Pricing and quoting, 29 October 2026
Day rate to price per m²: converting for subcontract work
To turn a day rate into a price per m², divide what your gang costs per day by the square metres it finishes in a day, add materials per m² with waste, then divide by (1 − your margin). A three-person gang costing £786 a day that lays 60 m² has a labour cost of £13.10 per m². Output is the number that decides the rate.
Why do main contractors ask for a rate per m²?
Because it lets them compare subbies on the same footing and price their own bill of quantities. A rate per m² also moves the output risk onto you: if the job goes slower than your rate assumes, you carry the loss. That's why the conversion has to start from what a day costs you, not from what other subbies are quoting.
If the main contractor sends a bill of quantities, the m² are already measured. The live guide on pricing a bill of quantities covers how to work through one line by line. If you have to take the areas off drawings yourself, see how to measure PDF drawings.
What does a day of your gang cost?
Start with the cost per man-day before profit: true labour cost plus your share of overheads. The worked example in overheads per man-day gets a six-person roofing firm to £238 of labour and £24 of overheads, so £262 per person per day. A three-person gang therefore costs £786 a day before any profit.
Don't use what you pay the lads per day. That leaves out holiday, employer National Insurance at 15% on pay above £5,000 a year, and every overhead the firm carries.
How do you convert it, step by step?
- Take the gang's cost per day.
People × cost per man-day. Three × £262 = £786.
- Measure your real output.
Square metres finished per gang-day, averaged over three or four recent jobs of the same type. Count set-up and clear-down days, not only the days you were laying.
- Divide.
£786 ÷ 60 m² = £13.10 labour per m².
- Add materials with waste.
Merchant price per m² plus your waste allowance for cuts, laps and breakages.
- Price to your margin.
Divide the cost per m² by (1 − margin). For 15%, divide by 0.85. Our guide to markup vs margin explains why you divide rather than add 15%.
Three-person roofing gang, supply and fit, 15% margin
A gang of three re-covering a 400 m² commercial roof, pricing per m² for a main contractor.
| Gang cost per day3 × £262 | £786 |
| Output per gang-daymeasured on recent jobs | 60 m² |
| Labour cost per m²£786 ÷ 60 | £13.10 |
| Materials per m²example merchant price | £9.00 |
| Waste allowance10% of £9.00 | £0.90 |
| Cost per m² before profit£13.10 + £9.90 | £23.00 |
| Price per m² at 15% margin£23.00 ÷ 0.85 | £27.06 |
| Whole roof400 m² × £27.06 | £10,824 |
Your numbers, not a promise. Change any figure to match your firm.
What happens to the rate if your output is wrong?
It moves fast. Output is the divisor, so a gang that lays 40 m² a day instead of 60 needs a rate about 28% higher to make the same margin. Here's the same gang and materials at different outputs.
| Output per gang-day | Labour per m² | Cost per m² | Price at 15% margin |
|---|---|---|---|
| 40 m² | £19.65 | £29.55 | £34.76 |
| 50 m² | £15.72 | £25.62 | £30.14 |
| 60 m² | £13.10 | £23.00 | £27.06 |
| 70 m² | £11.23 | £21.13 | £24.86 |
If you price at 70 m² a day and only manage 60, your cost is £23.00 against a price of £24.86. The margin drops from 15% to under 8%. On the 400 m² roof that's about £740 less profit.
I didn't even understand how to price in overheads.
For example, a roofer quoting commercial work at around £60 a square metre when it's going for nearer £36.50 will keep losing it. Knowing your own cost per m² tells you whether a market rate is one you can take, or one that only works for a gang with higher output or lower overheads.
What doesn't fit in a rate per m²?
Anything that costs the same whether the area is 20 m² or 200 m². Price these as separate lines, or a small area will lose money at your standard rate.
Labour-only or supply and fit: does CIS change the rate?
It changes what lands in your bank, not the rate. If you work under the Construction Industry Scheme, the contractor deducts 20% (registered) or 30% (unregistered) from the labour part of your invoice. Materials you bought for the job are not deducted from, so split them out clearly. With gross payment status, nothing is deducted.
On the 400 m² example, materials with waste are 400 × £9.90 = £3,960. That leaves £6,864 of the £10,824 invoice as labour and profit. A 20% CIS deduction on that is £1,373, so £9,451 arrives before VAT. Plan cash flow on that figure. Your accountant can confirm how your deductions are offset against tax.
Where Nexley fits
Nexley is the AI back office for UK trade firms: five AI assistants run your tenders, quotes, buying, scheduling and invoicing. It connects to the tools you already work in, you run it all from WhatsApp, and you approve everything. £799 a month.
Nexley keeps your cost per man-day, measured outputs and merchant prices in your price list, then drafts per-m² quotes from a voice note or a set of measurements: labour, materials with waste, margin and the separate lines for access and details. You check the rate and approve it before it goes to the main contractor.
Common questions
How do I find my real output per day?
Take three or four finished jobs of the same type. Divide the total m² by the total gang-days, counting set-up, clear-down and weather-lost days on site. That average is your output; your best day isn't.
Should I use a published price book rate instead?
Use it as a sense check. A price book doesn't know your gang size, your overheads or how fast you work. If your own rate comes out well above the book, look at output and overheads before cutting the price.
Does the rate per m² include VAT?
Price per m² before VAT. If the work is under the domestic reverse charge, the contractor accounts for the VAT; if not, add VAT at the standard 20% to the invoice. See VAT rates on GOV.UK.
What if the client wants a rate for labour only?
Drop the materials lines and keep labour, overheads and margin. Using the example, labour only would be £13.10 ÷ 0.85 = £15.41 per m² at 60 m² a day.
Sources
- GOV.UK: Rates and thresholds for employers 2026 to 2027
- GOV.UK: What you must do as a CIS contractor: make deductions and pay subcontractors
- GOV.UK: Holiday entitlement
- GOV.UK: VAT rates
Every rule, rate and date above was checked against these sources on the date shown at the top.
Topic: Pricing and quoting
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