By Joe Little March 3, 2026 12 min read

How to Calculate a Hedge Bet (Formula + Calculator)

Written by Joe Little

Calculating a hedge bet correctly is the single most important skill in matched betting. A miscalculation — even a small one — can turn a guaranteed profit into a partial loss. Ungambled's hedge calculator eliminates manual calculation entirely, but understanding the underlying math makes you a better-informed bettor and helps you verify results quickly. This guide covers the complete calculation methodology for every hedge type you will encounter.

The Standard Hedge Formula

For a standard two-sided hedge (back bet at one sportsbook, lay bet at another), the formula for your lay (hedge) stake is:

Lay Stake = (Back Stake × Back Odds) / Lay Odds

Where all odds are expressed in decimal format. To convert American odds: positive odds (+150) convert to decimal as (150/100) + 1 = 2.50. Negative odds (-150) convert as (100/150) + 1 = 1.667.

Worked Example: Standard Hedge

Back bet: $100 at +150 (2.50 decimal). Lay odds: -130 (1.77 decimal).

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The Free Bet Hedge Formula

Free bet hedging uses a modified formula because the free bet stake is not returned with winnings. Only the profit portion of a winning free bet is kept:

Lay Stake = (Free Bet Amount × (Back Odds - 1)) / Lay Odds

Using the same example with a $100 free bet at +150 (2.50 decimal) and lay odds of -130 (1.77 decimal):

This is why free bet conversion rates hover around 70–90% — the lay stake protects against both outcomes, but the free bet's no-stake-return property means the maximum capture is always less than 100% of face value.

Accounting for Lay Commission

When placing lay bets at a betting exchange, a commission is charged on winning lay bets. This commission (typically 2–5%) reduces your net lay winnings and must be factored into the calculation:

Adjusted Lay Liability = Lay Stake × (Lay Odds - 1)

Net Lay Win = Lay Stake × (1 - Commission Rate)

For most U.S. matched betting using traditional sportsbooks for lay positions (rather than exchanges), commission is not a factor. When using exchange-style products, Ungambled's calculator includes commission adjustment automatically.

The Profit Matrix: Mapping Every Outcome

For any hedge bet, it is worth mapping all possible outcomes before placing either bet. This is called the profit matrix and it looks like:

For a well-calculated matched bet, both outcomes should produce roughly equal net results. For a free bet conversion, the winning side should produce significantly higher profit than the losing side (which ideally produces zero loss). Ungambled's calculator displays this full matrix for every opportunity.

How Odds Differences Affect Your Hedge Quality

The closer the back odds and lay odds, the smaller your qualifying loss (or the higher your free bet conversion rate). Wide discrepancies between back and lay odds increase the cost of hedging. This is why market selection matters — choose markets where the price difference between the back sportsbook and the lay sportsbook is small. Ungambled's market scanner filters for optimal odds convergence across available markets.

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Frequently Asked Questions

What is decimal odds format?

Decimal odds express total payout per unit staked, including stake. +150 American odds = 2.50 decimal (win $2.50 for every $1 bet, including stake return).

How do I convert American odds to decimal?

For positive odds: decimal = (American / 100) + 1. For negative odds: decimal = (100 / |American|) + 1.

What is the qualifying loss in matched betting?

The qualifying loss is the small amount lost when placing the required bet to unlock a bonus. It equals the difference between your back stake and your lay liability.

Why does my calculation show a small loss?

A small qualifying loss is normal for deposit match and first-bet qualifying scenarios. The bonus value should always exceed this loss. If your calculation shows a loss larger than the expected bonus, recalculate with more favorable odds.

What happens if odds move after I calculate?

Odds movement changes the required lay stake and the profit outcome. Always recalculate if significant time has passed since your initial calculation. Ungambled's live odds feed flags movements in real time.

What is over-round in sports betting?

Over-round is the built-in sportsbook margin expressed as a percentage above 100% implied probability. A market with 105% over-round means the sportsbook takes a 5% margin on all bets in that market.

What is stake return in free bet hedging?

Stake return refers to whether the free bet's original stake amount is returned with winnings. SNR (stake not returned) free bets produce conversion rates of 70–90%. SR (stake returned) free bets can convert at higher rates.

Can I hedge a bet if back and lay odds are identical?

If back and lay odds are identical and there is no bonus, hedging produces zero profit and zero loss. Only when a bonus or odds discrepancy exists does hedging produce a positive expected return.

What is the maximum hedge profit possible?

Maximum hedge profit depends on the size of the bonus or odds discrepancy. For a $200 free bet at optimal odds, typical maximum profit is $160–180. For a large arbitrage opportunity, profit is limited by available stakes at the identified odds.

Does Ungambled's calculator handle all hedge types?

Yes. Ungambled's calculator handles standard hedges, free bet conversions, deposit match playthroughs, parlay hedges, and odds boost hedges — with full profit matrix display for each type.