Kronecker Symbol Calculator

Calculate the Kronecker symbol (a|n), extending the Jacobi symbol to all integers.

Enter Values

Definition

The Kronecker symbol extends the Jacobi symbol:

  • (a|0) = 1 if |a| = 1, else 0
  • (a|-1) = -1 if a < 0, else 1
  • (a|2) depends on a mod 8

(a|2) Values

(a|2) = 0 if a is even

(a|2) = 1 if a ≡ ±1 (mod 8)

(a|2) = -1 if a ≡ ±3 (mod 8)

Kronecker Symbol

(5|21) = 1

a
5
n
21
Result
1

Calculation Steps

Reduce a mod n: a = 5

Swap: now (1/5)

Final result

Result: 1

Applications

  • Quadratic forms
  • Class field theory
  • Quadratic number fields
  • Primality testing
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Editorial Note

MyCalcBuddy Editorial Team

This page is maintained as an educational calculator reference.

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Formula Source: Handbook of Mathematical Functions

by Abramowitz & Stegun

🔄Last reviewed: May 2026
✓Formula checks are based on standard references and internal QA review.