Retirement income calculator
Most pension calculators tell you what you might end up with. This starts from the income you want and works backwards to what you need to put in.
How this is calculated
The pot you need is the income you want from the pot divided by the withdrawal rate. At 4%, £24,000 a year needs a £600,000 pot.
Your existing pot is grown forward at the rate you entered. Whatever gap remains is what future contributions have to fill.
The monthly figure is the contribution that, compounded monthly at your growth rate, exactly closes that gap by your retirement age.
Nothing here is adjusted for inflation. A £30,000 income in thirty years buys considerably less than £30,000 today, so it is worth entering a target in future money or reducing the growth rate to a real return.
Rates used · 2026/27
| Withdrawal rate | 4% common, 3% cautious |
| Compounding | monthly |
| Inflation | not applied |
| State Pension | only if you enter it |
| Normal minimum pension age | 55, rising to 57 in 2028 |
Last checked July 2026. Source: HMRC and gov.uk.
Worked example
To draw £30,000 a year at a 4% withdrawal rate you need a £750,000 pot. A £45,000 pot growing at 5% reaches £201,048 by 65, leaving £548,952 to fund. That needs £660 a month from age 35. Drop the withdrawal rate to 3% and the pot needed rises to £1m.
Common questions
Should I include the State Pension?
Check your forecast on gov.uk first. It is real money but it does not start until State Pension age, which may be years after the retirement age you have entered, so a gap needs funding separately.
Is 4% safe?
It is a widely used starting point from US research, not a guarantee. Charges, a bad run of early returns and a long retirement all argue for something lower.
What about inflation?
Not applied. Either enter a target in future money, or subtract your inflation assumption from the growth rate to work in today's money.
Does my employer contribution count?
Yes. Add your contribution and the employer's together when comparing against the monthly figure this produces.