Work out basic probabilities from favorable and total outcomes, then combine two independent events using AND, OR, and NOT rules. Probability measures how likely something is on a scale from zero to one, and this calculator shows each answer three ways: as a reduced fraction, a decimal, and a percentage, so you can use whichever your assignment or bet slip expects. Enter the number of favorable outcomes and total outcomes for a single event to get its chance, then feed two event probabilities into the combination section to see the odds that both happen, that at least one happens, or that neither happens. It assumes the two events are independent, which is the most common textbook case. All of the math runs locally in your browser, so your numbers stay private and results are instant.
Work out basic probabilities from favorable and total outcomes, then combine two independent events using AND, OR, and NOT rules. Probability measures how likely something is on a scale from zero to one, and this calculator shows each answer three ways: as a reduced fraction, a decimal, and a percentage, so you can use whichever your assignment or bet slip expects.
Yes. Probability Calculator is completely free, with no sign-up and no usage limits.
Yes. Probability Calculator runs in any modern web browser. There is nothing to download or install.
Yes. Probability Calculator runs entirely on your device in your browser, so nothing you enter is uploaded to a server.