Construction Quote Margin Calculation: Formula, Coefficient and Example

The margin on a construction quote is the difference between the selling price excl. VAT (“HT” in French) and the job's cost price. To calculate it, subtract the cost price from the selling price, then express the result either as a share of the cost price (markup rate) or as a share of the selling price (margin rate).

The basic formula fits on one line: margin = selling price excl. VAT - cost price. The trap lies in what the cost price contains. A quote that compares the selling price only with materials and labour shows a flattering margin, but that margin ignores the company's overhead costs. All calculations in this article are made excluding VAT: VAT is part of neither the selling price nor the margin.

What are the four steps in building a selling price?

A quote's selling price is built in four steps. The direct costs (“débours sec”) cover the expenses directly tied to the job (materials, labour, subcontracting, hire, travel). The overheads (“frais généraux”) add the share of the company's structural costs that this job must cover. Adding the two gives the cost price. Finally, the margin is added to obtain the selling price excl. VAT.

What does the word “margin” mean in this article?

The word “margin” covers two notions. The gross margin is the selling price excl. VAT minus the direct costs. The margin after overheads is the selling price excl. VAT minus the cost price. Some quotes and tools call the latter “net margin”, a label that causes confusion: in accounting, net margin and net profit generally mean what remains after deducting the charges of the financial year, and their exact definition may vary, so check with your chartered accountant. This article therefore uses the expression “margin after overheads”. It measures a job's profitability once overheads are covered, without taking into account items specific to the accounting year, such as taxes or financial charges.

The amounts in the worked example are fictional and only illustrate the method: each company must use its own costs.

Key takeaways Margin = selling price excl. VAT - cost price. The cost price includes direct costs and overheads, not just materials and labour. The markup rate is calculated on the cost price, the margin rate on the selling price: the same percentage does not give the same price. To set a price, the margin rate is the most consistent with turnover tracking. Contingencies are dealt with before signing, in the direct costs, in the quote's assumptions or by change order (“avenant”), not after the fact. A margin calculated at quote stage must be compared with the margin achieved at the end of the job, and the coefficient must then be reviewed regularly.

Direct costs are all the expenses incurred directly to carry out a job, excluding overheads and margin. They answer the question: how much does the company pay out of its cash, or commit in working time, to carry out this specific quote? Any item that would not exist without this job belongs here.

How do you value labour in the direct costs?

Labour is the item most often misjudged. The loaded hourly cost is the full cost of one hour of work to the employer. It is not equal to net pay: it includes employment-related contributions and charges, as well as non-productive time. The method for calculating this cost is detailed in our article on the construction hourly rate. For the quote, each planned hour is valued at the company's own cost, per worker and per task, counting preparation, supply runs and cleaning.

How do you cost subcontracting in the direct costs?

The price invoiced by a subcontractor goes into the direct costs at its negotiated amount excl. VAT. The VAT treatment of subcontracted work is covered in the article on the French VAT reverse charge in construction subcontracting. In all cases, the margin is calculated on amounts excl. VAT, which makes the comparison between work packages done in-house and subcontracted ones consistent.

How do you check that the direct costs are complete?

Items should be checked job by job. A daily trip to a distant site, a scaffolding hire kept one week longer or a subcontractor who came twice instead of once all weigh on the direct costs. Incomplete direct costs mechanically lead to a selling price that is too low, whatever coefficient is applied afterwards. Reading the quote line by line before sending it, asking for each item whether it would disappear without this job, avoids most of these omissions.

Overheads are the company's running costs that cannot be attached to a specific job: rent for the premises or depot, administrative staff, vehicles, insurance, software, accounting. Direct costs alone are not enough to set a selling price: if the price does not cover these costs, the company loses money even when each job seems to generate a margin. This topic concerns small building companies as much as mid-sized construction companies, whose structure weighs more as it grows.

How do you calculate the overhead percentage?

The overhead percentage is calculated over a past period, generally an accounting year. You add up the period's overheads, add up the direct costs of all the jobs in the same period, then divide the first total by the second. This percentage is then applied to the direct costs of each new quote. It comes from the company's accounts: no sector-wide rate can replace it.

