Big Number Calculator
Add, subtract, multiply, divide, modulo, power, GCD and factorial on arbitrarily large whole numbers — hundreds or thousands of digits — instantly in your browser.
Enter whole numbers — spaces, commas and underscores are ignored. Division shows the decimal result plus the quotient and remainder.
Result
Big number names & scientific notation
Powers of ten and the name commonly given to each magnitude.
About Big Number Calculator
The big number calculator performs arithmetic on whole numbers of arbitrary size — hundreds or thousands of digits — without the rounding errors ordinary calculators introduce past 15 or so significant digits. It adds, subtracts, multiplies, divides, takes modulo and powers, finds the GCD of two numbers and computes factorials exactly.
Every operation runs locally using arbitrary-precision integer arithmetic in your browser, so nothing is uploaded. Division shows a decimal result to your chosen number of places plus the exact quotient and remainder; results come with a digit count, scientific notation and the approximate English name of the magnitude, from thousand through vigintillion to googol.
Spaces, commas and underscores in your input are ignored, so you can paste formatted numbers straight from documents. It is a free tool for number theory homework, cryptography exercises, combinatorics checks like 100! and the simple joy of seeing a 158-digit factorial written out in full.
How to use Big Number Calculator
- Enter the first whole number — separators like commas and spaces are fine.
- Choose the operation: add, subtract, multiply, divide, modulo, power, GCD or factorial.
- Enter the second number (not needed for factorial).
- For division, set how many decimal places to show.
- Read the exact result with its digit count, scientific notation and magnitude name, and copy it in one click.