Overtime Tax Calculator UK

Find out exactly how much of your overtime you keep after tax, National Insurance, and student loan deductions. See the effective tax rate on every extra hour.

Overtime in the UK is taxed at your marginal rate, which means every extra hour could be taxed more heavily than your regular pay. If your base salary sits near the top of the basic rate band (£50,270 for 2025/26), overtime can push you into the 40% higher rate bracket — and that is before National Insurance and student loan deductions.

This catches a lot of people off guard. You work an extra ten hours expecting a decent bump in your pay packet, but after tax, NI, and possibly student loan repayments, you might only keep 58p of every extra pound. If your total income is between £100,000 and £125,140, it gets even worse — the personal allowance taper creates an effective marginal rate of around 60%.

The ONS reports that UK employees worked an average of 1.2 hours of paid overtime per week in 2024 (ONS Labour Market Statistics, 2024). Our calculator shows the effective tax rate on your overtime so you can decide whether those extra hours are genuinely worth it.

How to calculate tax on your overtime

  1. Enter your base annual salary
  2. Add the number of overtime hours and your hourly overtime rate
  3. Select your tax code and student loan plan if applicable
  4. See your overtime take-home and the effective tax rate on each extra hour

Written by the CalcStack team · Last updated March 2026

£
£

Frequently asked questions

How is overtime taxed in the UK?▾
Overtime is taxed as regular income. It is added to your base salary and taxed at whatever band it falls into. If your base salary already uses your personal allowance and basic rate band, overtime may be taxed at 40% or even 45%.
Why does my overtime seem heavily taxed?▾
Your base salary already uses your tax-free personal allowance (£12,570) and possibly your basic rate band. Overtime sits on top, so it is taxed at your marginal rate — often 20%, 40%, or even 45% plus National Insurance.
Do I pay National Insurance on overtime?▾
Yes. Overtime earnings are subject to Class 1 National Insurance at 8% on earnings between £12,570 and £50,270, and 2% above that. This is in addition to income tax.
Is time-and-a-half overtime taxed differently?▾
No. The rate you are paid for overtime (1x, 1.5x, 2x) does not change how it is taxed. The total amount earned is simply added to your income and taxed at the applicable marginal rate.
Can overtime push me into a higher tax bracket?▾
Yes. If your base salary is near the boundary of a tax band (e.g., close to £50,270), overtime can push your total earnings into the higher rate band, meaning the overtime portion above the threshold is taxed at 40%.
How much of my overtime do I actually keep?▾
It depends on your tax band. A basic rate taxpayer keeps about 68p of every £1 of overtime (after 20% tax and 8% NI, plus student loan if applicable). A higher rate taxpayer keeps about 52p per £1.
Does overtime affect my student loan repayments?▾
Yes. Student loan repayments are based on total earnings. Overtime increases your total pay, which can increase your monthly student loan deduction by 9% (Plan 1, 2, 4, 5) or 6% (Postgraduate) of the additional amount above the threshold.
Is overtime included in pension contributions?▾
It depends on your employer. Some pension schemes are based on basic pay only, while others include overtime. Check your employment contract or ask your HR department.
Can I reduce the tax on my overtime?▾
You can reduce your overall tax by making pension contributions (which come off your taxable income), using salary sacrifice schemes, or claiming allowable expenses. However, you cannot specifically reduce tax on overtime alone.
How do I check if my overtime tax is correct?▾
Use the CalcStack payslip checker to verify your deductions, or compare your payslip with HMRC tax tables. If you believe your tax code is wrong, contact HMRC directly to have it corrected.

Related calculators

Take Home Pay CalculatorIR35 CalculatorDay Rate Calculator

© 2026 CalcStack — a Flavoureak UK Ltd product. Tax rates are based on 2025/26 HMRC rates. This calculator provides estimates only and is not financial or legal advice.