Contractor Day Rate Calculator United Kingdom

A day rate is easy to misread. £400 a day sounds like £104,000 a year, but only if you bill five days a week for all 52 weeks, which almost nobody does. This calculator converts your day rate into weekly, monthly and annual gross income and lets you set how many weeks you actually work, so the annual figure reflects a real contracting year.

From a day rate to a yearly figure

Weekly income is the day rate times the days you bill each week. Annual income is that weekly figure times the weeks you work. Monthly income is the annual total divided by twelve, an average rather than what lands in any particular month. The calculator shows all three, so you can see how a change to any input carries through.

Weeks worked is the input people get wrong. Using 52 assumes no holiday, no sick days and a new contract starting the morning after the last one ends. That never happens, and it overstates the annual figure by thousands of pounds.

Why billable weeks matter so much

Billable weeks have the biggest effect on the result, and they are your own assumption. A contractor on £400 a day, five days a week, earns £104,000 over 52 weeks but £92,000 over 46: a £12,000 difference from allowing six weeks off. The 46-week figure is closer to how a year actually goes.

To set your own figure, subtract from 52 the weeks you will not bill: annual leave, bank holidays, a buffer for illness and, hardest to predict, the gap between contracts. A well-connected contractor in a busy field might lose a week or two between contracts; someone in a quieter market might lose a month or more. If you are unsure, run a cautious year and an optimistic year. The spread between them is your income risk.

Comparing a day rate with a salary

People often run this calculation to weigh a contract against a permanent job, and the annual gross figure usually looks well ahead of the advertised salary. A permanent salary, though, comes with paid holiday, employer pension contributions, sick pay and the security of not having to find your next role. A day rate has to pay for all of that, which is why contractor rates carry a premium. This figure is gross billing, while the salary already includes paid time off that you fund yourself as a contractor.

A worked example

You bill £400 a day, five days a week, and expect 46 billable weeks after holidays and a fortnight between contracts. Weekly income is £2,000. Over 46 weeks, annual gross income is £92,000, an average of about £7,666.67 a month. At 48 billable weeks the annual figure rises to £96,000; at 44 it falls to £88,000.

Part-time and mixed weeks

Days per week does not have to be five. Set it to four for a four-day week, or use a half value like 2.5 if you split your time between clients or are winding down towards retirement. Every figure scales, so you can see what a shorter week does to your annual income before committing to it.

Assumptions and limitations

The calculator deals in gross income only. It does not deduct Income Tax, National Insurance, dividend tax, Corporation Tax, VAT, pension contributions or accountancy costs, and it makes no assumption about whether you trade through a limited company, an umbrella or as a sole trader, all of which change what you keep. It treats every billable week as a full week at your day rate, so variable weeks are averaged. For what actually reaches your bank account, follow up with a take-home or self-employed tax calculation and, for anything important, an accountant.

About This Contractor Day Rate Calculator

Use this contractor day rate calculator to get an instant estimate based on the figures you enter. Adjust the inputs above to match your situation, or browse all our calculators to plan your next step.