The calculator loads here when JavaScript is on. The worked example below shows how to do the sum by hand.
Work out your day rate
What you type stays in this browser tab. It isn't sent or saved anywhere.
Fill in what you want to take home to see your rates.
How the sum works
- Start with what you want to keep. The money you want in your own pocket over the year, after tax.
- Add the tax back on. As a sole trader you pay Income Tax and Class 4 National Insurance on your profit, so the profit has to be bigger than what you keep. The calculator works this out for the 2026 to 2027 tax year.
- Add what the business costs. Van, fuel, insurance, tools, phone, software and the accountant all come out of your takings before there's any profit.
- Count the days you can really work. 52 weeks minus holidays, bank holidays, sick days and days lost to weather, times the days you work each week.
- Divide. Takings needed divided by working days is your day rate. Divide that by the hours you can charge for in a day to get an hourly rate.
A made-up example
A sole trader wants to take home £35,000 a year. Their van and fuel cost £6,000, insurance £1,000, tools £1,500 and everything else £2,000: £10,500 in all. They take 6 weeks off and work 5 days a week, with 7 paid hours a day.
- Profit needed to keep £35,000: £42,880.81 (Income Tax £6,062.16, National Insurance £1,818.65)
- Takings needed: £42,880.81 + £10,500 = £53,380.81
- Working days: 46 weeks × 5 days = 230
- Day rate: £232.09, or £33.16 an hour for 7 paid hours
Materials you buy for a job are charged on top of these rates, with any mark-up you add.
Before you put your prices up
- Check what customers can see. Look at what other trades near you charge for the same work. A rate well above theirs needs a reason customers can see, like reviews, guarantees or getting it done sooner.
- Price the job, not just the day. Most customers want a price for the whole job. Use your day rate to work out the quote (the pricing guide shows how), then send the total. The free job quote template sets out the lines.
- Count the time you lose. Travel between jobs, quoting, chasing payment and admin all come out of your paid hours. Getting paid on the day saves the chasing.
- Watch the VAT threshold. If your takings go over £90,000 in any 12 months, you must register for VAT and add 20% to most customers' bills. The VAT threshold calculator checks your months.
- Put the tax aside as it comes in. The self-employed tax calculator shows the tax on a year's takings and how much to keep back each month.
The tax figures used
| What | Rate | On profit |
|---|---|---|
| Personal Allowance | 0% | Up to £12,570, reduced by £1 for every £2 over £100,000 |
| Basic rate Income Tax | 20% | £12,571 to £50,270 |
| Higher rate Income Tax | 40% | £50,271 to £125,140 |
| Additional rate Income Tax | 45% | Over £125,140 |
| Class 4 National Insurance | 6% | £12,570 to £50,270 |
| Class 4 National Insurance | 2% | Over £50,270 |
Class 2 National Insurance is treated as paid when profits are £7,105 or more, so there's nothing to add for it. The sum assumes the trade is your only income and you're a sole trader; Scotland has its own Income Tax bands, and a limited company is taxed differently. Sources: GOV.UK Income Tax rates, self-employed National Insurance rates and when to register for VAT.
Get paid the rate you set
In Knockround, quotes go out from your phone with a line for each part of the job, and the customer accepts with a tap. When the work's done, every invoice has a Pay button: send it by WhatsApp, text or email, or show the QR code on your phone, and your customer pays by Apple Pay, Google Pay or card. It marks itself paid and the money goes to your own Stripe account, so less of your week goes on chasing.
Try it on the plumbing demo, with made-up customers. It's free for 7 days with no card needed, then £19.99 a month.
Written by the Knockround team. Tax figures checked on GOV.UK on 29 October 2026. This is a planning guide, not tax advice: an accountant can tell you what applies to you.