Multiply Two or More Matrices
Use this calculator to multiply a chain of matrices in order: A × B × C × .... Enter one row per line and separate numbers with spaces or commas.
Tip: You can also use semicolons to separate rows, such as 1 2 3; 4 5 6.
What this calculator does
This multiple matrix multiplication calculator computes the product of several matrices in sequence. Instead of calculating only A × B, it supports longer expressions like A × B × C × D. The tool checks matrix dimensions, performs each multiplication step, and returns the final result matrix.
How to enter matrices correctly
- Enter each matrix in its own text box.
- Use one row per line.
- Separate values using spaces or commas.
- You may optionally type brackets; they are ignored by the parser.
Valid input examples
You can type any of the following formats:
1 2 3on one line and4 5 6on the next line1,2,3and4,5,6[1 2 3; 4 5 6]using semicolons for rows
Dimension rules for matrix multiplication
The key rule is simple: if matrix A has size m × n and matrix B has size p × q, then A × B is valid only when n = p. The result will have size m × q.
For multiple matrices, this must be true at every step. For example:
- (2 × 3) × (3 × 4) is valid and gives 2 × 4
- (2 × 4) × (3 × 2) is invalid because 4 ≠ 3
Why matrix chains matter
Matrix chain multiplication appears in many fields: machine learning, robotics, computer graphics, optimization, control systems, and numerical simulation. If you are working with transformations or linear models, you will often multiply several matrices in a row.
Even when mathematically valid, the order of operations can impact computational cost. This page multiplies from left to right, which is straightforward and useful for most practical input checks and quick calculations.
Common mistakes and fixes
1) Dimension mismatch
If you see an error about incompatible dimensions, inspect the number of columns in the current result and compare it to the number of rows in the next matrix.
2) Inconsistent row lengths
Each row in a single matrix must have the same number of entries. If one row is shorter, update the missing values.
3) Invalid numbers
Only numeric values are allowed. Remove text labels and symbols that are not part of a number.
Practical use cases
- Combining transformation matrices in 2D/3D graphics
- Evaluating linear algebra homework and exam preparation steps
- Testing neural network layer operations in small examples
- Verifying calculations in engineering and physics models
Final note
This tool is designed to be easy, fast, and transparent. It shows detected dimensions, validates input at each stage, and outputs a clearly formatted result matrix. For deeper workflows, you can copy the final matrix into Python, MATLAB, R, or any symbolic algebra package.