Get certified for free when you join Fabric Data Days 2026 and dive into Fabric, Power BI, SQL, AI, and other essential data skills.
Join nowTry your skills in the Power BI Dataviz World Championship! Round one ends June 26. Join now
Hi All,
I have two tables that are connected through a calendar table. The problem I am having is that in the first table I need to calculate an average of the last 12 months only even if the dates go back further and then divide that average by the total number of people in the second table e.g.
First Table
Department
Department Staff number Start Date
1 12345 10/10/2015
2 56745 01/09/2019
3 10101 15/10/2018
4 20202 20/01/2016
Second Table
Staff
Department Staff number Leaving Date
1 12345 01/03/2017
2 56745 22/09/2019
3 10101 13/04/2020
4 20202 19/10/2019
The calculation I have for the first table to calculate the average is
@UK_User123456 - Please check this out, let me know if this works. If this fix your problem, please tick this a solution and a thumps up.
Staff 12 MONTHS =
CALCULATE(
COUNTROWS('DEPARTMENT'),
FILTER(
ALL('Calendar'[Date]),
'Calendar'[Date] > TODAY() - 365 && 'Calendar'[Date] <= TODAY()
),
RELATEDTABLE('DEPARTMENT')
)
Total Staff = COUNTROWS('STAFF')
Average =
DIVIDE(
[Staff 12 MONTHS],
[Total Staff],
0
)
Hi @Manoj_Nair ,
How would the calculation work if put into the calculation I currently have in my post, as I need to be able to show these split down by month, so showing the split out by month in a matrix table?
Thanks
Hi @Manoj_Nair ,
Many thanks for this, is this meant to be two seperate calculation measures or one?
Don't miss out on Data Days, June 15 through August 7. Learn Fabric, Power BI, SQL, AI and more.
Check out the May 2026 Power BI update to learn about new features.
| User | Count |
|---|---|
| 23 | |
| 20 | |
| 19 | |
| 17 | |
| 11 |
| User | Count |
|---|---|
| 60 | |
| 55 | |
| 42 | |
| 38 | |
| 30 |