Factorial

How to use this calculator

1. Enter nonnegative integer in count.
2. Select Calculate and keep the output unit with the answer.

Before you use the answer

Choose the reference quantity before interpreting the number. A ratio, a percentage and a percentage-point difference may use the same observations while answering different questions. For recorded data, keep the original values beside the summary so an unexpected result can be traced back to its inputs.

Large factorials quickly exceed exact integer precision in JavaScript. Results above the safe-integer limit are approximate.

Does it save my inputs?

No calculation history is stored by this website. The calculator works locally in your browser. See the privacy policy for hosting and contact details.

Why might a result be approximate?

Measurement uncertainty, ideal-model assumptions and floating-point rounding can all matter. Displaying more digits does not improve the original measurement.