Probability Calculator
Statistics
Convert favourable and total outcomes into a probability.
Formula
P = favourable outcomes / total outcomes
- Use the units shown beside each field.
- Results update automatically whenever you change an input.
- Displayed values use up to four decimal places, or scientific notation for very small or large numbers. Calculations retain full precision.
- Assumes all outcomes are equally likely.
Example Calculation
Example inputs
- Favourable outcomes: 1
- Total outcomes: 6
One favourable outcome out of six is a probability of 16.67%.
Frequently asked questions
How do I use this calculator?
Enter favourable outcomes, total outcomes. The result updates automatically. Use Reset to restore the example values.
What method does it use?
P = favourable outcomes / total outcomes. Assumes all outcomes are equally likely.
Why might a rounded result differ?
The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.
Are my inputs saved online?
No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.
Check the assumptions and units before using this result. Read about calculation methods.