Big Number Calculator
Big Number Calculator works out Result and Result in the chosen base from First number, Second number and Operation. The default figures on this page give result of 1267650600228229401496703205376; change any entry and the result, the working and the sources update together.
Your figures
Updates as you typeHow this is worked out
1 step
- Repeated exact multiplication of 2, 100 times.
Its 5 worked examples are re-run on every release, last on 15 September 2026. What changed
Sources and references
2 sources
What the Big Number Calculator calculates
Exact arbitrary-precision integer arithmetic: add, subtract, multiply, divide with remainder, modulo, power, factorial, gcd, lcm and integer square root, with binary, octal, decimal and hexadecimal input and output.
How to use this Big Number Calculator
Enter First number, Second number, Operation and Input base. Result updates as you type, and “Use a worked example” loads checked figures you can adjust. Change one figure at a time to see what drives the result.
How the result is worked out
Open “How this is worked out” beside the result for the step-by-step calculation behind Result, Result in the chosen base and Result as a double (null if too large).
The method follows ECMA-262 ECMAScript Language Specification, Section 6.1.6.2 The BigInt Type (exact arbitrary-precision integer semantics, including truncated division and remainder) and Knuth, The Art of Computer Programming, Volume 2: Seminumerical Algorithms, Section 4.3 (multiple-precision arithmetic) and 4.5.2 (Euclid’s algorithm).
2 to the power 100 example
With First number: 2, Second number: 100, Operation: power, the calculator returns Result: 1267650600228229401496703205376, Number of digits: 31. This example is checked against an independent source in the test suite.
What you can compare
Change one input at a time to see how it affects Result, Result in the chosen base and Result as a double (null if too large). The inputs you can vary are First number, Second number, Operation, Input base and Output base.
Results are general information, not financial, tax, legal, medical or engineering advice. Check any decision that matters with a qualified professional.
See something wrong? Report a problem with this calculator
Frequently asked questions
What is the biggest number on a calculator?
Exact arbitrary-precision integer arithmetic: add, subtract, multiply, divide with remainder, modulo, power, factorial, gcd, lcm and integer square root, with binary, octal, decimal and hexadecimal input and output. On this page it is computed from First number, Second number and Operation and shown as Result, Result in the chosen base and Result as a double (null if too large).
How to calculate a large number?
Exact arbitrary-precision integer arithmetic: add, subtract, multiply, divide with remainder, modulo, power, factorial, gcd, lcm and integer square root, with binary, octal, decimal and hexadecimal input and output. Open “How this is worked out” beside the result to see each step for your own figures.
What information do I need for the Big Number Calculator?
You need First number, Second number, Operation, Input base and Output base. The page opens with default figures that give result of 1267650600228229401496703205376, so you can see the scale before entering your own.
What does this Big Number Calculator show?
It shows Result, Result in the chosen base, Result as a double (null if too large), Number of digits, Quotient, Remainder, Divides exactly? and Scientific notation, with the working and any warnings for your entries.
Can I check how the Big Number Calculator result was calculated?
Yes. The “How this is worked out” section shows the calculation steps, and the sources section identifies the references used for the method.