Guides · Updated 2026-10-15
Free calculators and templates for sole traders (UK)
This is a list of the free tools we've built, sorted by the job you're trying to do, alongside the official GOV.UK and HMRC tools worth bookmarking. Ours run in your browser, with no sign-up, and nothing you type is stored. Each one links the rules it uses, and tax figures are for the 2026 to 2027 tax year, checked on 15 October 2026. The full list without the explanations is on the free tools page.
Pricing a job
- Quote and VAT calculator: materials with markup, labour and VAT at 20%, 5% or 0%, or the construction reverse charge. Use it for every quote.
- Day-rate calculator: the day and hourly rate you need to hit a target income once costs and unpaid days are counted. Read how much to charge per hour alongside it.
- Markup and margin calculator: converts between the two, because a 25% markup is only a 20% margin.
- Price-change clause generator: plain wording for what happens if material prices move before you order, including a right to cancel for homeowners.
- AI tool break-even calculator: whether a monthly app pays for itself in hours saved and extra jobs won.
Tax and Self Assessment
- Self-employed tax calculator: Income Tax and Class 4 National Insurance on your profit, with CIS deductions taken off.
- Payments on account calculator: what you owe on 31 January and 31 July. This is the one that catches people out after their first year.
- Trading allowance calculator: the £1,000 allowance against your real expenses, and whether you need to register.
- Mileage allowance calculator: HMRC's flat rates of 55p then 25p a mile, against your actual van costs.
- Van capital allowances vs mileage calculator: claim the van and its running costs, or the flat rate, over the years you keep it. The choice sticks for that van.
- Working from home allowance calculator: the £10, £18 or £26 monthly flat rates, and the rates for B&B owners who live on the premises.
- Sole trader vs limited company calculator: take-home pay both ways, before you pay an accountant to set up a company.
- Corporation Tax calculator: 19% / 25% with marginal relief between £50,000 and £250,000.
- Student loan repayment calculator: Plan 2, Plan 5 and postgraduate thresholds for 2026 to 2027.
- Making Tax Digital checker: whether you start in April 2026, 2027 or 2028.
Official tools: HMRC's Self Assessment tax bill estimator, the simplified expenses checker and check if you need to tell HMRC about additional income.
VAT and CIS
- VAT threshold checker: your rolling 12-month turnover against the £90,000 threshold. See should I register for VAT?
- VAT Flat Rate Scheme calculator: your sector's flat rate, the 16.5% limited cost trader test, and a comparison with standard VAT.
- VAT reverse charge checker: six questions to tell whether the construction reverse charge applies, and what to put on the invoice.
- CIS deduction calculator: the deduction at 20%, 30% or 0% using HMRC's method. Background: CIS explained for subcontractors.
Official tools: check a UK VAT number before you accept a reverse charge invoice or a customer's VAT details, and the VAT rates page.
Taking on staff
- Cost of employing someone calculator: wages, employer National Insurance, Employment Allowance, the minimum pension and holiday, with the real cost per hour worked. It covers the 0% employer NI rate for apprentices under 25.
- Holiday pay calculator for irregular hours: holiday built up at 12.07% of hours worked, or rolled-up holiday pay.
- Statutory Sick Pay calculator: SSP from the first full day off sick, at £123.25 a week or 80% of average earnings.
- National Minimum Wage checker: April 2026 rates by age and apprentice status, with weekly and annual totals. Tips don't count towards the minimum.
- Statutory Maternity Pay calculator: 90% for 6 weeks, then £194.32 or 90% for up to 33 weeks.
- Statutory redundancy pay calculator: age bands, 20-year cap and £751 weekly pay cap from 6 April 2026.
Official tools: the holiday entitlement calculator for regular-hours staff, and the minimum wage calculator.
Getting paid
- Late payment interest calculator: statutory interest at 8% plus Bank Rate, and the £40, £70 or £100 fixed sum, for business customers. See how to chase a late payment.
- Stage payment schedule: split a long job into payments tied to stages of the work.
- Deposit refund calculator: when a homeowner cancels within 14 days, what you can keep for work done and what you must refund.
- Invoice template: includes what GOV.UK says an invoice must show, plus VAT, CIS and reverse charge options.
Paperwork for jobs
- Quote template: an itemised quote with VAT, deposit and validity.
- Terms and conditions template: plain-English terms for homeowner jobs, including the 14-day cancellation right.
Which one do I need?
| If you're asking… | Start with |
|---|---|
| What should I charge? | Day-rate calculator, then the quote calculator |
| How much tax will I owe, and when? | Self-employed tax calculator, then payments on account |
| Do I need to register for VAT? | VAT threshold checker |
| Do I charge VAT to this contractor? | Reverse charge checker |
| Can I afford an apprentice? | Cost of employing someone |
| They still haven't paid | Late payment interest |
When you're ready for an app instead of calculators, see free invoicing apps and AI tools for sole traders on a budget. The calculators give estimates based on published rules, not tax or legal advice. For anything large, check with an accountant.
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FAQ
Are these calculators really free?
Yes. There's no sign-up, and nothing you type is sent or stored; the sums run in your browser.
How up to date are the tax rates?
They're for the 2026 to 2027 tax year, checked against GOV.UK on 15 October 2026. Each calculator lists its sources, and we recheck them every April.
Can I link to or share a calculator?
Yes. Link to any page directly.