Big Number Calculator

Operation
Result1000000000000000000

The big number calculator performs arithmetic on integers far larger than a standard calculator can hold without losing precision. When both operands are whole numbers it uses arbitrary-precision integer math, so every digit of the answer is exact even for hundreds-of-digit results. If either value has a decimal point it falls back to ordinary floating-point arithmetic.

How it works

  1. Enter two values and choose an operation: add (+), subtract (−), multiply (×), divide (÷), power (^), or modulo (%).
  2. If both inputs are integers, the calculator switches to exact big-integer arithmetic. Division returns the integer quotient (truncated), modulo returns the remainder, and a negative exponent is rejected.
  3. If either input contains a decimal, it computes with standard double-precision floating point instead, and the exact result is returned as a string.

Worked examples

Compute 2 raised to the power of 100.

  1. Both inputs are integers, so exact big-integer arithmetic is used.
  2. Repeatedly squaring and multiplying gives the full 31-digit value with no rounding.

2^100 = 1267650600228229401496703205376, exact to every digit.

Multiply 123456789012345678901234567890 by 987654321.

  1. Both operands are integers well beyond normal precision limits.
  2. Big-integer multiplication produces the full product without losing any digits.

121932631124828532112482853211126352690.

Frequently asked questions

Why can a regular calculator not do this?
Standard calculators use floating-point numbers that hold only about 15–17 significant digits. Beyond that, low-order digits are rounded away. This tool uses arbitrary-precision integers, so large whole-number answers stay exact.
How does division work for big integers?
For two integers, division returns the integer quotient — the result is truncated toward zero and any fractional part is dropped. Use the modulo operation to get the remainder.
Can I use decimals or fractions?
You can enter decimals, but doing so switches the calculator to ordinary floating-point arithmetic, which can introduce rounding. Exact arbitrary precision applies only when both inputs are whole numbers.
What happens with a negative exponent?
In integer mode a negative exponent would give a non-integer result, so it is rejected and no answer is returned. Switch to decimal inputs if you need negative powers computed as floating point.