Mathlean · Online math workspace
Modular inverse calculator
Find a multiplicative inverse modulo an integer.
How to use this calculator
Edit ModularInverse(a,m). The inverse of 3 modulo 11 is 4 because their product is congruent to 1.
Tap the math below to edit it and see the result. Once a result is ready, press Tab on a hardware keyboard to accept it. Outside a matrix, Return completes the line; the phone math keyboard has the same Return action.
Try it here
Interactive tools require JavaScript. You can read the guide and example without it.
What to know
An inverse exists only when the input and modulus are coprime.
Mathlean combines visual mathematical input with computation and canvas tools. Results depend on the expression and available engine support; check important answers independently.