Probability Calculator
Calculate the probability of coin flips, dice rolls and simple events — as a percentage, decimal and odds. — free, fast and private.
Your probability will appear here.
Examples: 3 heads in 3 flips = 12.5%. Rolling a 7 with two dice = 16.67% (6 of 36 combinations). 1 favourable out of 4 = 25%.
How to use Probability Calculator
- Choose a probability type: coin flip, dice roll or simple event.
- Enter the details — flips and heads, the dice sum, or favourable and total outcomes.
- Click Calculate Probability.
- See the probability as a percentage, decimal and odds.
Note: this tool runs in your browser. Nothing is uploaded.
Frequently Asked Questions
What is the probability of getting heads 3 times in a row?
(1/2)³ = 1/8 = 12.5%. Each flip is independent, so you multiply the single-flip probability.
What is the most likely dice sum with two dice?
7 — it has 6 out of 36 combinations (16.67%), more than any other sum.
What are odds?
Odds compare favourable outcomes to unfavourable ones. A 25% probability (1 in 4) is odds of 1 : 3.
Is my data uploaded anywhere?
No. All calculations run in your browser and your numbers are never sent to a server.