Calculator
Bonus Bet (Free Bet) Calculator — Maximize Promo EV
A bonus bet (free bet) is different from cash — if it wins, you keep the profit but not the stake. That means the true value of a $100 free bet is less than $100. Enter the bonus amount and the odds you plan to use it at to see the expected cash value.
Expected cash value is what the bonus is actually worth in real money. Higher odds increase cash value up to a point — above +700 the win probability is too low.
Track this bet in your log →The face value of the free bet credited to your account
Sweet spot is +300 to +700 — free bets only return profit, not the stake itself
How this works
Formula
EV_bonus = bonus × (decimal - 1) / decimal × (1 - vig_adjustment)
Worked example
$100 free bet at +300 (4.00 decimal) → EV ≈ $100 × 3 / 4 = $75 expected cash value.
FAQ
What's the optimal odds for a free bet?
Generally +300 to +700. Too low and the small stake-return is wasted; too high and variance dominates.
Is a $100 free bet worth $100?
No — only the profit converts to cash, not the stake. Most free bets are worth 60–80% of face value.
Can I convert free bets to cash?
Indirectly, via low-risk hedging. Bet the free bet on one side and hedge with real money on the opposite side at another book.
Do bonus bets expire?
Yes — typically 7–14 days. Plan their use before grabbing the promo.
What about deposit-match promos?
Deposit matches require playthrough. Calculate effective bonus value as match × (1 - playthrough_vig_drag).