AUOdds

Dutching Calculator Australia: How to Work Out Racing Stakes Across Bookmakers

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

Key takeaways
  • A dutching calculator splits one total stake across several runners so that each one returns roughly the same amount if it wins.
  • A racing dutch only locks in a return at the prices shown when every runner is covered and the best prices add up to less than 100%.
  • Taking the best fixed-odds price for each runner from different licensed bookmakers is what can push a full field's book under 100%.
  • Scratchings, deductions, dead heats and rounding all shift your final numbers, so check them before and after you place each bet.
  • Prices move, stakes get limited and bets can be voided, so treat any margin as a return at the prices shown, not a promise.

A dutching calculator Australia punters can rely on has to handle a full racing field, prices in dollars and a different bookmaker for each runner. Most tools on page one don't. They use pounds, stop at two outcomes, or dutch three horses from one bookmaker and call it a system. This guide works through a full-field win dutch using the best price per runner across Sportsbet, TAB, Ladbrokes and others. You'll see how the book adds to under 100%, the exact stake for each runner, and what scratchings, dead heats and rounding do to the result. It's the same maths AUOdds uses when it sends an alert with stakes attached. The calculator steps are laid out so you can do them on your phone in under a minute.

In this guide
  1. Dutching calculator Australia: what is it and how does it work?
  2. How do you dutch a full field using the best price per runner?
  3. Why doesn't dutching only a few horses lock in a return?
  4. What do scratchings, dead heats and rounding do to your stakes?
  5. What makes the best dutching calculator for Australian racing?
  6. What are the real risks, and how do you stay in control?

Dutching calculator Australia: what is it and how does it work?

A dutching calculator splits one total stake across several selections so that each one returns the same amount if it wins. In racing, that means backing several runners in the same win market. Each bet is sized by its price: shorter prices get bigger stakes and longer prices get smaller ones.

The maths is simple enough to do on a phone. Here is the whole calculator, step by step.

The calculator

That is what anyone asking what is a dutching calculator really needs to know. It's a stake splitter, not a tipping tool. It doesn't pick winners. It just balances your money across outcomes.

Most generic tools stop at two or three outcomes, use pounds, or assume one bookmaker's prices. For Australian racing you need one that takes a full field in dollars. It also has to let you enter a different bookmaker against each runner, because the best price on the favourite and the best price on the roughie are rarely with the same bookmaker.

One more rule: use fixed odds only. Tote dividends aren't known until the pool closes, so you can't size stakes against them with any confidence.

How do you dutch a full field using the best price per runner?

Here's a six-runner race with the best fixed-odds win price for each runner taken from different licensed bookmakers. The prices are illustrative, but they reflect the kind of spread you can see in small fields.

The book adds to 97.21%. With a $500 total stake, the target return is $500 ÷ 0.9721 = $514.35. Dividing that by each price gives the exact stakes: $197.83, $107.16, $79.13, $57.15, $34.29 and $24.49.

In practice you'll round to whole dollars. One sensible set is $198, $107, $79, $57, $34 and $25, which still totals $500. The returns are then:

Whichever runner wins, you get back between $10 and $25 more than you staked, at the prices shown. That's about 2 to 5%. For context, AUOdds data shows a typical lock of 2.4% over the last 30 days, so a margin like this is at the healthy end.

Now compare the same six runners at a single bookmaker. Illustrative prices of 2.40, 4.40, 6.00, 8.00, 13.00 and 17.00 add to about 107%. Dutch that full field at one bookmaker and you lose around 7% whichever runner wins. The best price per runner is the whole point.

Why doesn't dutching only a few horses lock in a return?

Many dutching examples online pick the top three or four in the market and show a neat equal return. What they leave out is the rest of the field.

Take the same race and dutch only Runners 1, 2 and 3. Their prices add to 74.67%. With $500 spread across them, each returns about $669 if it wins. That looks like a strong result until you remember Runners 4, 5 and 6 can also win. Their combined implied chance, based on these prices, is about 25%. If any of them salutes, you lose the full $500.

That's a betting opinion, not a lock. Partial dutching can suit punters who have a genuine view that the outsiders can't win. But it carries the same exposure as any other bet, and a calculator can't remove that.

