Calculate difference with rules

[sanderson82]

Hi

I have a measure to calculate difference...

M3CostDiff = SUM('Contract Manager'[M3Cost]) - MAINLoads[TotalCostperM3]

'Contract Manager'[M3Cost] is populated via manual entry in a PowerApp

MAINLoads[TotalCostperM3] comes from a SQL table behind a manufacturing system.

The difference I'm calculating is what has been allowed against what the actual cost is.  My question is can I apply certain "rules" to the calculation.  For example

If 'Contract Manager'[M3Cost] has been populated eg £70, but the contract has not started so the value in the SQL table it either 0 or blank, the difference shows £70.

Is it possible in the calculation that if MAINLoads[TotalCostperM3] is 0 or blank it returns blank in the table?

[amitchandak]

Please share table structure, sample data and explain with data example.