The honest answer is smaller than the scary "£1 million" figure you hear, because the State Pension quietly does a lot of the work. Here is the simple maths, the income you might actually want, and a worked example for 2026/27.
Most retirement targets come down to one back-of-an-envelope rule:
The pot you need ≈ (your target income − the State Pension) × 25.
The "× 25" is the 4% rule (also called the rule of 25). The idea, from long-run studies of market returns, is that you can withdraw about 4% of your pot in the first year of retirement, increase it with inflation each year after, and have a good chance of the money lasting around 30 years. Because 1 ÷ 0.04 = 25, the pot you need is simply 25 times the income you have to fund yourself.
The key word is yourself. You don't need to fund your whole target income from savings, because the State Pension covers a big chunk first.
The full new State Pension for 2026/27 is about £12,548 a year (£241.30 a week), paid for life and increased each year under the triple lock. It comes out of your target income before you touch a penny of your own savings.
Put another way: because that income would otherwise need a pot of £12,548 × 25 to replace, the State Pension is effectively a hidden asset worth around £313,000. Most people never count it, which is exactly why they overestimate what they need.
The PLSA Retirement Living Standards put real numbers on three lifestyles. These are yearly figures for a single person and assume you own your home (they exclude rent and mortgage costs):
| Lifestyle (single) | Yearly income |
|---|---|
| Minimum | £13,900 |
| Moderate | £32,700 |
| Comfortable | £45,400 |
"Minimum" covers the essentials with a little left over; "moderate" adds more financial security and some luxuries like a couple of holidays; "comfortable" means more freedom and a newer car.
Take a single person who wants the "moderate" income of £32,700 a year. The State Pension covers £12,548 of it, so you only have to fund the gap yourself.
£32,700 target income − £12,548 State Pension = £20,152 to fund yourself
£20,152 × 25 = a pot of about £500,000.
Run the three lifestyles through the same maths and the single-person pots look like this:
| Lifestyle (single) | Income | Pot needed |
|---|---|---|
| Minimum | £13,900 | ~£34,000 |
| Moderate | £32,700 | ~£500,000 |
| Comfortable | £45,400 | ~£821,000 |
Notice how far the State Pension stretches at the lower end: a minimum lifestyle needs a pot of only around £34,000, because the State Pension almost covers it on its own.
Free calculatorEnter the income you want, choose single or a couple, and see the pot you need, with the State Pension's value shown separately.
Open the Retirement Number calculator →A couple gets two State Pensions, about £25,096 a year between them, and shares most living costs. So the pot a couple builds themselves is smaller than two single people would need. A "moderate" couple's income of £45,400 needs a combined pot of roughly £508,000. A couple wanting only a minimum lifestyle may need very little beyond their two State Pensions.
The rule of 25 gets you the right ballpark fast, but it is a starting point, not a guarantee:
The way to actually build the pot is to start early and let compounding work. See how much a monthly amount could grow with the Compound Growth calculator, and check how you compare for your age with Am I On Track?.
Take the income you want, subtract the State Pension (about £12,548 a year in 2026/27), and multiply by 25. A single "moderate" £32,700 income needs a pot of roughly £500,000.
Usually not. Once the State Pension is counted, a single "comfortable" £45,400 income needs about £821,000, and "moderate" around £500,000. A million is more than most people require.
Withdraw about 4% of your pot in year one, rising with inflation, with a good chance it lasts around 30 years. The pot is 25 times the income you fund yourself, because 1 ÷ 0.04 = 25.
Less than two singles. Two State Pensions (about £25,096 a year) plus shared costs mean a "moderate" £45,400 couple needs a combined pot of roughly £508,000.
Illustrative and educational only, not financial advice. This uses the "rule of 25" (4% guideline) and the PLSA Retirement Living Standards. Real outcomes depend on tax, your home, inflation, care costs and market returns, which this does not model precisely. Your capital is at risk. Always check gov.uk or speak to a qualified adviser.
Sources: gov.uk (State Pension, 2026/27), PLSA Retirement Living Standards, the 4% rule (Bengen / Trinity study).