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Matrix Multiplication Calculator

Multiply, add or subtract matrices of any size and find the determinant, inverse and transpose, then work out sin, cos, tan and their inverses in degrees or radians and solve a right triangle.

Updated November 4, 2026. Free, no sign-up; everything runs in your browser and nothing you type is stored.

Matrix multiplication calculator

Result
–

Trig calculator

–sin
–cos
–tan
–csc
–sec
–cot
–Converted
–arcsin
–arccos
–arctan

Right triangle from its two legs

–Hypotenuse c
–Angles opposite a and b
–Area

How matrix multiplication works

To multiply A (m × n) by B (n × p), each entry of the result is a row of A times a column of B, multiplied entry by entry and added. The number of columns of A must equal the number of rows of B, and the result is m × p. For A = [[1, 2], [3, 4]] and B = [[5, 6], [7, 8]]: the top-left entry is 1 × 5 + 2 × 7 = 19, so A × B = [[19, 22], [43, 50]]. Order matters: B × A = [[23, 34], [31, 46]].

Matrix calculator: determinant and inverse

For a 2 × 2 matrix [[a, b], [c, d]], the determinant is ad − bc and the inverse is (1 ÷ det) × [[d, −b], [−c, a]]. For A above, det = 4 − 6 = −2 and A⁻¹ = [[−2, 1], [1.5, −0.5]]. A matrix with determinant 0 has no inverse. Larger matrices are handled here by Gaussian elimination with partial pivoting.

Trigonometry calculator

In a right triangle, sin = opposite ÷ hypotenuse, cos = adjacent ÷ hypotenuse, tan = opposite ÷ adjacent (SOH-CAH-TOA); csc, sec and cot are their reciprocals. sin 30° = 0.5, cos 60° = 0.5, tan 45° = 1. To convert, degrees × π ÷ 180 = radians. With legs 3 and 4 the hypotenuse is 5 (Pythagoras) and the angles are 36.87° and 53.13°. This trig calculator gives exact values at the standard angles (tan 90° is undefined, not a huge number).

Common questions

How do you multiply two matrices?

Each entry is a row of the first times a column of the second, summed. [[1,2],[3,4]] × [[5,6],[7,8]] = [[19,22],[43,50]].

Can any two matrices be multiplied?

Only if the first has as many columns as the second has rows.

What is the determinant of a 2 × 2 matrix?

ad − bc. For [[1,2],[3,4]] it's −2.

What is sin 30 degrees?

0.5.

How do I convert degrees to radians?

Multiply by π ÷ 180: 30° = π/6 ≈ 0.5236 rad.

Sources

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General information, not financial, tax or legal advice. Check important numbers with the official source before acting on them.