AUOdds

Arbitrage Betting Calculator Free: Build an AU Google Sheet

By the AUOdds team · Updated 4 Nov 2026 · 7 min read

Key takeaways
  • Most free calculators are one-off web forms, so a Google Sheet with a built-in bet log gives you a record they can't.
  • Five tabs cover the essentials: 2-way, 3-way, racing field percentage, settings for rounding, and a bet log.
  • Rounding stakes to whole dollars or $5 steps costs margin, and the sheet should show exactly how much before you bet.
  • A sheet does the maths but can't find prices, so it works best alongside live lock alerts.
  • Prices move, stakes get limited and bets can be voided, so check every leg and use only licensed Australian bookmakers.

An arbitrage betting calculator free of charge is easy to find online, but nearly every one is a single web form that forgets your numbers when you close the tab. That works for a quick check. It fails the moment you want to know what you actually made, where prices moved, or which bets were voided. This guide shows you how to build a free Google Sheet that handles 2-way markets, 3-way soccer and racing field percentages. It also rounds stakes sensibly and keeps a proper bet log. Every formula is listed, with worked examples in Australian dollars. At the end we cover where a sheet stops being enough and how live lock alerts fit alongside it.

In this guide
  1. What Should an Arbitrage Betting Calculator Free Sheet Include?
  2. How Do You Set Up the 2-Way Tab?
  3. How Do the 3-Way and Racing Field Tabs Work?
  4. Why Does Rounding Matter in an Arb Betting Calculator?
  5. How Should You Set Up the Bet Log?
  6. Do You Still Need Lock Alerts If You Have a Free Sheet?

What Should an Arbitrage Betting Calculator Free Sheet Include?

Most free calculators do one job. You type two prices and a stake, and they show the split. That is fine for a quick check. But it leaves you with no record of what you actually placed, at what price, and how it settled. After a month of locks, that missing history is the bit that hurts.

A useful betting arbitrage calculator in Google Sheets keeps the maths and the record in one file. Set it up with five tabs:

Keep inputs in one colour (light yellow works well) and formulas in another. Then protect the formula cells so you can't overwrite them by accident. That small habit prevents most spreadsheet mistakes.

Everything below uses standard Google Sheets functions. You can build the whole file yourself in about 20 minutes and copy it as often as you like. You don't need a paid add-on, a script or a login to another service.

How Do You Set Up the 2-Way Tab?

Put the two decimal odds in B2 and B3, and your total stake in B5. Then add these formulas:

If B6 is under 1 (shown as under 100%), the prices form a lock. If it is 1 or more, there is no lock at those prices, however good one side looks.

Worked example. An AFL head-to-head market shows 2.08 at one licensed bookmaker and 1.98 on the other team at another. The arb % is 0.4808 + 0.5051 = 0.9858, or 98.58%. With a $500 total stake:

That locks in a return of about $7.19, or 1.44%, at the prices shown. Notice how thin that is.

Suppose one price moves from 2.08 to 2.02 before you place the second bet. That pushes the arb % just over 100% and turns the lock into a small loss. This is why you place the side most likely to move first. Always confirm the price on the bookmaker's own screen before you place the bet.

Add conditional formatting to B6: green under 100%, red at or above. You'll see at a glance whether a quote still works after you refresh the odds.

How Do the 3-Way and Racing Field Tabs Work?

For soccer win-draw-win, use the same logic with three rows. Odds go in B2, B3 and B4, and the arb % becomes =1/B2+1/B3+1/B4. Each stake is the total stake multiplied by that outcome's 1/odds, divided by the arb %.

Take A-League prices of 2.70, 3.50 and 3.05. They give 0.3704 + 0.2857 + 0.3279 = 0.9840, or 98.40%. That is a margin of about 1.6% at the prices shown. On a $600 total stake, the split is roughly $225.85, $174.21 and $199.94.

Three bets mean three chances for a price to shift or a stake to be cut. So treat 3-way locks as slightly harder to complete than 2-way ones.

The racing tab works differently. List every runner with the best available win price in column B. Column C holds =1/B2, copied down, and a total at the bottom adds the column. That total is the field percentage:

Scratchings are the big racing trap. A late scratching can bring deductions on other runners and change the maths after you've bet. Add a Scratched column with a tick box, and have the total ignore ticked rows. Re-check the total before every bet, and read each bookmaker's deduction rules before relying on a racing lock.

Why Does Rounding Matter in an Arb Betting Calculator?