Which methods can be used to spread overheads across quotes?

Two methods coexist. The first applies to the direct costs an overhead percentage, calculated as described above. The second builds overheads and margin into a single multiplier coefficient applied to the direct costs. The percentage and the coefficient are specific to each company and are revised periodically.

What is the risk if overheads are not covered by the price?

A quote whose price covers only the direct costs leaves the company financing its structure out of its own results. The flaw is rarely visible job by job, since each one shows a positive gross margin. It appears when the accounts are closed, when all the margins together no longer suffice to pay for rent, vehicles, insurance and administrative staff. Building overheads into the quote, through a percentage or a coefficient, avoids this gap.

What is the difference between markup rate and margin rate?

The markup rate (“taux de marge”) expresses the margin relative to the cost price: markup rate = margin / cost price. The margin rate (“taux de marque”) expresses the same margin relative to the selling price: margin rate = margin / selling price. For the same margin in euros, the margin rate is always lower than the markup rate, since the selling price exceeds the cost price.

Which one should you use to set a selling price?

The margin rate is the most consistent for setting a selling price. It is measured on the selling price, hence on turnover, the same base as the company's accounts and overhead tracking. A given margin rate means that this share of every euro invoiced remains after costs, which can be compared directly with a profit target or an annual budget. The markup rate, calculated on the cost price, gives a higher percentage for the same margin and is harder to read against turnover.

Neither rate is an industry standard. Both lead to the same price if you convert correctly. The useful rule is to choose a single rate for all quotes, state it in the internal method and never compare a markup rate with a margin rate.

How do you convert a rate into a selling coefficient (kpv)?

The selling coefficient, abbreviated kpv (selling price coefficient, “coefficient de prix de vente”) and also called the multiplier coefficient, is the number by which the direct costs are multiplied to obtain the selling price excl. VAT: kpv = selling price excl. VAT / direct costs. It condenses overheads and margin into a single figure.

• With a margin rate m and separate overheads: kpv = (1 + overhead rate) / (1 - m).
• With a markup rate t and separate overheads: kpv = (1 + overhead rate) × (1 + t).
• Without separate overheads: kpv = 1 / (1 - m) for a margin rate, kpv = 1 + t for a markup rate.

The kpv is valid only for the company that calculated it: reusing another company's means reusing its overheads and its targets.

What difference does confusing markup and margin make on the same cost price?

Take a fictional cost price of €7,820 (direct costs of €6,800 and overheads of €1,020). Depending on whether 25% means a markup rate or a margin rate, the selling price is not the same.

A manager who aims for a 25% margin rate but applies that percentage as a markup on the cost price sells for less than planned: they obtain a 20% margin rate, i.e. €9,775 instead of €10,426.67.

Illustration: fictional amounts The amounts below are invented to illustrate the calculation. They are neither a price list nor a standard rate for the sector: the loaded hourly cost, the overhead percentage and the margin target depend on each company.

Take a fictional finishing-trades quote, with a loaded hourly cost of €38, overheads of 15% of direct costs and a target margin rate of 20%. The table details each step.

The selling price excl. VAT is obtained by dividing the cost price by (1 - margin rate), here 1 - 0.20 = 0.80. The margins, the markup rate and the selling coefficient are then deduced.

How do you check the result of the calculation?

Three checks validate the result. The direct costs multiplied by the kpv give back the selling price (6,800 × 1.4375 = €9,775). The recalculated margin rate matches the target set at the start. The margin after overheads (€1,955) equals the gross margin (€2,975) minus the overheads (€1,020).

How do you calculate the margin on a multi-package quote with resold subcontracting?

On a quote with several work packages, the same method is applied package by package: direct costs, overheads and a selling price for each package, then the results are added up. This breakdown reveals the package that drags the margin down, which the total hides. For a package that is subcontracted and resold to the client, the subcontractor's price excl. VAT is the package's direct costs. The company adds the overheads tied to managing it (consultation, coordination, checking) and its margin. Applying the in-house labour coefficient to this package distorts the margin of one of the two.

