So; working from the efforts of gebobs combined with a lot of net searches I have come up with this: =COUNTIF(I13:AQ13;"="&Lists!F7)*Lists!I7+COUNTIF.. ....

This solution still needs a specific formula for each shift Code (and calculated Hours) in the Lists sheet.
However, because it is using each specific shift Code and calculated shift Hours cells from the Lists sheet it should respond to shift Code and Hours alterations.

The next problem I need to solve is to come up with a way to make the formula ignore blank cells so that should a new shift type (e.g. F3 @ 08:00-12:00) be added, the formula wont need to be altered to reflect the addition of a new Code>Hours row. That is, I would like to have the formula incorporate (without having to go back and alter the formula) some unused Code>Hours cells for each shift type (Early, Middle, Late,...) in the Lists sheet.

Any Ideas? :-)

Regards.