ROI in Sports Betting: How to Calculate It, With Examples

What ROI means in sports betting

ROI stands for return on investment. In betting, it compares your net result (everything you got back, minus everything you staked) with the total amount you staked.

ROI = (total returns − total staked) ÷ total staked × 100

“Returns” means what the bookmaker paid back, stake included: $18.50 for a $10 bet won at odds of 1.85, and zero for a lost bet. Two worked examples:

• A losing month. 50 bets of $10: you staked $500 and got $465 back. Net result: −$35. ROI: −35 ÷ 500 = −7%. On average, each dollar staked came back as 93 cents.
• A winning month. 40 bets for a total of $800 staked, $856 returned. Net result: +$56. ROI: 56 ÷ 800 = +7%.

A single bet has an ROI too, but it is never informative: a $20 bet won at 2.40 returns $48, a net result of +$28 and an ROI of +140%. Lost, it is −100%. ROI only starts to mean something across many bets.

Void, cashed-out and pending bets

A void bet returns its stake, so it adds nothing to your net result. Most trackers leave voids out of the total staked; including them lowers ROI slightly. Either is fine as long as you always do the same. A cash-out counts as a settled bet whose return is the amount you cashed out. Pending bets stay out of the calculation until they are settled.

Calculate your ROI

Take your totals from your record, for a week, a month or everything so far. If you do not have one yet, our guide on how to track your sports bets explains what to note, and the free betting spreadsheet adds it all up for you.

The number of bets is optional: it only gives the average stake, which is handy to check against the budget you set yourself. The calculator also has a page of its own.

ROI, yield and return on bankroll

You will see yield used as often as ROI on betting forums. In practice, most people mean the same calculation by both words: net result divided by total staked. A yield of 4% and an ROI of 4% usually describe the same thing.

The confusion comes from a third measure that some people also call ROI: the return on bankroll, which divides the net result by the money set aside for betting rather than by the total staked. Because stakes turn over, the total staked over a season is often several times the bankroll, and the two numbers end up far apart.

Say you start the season with a $1,000 bankroll, stake $3,000 in total over the months and finish $90 up. Your ROI on stakes is 90 ÷ 3,000 = 3%. Your return on bankroll is 90 ÷ 1,000 = 9%. Same bets, same result, two numbers three times apart.

Why ROI says more than profit alone

The net result tells you whether you are up or down. ROI tells you how that result compares with what it took.

On profit alone, month A looks like the best one. Per dollar staked, it is month B. And month C shows a loss that looks small in dollars but is large in proportion. ROI is what lets you compare periods, bankrolls or bet types of very different sizes.

It works the other way too: ROI hides volume. A small ROI on a large total staked can mean bigger swings in money than a large ROI on small stakes. Always read ROI next to your total staked, which is the number that tells you how much room betting takes in your budget. Our guide to bankroll management covers how to set that budget.

Win rate vs ROI: why winning often can still lose money

Win rate is the share of your settled bets that won. It is easy to understand, which is why it is quoted so often, but on its own it says nothing about money. What matters is how win rate and odds combine.

For bets at the same odds with the same stake, the arithmetic is simple. A bet at odds of 2.00 needs to win half the time to break even; at 1.50, two times out of three.

Break-even win rate = 1 ÷ odds

ROI = win rate × odds − 1

Winning 60% of your bets at 1.50 loses 10% of what you stake, while winning 35% at 3.20 comes out 12% ahead. A win rate is only high or low compared with the odds it was achieved at.

Average odds as a shortcut

Real records mix many odds, so the formula becomes an approximation using your average odds. With average odds of 2.10 and a win rate of 45%: 0.45 × 2.10 − 1 = about −5.5%. The true figure depends on which bets won and how much you staked on each, so use the shortcut as a sanity check and your actual returns for the real ROI.

Why ROI over a few bets is mostly noise

ROI is a percentage of what you staked, and over a small number of bets, a couple of results move it a long way. Take 20 bets of $10 at odds of 2.00, so $200 staked:

• 10 wins: $200 returned, ROI 0%.
• 12 wins: $240 returned, ROI +20%.
• 8 wins: $160 returned, ROI −20%.

Two results either way swing ROI by 20 points. Over 500 bets of the same kind ($5,000 staked), the same two extra wins add $40, or 0.8 of a point.

Longer odds make it worse. Over 30 bets of $10 at 8.00 ($300 staked), four wins return $320 (ROI +6.7%) and three wins return $240 (ROI −20%). A single result moves ROI by almost 27 points.

So an ROI over a few dozen bets describes what happened; it does not tell you what will happen next. The more bets behind a number, the less any single result can move it. Our variance simulator shows it on thousands of simulated bettors.

Reading ROI by sport, market and bet type

Once you have a few hundred bets, breaking ROI down is where your record gets interesting. The usual cuts:

• By sport and competition.
• By market: match result, totals, handicaps, player props…
• Singles versus parlays, and parlays by number of legs. Our article on parlays and singles explains why the two tend to differ.
• By odds range: favourites, middle odds, long shots.
• Live versus pre-match, and by stake size.

Each cut splits your bets into smaller groups, and smaller groups are noisier. If 25 of your 300 bets are on tennis, a tennis ROI of +15% (say $250 staked, $37.50 net) rests on a handful of results: one win turning into a loss at odds of 2.00 brings it down to +7%.

Always look at the number of bets next to each ROI. Large differences backed by many bets are worth noticing; the rest is a description of a short stretch.

Beyond ROI: the other numbers worth reading

ROI sums up your results in one figure. A few other metrics describe how you got there, and BetTrack Pro works them out from every bet you log:

• Average and median odds. When the average is well above the median, a few long shots are pulling it up.
• Max drawdown: the deepest drop in your balance, from a high point to the lowest point that followed.
• Recovery time: how long it took to climb back to the previous high, or “ongoing” if it has not happened yet.
• Volatility: how widely your results swing.
• Sharpe ratio: your average result relative to those swings.
• Streaks: your longest winning and losing runs.

Drawdown and losing streaks are the most useful of the lot for keeping a budget: they show how far a bad run has already taken you, which is what a budget has to be able to absorb.

ROI over the long run, and what it cannot tell you

Bookmakers build a margin into every price. On a two-way market priced at 1.91 on each side, the implied probabilities add up to about 104.7% instead of 100%. If both sides really had a 50% chance, a bet on either would have an ROI of 0.5 × 1.91 − 1 = −4.5% in the long run. Our guide to implied probability shows how to measure that margin in any market.

That is why, across many bets, the average bettor’s ROI drifts below zero, and why a positive ROI over a short stretch says little about the next one. ROI describes your past results; it does not change the odds, and no number in your record turns betting into a reliable income.

What ROI and your total staked can do is show you clearly what betting costs you. If that cost is more than you planned, or if you notice yourself raising stakes to win money back, that is the moment to slow down or stop.

Frequently asked questions