A lock needs two things together:

This is why a horse racing dutch betting calculator built for locks asks for the whole field. It should also warn you if a runner is missing from the list. Small fields of five to eight runners are where full-field locks turn up most often, because there are fewer prices that all need to line up at once.

Big fields aren't off limits. But with 14 runners, every leg is another price that can move before you finish placing your bets.

What do scratchings, dead heats and rounding do to your stakes?

These three are where a clean calculator result meets real settlement rules. Check each bookmaker's racing rules, because the detail varies.

Scratchings. If a runner you've backed is scratched, that bet is normally refunded. A full-field dutch stays covered, because every remaining runner already has a bet on it. The catch is deductions. Many bookmakers apply a deduction to fixed-odds win bets placed before a late scratching, and the size usually depends on how short the scratched runner was. A scratched favourite can take a large bite out of the remaining returns and turn a thin margin into a small loss. A scratched roughie usually changes very little. Before placing, check the scratching status for the race. Remember that a refunded stake is only a refund, not part of your margin.

Dead heats. Bookmakers typically settle dead heats by paying the winning price on a share of the stake. A balanced dutch handles this well. If Runners 3 and 4 dead heat in the example, half of $79 at 6.50 returns $256.75 and half of $57 at 9.00 returns $256.50. That's $513.25 in total, close to the target.

Rounding. Whole-dollar stakes spread your returns, as the example showed ($510 to $525). Round the big stakes first and adjust the small ones. Then check that the lowest return still beats your total stake. Some punters round to the nearest $5 so the bets look less unusual, but on a 2 to 3% book that can wipe out the margin. Recalculate after rounding every time.

What makes the best dutching calculator for Australian racing?

The best dutching calculator is the one that matches how Australian racing markets actually work. Use this checklist when comparing tools, spreadsheets or a dutching calculator app.

That last point is the hard one to do by hand. Comparing nine bookmakers across every runner in every race, quickly enough to act, is a lot of tabs. AUOdds tracks about 15,000 prices at any moment across 9 bookmakers, with prices about 10 seconds old. Alerts arrive with the stake for each outcome already worked out, and you still place each bet yourself.

Whichever tool you use, keep a simple record of every dutch: race, runners, bookmaker, price, stake and result. It's the quickest way to recognise whether your rounding, timing or scratchings are costing you.

What are the real risks, and how do you stay in control?

A dutch locks in a return at the prices shown when you place it. Several things can change that.

Use only bookmakers licensed in Australia. The ACMA lets you check whether a gambling operator is legal before you open an account.

On tax, the ATO's Taxation Ruling IT 2655 covers when gambling winnings are taxable. Winnings from recreational betting generally aren't, but betting that looks like a business can be treated differently. Get advice if you're unsure.

Finally, keep it in proportion. Gambling is for adults 18 and over. Set a budget you can afford to lose, because individual legs can and do go wrong. If betting stops being enjoyable, BetStop, the National Self-Exclusion Register, lets you exclude yourself from licensed online and phone wagering providers. Gambling Help Online offers free, confidential support at any hour.

Frequently asked questions

What is a dutching calculator?

It's a tool that splits one total stake across several selections so each returns about the same amount if it wins. For racing, you enter each runner's decimal price, and it works out the book and the stake for each runner. It doesn't pick winners. It only balances your money across the outcomes you choose.

Can dutching a horse race lock in a return?

Only if you cover every runner and the best available prices add to less than 100%. Dutching a few horses leaves you exposed to the rest of the field. Even with a full field, prices can move, stakes can be limited and scratchings can bring deductions, so the return only applies at the prices you actually get.

Do I need a dutching calculator app, or will a spreadsheet do?

A spreadsheet handles the maths fine: 1 ÷ odds for each runner, total stake ÷ book for the target return, then target ÷ odds for each stake. The harder part is finding the best price per runner across bookmakers quickly. An app with live prices saves that searching, but either way, check every number before placing.

What happens to my dutch if a horse is scratched?

The bet on the scratched runner is normally refunded, and your other bets usually stand. Because a full-field dutch already covers every remaining runner, you stay covered. Deductions may apply to fixed-odds win bets placed before a late scratching, which can reduce or remove your margin. Check each bookmaker's racing rules.

Sources

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

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.