Pension Pot Calculator (UK)
How much will your pension be worth at retirement — and what income can it provide? Enter your current pot, monthly contribution and years to go, with tax relief included automatically.
How to use this calculator
- Enter current pension pot.
- Enter monthly contribution you pay in.
- Enter years until retirement.
- Enter expected annual growth.
- Your results appear instantly below and update as you change the numbers.
How this calculator works
Pension contributions get tax relief at your marginal rate. Under relief at source, a basic-rate taxpayer paying £200 a month sees £250 land in the pot (the provider claims the extra 20% from HMRC). The calculator grosses up your contribution, compounds it along with your existing pot at your chosen growth rate, and reports the projected pot plus a sustainable monthly income using the common 4% drawdown rule of thumb. Worked example: £20,000 now plus £200 net a month (→ £250 gross) growing at 5% for 25 years reaches about £218,500 — supporting roughly £730 a month of retirement income before tax, on top of the full new state pension (about £11,975 a year in 2025/26).
Frequently asked questions
How much tax relief do I get on pension contributions?
Basic-rate taxpayers get 20% added automatically. Higher-rate (40%) and additional-rate (45%) taxpayers claim the extra 20–25% back through their Self Assessment return. Your total contributions are capped at the £60,000 annual allowance (2026/27), or 100% of your earnings if lower.
What is the 4% rule?
A widely used planning benchmark: withdrawing 4% of your pot a year (rising with inflation) is historically likely to make the money last at least 30 years. It's a starting point, not a guarantee — your actual sustainable income depends on market returns, charges and how long you'll live.
Should I use a pension or an ISA?
Pensions win on tax relief and employer matching but lock money away until 55 (57 from 2028). ISAs are flexible and tax-free but get no top-up. Most people use the pension for the employer match and long-term retirement money, and ISAs for goals that might need the cash earlier.
What about the state pension?
The new state pension is separate from your private pot. You usually need 35 qualifying years of National Insurance for the full amount (about £11,975 a year in 2025/26, uprated by the triple lock). Check your National Insurance record on GOV.UK — gaps can often be filled cheaply.
Disclaimer: Results are estimates for general information only and do not constitute financial, tax, or legal advice. Figures reflect the current tax year and may change. Always confirm current limits and consult a qualified professional before making decisions. Official figures: GOV.UK income tax rates · National Insurance · Stamp Duty Land Tax.