Measure displaying correctly in matrix but not totaling correctly

[effertz12]

My company does monthly forecasts for the year and i currently have a measure to calculate the error percentage of our forecasts from one month previously. i have this formula, which im sure isnt written fantastically since i am new to dax:

i want to sum up each percentage value and take an average and display it on a card but it doesnt show the correct summed total. I understand why it doesnt show the correct total but i cant for the life of me figure out how to get it right. 

the matrix itself is working fine because it has month columns for the measure to use, but the total it shows when displayed on a card is -13%

any help would be great thanks!

[v-yetao1-msft]

Hi @effertz12 

What is the actual value? Is it a measure or a calculated column? The data you provide now is not clear, so I can't figure out the reason. If possible, can you provide me with samples (data and formulas) ?

Best Regards

Community Support Team _ Ailsa Tao

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

[effertz12]

Month and forecast name are both in the same table. Each forecast contains every month until dec 2022. I am using the comparison between 'stepchart5'[month text] and 'stepchart5'[forecastname].[date] to find only the units that are forecasted at the 1 month out from the actuals to compare them. if that makes sense

[m3tr01d]

Hello,
the month field is coming from what table on your chart?