Subtract value from a max sum

Hi guys
I have an excel problem I can't solve myself.

A customer save up half an hour each week.
A1 (week 1) = 0,5
B1 (week 2) = 0,5
C1 (week 3) = 0,5
Etc.

A customer can max save up 6 hours in total.

Then I have a row with the spendings:
A2 (week 1) = (blank)
B2 (week 2) = (blank)
C2 (week 3) = 1
Etc.

I can't figure out this:
If a customer save up and dont spend any until week 24. I can get sum to show 6 by using the IF formula.
And thats great.
The problem is that when the customer spend 3 hours in week 24. The result should be 3 hours left.
But it still shows 6 (because he saved up 12 hours before he spent any, But he can only save up 6 hours).

Sorry for my bad english.
I hope I made myself clear.

Can Anybody help me?

Cheers,
Martin

Hi there. welcome to the forum. Does this do what you want? If not, please attach an Excel sheet, showing your data layout.

=MIN(6,SUM(A1:X1))-SUM(A2:X2)

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OK. I see it... I was looking at your most recent post...

Try this... My Danish is non-existent, but I think that this is compatible with your data layout.