Determinant 4x4 Calculator

Summary

Enter a 4x4 matrix and get the determinant instantly with full cofactor expansion steps shown.

How it works

1. Enter the sixteen elements of your 4x4 matrix into the grid.
2. The calculator expands along the first row using cofactor expansion (Laplace expansion).
3. Each of the four first-row elements is paired with its signed 3x3 minor (cofactor).
4. Each 3x3 minor is evaluated using its own cofactor expansion.
5. The four cofactor products are summed to produce the final determinant.
6. All intermediate 3x3 minors and their values are shown for full transparency.

Use cases

• Verify hand-computed 4x4 determinants for linear algebra assignments.
• Check whether a 4x4 matrix is singular before inverting it.
• Learn cofactor expansion step by step with a clear worked example.
• Evaluate invertibility before solving a 4-variable system of linear equations.
• Compute the determinant needed for Cramer's rule with four unknowns.
• Quickly test multiple 4x4 matrices when studying for exams.
• Cross-check results from other tools or software.

Frequently Asked Questions