Compute a modulo, an inverse or a modular power

Compute a modulo, an inverse or a modular power. Handy for students, analysts and engineers checking a calculation or conversion before using the result.

Compute a modulo, an inverse or a modular power. See the result immediately in your browser, with no account, upload or stored data.

How to use

Enter the requested operation on the first line: mod, inv or pow.
Enter the operands separated by a space on the second line.
Enter the modulus on the third line.
Run the calculation to get the displayed result.
Clear the fields to test another calculation.

Example

In the sample, the pow operation uses operands 2 and 10 with a modulus of 1000. Look at the displayed result to check the modular power; this is useful in cryptography or arithmetic exercises.

Input

pow
2 10
1000

Output

Limits and formats

Division by zero or invalid moduli will stop the calculation.
A modular inverse exists only when the numbers are coprime.
Operands should be integers for the offered operations.
Very large numbers may be rounded or rejected.

Where processing happens

The values you enter are handled in your browser. No external transfer takes place, no account is required, and the content is not stored after the calculation.

Frequently asked questions

What is the difference between mod, inv and pow?

mod returns the remainder of a division, inv finds the modular inverse of a number, and pow computes a power modulo an integer. Each operation expects suitable operands and a consistent modulus.

Why can a modular inverse fail?

A modular inverse exists only when the number and the modulus are coprime, meaning they share no common divisor other than one. If that condition is not met, no integer satisfies the expected equality.

Can I use decimal numbers?

The tool is intended for modular arithmetic with integers. Decimals, fractions or symbols may be rejected or may prevent the calculation. Enter whole numbers to get a usable result.