Modular inverse calculator

Client

Enter integer a and modulus m. The result is x with a·x ≡ 1 (mod m) when coprime.

About Modular inverse calculator

Compute the modular multiplicative inverse with the extended Euclidean algorithm—in your browser. The interactive transform on this page runs in your browser tab—Toolcore does not need your paste for the core operation described above.

How to use this page

Paste or type in the main workspace, run the primary action from the toolbar, then copy or download the result. Use Load example when the page offers it, or URL prefill (?q= / ?qb=) so agents and tickets open the same input.

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Nearby workflows on Toolcore

  • Modulo calculator — Integer remainder and truncated quotient (a mod b)—BigInt math in your browser. when units or numeric output should be checked on a related calculator.
  • GCD & LCM calculator — Greatest common divisor and least common multiple for two non-negative integers—BigInt, local only. when units or numeric output should be checked on a related calculator.
  • Modular exponentiation — Fast modular power a^b mod m for large exponents—binary exponentiation in the browser. when units or numeric output should be checked on a related calculator.
  • Math expression evaluator — Evaluate basic + − × ÷ arithmetic with parentheses in your browser—no variables. when units or numeric output should be checked on a related calculator.

Common use cases

  • Modular inverse calculator for quick local checks without uploading data.
  • Copy results into tickets, docs, or classroom notes.

Common mistakes to avoid

  • Unexpected input shape

    See the intro and how-to notes for accepted formats.

FAQ

Is processing local?

Yes—this runs entirely in your browser.

Agent prefill?

Use q or qb for the main text field when supported.

More tools

Related utilities you can open in another tab—mostly client-side.