What are the odds of winning Premium Bonds?
Each eligible £1 Bond is an entry in a monthly prize draw. A larger eligible holding gives you more entries. It improves the chance of winning something, but it cannot guarantee a prize in a particular period.
Per-Bond odds and your whole holding
For the included October 2026 draw, NS&I published monthly odds of 1 in 21,000 per eligible £1 Bond. That number describes one Bond, not the chance for your entire holding. Our calculator combines the entries in a holding using the published number of prizes and £1 Bonds in the draw.
What does that mean over a year?
The examples below use October 2026’s prize fund and odds for all 12 draws, with the same balance and no reinvestment. They are estimates, not predictions.
| Eligible holding | At least one prize | No prize |
|---|---|---|
| £100 | 5.55% | 94.45% |
| £1,000 | 43.53% | 56.47% |
| £10,000 | 99.67% | 0.33% |
| £50,000 | >99.9999% | <0.0001% |
Why the average doesn’t tell the whole story
A chance of winning something says nothing about the size of the award. A £25 prize and a jackpot both count as a win in that statistic. Expected winnings include every prize size, so rare large prizes affect the average much more than they affect an everyday result.
The calculator shows expected winnings, the chance of no prizes and a range of possible winnings. You can also check the chance of winning a single prize of a chosen size or larger. Several smaller prizes adding up to that amount don’t count for that calculation.
Calculate the chances for your holding. For the formulas and approximation limits, see our methodology.