Sports Betting ROI: How to Calculate and Track Your Real Return
Sports betting ROI measures profit per dollar wagered. Learn the formula, 3 worked examples, realistic benchmarks (2-5%), and why ROI without turnover is meaningless.
What Sports Betting ROI Actually Measures
Sports betting ROI (return on investment) is your net profit divided by your total amount wagered, expressed as a percentage. It tells you how much you earn per dollar risked. Not per dollar in your bankroll. Not per bet won. Per dollar wagered.
The formula:
ROI = (Total Profit / Total Amount Wagered) x 100
If you wagered $10,000 over a month and your net profit is $250, your ROI is 2.5%. That number sits at the heart of every serious bettor's tracking system because it normalizes performance across different bet sizes, odds, and time periods.
ROI is not the same as return on bankroll. A bettor with a $5,000 bankroll who wagers $50,000 in a month (10x turnover) and earns 2% ROI has made $1,000. That is a 20% return on bankroll. The ROI is modest. The dollar return is not. This distinction matters, and most bettors confuse the two. Use the edge calculator to test whether your historical results reflect genuine skill or variance, then calculate ROI from the actual numbers.
How to Calculate Betting ROI: 3 Worked Examples
The formula is simple. Applying it correctly requires tracking every dollar wagered, including losses.
Example 1: Flat bettor on moneylines. You place 200 bets at $100 each over a season. Total wagered: $20,000. You end the season with $20,600 in your account (starting from $20,000 deployed across the season). Net profit: $600.
ROI = ($600 / $20,000) x 100 = 3.0%
Example 2: Variable bet sizes. You place 150 bets. Some at $50, some at $200, some at $500. Total wagered: $18,750. Net profit: $375.
ROI = ($375 / $18,750) x 100 = 2.0%
The denominator is total dollars wagered, not number of bets. A single $500 bet contributes 10x more to the denominator than a $50 bet. This is why tracking individual wager amounts is non-negotiable.
Example 3: Negative ROI reality check. You place 100 bets at $100 each. Total wagered: $10,000. You lose $450 over the sample.
ROI = (-$450 / $10,000) x 100 = -4.5%
A -4.5% ROI is roughly what the vig costs on standard -110 lines. If your ROI hovers around -4% to -5%, you are betting at market odds with no edge. The vig explanation breaks down exactly why the house takes that slice.
Realistic ROI Benchmarks: What Good Actually Looks Like
The most dangerous number in sports betting is someone else's claimed ROI from a 50-bet sample. Here is what the data actually shows across thousands of tracked bettors.
| Bettor Type | Typical ROI | Sample Size Needed |
|---|---|---|
| Recreational bettor | -5% to -10% | Any |
| Break-even bettor | -2% to +1% | 500+ bets |
| Competent sharp | +2% to +5% | 1,000+ bets |
| Elite sharp (top 1%) | +5% to +8% | 2,000+ bets |
| Claimed online tout | +15% to +30% | 47 bets (suspicious) |
A 3% ROI over 1,000+ bets is genuinely excellent. It means you are consistently finding and exploiting edges that most of the market misses. The sharp betting guide covers the pipeline that produces these numbers: de-vig the line, calculate EV, size with Kelly, verify with CLV.
Anyone claiming double-digit ROI over a large sample is either cherry-picking their tracking window, excluding certain bet types, or lying. The vig on most markets ranges from 4% to 10%. Overcoming that margin consistently by more than a few percentage points requires institutional-grade models or closing line value that books would quickly identify and limit.
ROI vs Win Rate: Why They Measure Different Things
Win rate tells you what percentage of bets you won. ROI tells you what percentage of dollars wagered you kept as profit. These two numbers can move in completely opposite directions.
High win rate, low ROI. A bettor who exclusively takes -300 favorites wins 72% of bets but needs to win 75% just to break even after vig. Win rate looks great. ROI is negative.
Low win rate, high ROI. A bettor who targets +200 underdogs wins 38% of bets. At +200 odds, break-even is 33.3%. That 38% win rate produces an ROI of roughly 14% on those specific bets.
Here is the math on both:
Favorite bettor: 100 bets at $300 to win $100 each. Wins 72 bets. Revenue: 72 x $100 = $7,200. Cost: 100 x $300 = $30,000. Net: -$22,800 + $7,200... wait. Let's be precise. Total wagered = $30,000. Returns from wins = 72 x $400 (stake + profit) = $28,800. Returns from losses = $0. Net profit = $28,800 - $30,000 = -$1,200. ROI = -4.0%.
Underdog bettor: 100 bets at $100 to win $200 each. Wins 38 bets. Total wagered = $10,000. Returns from wins = 38 x $300 = $11,400. Net profit = $11,400 - $10,000 = +$1,400. ROI = +14.0%.
The favorite bettor wins nearly twice as often but loses money. The underdog bettor loses most bets but profits handsomely. ROI captures this. Win rate obscures it. Track both, but make decisions based on ROI.
For any individual bet, use the EV calculator to check whether the expected return is positive before the bet is placed. For the full explanation of how expected value drives every profitable betting decision, read the expected value guide.
How Turnover Transforms ROI Into Real Dollars
A 3% ROI sounds small until you multiply it by turnover. Turnover is the total amount wagered divided by your starting bankroll. It is the multiplier that converts a modest ROI into meaningful income.
