ROI = net profit ÷ total amount staked × 100. For €400 staked and €420 returned: net profit +€20, ROI +5%. ROI measures an observed performance on bets already settled — on its own it says neither whether it's significant nor whether it's repeatable. Read it alongside the volume, the average odds and the variance they produce.
The essentials in a few seconds
ROI relates the net profit of a betting record to total staked. ROI = net profit ÷ total amount staked × 100. For €400 staked and €420 returned, net profit comes to +€20 and ROI to +5%.
It's an observed performance, not a demonstrated one. An ROI only becomes interpretable alongside the volume of bets that produced it and the average odds they were taken at.
Net profit and volume staked
Net profit on its own says nothing: two records can show the same net profit with completely different volumes. A profit of +€40 on €100 staked and a profit of +€40 on €4,000 staked don't describe the same thing — the first doubled the stake, the second barely exceeded it.
ROI exists precisely to make these two situations comparable: it relates the result to the volume committed, which net profit does not.
The formula
ROI = net profit ÷ total amount staked × 100. Net profit is the sum of returns collected, minus stakes, across all bets settled.
This page uses the most common convention: ROI calculated on total stakes committed. Another convention exists and circulates under the same name — a calculation relative to average bankroll rather than total staked, sometimes called "yield". The two measure a related idea with a different denominator: always state which base you're using before comparing two figures, including your own from one period to the next.
Calculate a net profit and an ROI
Enter the total staked and the total returned over the period observed.
The sum of every stake already settled over the period observed.
The sum of every return collected on those same bets, winnings included.
Result
- Net profit
- +€20.00
- ROI
- +5.00%
Warning:
ROI describes a performance observed on the bets entered. It says nothing about whether it is significant or reproducible.
ROI or yield: what the two words cover
In everyday sports betting usage, ROI and yield describe the same calculation. The distinction, where it exists, comes down to the denominator: total staked for one, average bankroll committed for the other. This page does not create a separate page for yield — the intent behind the two words is too close to justify two separate URLs.
The break-even point by odds
At a given average odds, there's a minimum strike rate below which the result is negative: 1 ÷ average odds. At an average odds of 1.50, you need about 66.7% success to break even. At 2.50, you need 40%.
| Average odds | Break-even point (1 ÷ odds) |
|---|---|
| 1.50 | 66.7% |
| 2.00 | 50.0% |
| 2.50 | 40.0% |
| 3.00 | 33.3% |
This threshold explains why a strike rate never reads on its own: 55% success is comfortably positive at an average odds of 1.50, and clearly negative at an average odds of 2.50.
Two profiles, the same number of bets
A strike rate sometimes ranks two records in the opposite order to their real ROI. Two bettors, 20 bets each, €10 per bet, €200 staked on both sides.
| Indicator | Profile A | Profile B |
|---|---|---|
| Bets won | 10 / 20 | 8 / 20 |
| Strike rate | 50% | 40% |
| Average odds | 1.50 | 2.50 |
| Returns collected | €150 | €200 |
| Net profit | −€50 | €0 |
| ROI | −25% | 0% |
The profile that wins more often loses money; the one that wins less often breaks even. A strike rate never reads without the average odds that come with it.
"+20% ROI, my method is good."
Without the volume of bets and the average odds that produced it, this figure is not interpretable. A high ROI on few decisions looks a lot like a favourable run due to chance.
Profile A vs profile B: is the same number enough?
Take the cluster's two canonical examples: 10 bets at +30% ROI, and 2,000 bets at +3% ROI. Is profile A necessarily better? No — missing are the variance that comes with each, the sample size, the stability of the odds and the period covered.
Profit — an amount. ROI — that amount relative to volume staked. Bankroll growth — how the capital evolves, which also depends on stake sizes and how they change.
An ROI of +30% on 10 bets fits almost entirely within the range produced by variance on such a small sample. An ROI of +3% on 2,000 bets has far less room to be explained by chance alone — without that guaranteeing it will repeat.
Why variance dominates on a small sample →
What determines the amount of data needed to decide →
What ROI doesn't say
ROI says nothing about the risk taken to get it, nor about the quality of the prices the bets were placed at. Two records with the same final ROI can have gone through very different dips in capital.
A positive ROI does not mean a method delivers over the long run. A negative ROI does not mean it doesn't — on a small sample, both can be down to variance.
What the final ROI never shows: the path taken →
How to keep the data that lets you calculate it
An honest ROI assumes a complete record — losses included, with no period erased. The tracking method, column by column, is covered on a dedicated page.
The data to record for every bet →
ROI observes what happened. Expected value describes what should happen on average, if the estimate used is accurate — the next step for understanding why a result often diverges from what was expected.
Responsible gambling. A positive ROI over one period guarantees nothing for the next. A stake can be lost in full. Set a budget before you play and use the limit-setting or self-exclusion tools licensed operators provide. Learn more about responsible gambling.
Dig into the market
Odds movements are only part of the story. Here are the next topics to read.
Profitability and risk: the complete guide
The full picture: profit, ROI, expected value, variance, sample size, drawdown, risk.
Read the guideTracking your bets
The data to record so you can calculate an honest ROI.
See how to trackVariance: why results swing
What separates a solid ROI from an ROI down to chance.
Understand varianceHow many bets to judge a performance?
What the reliability of an observed ROI depends on.
See the methodDrawdown: measuring the dips in a bankroll
What the final ROI never shows: the path taken to get there.
Understand drawdownAssessing a tipster
Why a high strike rate can hide a negative ROI.
See the methodFrequently asked questions
How do you calculate the ROI of a betting record?
Divide net profit (returns collected minus stakes committed) by total staked, then multiply by 100. A profit of €20 on €400 staked gives an ROI of +5%.
What's the difference between ROI and yield?
In everyday sports betting usage, the two words describe the same calculation: net profit relative to total staked. Some conventions distinguish a calculation on stakes from one on average bankroll — always state which base you're using before comparing two figures.
Is an ROI of +10% a good result?
It depends entirely on the volume of bets and the average odds that produced it. A +10% on 15 bets is almost entirely attributable to variance; the same figure on 3,000 bets describes a very different reality.
Does ROI measure skill?
Not on its own. ROI describes what happened over a set of bets already settled. It says nothing about the risk gone through to get there, nor the probability that the result will repeat.
What is the break-even point by odds?
It's the minimum strike rate needed to avoid losing money at a given average odds: 1 ÷ average odds. At 1.50, you need about 66.7% success; at 2.50, 40%.
Why can two identical ROIs describe different situations?
Because ROI says nothing about the volume, the average odds, or the variance that comes with them. An ROI of +5% on 20 bets and an ROI of +5% on 3,000 bets don't carry the same weight of proof.