How to Calculate Betting ROI in a Spreadsheet

Why ROI Is the Number That Matters

A bettor hitting 56% on spread bets sounds impressive. But if every winning bet pays -110 and every losing bet costs -110, the 56% win rate barely covers the vig. The real question is never how often you win — it's how much you make per dollar wagered.

That's what ROI measures. Return on investment in betting is the ratio of your net profit to your total stake, expressed as a percentage. It accounts for the actual size of your wins and losses, not just their frequency. It adjusts for different bet sizes. And it's directly comparable across any time period, sport, or market type.

If you only track one analytical metric on your betting, make it ROI. Everything else is context.

The Formula

Betting ROI uses a single, simple formula:

ROI = (Net P&L ÷ Total Staked) × 100

Breaking each component down:

• Net P&L — your total profit or loss across all bets in the period. This is the sum of what you won on winners minus what you lost on losers. If you wagered $100 on a -110 line and won, your P&L on that bet is approximately +$90.91. If you lost, it's -$100.
• Total Staked — the sum of every stake you placed, win or lose. If you placed 20 bets at $50 each, total staked is $1,000 regardless of results.

The result is a percentage. A positive ROI means you're making money long-term. A negative ROI means you're losing. Zero means you're breaking exactly even — which, given the built-in vig, is already doing better than most.

Worked Example

Let's run through realistic numbers.

You place 100 bets over a two-month stretch. Your average stake is $50. Total staked: $5,000.

At the end of the period, you tally your results: you're up $340 in profit after accounting for all wins and losses.

Plug those into the formula:

ROI = (340 ÷ 5,000) × 100 = 6.8%

A 6.8% ROI over 100 bets is the result of a genuinely profitable bettor. Most sharp bettors who make money consistently operate in the 3–8% ROI range over large samples. It sounds like a thin margin — and it is — but at volume it compounds into real money.

Now consider the alternative: same 100 bets, same $5,000 staked, but you're down $180. ROI = (−180 ÷ 5,000) × 100 = −3.6%. That's not catastrophic — it's roughly what you'd expect from a bettor with no edge paying standard vig — but it tells you clearly that over the long run, that approach loses money.

The Google Sheets / Excel Formula

If your spreadsheet has a Stake column and a P&L column, the ROI formula is a single cell:

=SUM(J2:J1000)/SUM(G2:G1000)*100

In this example, column G holds the stake for each bet and column J holds the P&L (positive for wins, negative for losses). Adjust the column letters to match your own layout.

A few practical notes on setting this up:

• Put the ROI formula in a summary row above or below your bet data — row 1 or a dedicated summary tab. Don't bury it in the middle of the data where it's easy to lose track of.
• Use a large range like J2:J1000 rather than a range that ends at your current last row. This way the formula updates automatically as new bets are added without you needing to adjust it.
• Make sure your P&L column captures the net result — profit on a win, negative stake on a loss. Some spreadsheet templates record gross return instead of net; the formula won't work correctly if P&L includes the returned stake on winners.
• Label the cell clearly: "Overall ROI (%)" in the adjacent column. When you have five different ROI calculations for different segments, clear labels prevent confusion.

For a complete guide to building the underlying tracking sheet, see our post on tracking bets in Google Sheets or the guide for Excel users.

What's a Realistic ROI to Aim For?

Context matters here, and most bettors lack it.

The bookmaker's built-in edge — the vig or juice — is typically 5–10% of total stakes for standard lines. A bettor with no edge at all will drift toward approximately −5% ROI over a large sample. That's the baseline you need to beat just to break even.

Recreational bettors who track their bets seriously and think about line value can realistically target 0% to +3% ROI long-term. It sounds unimpressive, but it means you're covering the vig and holding your own against a market that's designed to take money from you.

Sustained ROI of 3–5% over 500+ bets is exceptional. It's the territory where serious recreational bettors operate when they've found genuine edges in specific markets. Professional sharp bettors often target similar numbers — the edge in efficient betting markets is genuinely thin.

A word on sample size: 50 bets is not enough to draw conclusions. At 50 bets, a 10% ROI might just be variance. At 500 bets, a 5% ROI is a statistically meaningful signal. Don't read too much into short-run results — positive or negative.

Track ROI by Segment, Not Just Overall

Your overall ROI is a headline number. The segment breakdowns are where you actually learn something.

The analysis is simple to run in a spreadsheet: filter by a column, and the ROI formula recalculates automatically for that filtered subset. Useful segments to examine:

• By sport — NFL, NBA, MLB, NHL, soccer, and so on. Most bettors have one sport where they genuinely have an edge and several where they don't.
• By market type — moneylines vs. spreads vs. totals vs. player props. Your win rate and ROI often differ dramatically across market types even within the same sport.
• By sportsbook — if you bet across multiple books, which ones are you winning on? This can surface line shopping opportunities.
• By bet size tier — are your biggest bets performing better or worse than your average bets? Confidence should correlate with bet size, but often doesn't.
• By time period — is your ROI improving or declining over time? A downward trend might mean a market has become more efficient, or that you've drifted from the approach that was working.

Concrete example: overall ROI of +2.1% looks fine. But filtered by sport, you find you're +12% ROI on NBA totals across 80 bets, and −8% ROI on NFL spreads across 60 bets. The overall number is masking a profitable specialty and a costly habit. Without the segment view, you'd never know to double down on NBA and scale back on NFL.

This is the type of analysis that serious bet tracking enables — but only if the underlying data is complete and accurate.

The Data Quality Problem

Here's the thing about ROI analysis: it's only as good as the data going into it.

A spreadsheet where you've logged 80% of your bets — skipping the losses when you didn't feel like recording them, or forgetting to enter the Wednesday night parlay — gives you a ROI number that's flattering and wrong. Selective logging inflates ROI because bettors disproportionately skip losses. If your spreadsheet makes you feel like you're winning but your bankroll says otherwise, this is usually why.

Manual entry also introduces errors. A mistyped stake, a wrong odds entry, a line where you recorded -110 but you actually got -115 — individually small, but across hundreds of bets they corrupt the output.

S2S Bets removes both problems. Because each bet is logged from a screenshot of the actual bet slip, there's no selective entry — every bet you took the screenshot of is in the spreadsheet with the exact figures from the confirmation. The source of truth is the sportsbook's own confirmation screen, not your memory.

For a complete picture of your ROI, you need a complete and accurate record. That starts with screenshot-based tracking that doesn't depend on you to type everything correctly every time.

Once you've got a handle on ROI, the next metric serious bettors track is closing line value. Read our guide on what CLV is and why it predicts long-term profitability better than results alone.