What daily rate do you need to match your salary? How much tax will HMRC take from your side income? Two calculators that give you the specific figures — no guesswork.
Enter your salary to see the day rate needed to match your current take-home.
Please enter a valid salary.
How much extra tax will you owe on income earned on top of your salary?
Please enter a valid salary.
Please enter a valid side income amount.
Enter your details above to see your rate or tax figure.
Whether you're pricing your time or planning your tax bill — get the answer in seconds.
Type your current salary for day rate, or your salary plus side income for tax.
Day rate accounts for employer NI, pension, gaps, and 165 billable days. Tax shows your exact marginal rate.
Walk into your first client conversation knowing your floor — or set aside the right amount for January.
Every figure is UK-specific. No US tax rates, no generic advice.
Your employer currently pays 13.8% NI on your salary. As a contractor, you replace that cost. The calculator factors it in automatically.
Conservative, market rate, and premium — so you understand your floor and ceiling before any negotiation.
Side income is taxed at your marginal rate — often 40% for higher-rate earners. The calculator shows the real take-home from every pound of side income.
Class 4 NI is 6% on self-employment profit above £12,570 — often overlooked when people estimate their side income tax bill.
Personal allowance (£12,570), basic rate threshold (£50,270), and Class 4 NI rates all updated for the current tax year.
Calculations happen in your browser. Nothing is logged or stored. Use it as often as you like, completely free.
Every calculation a UK self-employed person needs.
Convert your day rate to an hourly figure, or find what hourly rate you need.
See exactly what you take home under each model at the same gross income.
Run through the key IR35 indicators to assess your contract status risk.
Track your rolling 12-month turnover against the £90,000 VAT registration threshold.
What yield, capital, or monthly investment gets you to your target passive income?
Compare tax-efficient structures at different income levels.
Plain-English breakdowns of the questions every UK side-hustler asks.
The day rate calculator shows your floor. This guide explains the UK market rates by sector, how to justify your number, and the most common pricing mistakes first-time contractors make.
Read guideHMRC taxes your side income at your marginal rate — which for a £40k employee earning side income is often 29% (20% income tax + 9% Class 4 NI). Here's what you actually take home.
Read guidePension, sick pay, employer NI, holiday pay, equipment — the real comparison between employment and contracting across five salary levels, using the day rate calculator's breakdown.
Read guideHonest answers about rates, tax, and UK self-employment.
Three things inflate your required rate: first, you replace your employer's NI contribution (13.8% of earnings above £9,100) — that cost disappears for them when you go self-employed, but you're now responsible for it. Second, you lose 36 days of paid leave (28 holiday + 8 bank holidays) that you were previously paid for. Third, contract gaps between engagements — typically 10–20% of the year — mean you earn nothing during that time. Combined, this typically adds 40–60% to the simple salary/days formula.
Yes, if your self-employment income exceeds £1,000 in a tax year (the "trading allowance"), you must register for Self Assessment and file a tax return. You must register by 5 October in the year after the tax year ends. Failing to register can result in penalties. Registration is free and takes about 10 minutes on gov.uk — the calculator tells you how much to set aside before you do.
If your employment salary keeps you within the basic-rate band (below £50,270 total income), your self-employment profit is taxed at 20% income tax plus 6% Class 4 NI — that's 26% combined. If your combined income pushes into the higher-rate band (above £50,270), the portion above that threshold is taxed at 40% income tax plus 2% Class 4 NI — 42% in total. The calculator applies whichever rate applies to your specific figures.
Yes — as a sole trader, you pay tax on profit, not revenue. Allowable expenses include equipment, software subscriptions, professional memberships, home office costs (a portion of your bills), travel for work, and professional training directly related to your trade. The calculator uses your gross side income — enter your profit (income minus allowable expenses) to get the most accurate tax figure.
Conservative is the absolute floor — the minimum rate at which you break even financially compared to your employed position, assuming 165 billable days. Market rate adds a 15% uplift to reflect the typical premium contractors command for flexibility and expertise. Premium adds 35% — relevant for in-demand specialists or high-cost London markets. Your negotiating position determines where in the range you land; the conservative rate is the number below which you're effectively paying to work.
The tax calculations use current 2026/27 HMRC rates and thresholds and are accurate for straightforward UK employment plus sole-trader side income. They do not account for pension contributions reducing your taxable income, student loan repayments, or Scotland's different income tax bands. For complex situations — multiple income streams, IR35, VAT, or limited company structures — consult a qualified UK accountant. This tool gives you an informed starting point, not a formal tax calculation.