Calculating the Matrix Determinant on the Fly in MS Excel
1. Create a square matrix in Microsoft Office Excel with values.
2. Type an equal sign (=) followed by MDETERM in an empty cell. While typing, you’ll notice that Excel automatically gives you a list of functions beginning with what you have already written. Many more functions are available in Microsoft Office Excel 2007.
3. After the opening parenthesis, select your matrix data. You'll instantly see the determinant being calculated. Excel updates this value if you change the source data.