Premium Bond Calculator
Enter how much you hold in Premium Bonds — see your statistically expected winnings at the current NS&I prize fund rate, and your chances in each monthly draw.
How it works
Premium Bonds pay no interest — instead every £1 bond enters a monthly prize draw. The advertised "prize fund rate" (4.35% from the September 2026 draw) is the total prize pot as a share of all bonds held: it is the MEAN return across all holders, not what a typical holder receives. Odds are 21,000 to 1 per £1 bond per draw.
A worked example: enter a £5,000 holding and the calculator shows a statistically expected £217.50 a year — £5,000 × 4.35%. The odds tell the other half of the story: 5,000 entries at 21,000-to-1 works out at an expected prize roughly once every four months, so a normal year brings about three prizes, and a prize-free run of several months is entirely ordinary rather than a sign something is wrong.
The maths scales down brutally: a £1,000 holder expects a prize about once every 21 months (21,000 odds ÷ 1,000 bonds = 21 draws per expected win). This is why "expected winnings" for small holdings should be read as a long-run average across many years — in any single year, the most likely outcome for a small holder is winning nothing at all.
The honest statistics: because the fund includes two £1 million jackpots and other big prizes, the MEDIAN holder earns noticeably less than the headline rate — most of the "average" is carried by a lucky few. Small holdings feel this hardest: £100 in bonds expects less than one prize every four years. Large holdings (£10,000+) see returns cluster closer to (but still typically below) the fund rate.
The commonest mistake is reading the prize fund rate as an interest rate — treating 4.35% as something your money will earn. It is neither guaranteed nor evenly distributed: it is the size of the prize pot relative to all bonds held, and your personal outcome is a lottery draw around (and typically below) that figure. The second mistake is comparing bonds against savings rates without adjusting for tax — for taxpayers who have used their savings allowance, the tax-free nature of prizes changes the comparison substantially.
Genuine advantages: prizes are TAX-FREE (valuable for higher-rate taxpayers who've used their savings allowance), and capital is 100% HM Treasury-backed with easy withdrawal. HONEST NOTE: the rate is variable — NS&I changes it without notice (this page shows the rate effective from the September 2026 draw and is checked monthly); and in most months your real return is below inflation, so bonds suit "fun + safety" money, not core savings.
What the result represents: the mean expected annual winnings for the holding you enter, at the current prize fund rate — a statistical benchmark, not a forecast of your year. It includes nothing about capital growth because there is none: bonds are always worth their face value, your return comes only from prizes, and in a month with no win your money has earned nothing at all.
FAQ
How much will I win with £50,000 in Premium Bonds?
Statistically about £2,175 a year at the 4.35% prize fund rate — but that is the mean, not a promise: a typical (median) year for a £50,000 holder lands somewhat lower, because part of the fund sits in rare big prizes. With 50,000 entries at 21,000-to-1 odds you'd average roughly 2-3 prizes a month, mostly £25-£100. Every prize is tax-free, which for a 40% taxpayer makes the effective comparison rate against taxable savings about 7.25%.
Are Premium Bonds better than a savings account?
It depends on your tax position and luck tolerance. Versus a taxable account: a 40% taxpayer who has used the £500 personal savings allowance needs roughly a 7%+ gross savings rate to beat a 4.35% tax-free expected return — hard to find. Versus an ISA: a cash ISA paying more than the prize fund rate beats bonds for the MEDIAN holder with certainty. Bonds' unique sell is the lottery upside with zero capital risk; their weakness is that the typical return trails the headline rate.
What are the actual odds of winning £1 million?
Two £1M jackpots are drawn monthly among tens of billions of eligible £1 bonds — for a £50,000 maximum holder the chance is roughly 1 in 500,000 per draw, i.e. about once per 42,000 years of holding. Realistic expectations should centre on the frequent small prizes (£25-£100). Prizes are paid automatically to your bank or reinvested; unclaimed prizes never expire, and you can check old bonds on the NS&I prize checker.
How much would I win with £5,000 in Premium Bonds?
The statistical mean is £217.50 a year (£5,000 × 4.35%), arriving as roughly three prizes in a typical year given 21,000-to-1 odds per £1 bond. The honest caveat applies with full force at this size: the median outcome sits below the mean, months with nothing are completely normal, and a bad year can genuinely bring zero — the headline rate is an average across all holders, not a promise to each one.
Is the prize fund rate guaranteed?
No — NS&I varies it without notice, and this page shows the rate effective from the September 2026 draw, checked monthly. A rate change alters the prize pot for future draws only; your capital is untouched either way. Anyone comparing bonds against a fixed-rate savings account should remember one side of that comparison can move at any time.
Are Premium Bond winnings taxable?
No — every prize from £25 to £1 million is completely tax-free, needs no reporting, and uses none of your savings allowance. That is worth most to higher-rate taxpayers who have already used their £500 personal savings allowance: for a 40% taxpayer in that position, the 4.35% tax-free expected return compares against taxable savings at roughly 7.25% gross.
Can I lose money in Premium Bonds?
Not in nominal terms — bonds are always redeemable at face value, capital is 100% HM Treasury-backed, and withdrawal is straightforward. The genuine risk is quieter: in most months the real (after-inflation) return is negative, and a holder who wins nothing has earned nothing while prices rose. You cannot lose the pounds; you can very easily lose purchasing power.
Do unclaimed prizes expire?
Never — there is no time limit on claiming, and old wins wait indefinitely. If you hold bonds bought years ago (or inherited paperwork suggests someone did), run the numbers through the NS&I prize checker. Setting prizes to pay automatically to your bank, or to reinvest into more bonds, avoids the problem arising in the first place.