Probability of Not Happening Calculator
🎲 Statistics & probability. Use the Probability of not happening formula to find p(not a), p(a): pick the value you want, type the others, and the answer updates as you go.
P(not A)0.7
Pick the ○ next to the value you want to find, fill in the others, and it solves as you type.
What each letter means
| Quantity | Unit |
|---|---|
| P(not A) | no unit |
| P(A) | no unit |
Worked example
Find the p(not a) when P(A) = 0.3.
Using P(not A) = 1 - P(A): P(not A) = 0.7.
Frequently asked questions
What is the formula for Probability of not happening?
P(not A) = 1 - P(A).
What do the letters stand for, and what units are used?
P(not A), P(A).
How do you calculate p(not a)?
Put the values into P(not A) = 1 - P(A). For example, with P(A) = 0.3, p(not a) = 0.7.
Can I solve for a different value?
Yes. In the calculator above, pick the circle next to any value (p(not a), p(a)) and fill in the others: it rearranges the formula for you.
