Your chances of winning, worked out
If a draw publishes a ticket cap, your chance is simply your tickets divided by that cap, and you can work it out before you spend anything. If it does not, you cannot, because the total number of entries does not exist until the draw closes. That single difference decides whether the odds on a competition are a fact or an estimate, and it is the first thing worth checking on any site, this one included.
Capped draws: the sum takes ten seconds
A capped competition fixes the number of tickets before it opens. Say the cap is 20,000 and you hold 100 tickets. Your chance is 100 in 20,000, which is 1 in 200. Nothing anybody does afterwards changes it: if the draw sells out your odds are the same as they were the minute you entered, and if it only half sells they are better.
That is the entire calculation. The only wrinkle is a draw with several winners, where you want the chance of winning at least one prize rather than a named one, and the odds calculator handles that for you.
Our draws, at the smallest order anyone can place
| Draw | Ticket cap | 25 tickets cost | Chance |
|---|---|---|---|
| £250 Tax-Free Cash | 20,000 | £2.25 | 1 in 800 |
| £500 Tax-Free Cash | 27,000 | £2.25 | 1 in 1,080 |
Caps are published on each competition page before entry opens, so these are checkable rather than quoted. Tickets are 9p each in minimum orders of 25, or free by post on the same odds.
Uncapped draws: the sum cannot be done yet
Some of the largest UK draws do not cap entries at all. They keep selling until the closing date, which means every entry made after yours makes yours worth slightly less, and the denominator you would need is not known until it is all over.
Omaze UK is the clearest example, and it is worth being precise about it rather than vague. Omaze UK house draws are open-ended. There is no published ticket cap, and the total number of entries is not published before or with the result. So a figure for “the odds of winning an Omaze house” quoted while the draw is open is an estimate somebody has made, not a published number.
Two things worth saying in the same breath, because a comparison that leaves them out is not a fair one. First, an uncapped draw is an ordinary and lawful way to run a competition, not a trick: it is simply a different product, and the prizes are real. Second, omaze publishes a free postal entry route, and states that a postal entry has the same chance of winning as any one paid entry, with no limit on how many may be sent.
Checked 30 October 2026 against Omaze UK’s own published entry pages (postal entry route). Terms change: check the draw’s own rules before you enter it.
What this means when you are deciding
It is not that one model is honest and the other is not. It is that they answer different questions. An uncapped draw asks you to buy on the strength of the prize. A capped one lets you price the chance first and decide whether it is worth it to you. If you like knowing the number before you spend, look for the cap; if the cap is not on the page, the odds are not knowable, and no amount of reassurance changes that.
The same test cuts both ways, which is why our caps are on every competition page and why the calculator takes any cap, not only ours. The rest of the checks worth making before you enter anywhere are set out in how to check a competition is genuine.
Questions people actually ask
What are the chances of winning an Omaze house?
Nobody can tell you, including Omaze, until the draw closes. Omaze UK house draws are open-ended. There is no published ticket cap, and the total number of entries is not published before or with the result. Your chance is your entries divided by the final total, and the final total is not known while the draw is open — so a figure quoted before it closes is a guess. What you can check instead is the free route: omaze publishes a free postal entry route, and states that a postal entry has the same chance of winning as any one paid entry, with no limit on how many may be sent. Checked 30 October 2026.
How do I work out my odds in a prize draw?
If the draw has a published ticket cap, divide your tickets by the cap. A hundred tickets in a twenty thousand ticket draw is 100 in 20,000, or 1 in 200. If there is more than one winner the sum changes slightly, because you want the chance of winning at least one of several draws rather than one. If the draw has no cap, the arithmetic cannot be done until entries close, because the denominator does not exist yet.
Why can you work out the odds on some competitions and not others?
Because of one design decision: whether the operator fixes the number of tickets in advance. A capped draw sets the total before it opens, so your chance is fixed the moment you enter and can be calculated by anybody. An uncapped draw keeps selling, so every later entry dilutes every earlier one and the final odds are only knowable afterwards. Both are lawful and both are common. They are simply different products, and only one of them can be checked before you pay.
Do free postal entries have the same chance as paid tickets?
They must, and on any properly run UK competition they do. A free entry route on worse odds would make the paid route the only real way in, which is the thing the free route exists to prevent. On our draws a postal entry takes a ticket number from the same pool and appears in the same draw as a paid one. The larger operators state the same.
Does buying more tickets guarantee a win?
No, and no honest operator will tell you otherwise. More tickets raise your share of a fixed pool and nothing more. In a 20,000 ticket draw, 1,000 tickets is a 1 in 20 chance, which also means 19 times out of 20 it loses. Work out what you are spending before you decide, and never spend money you need.
Know the number before you spend
Every Grand Draws competition publishes its ticket cap, so your chance is a fact you can check rather than a figure we quote. Free postal entry on the same odds. 18+.
Your ticket could be next
Every competition has published odds, a draw anyone can verify and a free postal route. 18+.