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Betting variance calculator
Enter your average odds, number of bets, stake and edge, and this betting variance calculator shows how far your results could swing. With a 5% edge at 3.0, 500 bets of £10 expect £250.00 profit, but 95% of the time the result is between -£377 and £877.
Reading the betting variance calculator: edge, range and chance you're down
Your edge, or yield, is the profit you expect per £1 staked, as a percentage. A 5% edge means you expect 5p profit per £1 over the long run. Enter 0 to see what pure luck looks like.
The likely range covers 95% of outcomes. The chance you're down is the chance of finishing all the bets with a loss even though your edge is real. Bets to prove it is roughly how many bets it takes before a profit is unlikely to be luck. The chart draws twenty random runs, so press Run again to see different ones.
The range widens as you bet more, but expected profit grows faster
| Bets | Expected profit | Likely range | Chance you're down |
|---|---|---|---|
| 100 | £50 | -£230 to £330 | 36% |
| 500 | £250 | -£377 to £877 | 22% |
| 1,000 | £500 | -£387 to £1,387 | 13% |
| 5,000 | £2,500 | £517 to £4,483 | 1% |
The range in pounds keeps getting wider, but the expected profit grows faster. So a real edge only shows clearly after thousands of bets.
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Read the guide: Betting variance: why good bets lose and how long luck lastsRead →Questions people ask
What is a good yield in betting?
Over thousands of bets, a yield of a few percent is good. Yields far above that over a small number of bets are usually variance, not skill.
How is the range worked out?
From the spread of results you'd expect at those odds, using a normal approximation. It's close once there are a few dozen bets.
Why do my odds matter so much?
At bigger odds you win less often, so results swing more. The same edge takes far more bets to show up at 6.0 than at 2.0.