Probability Calculator
Probability as a percentage, decimal and '1 in X' odds.
Probability Calculator
| Probability | 16.67% |
| Probability (decimal) | 0.1667 |
| Odds | 1 in 6 |
Rolling a specific number on a fair die: 1 ÷ 6 = 16.67%, or 1 in 6.
In single-event mode, enter favorable and total outcomes — rolling a 6 on a die is 1 favorable outcome out of 6 — to get the probability as a percentage, a decimal and in '1 in X' form.
In combined mode, enter the percentage probabilities of two independent events to find the chance that both happen. Independence matters: drawing two aces without replacement is not independent, so this combined mode does not apply to it.
The formula
Worked example
Rolling a specific number on a fair die: 1 ÷ 6 = 16.67%, or 1 in 6.
The example is pre-loaded in the result panel — press Calculate with your own numbers to replace it.
Frequently asked questions
What does '1 in X' mean?
It is the reciprocal of the probability: an event with probability 0.25 happens on average once in every 4 tries — '1 in 4'. It describes long-run frequency, not a guarantee within any 4 tries.
When can I multiply two probabilities?
Only when the events are independent — the outcome of one does not change the other's odds. Two coin flips are independent; two cards drawn from the same deck without replacement are not.
Category: Everyday Life calculators
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