Premium Bonds calculator
The million is real. So is what it costs you.
Premium Bonds are capital-safe, tax-free and genuinely fun. At typical luck they are also behind a plain savings account, and the less you hold the further behind. This works out by exactly how much, and shows you the odds without flattering them.
Your Bonds
£25 minimum, £50,000 maximum - that ceiling is NS&I’s, not ours.
The best easy-access rate with no balance cap and no introductory bonus, so it is a rate you could put the whole holding into.
What the dream costs you
That is the gap after 5 years: £6,259 in a 4.5% savings account against £5,850 in Bonds at typical luck, which is £850 of prizes over the 5 years. Your money is never at risk in either. What you are spending is the difference.
Over 5 years, £5,000 in Premium Bonds at typical luck reaches £5,850, against £6,259 in a 4.5 percent savings account. The gap is £409. Typical winnings are £150 a year, a return of 3.0%. The chance of winning nothing at all next year is 6.5%. The odds of a one million pound prize this year are 1 in 1,140,000.“Typical luck” means what most people holding this amount actually win in a year. The numbers below show why that is not the headline rate.
What typical luck actually looks like.
Typical winnings a year
£150
A real return of 3.0%
NS&I’s 3.80% is the average, which would be £190 here. A few huge prizes drag the average up, so most holders of £5,000 win less than that.
Chance of winning nothing
6.5%
Across all twelve draws next year
Twelve draws, £5,000 of Bonds, not a single prize. Straight from NS&I’s published odds of 1 in 22,000 per £1 Bond.
Odds of the £1m this year
About 1 in 1,140,000
Two jackpots, every month
2 jackpots a draw, drawn from 137 billion eligible £1 Bonds. Somebody wins it. Twice a month, somebody really does.
Your real return depends on how much you hold
| Holding | Real return | Typical prizes a year |
|---|---|---|
| £100 to £1,000 | 0% | Nothing at all |
| £10,000 | 3.0% | About £300 |
| £25,000 | 3.2% | About £800 |
| £50,000 (the max) | 3.3% | About £1,650 |
With a small holding, a typical year wins nothing. The bigger the holding, the closer you get to the 3.80% headline, but even at the £50,000 maximum a typical year falls short of it.
“Agent Million knocks on two doors a month. Those are real people, and one day one of them could be you. The £409 is what happens in the meantime, whatever the doorbell does.”
Side by side
£5,000 over 5 years, both ways
| Year | Savings account at 4.5 percent | Premium Bonds at typical luck |
|---|---|---|
| 0 | £5,000 | £5,000 |
| 1 | £5,230 | £5,150 |
| 2 | £5,470 | £5,300 |
| 3 | £5,721 | £5,475 |
| 4 | £5,984 | £5,650 |
| 5 | £6,259 | £5,850 |
Premium Bonds are not a disaster, they are quietly second. The shaded wedge is the whole argument, and it widens every year you leave it.
Three things this tool will not pretend about
Prizes are tax free. That is worth real money to a higher-rate taxpayer holding savings outside an ISA, and worth nothing at all to someone whose interest already fits inside their Personal Savings Allowance, so the comparison above is closer for some readers than others.
The headline rate is an average, and most people do not get it. Two £1m prizes and a long tail of £100,000 and £50,000 ones drag the average upwards. So this page compares your savings against the typical return for the amount you hold, worked out from NS&I’s full prize table. Some years you will beat it, most years you will not.
The zero-prize figure is the exact one. It needs no assumptions about the prize distribution at all: it comes straight from NS&I’s published odds for a single £1 Bond, so it is a calculation rather than an estimate. That 6.5% is real.
How this works
Premium Bonds are modelled at the typical (median) return for your holding: what a holder of exactly that many £1 Bonds wins in at least half of all years, worked out exactly from NS&I’s prize table for the August 2026 draw and the prize odds. NS&I’s prize fund rate of 3.8% (from the July 2026 prize draw) is the average across everyone, and a handful of large prizes put it above what a typical holder receives. Each point on the Bonds line is the typical total won up to that year, worked out over the whole period rather than one year repeated, with winnings put back into Bonds at each year end up to the £50,000 limit. The zero-prize odds use NS&I’s published 1 in 22,000 chance for a single £1 Bond in a monthly draw, which applies from the July 2026 prize draw (shortened from 23,000 to 1). The £1m odds use 2 jackpots per draw and the 136,975,958,547 eligible £1 Bonds in the July 2026 draw (moves every month), which is a number that changes every month. Savings interest compounds monthly and is left to roll up. Rates on both sides can change at any time, and NS&I has moved this one twice in a year. This is not financial advice. These are ideas to make you a little bit richer.
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