Stakes like $243.84 look odd on a betting slip. Many arbers round to whole dollars or $5 steps, so they can place bets quickly without typing cents. Whatever your reason, rounding changes the result, and a good arb betting calculator shows you by how much.

In the Settings tab, put your rounding step in B1 (for example 1 or 5). On the 2-way tab, add three rows:

Go back to the AFL example and round to $1. You bet $244 at 2.08 and $256 at 1.98. Returns are $507.52 and $506.88, so the worst case is $6.88 instead of $7.19.

Round to $5 instead and you bet $245 and $255. That returns $509.60 or $504.90. The worst case drops to $4.90, and one outcome now carries most of the margin.

Side by side:

On a lock of under 1.5%, a coarse rounding step can eat a third of the margin. The sheet makes that trade-off visible, so you decide deliberately rather than guess. Format B14 to turn red below zero. If rounding ever pushes the worst case into the red, skip the bet.

How Should You Set Up the Bet Log?

The log is what separates this sheet from free web forms. Fill in a row the moment each bet is confirmed. Useful columns include:

After a few weeks, run a pivot table on the log. It answers questions a calculator never can:

Those answers tell you whether your process is working.

Track your balance at each bookmaker too. Arbing moves money between accounts constantly. A simple running balance column stops you finding out mid-lock that one account is short.

On tax, the ATO's ruling IT 2655 explains that gambling winnings are generally not assessable income for most people. A betting activity run as a business can be treated differently. The ATO also covers this on its gambling winnings page.

Whatever your situation, your log is useful evidence, so keep it complete. Get advice from a registered tax agent if you are unsure where you sit.

Do You Still Need Lock Alerts If You Have a Free Sheet?

A spreadsheet does the maths perfectly, but it can't find the prices. Any arbitrage calculator Australia punters use, free or paid, only works once you've spotted prices that form a lock. And those prices don't sit still for long.

AUOdds data shows 3,861 locks across 9 Australian bookmakers in the last 30 days, with 830 in the last 7 days. The typical lock was 1.4%. Behind those numbers are about 15,000 prices tracked at any moment, each roughly 10 seconds old.

Scanning that many prices by hand across several apps isn't realistic. A sensible split is this: alerts find the lock and suggest stakes, and your sheet records what you actually got.

Whichever route you take, the real risks stay the same:

Only use licensed Australian bookmakers, which you can check on the ACMA register. Stick to pre-match markets, because online in-play sports betting isn't offered to Australians.

Arbitrage is still gambling with real money, and you must be 18+ to bet. If it stops feeling under control, BetStop, the National Self-Exclusion Register, lets you block yourself from licensed online bookmakers. Gambling Help Online also offers free, confidential support at any hour.

Frequently asked questions

Is there a free arbitrage betting calculator for Google Sheets?

You can build one yourself in about 20 minutes using the formulas in this guide. It only needs standard functions such as SUM, MIN and MROUND, so there are no add-ons or scripts. Make a master copy and protect the formula cells. Then duplicate it whenever you want a fresh log for a new month or season.

What arb % counts as a lock?

Any arb % under 100% means the prices shown lock in a return if every leg is placed at those odds. In practice, locks are thin. AUOdds data puts the typical lock at 1.4% over the last 30 days. Anything that looks far bigger deserves a second check for a stale price, the wrong market or a likely void.

Should I round my stakes?

Rounding to whole dollars or $5 steps makes bets quicker to place, but it costs margin. On a $500 lock at 1.44%, $1 rounding cut the worst case from $7.19 to $6.88. Rounding to $5 cut it to $4.90. Let the sheet show the cost, and skip any bet where rounding pushes the worst case below zero.

Do I need to pay tax on arbitrage winnings?

For most people, gambling winnings are not assessable income, according to the ATO's ruling IT 2655. Someone running betting as a business may be treated differently. Your position depends on factors such as scale, organisation and system. Keep your bet log complete, and talk to a registered tax agent if you are unsure.

Sources

  1. Taxation Ruling IT 2655: gambling and betting winnings, Australian Taxation Office
  2. Crypto asset prizes and gambling winnings, Australian Taxation Office
  3. Check if a gambling operator is legal, Australian Communications and Media Authority
  4. BetStop: the National Self-Exclusion Register, Australian Communications and Media Authority
  5. BetStop, Australian Government

More guides

18+ only. Betting involves risk, and prices and limits can change before you place a bet. If gambling isn't fun any more, Gambling Help Online (1800 858 858) is free and confidential, and BetStop lets you exclude yourself from every licensed Australian bookmaker.