Big Number Calculator Online
Add, subtract, multiply, divide, and raise very large integers to a power with exact precision — computed right in your browser.
The Big Number Calculator runs entirely in your browser. The integers you type never leave your device and nothing is uploaded to ArrayKit.
Open the Exponent Calculator
About Big Number Calculator
Big Number Calculator does exact arithmetic on integers of any size, well beyond the roughly 15-16 digits a normal calculator or spreadsheet can handle before it starts rounding. Enter two large integers, pick add, subtract, multiply, divide, mod, or power, and the calculator returns the full, exact result down to the last digit. It is built for anyone who needs precise big-integer math — checking a cryptography exercise, verifying a factorial or combinatorics result, exploring number theory, or just multiplying two 20-digit numbers without losing accuracy. Division and mod use integer (truncated) division, and the power operation is guarded so an accidentally huge exponent cannot freeze the tab. Everything computes instantly on your device — the numbers you type are never uploaded anywhere.
Features
- Exact arithmetic on integers of unlimited length — no rounding, ever
- Add, subtract, multiply, divide, mod, and power (exponent) operations
- Integer division and mod truncated toward zero, matching standard big-integer libraries
- Guards against exponents so large the result would be unreasonably huge
- Clear error messages for invalid input, non-integer values, and division by zero
- Copy the full result or a plain-text summary of the calculation in one click
- Instant results as you type, with no page reloads
- Runs entirely in your browser — your numbers never leave your device
How to use the Big Number Calculator
- Enter the first integer in Number A
- Choose an operation: add, subtract, multiply, divide, mod, or power
- Enter the second integer (or the exponent for power)
- Read the exact result and copy it or the full summary
Example
Input
2^100
Output
1267650600228229401496703205376
2 raised to the power of 100, computed exactly with no rounding.
Common errors & troubleshooting
- Big Number Calculator shows "is not a valid integer." — Only whole numbers are accepted — remove decimal points, commas, spaces, and scientific notation like 1e10, and keep at most one leading + or - sign.
- "Cannot divide by zero" appears for divide or mod. — Enter a non-zero divisor. Division and remainder are undefined when the second number is 0.
- Power shows "the result would exceed" a digit limit. — The exponent you entered would produce a result too large to compute instantly. Try a smaller base or exponent, or split the calculation into smaller steps.
- A regular calculator gives a slightly different answer for large multiplication. — Most calculators and spreadsheets store numbers as 64-bit floating point, which loses precision past about 15-16 digits. The Big Number Calculator keeps every digit exact.
Frequently asked questions
- What is a Big Number Calculator?
- It is a calculator that performs exact arithmetic — add, subtract, multiply, divide, mod, and power — on integers of any size, using arbitrary-precision math instead of the limited-precision numbers built into most calculators.
- How large a number can the Big Number Calculator handle?
- There is no fixed digit limit for add, subtract, multiply, divide, or mod — they stay exact for integers with hundreds or thousands of digits. The power operation is capped so an extreme exponent cannot produce a result too large to compute instantly.
- Does the Big Number Calculator round large results?
- No. Unlike a standard calculator or spreadsheet, which switches to floating point and loses precision past roughly 15-16 digits, this tool keeps every digit exact for the operations it supports.
- How does division work in the Big Number Calculator?
- Division and mod use integer (whole-number) division, truncated toward zero — the same convention most programming languages use for big-integer types. For example, -17 divided by 5 gives -3 with a remainder of -2.
- Can I use the Big Number Calculator for negative integers?
- Yes. Both numbers can be negative for add, subtract, multiply, divide, and mod. The exponent in a power calculation must be zero or positive.
- Are the large numbers I enter in the Big Number Calculator uploaded anywhere?
- No. The Big Number Calculator runs entirely in your browser. The integers you type never leave your device and are not uploaded to ArrayKit.
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