Free Sportsbook Promo Conversion Tools
The free alternative to $99–199/month promo hunting subscriptions. 27+ calculators for matched betting, arbitrage, EV, promo conversion, and bankroll management — built for serious sports bettors who do the math.
PromoGrind is a math calculator for sportsbook promotional offers — like a mortgage calculator for bonus bets. You enter numbers, it outputs conversion values, EV, hedge amounts, and profit projections. It does not place bets, access sportsbook accounts, or handle money of any kind.
Calculate exact cash value of any bonus bet offer
Find optimal profit boost usage and hedge amounts
2-way and 3-way arb detection and stake sizing
Bankroll-optimal bet sizing for +EV opportunities
True EV calculation with devigged fair odds
Track every bet and promo result over time
PromoGrind is a product of VaultSpark Studios LLC, an independent software studio building tools for sports bettors, traders, and analysts. VaultSpark Studios products share a common "Vault" account system, giving users single sign-on across the studio's tool ecosystem.
We build PromoGrind because the best promo hunting tools cost $99–199/month. The math isn't complicated — it just takes good software. We built it and made it free.
PromoGrind is supported by affiliate partnerships with the sportsbooks listed in the app. If you sign up at DraftKings, FanDuel, BetMGM, or any other listed sportsbook through our links, we may earn a commission. This never influences our calculator math — the numbers are the numbers. See our Affiliate Disclosure for full details.
PromoGrind is not a licensed gambling operator. We are a third-party educational software tool. Matched betting and promo hunting are legal in all US states where sports betting is authorized (30+ states as of 2026). See our Compliance & Regulatory Status page for full details.
Must be 21+ (18+ in some states). Gamble responsibly. If gambling is causing problems, call 1-800-GAMBLER.
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