The margin calculated at quote stage rests on forecasts, whereas the job produces variances. Since the selling price is fixed at signing, any unplanned expense reduces the margin by the same amount. These variances most often come from identifiable causes, which can be controlled as early as the preparation of the quote.

Which mistakes erode a job's margin?

• Forgotten or underestimated overheads: the price covers the direct costs but not the structure.
• Unpriced contingencies and losses: material offcuts, rework, breakage, unplanned waste removal.
• Underestimated hours: preparation, supply and cleaning time is not counted.
• Discounts not passed through: a discount granted to the client reduces the margin without the price of materials having fallen.
• Extra work without a change order (a written amendment to the contract), or a longer job duration.

How do you build contingencies and unforeseen events into the quote before signing?

A contingency is a possible event that increases a job's cost without appearing in the initial quantity survey. Before signing, distinguish those you can price from those you can only frame. Offcuts, losses, breakage and waste removal can be priced: build them into the quantities or into a dedicated line of the direct costs, relying on the variances observed on the company's previous jobs. Causes that cannot be seen before opening up, such as the condition of a substrate or difficult access, are framed in writing.

1. Visit the site and note what remains unknown (substrate, access, existing services).
2. Price usual losses into the quantities, based on your past jobs.
3. Write the assumptions used and the exclusions into the quote: what is included, what is not.
4. Provide that any work outside the quote goes through a change order signed before it is carried out.
5. Review the coefficient: its margin share must not serve as a reserve for contingencies that were never priced.

A coefficient does not protect against the unforeseen if it was not calculated for that. If the margin has to absorb a contingency, the margin achieved will be lower than the target, and the margin rate obtained will show it. For the legal terms of a change order or a price revision clause, consult your legal adviser.

What happens to the margin if the job takes 10 more hours?

Let us return to the fictional quote. The job takes 10 h more than planned, at the same loaded hourly cost of €38: the cost price rises by 10 h × €38 = €380. Overheads are assumed unchanged and the selling price stays at €9,775.

The overrun hours remove €380 of margin, about one fifth of the planned margin after overheads. The margin rate falls from 20% to 16.11% (1,575 / 9,775), and the markup rate from 25% to 19.21% (1,575 / 8,200).

How do you compare the quote and the actual result at the end of the job?

1. Collect the actual expenses for each item: materials invoices, recorded hours, subcontracting and hire invoices, travel expenses.
2. Recalculate the actual direct costs, then the actual cost price using the company's overhead percentage.
3. Calculate the actual margin and measure the variance item by item against the quote.

This variance, and not the overall margin alone, shows what to correct in later quotes: quantities, time, coefficient or overhead percentage. For long jobs, invoicing progress through a progress invoice (situation de travaux) makes it possible to track these variances along the way.

Tracking the profitability of a construction quote is not limited to checking one job: you also need to regularly review the assumptions used to set prices. The selling coefficient and the overhead percentage come from the accounts of a given period. They stop being reliable when the structure changes: new premises, a hire, an additional vehicle, higher insurance costs or a change in job volume.

When should you review the coefficient and the overhead percentage?

A review is needed at least after each closing of the accounts, then at each significant change of structure. The percentage is recalculated by dividing the period's overheads by the direct costs of the same period, then the new coefficient is derived while keeping the target margin rate: kpv = (1 + new overhead percentage) / (1 - margin rate). A coefficient left unchanged while structural costs evolve leads to selling below the necessary price.

Why compare several jobs?

An isolated variance may come from a contingency. The same variance repeated across several jobs signals a wrong assumption in the quotes. To spot it, compare the margins achieved from several angles:

• By type of work: some jobs systematically yield less than planned.
• By item: hours that are always exceeded or materials that are undervalued show what to correct in quantities and times.
• By job size or by client: a coefficient suited to a small job does not necessarily suit a large one.

Where can you find a calculation tool?

To redo the calculation with your own figures, the construction calculators in the resources section can serve as a starting point, as can a spreadsheet. A invoicing management or financial management tool can then make it easier to reconcile planned and achieved margin, job by job. Whatever the tool, the reliability of the result depends on the quality of the data entered: recorded hours, invoices attached to the right job, up-to-date overheads.