Stock list calculation problem

Hi All,

I am trying to produce a simple stock control sheet,

I have a carried over level of 775

I have column ‘C’ as the stock level so ‘C5’ is currently at 625 ‘C6’ is blank and will be filled in after the monthly stock count on the first of the month.
Column ‘J’ is for total stock and ‘J5’currently reads 625 also
Column ‘K’ is stock used and stands at 150
Column ‘I’ is for stock received after the first of the month and ‘I5’ is blank (nothing received)
All good so far !!!
Column ‘J’ is the sum of ‘C5+I5’ (consecutive numbers as you work down the column)
Column ‘K’ is the sum of ‘J4-C5’ (as above)
That’s where the good ends !!!

I have a running total for quick view which I link to a front page so that we can see the current usage total as the year progresses. The total in this cell is reading 775 as a total usage instead of the correct figure of 150 as in ‘K5’. You see ‘K6’ is already calculating ‘J5-C6’ but ‘J5’ is empty because it’s not the first of the month yet, how do I stop the cells in column ‘K’ calculating if the cells in column ‘C’ are empty.

Or as usual am I making this complicated !!!

Thanks for reading,

Andy.