What could your Premium Bonds win? See what a typical holder actually gets, not just the average, plus your odds each month and the full prize breakdown.
Updated for the September 2026 prize draw · last updated 13 September 2026 · prize numbers from NS&I
Premium Bonds don't pay interest. Instead NS&I puts a prize fund rate (4.35% from the September 2026 draw, up from 3.80%) into a monthly prize draw, and every £1 bond has odds of 21,000 to 1 of winning in each draw. So your average annual prizes work out at roughly your holding times the rate.
The word doing all the work there is "average". A handful of enormous prizes pull the mean upwards, so most holders win less than the headline rate suggests. That is why this calculator shows you the median as well: the level a typical holder lands on, with half doing better and half doing worse.
The gap between the average and the typical result is not a rounding error. At small holdings it swallows the whole return.
| Holding | Typical year | Average year | Win in a month | Nothing all year |
|---|---|---|---|---|
| £500 | £0 | £22 | 2.4% | 75.1% |
| £1,000 | £0 | £44 | 4.7% | 56.5% |
| £5,000 | £150 | £217 | 21.2% | 5.7% |
| £10,000 | £350 | £435 | 37.9% | 0.3% |
| £20,000 | £725 | £870 | 61.4% | under 0.1% |
| £40,000 | £1,500 | £1,740 | 85.1% | under 0.1% |
| £50,000 | £1,900 | £2,175 | 90.8% | under 0.1% |
Read the first two rows again. With £1,000 in Premium Bonds, the single most likely outcome across a whole year is nothing at all, and that happens about 56% of the time. The £44 average is real, but it is an average taken across everyone including the two people who win £1 million.
The gap narrows as the holding grows. At the maximum £50,000 a typical year is about £1,900 against a £2,175 average, so the headline rate overstates the typical result by roughly 14%.
There were 6,533,031 prizes worth £497,326,725 in total. Almost all of them were small.
| Prize | Number of prizes | Share of all prizes |
|---|---|---|
| £1,000,000 | 2 | 0.00003% |
| £100,000 | 95 | 0.001% |
| £50,000 | 192 | 0.003% |
| £25,000 | 382 | 0.006% |
| £10,000 | 954 | 0.01% |
| £5,000 | 1,909 | 0.03% |
| £1,000 | 19,892 | 0.30% |
| £500 | 59,676 | 0.91% |
| £100 | 2,366,135 | 36.22% |
| £50 | 2,366,135 | 36.22% |
| £25 | 1,717,659 | 26.29% |
Prizes of £25, £50 and £100 make up 98.7% of every prize handed out. If you win, you have almost certainly won a small one. NS&I splits the fund into three equal-ish bands by value: 10% goes to prizes of £5,000 and up, 10% to £500 and £1,000 prizes, and 80% to the £25 to £100 prizes.
The average is easy: your holding times the prize fund rate. The typical result is the harder number, and it is the one most calculators skip.
Every Premium Bonds prize is a multiple of £25, and wins arrive independently at a known rate. That makes a year's winnings a compound Poisson quantity, so instead of running a random simulation we compute the exact probability of every possible annual total using Panjer recursion, then read off the point where half of holders fall below. No random seeds, no sampling error, same answer every time.
The prize counts come from NS&I's published allocation for the September 2026 draw. We check them against each other before publishing: the counts sum to the 6,533,031 prizes and £497,326,725 that NS&I reports, the three prize bands split the fund 10/10/80 exactly as NS&I describes, and the implied £137.19bn of eligible bonds at a 4.35% annual rate produces a monthly fund within £300 of the published £497,326,725. Three independently published figures that agree to six decimal places give us confidence the inputs are right.
It cannot tell you what you will win. It describes the distribution of outcomes, not your outcome. The prize fund rate, the odds and the prize mix are all variable and NS&I changes them, most recently in September 2026. If you move the rate slider away from 4.35%, we scale the number of prizes to match while holding the prize mix constant, which is an approximation of how NS&I would rebalance.
Sources: NS&I Premium Bonds (prize fund rate 4.35%, odds 21,000 to 1, from the September 2026 draw) and NS&I monthly prize allocation (September 2026 draw). Prizes are free of UK income tax and capital gains tax, and capital is backed by HM Treasury. Rates, odds and prize numbers change; we re-check this page when NS&I updates them.
Illustrative only, not financial advice. The figure shown is the average (mean) at the rate you set; because prizes are highly skewed, most holders win less, and there is no guaranteed return. Prize fund rate and odds are set by NS&I and change over time. Prizes are tax-free; capital is backed by HM Treasury.
Compare with the Compound Growth calculator.