Hi Maarten,

If your table resides in cells B2:F5 (values, not row or column
titles!), then select cells B7:E10 and array enter

=MMULT(B2:F5,TRANSPOSE(B2:F5))

(enter with CTRL+SHIFT+ENTER).

Please notice that no empty cell is allowed in B2:F5 (see help on
MMULT).

HTH,
Bernd