UK Income Tax Calculator (PAYE & NI)

Income Tax Bands

UK income tax (for England, Wales, and Northern Ireland — Scotland sets its own bands) works through a series of bands, each taxing a portion of your income at a rising rate. The personal allowance — the amount you can earn tax-free — is £12,570; you pay 0% on income up to this. The basic rate of 20% applies from £12,571 to £50,270. The higher rate of 40% applies from £50,271 to £125,140. The additional rate of 45% applies above £125,140. A critical and often-misunderstood quirk: the personal allowance tapers away once you earn over £100,000, reducing by £1 for every £2 earned above that, disappearing entirely at £125,140. This creates an effective marginal rate of around 60% on income between £100,000 and £125,140 — a notorious 'tax trap' where each extra pound is heavily taxed. Because the bands are marginal, earning into a higher band only taxes the portion above the threshold at the higher rate, not your whole income — so a small pay rise crossing a threshold never leaves you worse off overall (except via the personal-allowance taper and certain benefit cliffs). Allowances and thresholds are frozen or changed in Budgets, and frozen thresholds combined with rising wages pull more people into higher bands over time ('fiscal drag').

National Insurance

National Insurance (NI) is a second tax on earnings that sits alongside income tax, and it's easy to forget when estimating take-home pay. Employees pay Class 1 NI at 8% on earnings between £12,570 and £50,270 a year, and 2% on earnings above £50,270 (2026/27 rates). Note the structure differs from income tax: NI's main rate actually drops to 2% above the upper threshold, so the combined marginal rate of income tax plus NI is 28% in the basic band rising to 42% in the higher band, then 47% at the additional rate. Your employer also pays employer's NI (13.8% above a lower threshold) on top of your salary, but that doesn't come out of your pay — though it's part of why total employment cost exceeds your gross salary. NI differs from income tax in other ways: it's calculated per pay period rather than cumulatively over the year (so irregular earnings can be taxed differently), and it isn't charged on pension income or most savings and dividend income. NI contributions also build entitlement to the State Pension and certain benefits, so they're not purely a tax. Rates have changed several times recently, so confirm the current figures when estimating your take-home pay precisely.

Salary Sacrifice Pensions

Salary sacrifice is one of the most tax-efficient ways to save for retirement, and it materially changes your take-home pay calculation. Under salary sacrifice, you formally give up part of your gross salary in exchange for an equivalent employer pension contribution. Because the sacrifice happens before income tax and National Insurance are calculated, you save both — unlike some other pension arrangements where only income tax relief applies. A worked example: a 5% contribution on a £45,000 salary reduces your taxable and NI-able pay by £2,250. A basic-rate taxpayer saves 20% income tax and 8% NI on that — around £630 — so £2,250 goes into your pension at a real cost to your take-home of only about £1,620. For higher-rate taxpayers the saving is greater still, and many employers also pass on their own NI saving into your pension, boosting it further. Salary sacrifice can also help you stay below key thresholds — for instance, sacrificing enough to keep adjusted income under £100,000 preserves the full personal allowance and avoids the 60% trap, or under £50,270 to retain Child Benefit. There are limits (you can't sacrifice below minimum wage, and the annual pension allowance applies), and reducing your gross pay can affect mortgage borrowing assessments and some benefits, so weigh those factors. This calculator's take-home figures shift noticeably once pension sacrifice is included.

When to Seek Financial Advice

Calculator results provide estimates based on stated inputs and should not replace professional financial advice for significant decisions. Free, regulated financial guidance is available through MoneyHelper (moneyhelper.org.uk, 0800 011 3797) for general money queries. Regulated independent financial advisers (IFAs) — find one at unbiased.co.uk — provide personalised advice on mortgages, pensions, investments, and insurance. Advice fees are typically £150-350 per hour or a percentage of assets