Turn favorable and total outcomes into a probability, a percentage and the odds for the event.
Calculations happen locally. We do not send your values to our server.
Rolling a 6 on one die is 1 out of 6, about 16.66666667%. Drawing a heart from a 52-card deck is 13 out of 52, exactly 25%, and drawing an ace is 4 out of 52, about 7.69230769%.
The probability is the favorable outcomes divided by the total outcomes, and the percentage is that value multiplied by 100. The odds for the event compare successes with failures: with 3 successes among 8 outcomes the probability is 37.5% while the odds are 3 to 5, shown as 0.6 to 1. Favorable outcomes cannot exceed the total.
This model assumes every outcome is equally likely and counted once, so it does not fit weather forecasts or sports results, where outcomes have different chances. A certain event such as 10 out of 10 has a probability of 100% and no failures, so its odds cannot be written as a finite ratio.
Enter how many outcomes count as a success and how many equally likely outcomes exist in total. Rolling a 6 on one die is 1 out of 6, about 16.67%. Drawing a heart from a standard 52-card deck is 13 out of 52, exactly 25%, and drawing an ace is 4 out of 52, about 7.69%. The result is shown as a percentage, as a decimal probability between 0 and 1, and as odds for the event.
Probability compares successes with all outcomes; odds compare successes with failures. For 1 in 6, there is 1 success and 5 failures, so the odds for are 1 to 5, shown as 0.2 to 1. For 3 successes among 8 outcomes, probability is 37.5% while odds for are 3 to 5, or 0.6 to 1. A certain event such as 10 out of 10 has a probability of 100% and no failures, so odds cannot be expressed as a finite ratio.
This calculation assumes every outcome is equally likely and counted once. Rolling two dice and getting a double six is 1 out of 36, about 2.78%, because there are 36 ordered pairs. It does not apply when outcomes have different chances, such as weather or sports results, and it does not combine several events: the chance of two separate sixes in a row is found by multiplying 1/6 × 1/6. Past results do not change the probability of the next independent roll.
| Input | Result |
|---|---|
1 / 6 | 16.66666667% · 0.2 : 1 |
13 / 52 | 25% · 0.33333333 : 1 |
4 / 52 | 7.69230769% · 0.08333333 : 1 |
3 / 8 | 37.5% · 0.6 : 1 |
1 / 36 | 2.77777778% · 0.02857143 : 1 |
10 / 10 | 100% · — |
Probability compares successes with all outcomes, while odds compare successes with failures. For 1 in 6 there is 1 success and 5 failures, so the probability is about 16.66666667% and the odds for are 1 to 5, displayed as 0.2 to 1. Betting odds are usually quoted the other way round, as odds against.
Multiply the probabilities of independent events. Rolling two sixes in a row is 1/6 × 1/6, which is 1 out of 36, about 2.77777778%. That matches counting the 36 ordered pairs of two dice directly. Past results do not change the next independent roll.
Yes. Zero favorable outcomes gives 0%, an event that cannot happen in this model, and 10 out of 10 gives 100%, an event that always happens. Values outside that range are impossible, which is why the tool rejects more favorable outcomes than total outcomes.
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