Perform arbitrary-precision integer math on numbers too large for standard calculators.
Overview
Spreadsheets and handheld calculators often round or overflow when integers exceed their digit limits. Cryptography keys, combinatorial counts, and astronomical estimates can require hundreds of digits that must remain exact.
A big number calculator stores integers as digit arrays or strings and applies schoolbook algorithms for addition, subtraction, multiplication, and division without floating-point error. That preserves every digit in the result.
Use this tool when factorials, powers of large bases, or cumulative products outgrow double-precision limits. For division, remember integer division returns quotient and remainder rather than a decimal approximation unless you switch modes.
Exact integer arithmetic is slower than hardware floats but indispensable when correctness matters more than speed, such as verifying a published prime or reproducing a competitive programming output.
Steps
Select add, subtract, multiply, divide, or power as supported.
Paste the full large integer without separators if required.
Provide the second value for binary operations.
Execute with arbitrary-precision arithmetic.
Transfer the full output string to your document or code.
Repeat with tiny inputs to confirm operation logic.
Math
Arbitrary-precision integer algorithms (digit-by-digit carry/borrow)
Each operation processes digits from least significant to most, propagating carries or borrows, analogous to pencil-and-paper methods but scaled to any length.
Worked cases
Digit-wise addition with carries
111111111011111111100
999999999999^2
999999999998000000000001
Quotient and remainder via long division
Exact quotient and remainder returned separately.
Why use this
Questions