# MMULT

Returns the matrix product of two arrays. The result is an array with the same number of rows as array1 and the same number of columns as array2.

Syntax

MMULT(array1,array2)

Array1, array2     are the arrays you want to multiply.

Remarks

• The number of columns in array1 must be the same as the number of rows in array2, and both arrays must contain only numbers.
• Array1 and array2 can be given as cell ranges, array constants, or references.
• MMULT returns the #VALUE! error when:
• Any cells are empty or contain text.
• The number of columns in array1 is different from the number of rows in array2.
• The size of the resulting array is equal to or greater than a total of 5,461 cells.
• The matrix product array a of two arrays b and c is:

where i is the row number, and j is the column number.

• Formulas that return arrays must be entered as array formulas.

Example 1

The example may be easier to understand if you copy it to a blank worksheet.

1. Create a blank workbook or worksheet.
2. Select the example in the Help topic.

Note   Do not select the row or column headers.

Selecting an example from Help
1. Press CTRL+C.
2. In the worksheet, select cell A1, and press CTRL+V.
3. To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Tools menu, point to Formula Auditing, and then click Formula Auditing Mode.
A B
Array 1 Array 1
1 3
7 2
Array 2 Array 2
2 0
0 2
Formula Formula
=MMULT(A2:B3,A5:B6)

Note   The formula in the example must be entered as an array formula. After copying the example to a blank worksheet, select the range A8:B9 starting with the formula cell. Press F2, and then press CTRL+SHIFT+ENTER. If the formula is not entered as an array formula, the single result is 2.

Example 2

The example may be easier to understand if you copy it to a blank worksheet.

1. Create a blank workbook or worksheet.
2. Select the example in the Help topic.

Note   Do not select the row or column headers.

Selecting an example from Help
1. Press CTRL+C.
2. In the worksheet, select cell A1, and press CTRL+V.
3. To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Tools menu, point to Formula Auditing, and then click Formula Auditing Mode.
A B
Array 1 Array 1
3 0
2 0
Array 2 Array 2
2 0
0 2
Formula Formula
=MMULT(A2:B3,A5:B6)

Note   The formula in the example must be entered as an array formula. After copying the example to a blank worksheet, select the range A8:B9 starting with the formula cell. Press F2, and then press CTRL+SHIFT+ENTER. If the formula is not entered as an array formula, the single result is 6.

Applies to:
Excel 2003