How to Make Sure Trade Jobs Cover Your Business Overheads

A job can make money on paper while the business as a whole struggles. That happens when the selling price covers materials, site labour and subcontractors but does not contribute enough towards van finance, insurance, software, rent, administration and the other costs of staying in business.

The practical answer is to measure two things separately: what each job leaves after its direct costs, and what the business leaves after all its overheads. You can then calculate how much completed work needs to contribute towards those overheads instead of hoping that a healthy-looking job margin will be enough.

Job contribution is not the same as whole-business profit

Start with the money earned from completed work and deduct the costs that belonged directly to those jobs. The amount left is the jobs’ contribution towards overheads and profit.

Job contribution = completed job revenue − direct job costs

You then deduct the wider costs of running the business.

Operating profit before tax = completed revenue − direct job costs − business overheads

Accountants may use more specific terms such as gross profit, contribution and operating profit depending on how the accounts are prepared. The important commercial principle is that direct job costs and whole-business running costs should not be confused.

A simple building-business example

Suppose a small builder completes £24,000 of work during a month. The completed jobs look healthy until the business overheads are included.

The work contributed £8,000 after direct costs, but the business did not make £8,000. Once the costs of keeping the operation running were paid, £2,500 remained before tax and any other adjustments.

Which costs are direct job costs and which are overheads?

A direct cost exists because a particular job is being carried out. An overhead supports the wider business and would usually remain even if one specific job disappeared from the diary.

There is not always one universal answer. Fuel used for a distant one-off project might be treated as a direct job cost when it can be measured reliably, while ordinary van running costs may remain overheads. Site labour can be assigned directly where accurate job records are available, while administration time, idle time and general supervision may sit outside individual jobs.

The key is to adopt a reasonable rule and apply it consistently. Do not allocate a cost to a project and then include it again in overheads, because that counts it twice.

How to calculate your trade-business overheads

1. Choose a useful period

An annual calculation works well for setting targets because it captures quarterly and yearly bills. Monthly monitoring is useful for spotting changes. Ideally, build an annual overhead budget and divide it into a monthly benchmark.

2. List regular and irregular running costs

Review bank transactions, expense records, finance agreements, insurance schedules and supplier contracts. Include costs that are easy to overlook because they are paid annually or only occasionally.

• Van finance, servicing, road tax and general running costs
• Business insurance
• Telephone and software subscriptions
• Workshop, office or storage costs
• Accountancy and professional fees
• Advertising, website and lead-generation costs
• Training, accreditations and memberships
• Administrative wages and relevant employer costs
• Small tools, replacements and general consumables not assigned to jobs
• Bad-debt and general contingency allowances where appropriate

Convert annual and quarterly bills into annual figures before calculating the monthly average. A £2,400 annual insurance bill, for example, represents an average overhead of £200 per month even though the cash leaves the bank in one payment.

3. Build an annual overhead budget

A small trade business might arrive at the following estimate:

That business must generate an average of £5,500 per month from completed work just to cover these overheads. It still needs additional contribution if the owner wants the business to produce a profit.

Be careful when considering the owner’s own income. A limited-company director’s salary may appear as a business cost. A sole trader’s personal drawings do not normally reduce accounting profit in the same way. However, the pricing plan still needs to produce enough profit to support the owner. Discuss the accounting and tax treatment with an accountant where necessary.

Turn the annual figure into an overhead recovery target

An overhead recovery target shows how much each productive day, hour or pound of sales needs to contribute towards running the business.

Recovery by productive day

If annual overheads are £66,000 and the business expects 440 productive person-days during the year:

£66,000 ÷ 440 = £150 of overhead per productive person-day

A project needing two people for four days uses eight productive person-days. It therefore needs to contribute approximately £1,200 towards overheads before producing the intended business profit.

Use realistic productive capacity. Do not divide by every weekday in the year. Allow for holidays, quoting, training, administration, sickness, gaps between work, bad weather and time spent correcting problems. Otherwise, the daily recovery target will be artificially low.

Recovery as a percentage of sales

You can also compare overheads with expected annual revenue. If overheads are £66,000 and expected sales are £330,000:

£66,000 ÷ £330,000 × 100 = 20% of sales

This means 20p from every £1 of expected sales is needed for overheads. It is a useful whole-business benchmark, but it can be a blunt pricing tool. A material-heavy kitchen installation and a labour-heavy decorating project can have very different direct-cost structures even when their selling prices are similar.

Calculate break-even sales from contribution margin

If completed work normally leaves a 35% contribution after direct job costs, annual break-even revenue can be estimated as follows:

£66,000 overheads ÷ 35% contribution margin = approximately £188,571 of annual sales

If the business also wants £40,000 of profit before tax and other year-end adjustments:

(£66,000 overheads + £40,000 target profit) ÷ 35% = approximately £302,857 of annual sales

This does not guarantee the target. It gives the business a commercial benchmark against which pricing, capacity and completed performance can be reviewed.

Why adding a standard mark-up does not always solve the problem

A standard mark-up on materials may help, but it does not automatically cover every overhead. For example, buying materials for £10,000 and adding 20% produces a £12,000 selling price and £2,000 of contribution. If the job needs £3,000 towards overheads and target profit, the mark-up is insufficient.

Mark-up and margin are also different calculations. A 25% mark-up on £8,000 of cost gives a £10,000 price, but the resulting margin is 20% of the selling price. Confusing the two can leave less contribution than expected.

A stronger pricing check considers direct job costs, required overhead contribution, risk and the intended profit. Market conditions still matter, but they do not make the business’s cost base disappear.

Common reasons overhead calculations become unreliable

• Mixing project purchases with general expenses: this makes both job performance and overheads difficult to trust.
• Forgetting annual costs: insurance, memberships, servicing and professional fees can make a seemingly good month look much weaker later.
• Using bank balance as profit: the account may contain customer deposits, VAT, tax reserves or cash needed for future work.
• Ignoring quiet and non-billable time: overhead recovery must be based on realistic productive capacity.
• Leaving old figures unchanged: finance agreements, wages, insurance and software prices change.
• Allocating every cost by guesswork: forced allocations can create false job precision while hiding the true cost of operating the business.
• Reviewing one month in isolation: completion dates and seasonal work can create uneven results, so use quarterly and year-to-date views as well.

A better monthly routine

1. Record each purchase and decide whether it belongs to a specific project.
2. Keep genuine business-wide costs unallocated as overheads.
3. Check that regular costs such as rent, van finance, insurance and software have been recorded.
4. Review completed revenue and direct job costs for the same period.
5. Deduct overheads to see what the business retained before tax and other adjustments.
6. Compare the result with the overhead budget, pricing target and previous periods.
7. Investigate significant changes rather than waiting until year end.

Tools2Done supports this separation by allowing expenses to be linked to a project when they are direct job costs, while unallocated expenses remain business overheads. Regular costs can be set up as recurring expenses, and Management Accounts bring completed revenue, job costs, overheads, profit and margin into one view.

This does not replace pricing judgement or advice from an accountant. It makes the underlying records easier to inspect, so decisions are based on more than a full diary or a healthy-looking bank balance.

Your next practical step

List the costs your business would still pay during a quiet month. Turn annual bills into monthly amounts, total the result and compare it with what completed jobs have actually contributed after direct costs. If the gap is too small, review pricing, productive capacity and unnecessary overheads before simply taking on more work.