Matrix Addition Calculator

Adding Matrices, Cell by Cell

Matrix addition is the most literal of the matrix operations: line up two matrices of the same size and add each pair of matching entries. No cross-multiplication, no determinants — just position-by-position addition, which is why it only works when both matrices share identical dimensions.

The Formula

C = A + B (element-wise addition)
Cij = Aij + Bij

Worked Example

For A = [1, 2; 3, 4] and B = [5, 6; 7, 8]:

Matrix addition, cell by cell
PositionCalculationResult
Row 11+5, 2+66, 8
Row 23+7, 4+810, 12

Result matrix: [6, 8; 10, 12].

Where This Matters

  • Combining datasets — summing matrices of sales, sensor readings, or grades across two periods to get combined totals.
  • Image processing — blending or adjusting images represented as pixel-value matrices uses element-wise addition.
  • Superposition in physics — adding transformation or state matrices to combine multiple simultaneous effects.

How to Use This Calculator

  1. Choose the matrix size: 2 x 2 Matrices or 3 x 3 Matrices.
  2. Enter each cell of Matrix A (A row1 col1, A row1 col2, and so on).
  3. Enter each cell of Matrix B in the same layout.
  4. Select Calculate to get the sum matrix.

Related Calculations

Need to subtract instead? Use the Matrix Subtraction Calculator, or combine matrices by multiplication with the Matrix Multiplication Calculator.