin, multiplier, margin-on-price: what's the difference?

The margin applies to the cost price: 600 € × 1,30 = 780 €, i.e. a 30% margin. The margin-on-price is expressed as a percentage of the selling price: on this same job, 180 € of margin on 780 € makes 23%. The multiplier is simply (1 + margin): 1,30 here. All three say the same thing, but confusing the first two systematically overstates your profitability.

How do you know if a job was really profitable?

Take the quote again at the end of the job and replace the assumptions with the real figures: hours actually spent, materials actually used, trips and rework included. Then compare the margin achieved with the margin planned. A two-hour gap on an 8-hour job is enough to turn a 30% margin into 16%: it's the only check that really improves your next quotes.

Should you bill for travel and quoting time?

Either you bill them explicitly (a travel fee, a paid quote beyond a certain complexity), or you fund them through your hourly rate — but you can't do neither. Working out the hourly rate on genuinely billable hours is precisely what lets you get this non-productive time paid for without having to bill it line by line.

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