How much should I charge per day as a tradesperson?

Start with what you want to take home and add what the business costs you each year: van, fuel, insurance, tools, phone, software, accountant. That is the money the year has to bring in.

Then count the days you can really bill. Take 52 weeks, remove holidays, bank holidays and sick days, multiply by the days you work a week, and take off the share of days spent quoting, driving to the merchant, doing paperwork or waiting between jobs.

Divide the money by the billable days. That is your day rate before VAT.

With the starting figures in the calculator: £40,000 to earn plus £9,000 of costs is £49,000 a year. Six weeks off at five days a week leaves 230 working days, and with 20% of those spent on work you cannot bill, 184 billable days.

£49,000 divided by 184 is about £266 a day, or roughly £33 an hour over an eight-hour day. Charging £200 a day on the same year would leave you about £12,000 short.

The earnings figure is before tax, so income tax and National Insurance come out of what you take home. If you are VAT registered, VAT goes on top of the job price.

Dividing by 260 working days. Nobody bills 260 days: holidays, bad weather, quoting and gaps between jobs take a large part of the year.

Forgetting the costs that never reach an invoice: van, insurance, tools wearing out, accountant, phone. They come out of your day rate.

Copying a rate from another trader. Their costs and billable days are not yours. Use the calculator for the minimum, then check it against what local firms charge.

Pricing the day but not the materials. Add the materials, a handling allowance and waste disposal to the job price, as the second step of the calculator does.