Consider two bettors, both with a $10,000 bankroll and a 3% ROI:
| Metric | Low Turnover | High Turnover |
|---|---|---|
| Monthly turnover rate | 2x | 8x |
| Total wagered per month | $20,000 | $80,000 |
| Monthly profit (3% ROI) | $600 | $2,400 |
| Annual profit | $7,200 | $28,800 |
| Return on bankroll | 72% | 288% |
Same ROI. Same bankroll. 4x the profit because of volume. The bankroll turnover guide walks through the compounding math and explains why 200 bets at a small edge beat 5 bets at a large edge. The turnover calculator models these scenarios with your actual numbers.
This is also why professionals care about bet frequency and settlement speed. Every hour your capital sits idle waiting for a game to start or a contract to settle is turnover you are not capturing. Short-duration bets recycle capital faster, which means more total wagered, which means more total profit at the same ROI.
Tracking ROI Properly: What Most Bettors Get Wrong
Accurate ROI requires accurate data. Here are the four tracking mistakes that corrupt your numbers.
Mistake 1: Using net deposits instead of total wagered. If you deposit $1,000 and withdraw $1,200, that is not a 20% ROI. You need to know the total amount wagered. If you recycled that $1,000 through 50 bets totaling $8,000, your actual ROI is $200 / $8,000 = 2.5%.
Mistake 2: Excluding losing streaks. Cherry-picking your best months or ignoring a bad week inflates your perceived ROI. Track every bet from day one. No exceptions.
Mistake 3: Ignoring the denominator. ROI is profit divided by total wagered, not by bankroll, not by number of bets, not by deposits. Get the denominator wrong and the number is meaningless.
Mistake 4: Too small a sample. With standard -110 bets, you need roughly 1,000 bets before your ROI stabilizes enough to distinguish skill from luck. At 500 bets, a "skilled" bettor with 3% true ROI has roughly a 30% chance of showing a negative ROI due to variance alone. The edge calculator runs a statistical test on your record to determine whether your results are likely skill or noise.
ROI on Prediction Markets
The ROI formula works identically on prediction markets, but the inputs look different. On Kalshi or Polymarket, you buy contracts at a price between $0.01 and $0.99. Your "wager" is the contract price. Your profit is $1.00 minus the price (if the contract resolves yes) or zero (if it resolves no).
Example: You buy 100 contracts at $0.40 each on Kalshi. Total wagered: $40. If the event occurs, you receive $100. Net profit: $60. ROI on this single trade: ($60 / $40) x 100 = 150%.
But that single-trade ROI is misleading in isolation. Across a portfolio of 50 trades at various prices, the aggregate ROI is what matters. And prediction market fees reduce your effective ROI. Kalshi charges a taker fee of roughly 7% x p x (1-p) per contract. Polymarket takes 2% of net profits. These costs compound across hundreds of trades and can turn a marginally positive ROI negative. The prediction market fees guide breaks down exactly how much each platform skims.
The bigger ROI challenge on prediction markets is turnover. Long-dated contracts (will inflation exceed 3% by December?) lock capital for months. Your per-trade ROI might be strong, but your annualized return suffers because turnover drops below 4x per year. Short-duration daily and weekly contracts on Kalshi solve this problem. The turnover calculator models how contract duration affects annual profit at any given ROI.
The ROI Number That Actually Matters
ROI in isolation is one-third of the picture. The complete performance equation is:
Annual Profit = ROI x Total Amount Wagered per Year
And total amount wagered per year is:
Total Wagered = Bankroll x Turnover Rate x 52 weeks
So the three variables that determine your income are ROI (edge per dollar), turnover rate (how fast capital recycles), and bankroll size. You control all three. The Kelly Criterion optimizes bet sizing to maximize long-term growth. The edge calculator verifies your edge is real. The turnover calculator shows what volume does to the bottom line.
A 2% ROI is not a small number. It is a number that, multiplied by enough turnover, funds a living. The math is not complicated. But it requires tracking every bet, calculating the right denominator, and having the patience to let a 1,000-bet sample reveal whether your edge is real.
Frequently asked questions
- What is a good ROI for sports betting?
- A 2-5% ROI over 1,000+ bets is considered strong. Elite sharps rarely sustain above 5-8%. Anyone claiming consistent double-digit ROI over large samples is almost certainly misrepresenting their results.
- How do you calculate sports betting ROI?
- ROI = (Net Profit / Total Amount Wagered) x 100. If you wagered $15,000 and profited $450, your ROI is 3%. The denominator is total dollars wagered, not your bankroll or number of bets.
- What is the difference between ROI and win rate in betting?
- Win rate is the percentage of bets won. ROI is the percentage of dollars wagered that you keep as profit. A bettor can have a 70% win rate and negative ROI by betting heavy favorites, or a 35% win rate and positive ROI by targeting underdogs at value prices.
- How many bets do I need before ROI is meaningful?
- At least 500 bets for a rough signal, and 1,000+ for statistical reliability. With standard -110 odds, a bettor with a true 3% edge has about a 30% chance of showing negative ROI after just 500 bets due to variance.
- Can you make a living from a 2% sports betting ROI?
- Yes, if turnover is high enough. A 2% ROI on $80,000 wagered per month produces $1,600 monthly profit. The key is bankroll size and bet frequency, not ROI alone. The turnover calculator models these scenarios.