Betting ROI and Yield Calculator
Enter a betting record to get the yield on turnover, the return on your bankroll and the win rate behind them. The calculator then asks the question most records skip: with this many bets at these prices, how much of the result could be luck?
In one line: yield = profit ÷ total staked. A 5% yield over 500 bets at average odds of 2.00 has a 95% range of about −3.8% to +13.8%: it needs around 1,533 bets to be clear of zero.
“Returned” means everything paid back, stakes included; a void bet counts as staked and returned. The confidence range assumes roughly flat stakes on single outcomes at the average price. To turn the record into a win rate target for a given price, use the break-even odds calculator.
Result
The range includes zero: not yet distinguishable from luck.
Yield, ROI and the Size of the Sample
Yield measures how much each pound staked made: it is the figure to compare between records of different sizes. Return on bankroll measures what happened to the money you set aside, and it grows with turnover: the same 5% yield turned over five times is a 25% return on the bankroll, and a −5% yield turned over five times is a quarter of it gone.
Worked example: 500 bets, £5,000 staked, £5,250 back
Profit £250, yield 5%, and on a £1,000 bankroll a 25% return. At average odds of 2.00 the break-even win rate is 50%; a 5% yield means a 52.5% win rate. Each £1 bet either wins £1 or loses £1, so its result has a standard deviation of almost exactly 1 (0.9987). Over 500 bets the yield's standard error is 0.9987 ÷ √500 = 4.47 points, and the 95% range is 5% ± 1.96 × 4.47 = −3.8% to +13.8%. The record is consistent with a 5% edge, and also with none.
Bets needed for a yield to be clear of zero
Flat stakes, 95% confidence, solved from n = (1.96 × σ ÷ yield)². Longer prices mean fewer winners and much more noise.
| Average odds | 2% yield | 5% yield | 10% yield |
|---|---|---|---|
| 1.50 | 4,702 | 726 | 169 |
| 2.00 | 9,600 | 1,533 | 380 |
| 3.00 | 19,396 | 3,146 | 803 |
| 5.00 | 38,988 | 6,373 | 1,648 |
Two practical consequences. A tipster record of a few hundred bets says very little, whatever the yield; ask for the number of bets and the average price before the percentage. And because the bookmaker margin is a few per cent on most markets (the margin calculator shows it for any price), a long run of bets at the usual prices drifts towards a negative yield of about that size. Staking more on bigger perceived edges, as the Kelly criterion does, changes bankroll growth but not the arithmetic of the yield.
Frequently Asked Questions
What is the difference between ROI and yield in betting?
Yield is profit divided by the total amount staked (turnover): £50 profit on £1,000 of bets is a 5% yield. ROI is often used to mean the same thing, but strictly it is profit divided by the money you started with: the same £50 on a £250 bankroll is a 20% return on the bankroll. Yield compares records; bankroll ROI tells you what happened to your money.
How do you calculate betting yield?
Add up every stake, add up every return (stakes back plus winnings), subtract stakes from returns to get the profit, then divide the profit by the stakes. 500 bets of £10 is £5,000 staked; if they returned £5,250 the profit is £250 and the yield is 5%.
What is a good yield in sports betting?
Over thousands of bets, any positive yield is rare, because the bookmaker margin starts every bettor at a loss of a few per cent. The more useful question is whether a yield is real: at average odds of 2.00, a 5% yield over 500 bets has a 95% range of roughly −3.8% to +13.8%, which still includes zero.
How many bets do you need before a yield is meaningful?
More than most people think. With flat stakes at average odds of 2.00, it takes about 1,533 bets for a 5% yield to sit clear of zero at 95% confidence, about 380 for 10% and about 9,600 for 2%. At average odds of 5.00 the numbers roughly quadruple, because longer prices make results noisier.
Does the calculator work for each-way bets and accumulators?
Yes for the yield itself: count each each-way bet's full stake (both parts) and each accumulator as one bet. The confidence range assumes flat stakes on single outcomes at the average odds you enter, so for accumulators at long prices treat it as a lower bound on the uncertainty.
Keeping a record is one of the most useful habits in betting: it shows what you have really spent. If the numbers worry you, deposit limits and time-outs are available on every UK-licensed site. 18+. See our responsible gambling resources.