Mines Calculator
Calculate exact payout, survival probability, and expected value for Stake Mines with N bombs on 5×5 grid.
Mines Probability Calculator
Stake Mines runs on a 5×5 grid (25 tiles). You place 1–24 bombs, then reveal tiles one by one — each safe pick multiplies your payout. This tool computes the exact combinatorial payout, survival probability, and expected value for any combination of bombs and gems collected. Uses the standard provably-fair Mines formula with a 1% house edge.
Result
Enter bombs and gems to see exact multiplier, survival probability, and expected value.
The math (provably-fair Mines)
- Survival probability after
ggem picks withbbombs:P = ∏(safe_i / remaining_i)fori = 0..g-1, which simplifies toC(25−b, g) / C(25, g). - Fair payout (no house edge):
1 / P— i.e. the inverse of survival probability. - Casino payout:
fair × (1 − HE)where HE ≈ 1% on Stake. - Expected value:
EV = bet × (payout × P − 1)— always slightly negative due to house edge.
Optimal strategy notes
The house edge is constant — picking more gems doesn't change EV per dollar. What changes is variance. Picking 1 gem with 3 bombs is near-certain (~88%) for a tiny multiplier. Picking 5 gems with 3 bombs is ~56% — bigger multiplier, more bust risk. Picking 10 gems with 3 bombs is ~22%. Match the variance to your bankroll, not your hopes.