Big Number CalculatorFree online math calculator — instant results, no sign-up
Exact arithmetic on very large integers.
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About the Big Number Calculator
The Big Number Calculator performs exact arithmetic on arbitrarily large integers without precision loss or scientific notation rounding. It is useful for students, programmers, and mathematicians working with large numbers in combinatorics, cryptography, and number theory.
- A
- The first operand, entered as a whole integer of any digit length (positive or negative).
- Op
- The arithmetic operator to apply: addition (+), subtraction (−), multiplication (×), or exponentiation (^).
- B
- The second operand, entered as a whole integer. For exponentiation (^), this must be a non-negative integer.
Formula and method
Depending on the chosen operator: Addition = A + B, Subtraction = A − B, Multiplication = A × B, Exponentiation = A^B
- AThe first arbitrary-precision integer operand
- OpThe mathematical operation (+, −, ×, or ^)
- BThe second arbitrary-precision integer operand (exponent for ^)
- ResultThe exact integer result evaluated using arbitrary-precision arithmetic
The tool parses both inputs directly into native arbitrary-precision integers (BigInt) and evaluates the selected operation exactly without floating-point approximations. If an input contains non-integer characters or a negative exponent is used, it returns an error message indicating integers only.
Worked example
These are the calculator's starting values and the results it actually produces for them.
Inputs
- A123456789012345678901234567890
- Op+
- B987654321
Results
- Result123456789012345678902222222211
How to use the Big Number Calculator
- 1Enter an integer of any length into field A.
- 2Select the desired operation: addition (+), subtraction (−), multiplication (×), or exponentiation (^).
- 3Enter the second integer into field B.
- 4Read the exact full-precision integer output in the Result field.
Reading your result
The result is displayed as a full string of exact digits without decimal points or scientific notation. If any input contains decimals, fractions, letters, or an unsupported negative exponent, the calculator displays 'Integers only'.
Limitations
The calculator does not perform division or fractional arithmetic; all inputs must be whole integers. Exponentiation with excessively large powers may exceed browser memory or processing limits.
Common questions
Why does standard calculator software round large numbers?+
Standard calculators rely on 64-bit double-precision floating-point numbers, which lose exact integer precision past 15 to 17 digits (9,007,199,254,740,991). This calculator uses arbitrary-precision integers so every single digit is preserved.
Why is division not available in this tool?+
The tool is strictly an integer arithmetic engine. Division of arbitrary integers often produces non-terminating or fractional results that cannot be represented as exact integers.
Can I raise a number to a negative power?+
No. Raising an integer to a negative power produces a fractional value (e.g., 2^(-1) = 0.5), which is not an integer and will trigger the 'Integers only' message.
Does the calculator save my information?+
Calculations run in your browser. While signed in, inputs and results are automatically recorded in account history; saving a result creates a separate saved record.
Further reading
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Results are estimates for informational purposes and are not financial, medical or legal advice.