About the Matrix Multiplication Calculator
Multiply two matrices (A × B) when the columns of A match the rows of B, with the result size shown.
Also known as: multiply matrices, matrix product, dot product of matrices.
How to use this calculator
- Enter matrix a (rows on new lines), matrix b.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
(AB)ᵢⱼ = Σₖ Aᵢₖ·Bₖⱼ
Worked example
Using the values pre-filled in the calculator above:
- Matrix A (rows on new lines): 1 2 3 0 1 4 5 6 0
- Matrix B: 2 0 1 1 3 2 1 1 1
the calculator returns:
- A × B: [ 7 9 8 ] [ 5 7 6 ] [ 16 18 17 ]
- Result size: 3 × 3