Mines calculator

It turns a mine count and a number of revealed gems into three figures for a 25-tile board: multiplier, win chance and payout. Set mines from 1 to 24, gems up to 25 minus the mines, and a bet; the sliders, the grid and the 24 × 24 payout table all drive the same calculation. Every figure comes from the published 99% RTP formula rather than from recorded rounds, and the arithmetic runs in your browser as you change the inputs.

Multiplier = 0.99 × C(25, gems) ÷ C(25 − mines, gems), and win chance is that fraction the other way up: C(25 − mines, gems) ÷ C(25, gems). C(n, r) is the number of ways to choose r tiles out of n, so the upper term counts every set of picks you could make and the lower one counts only the sets holding no mine. The 0.99 is the 1% house edge. Shuffle publishes the identical formula for its own Mines game.

A $1 bet at 3 mines with 5 gems shows 2.00x, a 49.57% win chance and a $2.00 payout — the state the page loads in. The chance is the reveals multiplied without replacement: 22÷25 × 21÷24 × 20÷23 × 19÷22 × 18÷21 = 0.4957. Divide the 0.99 return by that and the multiplier is 1.9974, which the page rounds to 2.00x.

5,148,297.00x, at 13 mines with 12 gems revealed. The same figure sits at 12 mines with 13 gems, because the formula treats the two counts interchangeably; the win chance there reads 0.000019%. Shuffle publishes 5,148,297× as the maximum payout on its own Mines game. The largest single-reveal figure is 24.75x — one safe tile at 24 mines, a 4.00% chance.

None of them — the return is 99% at every setting. Multiplier × win chance comes to 0.99 unrounded in all 300 valid cells: 5 mines with 5 gems reads 3.39x at 29.18%, 10 mines with 7 gems reads 73.95x at 1.34%, and both land on the same 99%. What the mine count changes is the spread, not the return — low counts pair small multipliers with high win chances, high counts pair large multipliers with low ones.

Both moves make the run less probable, and the multiplier is 0.99 divided by that probability. At 3 mines, one gem pays 1.13x at an 88.00% chance, ten gems pay 5.00x at 19.78% and twenty pay 227.70x at 0.43%. Adding mines works the same way from the other side: a single gem pays 1.13x at 3 mines and 4.95x at 20. The 1% edge never moves.

It is the chance that every gem you have set clears on a fresh board, not the chance of one more tile. At 3 mines with 5 gems that is 49.57%; the chance the sixth tile is safe is (25 − 3 − 5) ÷ (25 − 5) = 85.00%, which the calculator never displays. Drop gems to zero and the Interactive simulator reads 1.00x at 100%, with nothing yet risked; the quick calculator above it falls back to one gem instead.

No. The bet scales the payout only; the multiplier and win chance come from the mine and gem counts alone. The field starts at zero and steps in 0.01, and the dollar sign is a label — the calculator converts no currency, so the payout comes back in whatever unit you entered. Set the bet to zero and both the multiplier and the chance stay where they were.

It reproduces the 25-tile, 99% RTP formula those Originals use. Shuffle publishes the whole ladder — a 5×5 grid, 1 to 24 mines, 300 valid setups and a 1% edge at every one — and Stake's public games API returned the same 1.00% house edge for Mines when we read it on 20 August 2026. We found no published Mines RTP from BC.Game, so check a casino's own game rules before relying on a payout shown here.

Displayed to two decimals, computed unrounded. A $10 bet at 3 mines and 5 gems pays $19.97 rather than $20.00, because the multiplier behind the 2.00x is 1.99737. Win chance shows two decimals down to 0.01% and two significant figures below that. Ten of the table's 300 valid cells land a hundredth low — 1 mine with 3 gems shows 1.12x against an exact 1.13x — because the engine multiplies the reveals one at a time.

No. The calculator never touches a casino round: no server seed, no client seed, no nonce, no connection to a game. The grid is a way of setting the gem count, not a board being read, and clicking a tile changes nothing but that count. To recover the real layout of a round you have played, use the provably fair verifier after your seed pair has been rotated.

The calculator answers a maths question — multiplier, win chance and payout for a chosen mine and gem count. The pattern generator answers a layout question: it shuffles the 25 tile positions in your browser and marks the mine and diamond counts you ask for. Its output is a random arrangement made on your device, not a casino board, and the two tools share no data.

Yes. Every figure is worked out inside the page after it loads, and the mine count, gem count and bet are never sent to CasinoDrop or anywhere else. No account or sign-in is involved, and nothing you type is stored between visits. The page loads site analytics as every page does, but none of your calculator inputs are included in that or in any other request.