See how changing your contribution % affects your monthly take-home and retirement pot — with tax relief and employer matching built in.
Pension contributions attract tax relief at your marginal rate, so a £100 contribution costs a basic-rate taxpayer £80 and a higher-rate taxpayer £60. You can contribute up to £60,000 or 100% of your earnings a year, whichever is lower. Salary sacrifice reduces gross pay before both income tax and National Insurance and so costs less again; relief-at-source contributions save income tax only.
Pension contributions are one of the most tax-efficient ways to save in the UK. When you contribute more to your pension, the government tops it up through tax relief — meaning the actual cost to your take-home pay is much less than the headline contribution amount.
| Tax Band | Extra £100 into pension | Take-home cost | Tax relief |
|---|---|---|---|
| Basic rate (20%) | £100 | £80 | £20 |
| Higher rate (40%) | £100 | £60 | £40 |
| Additional rate (45%) | £100 | £55 | £45 |
Salary sacrifice reduces your contractual salary, so you pay less National Insurance as well as income tax. A basic-rate taxpayer contributing via salary sacrifice saves an additional 8% in NI — so a £100 pension contribution costs only ~£72 net. Your employer also saves employer NI (15% above £5,000), and some pass this saving back into your pension.
Relief at source is contributed from net pay and topped up with basic-rate tax relief automatically. Higher and additional rate taxpayers must claim extra relief through Self Assessment.
Many employers match contributions up to a cap. Where a match is available, contributing enough to capture it means the employer pays in alongside you — under a 1:1 match, each extra £1 you contribute is accompanied by £1 from your employer, up to the cap. Matching terms are set by your employer’s scheme, so check your scheme rules before changing your contribution. Money paid into a pension is not normally accessible before age 55 and is taxable on withdrawal beyond the tax-free lump sum.
An extra £100/month into your pension at 30, growing at 6%, adds roughly £100,000 to your pot by age 67 (pre-charges). At 40, the same extra £100 adds roughly £50,000. Starting earlier matters — but it's never too late to increase contributions.
The pension and tax figures applied here. Official figures last checked on 2 September 2026.
Official figures this calculator applies
UKCalc assumptions — not official figures
The £100,000 band. Between £100,000 and £125,140 the personal allowance withdraws at £1 for every £2, giving a 60% marginal Income Tax rate across the whole of that range. A pension contribution that brings adjusted net income back below £100,000 is relieved at that effective rate, which is why contributions in this band are unusually efficient.