How to calculate the average of length of two dates?

[Shayan_Seyedi]

I'm trying to calculate the average length of membership between the date the member was added and date that they were signed off. Can you check if below formula is correct?

Avg. Length of Membership =
AVERAGEX(
KEEPFILTERS(VALUES('productiondb ngo_member_removed'[end])),
CALCULATE(COUNTA('productiondb ngo_member_removed'[start]))
)

[Greg_Deckler]

That doesn't look correct. I would expect that you would need to do a DATEDIFF between the start and end dates and then take the average of that.