What do you need to earn in a day?

Start with your own costs

Before deciding what to charge, write down what the business costs to run. The van payment is easy to remember. Tool replacement, insurance renewals, scheme fees and the small monthly subscriptions are easier to miss.

Use the amount your business actually bears. A yearly bill needs spreading across the year; a monthly bill needs multiplying by twelve. Keep money put aside for future replacements visible, even though its tax treatment may differ from an expense already paid.

• Van, fuel, insurance, servicing and breakdown cover.
• Tools, test equipment, calibration and replacement costs.
• Business insurance, accounts, phones and subscriptions.
• Training, registrations, waste arrangements and other running costs.

Count the days you can actually invoice

A five-day working week does not mean five chargeable days every week. Holidays, bank holidays, illness, quoting, paperwork and empty diary gaps all reduce the time available to earn.

Use your own diary to make an honest estimate. Do not count the same day twice: if you have already allowed a full day for quoting each week, keep that allowance separate from holiday days. A half-day here and there matters too.

Work backwards from take-home pay

The money you want in your personal account is not the same as business revenue. A sole trader needs to cover overheads and allow for tax and National Insurance before reaching that take-home target.

The free calculator works through that estimate for you. It currently covers sole traders in England, Wales and Northern Ireland, using 2026/27 assumptions. It does not calculate limited-company salary and dividends or Scottish Income Tax.

A worked example

These are illustrative numbers, not a recommended rate or an industry average. Suppose a business needs £72,000 of annual revenue to cover its entered costs and target pay. With 200 billable days, the starting target is £360 per day. With 180 days, the same target becomes £400 per day.

The difference is the time available to recover the money. Filling the diary with work below your own recovery target may leave very little room for a delayed job or an unexpected bill.

£72,000 annual revenue target ÷ 200 billable days = £360 per day. Materials, subcontractors and other direct job costs still need accounting for separately.

Use the number as a check

A daily target is a planning tool. It is not a complete quote for every job. Access, travel, materials, specialist equipment, uncertainty and the responsibility involved can all change what a particular job needs to earn.

Compare the estimate with completed jobs. How long did the work actually take? What costs were missed? What was left? If you employ staff, the calculator result is a whole-business target, not a price to charge for each engineer.

Check the tax assumptions with your accountant, then use your own figures to make the next pricing decision.