Sorry Guys,
Yes I should have been more specific (slaps own wrist).

AlphaFrog, I've placed the code in the sheet1 and so expected it to work when I enter one of the values in E15. However, when I do enter one of the values nothing happens other than that value being entered in E16.

Yudlugar, when I run your code I am expecting it to update automatically and when I tried your code I get: Compile error, User defined type not defined amd it highlights the very first row: Private Sub Worksheet_Change(ByVal target As ref)

Many thanks