Bonus-buy features (also called feature buy or bonus bet) let you purchase direct entry to a slot's bonus round for a fixed multiple of your base bet (typically 50–200x). The advertised RTP for the feature may differ significantly from the base game RTP, and from the published overall RTP. This calculator shows the true RTP of a bonus-buy at any bet size.

Enter the feature buy cost, the published feature RTP, the base game RTP, and your bankroll. The calculator returns: the true expected value of the feature at your stake, the variance per feature, the breakeven hit frequency needed, and the projected bankroll trajectory over 100 consecutive bonus buys. Most feature buys are negative-EV in the long run — the casino always wins on average.

Bonus buys were banned by UKGC in 2019 for UK-licensed casinos, so this calculator is most useful for players on offshore sites. UK players should note: any casino offering bonus buys to UK players is non-compliant with UKGC rules and should be avoided for safety reasons. See our casino blacklist for operators we don't recommend.