Money & odds
Odds and ticket maths: what your £2 actually buys
Your chance of winning a competition is simple arithmetic, and so is its value. Work out both before you buy.
Unlike a scratchcard or a slot machine, a prize competition shows you almost everything you need to calculate your chances: the number of tickets, the price and the prize. The maths is primary-school division, but very few people actually do it.
Your chance of winning
If a competition has a maximum of N entries and you hold k of them, your chance of winning the single main prize when it sells out is k ÷ N. One ticket out of 5,000 is a 1 in 5,000 chance, or 0.02%. Ten tickets out of 5,000 is 1 in 500, or 0.2%.
If the competition does not sell out but is drawn anyway, your chance improves, because you are divided by the tickets actually sold rather than the maximum. That is why it is worth knowing what the terms say happens at the deadline.
Expected value, the number operators do not advertise
Expected value (EV) is the average amount a ticket "returns" if the same draw were run thousands of times. For one main prize it is the prize value multiplied by your chance of winning.
Example: a car worth £30,000, 25,000 tickets at £2.49. One ticket has a 1 in 25,000 chance. EV = £30,000 ÷ 25,000 = £1.20. You paid £2.49, so on average you get back about 48p in every pound. The rest covers the operator's costs, marketing, the free postal entries and their profit.
| Prize value | Max tickets | Price | Total if sold out | Value back per £1 |
|---|---|---|---|---|
| £30,000 | 25,000 | £2.49 | £62,250 | 48p |
| £5,000 cash | 3,999 | £1.99 | £7,958 | 63p |
| £1,200 phone | 1,500 | £0.99 | £1,485 | 81p |
| £80,000 car | 199,999 | £0.79 | £157,999 | 51p |
Why "value back" below £1 is normal
Every prize draw that is a business returns less than it takes, in the same way the National Lottery does. A return of 50-70p in the pound is common in the sector. The point of the calculation is not to find a "profitable" draw, because there almost never is one. It is to compare draws with each other and to see what you are paying for the entertainment.
Entering lots of draws does not add up the way you think
If you enter 50 different draws with a 1 in 5,000 chance each, your chance of winning at least once is not 50 in 5,000 (1%). It is 1 − (1 − 1/5000)^50, which is just under 1%. The difference is small at these odds. What matters is that each draw is independent, and your total spend grows in a straight line while your chances creep up slowly.
Instant wins and multiple prizes
Some competitions have dozens of instant-win prizes as well as a main prize. To compare those fairly, add up the value of every prize and divide by the total number of tickets. That gives the average value per ticket. Be aware that instant-win prizes are often site credit rather than cash, and credit is worth less to you than money.
Want to skip the arithmetic? Use our odds & value calculator.
General information only, not legal, tax or financial advice. Questions or corrections? [email protected]