Profit Boost Calculator

A profit boost multiplies your profit, not your stake and not your payout. With $100 at −110 (21/11 decimal), the base profit is $90.91. A 25% profit boost adds $22.73 extra on top of that profit — the stake itself is never boosted — for a total profit of $113.64 and a payout of $213.64.

A profit boost takes a percentage (e.g. 25%) and applies it to your profit. An odds boost instead gives you a new, higher price outright: $10 at +150 boosted to +200 simply pays out as if you had bet at +200, adding $5.00 of extra profit for a total profit of $20.00 (effective odds 3.00). Converting one into the other is what the calculator's "equivalent profit boost %" figure is for.

If a promo caps the extra winnings a boost can add, enter that cap as "max extra winnings". The same $100 example capped at $10 extra turns $22.73 of raw extra into $10.00 (capped), cutting the effective boost from 25.00% down to an equivalent of 11.00%. That cap is the only limit this calculator models. Promos often add others — a maximum qualifying stake, a total payout ceiling, specific eligible markets, or paying the boost as a free bet rather than cash — none of which appear here. Always check the promo's terms before you rely on the number.

Whenever your honest win probability, multiplied by the boosted decimal odds, is greater than 1. At −110 (implied 52.38%) with a 50% true win chance, that math already fails on the unboosted price — the bet is −4.55% EV — but the 25% boost lifts the decimal odds to 2.14 and flips it to 6.82% EV, an expected profit of $6.82 on $100. So a boost can turn a negative-EV bet positive; whether it does depends entirely on how far the boosted price pushes probability × odds past 1. If a bet is still negative EV after the boost, the expected loss is smaller than before, not eliminated. Strip the vig from the market first with the no-vig calculator for a market-implied estimate with the bookmaker margin removed — still an estimate, not a guarantee, since the EV shown here is only as good as the number you type in.

Yes — enter the parlay's combined odds as the "odds" field, exactly as your bookmaker displays them for the whole slip. Build that combined price first with the parlay calculator, then bring it here. Remember a boosted parlay is still a parlay: see the Parlay Reality Check for how fast the sportsbook's edge compounds as you add legs.