Bonus bet conversion rates: what the math allows
Published 2026-09-29 · Updated 2026-09-30
How much of a bonus bet can you actually turn into cash? The answer is arithmetic, not luck, and it depends mostly on the odds you choose. Here is the formula, a table of what it produces, and the trade-offs.
How conversion is calculated
Conversion rate is the share of a bonus bet's face value that you can turn into cash by hedging. If a $100 bonus bet ends up as $65 of cash, it converted at 65%. The calculation is the calculated result of the hedged pair divided by the bonus amount.
Because a bonus bet's stake isn't returned when it wins, its value comes entirely from the winnings. That's why the odds you put it on matter so much.
The ceiling: one minus the implied probability
If the bet on the other side were priced with no sportsbook margin at all, conversion would equal 1 minus the implied probability of the bonus bet's odds. At +200 the implied probability is 33.3%, so the ceiling is 66.7%. At +100 it is 50.0%, and at +500 it is 83.3%.
What real prices do to it
Real prices carry a margin, and you pay it on the hedge. The table shows the ceiling next to what the same bonus converts to when the two prices add up to a standard -110 / -110 margin.
| Odds on the bonus bet | Ceiling (no margin) | With a typical margin | Hedge needed for a $100 bonus | Hedge odds assumed |
|---|---|---|---|---|
| +100 | 50.0% | 45.2% | $55 | -121 |
| +150 | 60.0% | 52.8% | $97 | -184 |
| +200 | 66.7% | 57.1% | $143 | -250 |
| +300 | 75.0% | 60.7% | $239 | -394 |
| +400 | 80.0% | 61.0% | $339 | -556 |
| +500 | 83.3% | 59.5% | $440 | -740 |
| +700 | 87.5% | 54.2% | $646 | -1192 |
Assumes the two sides' prices add up to 104.8%, the margin in a standard -110 / -110 market, and a $100 bonus bet whose stake isn't returned. Calculated with the same engine as the bonus bet calculator.
Longer odds help, up to a point
The ceiling keeps rising with the odds, but the margin you pay is charged on the hedge, and the hedge grows with the odds. In this model the two balance around +360: conversion climbs to about 61% and then slips, and by +700 it is back to 54.2%.
The hedge is also your own cash. A $100 bonus at +200 needs a hedge of about $143; at +500 it needs about $440. The hedge sportsbook's maximum bet, or your bankroll, can cap it before the math does.
What raises conversion in practice
- Aim for the middle of the range rather than the longest odds available: in the table, conversion is highest near +360 and the hedge stays far smaller than at +700.
- Shop the hedge. A few cents better on the other side comes straight out of the margin you'd otherwise pay.
- Prefer markets where the two sides are priced close to each other's fair value, such as main lines. Markets with wide margins cost more to hedge.
- Check the promotion's minimum odds, expiry and eligible markets before choosing the bet.
- Round stakes down to whole dollars if you want them to look ordinary. The calculator shows what that costs.
How much to bet on the other side, and what share of the bonus becomes cash.
Frequently asked questions
What is a good bonus bet conversion rate?
It depends on the odds you use and the margin on the hedge. The math sets a ceiling of 1 minus the implied probability of the bonus odds, which is 66.7% at +200, and real prices land below that. The table on this page shows the calculated rates.
Does a longer-odds bonus bet always convert more?
Up to a point. The ceiling rises with the odds, but so does the size of the hedge you pay margin on. With a standard margin the calculated conversion peaks around +360 and then slips, and the hedge keeps growing, so the longest odds are rarely the best choice.
Does rounding my hedge matter?
Only slightly. Rounding the hedge down to a whole dollar moves the result by cents, and the calculator's rounding row shows the exact cost.
Is the calculated result locked in?
It's calculated at the prices you enter. Odds move and bets can be voided, so confirm both prices before placing either bet.
Want the bet found for you?
Pro searches live odds across the sportsbooks you hold and returns the bet, the hedge and the calculated result.
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