Calculate Number Product

Yes, absolutely secure. The tool runs 100% client-side in your browser – no server calls, no telemetry on your input, and the textarea contents never leave the page.

Yes, completely free – no registration, subscriptions, or usage limits. Multiply as many lists as you need.

Yes. Once the page has loaded, every calculation happens locally. You can disconnect from the network and the tool keeps working.

Positive, negative, integers, decimals, and scientific notation (e.g. 1.23e5). Separators can be commas, spaces, tabs, semicolons, or line breaks – mix them freely.

Up to 100,000 values in a single pass. For lists that large the tool briefly disables the button and shows “Calculating…” while the product runs.

The product collapses to 0, because any number multiplied by 0 equals 0. The stats line flags the zero count so you can confirm it was intentional.

Negatives multiply normally. An even count of negatives gives a positive product; an odd count gives a negative product. The stats line reports the count of negative inputs.

No – when every input is an integer, the tool automatically computes a BigInt product in parallel with the float product. The exact integer appears below the float display, so 50! is rendered with every digit.

Whenever the absolute value of the float product reaches 10^15 or falls below 10^-6. At that magnitude, locale-grouped decimals lose readability, so the display switches to six-digit exponential form.

The tool stops at the first unparseable token and returns an error like Could not parse: 'foo' - please check your list. so you can fix the one bad value instead of hunting through the whole list.