DAX subtraction formula without summing up when there are multiple entries of the same category

[Anonymous]

Hello everyone,

I have a formula which does a basic subtraction:

MAX_LOAD_LENGTH minus LDM =

SUM('Truck_Info'[MAX_LOAD_LENGTH]) - SUM('Truck_Info'[LDM])

the max load length is the capacity and ldm is the load  with one row being one truck/drive. Now there can be multiple routes a day for the same truck when its a short route, meaning the truck 5 could exist 3 times. In this case the formula sums the values of those 3 entries and subtracts it. I don't want this even if it exists multiple times I still want it to only do it for that specific truck. I think i need to convert this to a calculated column to avoid the summing up when there are multiple entries of the same category.

example of data:

Truck | MAX_LOAD_LENGTH | LDM

5           10                                5

5           10                                3
5           10                                2

In the current situation the result would be:

Truck   |  FREE LDM
5              20

I want it to be like this
Truck  |   FREE LDM
5                5
5                7
5                8

[Nathaniel_C · Accepted solution]

Hi @Anonymous ,
Your issue may be as easy as checking Don't Summarize, by clicking on the fields that you are bringing in. See pics. I also did another measure that you might use, although I think yours is fine. Measures are superior to doing a calculated column. 
Let me know if you have any questions.

If this solves your issues, please mark it as the solution, so that others can find it easily. Kudos 👍are nice too.
Nathaniel

MAX_LOAD_LENGTH minus LDM 1 = 
MAX(mytable[MAX_LOAD_LENGTH]) - Max(mytable[LDM])