Mines odds calculator

How to read the table

The rows go down in clicks. Chance you got this far is the probability that every one of your first k clicks was safe. Fair multiplier is 1 divided by that chance. Paid multiplier is the fair one times the RTP you picked, cut to the cent for Spribe and rounded to the cent for Turbo Games, as each studio's demo does.

Take 3 mines and 6 clicks. The chance of six safe clicks is 42.1%, the fair multiplier is 2.37× and Spribe pays 2.30×. If you cashed out at the sixth click every time, you would win 2.30× your stake 42.1% of the time and lose it the rest: 0.421 × 2.30 = 0.97. That 0.97 is the RTP, and it comes out the same for every row.

The formula

With m mines, the first click is safe with chance (25 − m) ÷ 25. After k safe clicks there are 25 − k tiles left and still m mines, so the next click is safe with (25 − m − k) ÷ (25 − k). Multiply those fractions for the clicks you plan and you have the chance in the second column.

I checked this against something the provider publishes. Spribe's rules give the maximum odds as 5,044,291×. Clearing a grid with 12 mines has a fair multiplier of 5,200,300 (the number of ways to hide 12 mines in 25 tiles), and 5,200,300 × 0.97 = 5,044,291. The same number to the last digit. Spribe's demo table confirms the rest: all 290 cells for 1 to 20 mines are the fair multiplier times 0.97, cut down to the cent (18 of them show one cent less, where the exact value is already a round number of cents).

What the numbers say about mine counts

• More mines don't change the average. At 97% RTP you get back 97 cents per dollar on average with 1 mine or 20. How the same maths plays out in Plinko and crash games is in Mines vs Plinko and crash games.
• More mines change the spread. With 1 mine you win small amounts often; with 10 mines two clicks already pay 2.77×, but you get through both only 35% of the time.
• Doubling is always a little under a coin toss. Whatever the mine count, the click where the paid multiplier first passes 2× is reached 35–48% of the time.

Three RTPs, one grid

The selector covers the versions on this site. Spribe lists 97% for its Mines; the game info inside each casino shows the RTP that casino runs. The Turbo Games studio lists 95% for its Mines, so every row pays about 2% less than Spribe. Stake's in-house Mines is listed at 99%, but Stake's own terms exclude Australia, so it's there for comparison. "Fair" shows the game with no cut at all, the baseline the others are measured against.