Retirement? Great post. Some people can never retire. Check also my post here about how pension funds can rob your retirement savings!!

I post it because it is relevant to your post @pycan.

Replying on you.

I think any amout of sats to keep my current life style.

If you have a lifestyle of say: Going on vacation once Eating out once a month Driving a car Windsurfing Buying books Groceries

You can calculate how much inflation there is for this life style of goods and services after your retirement.

And then based on the USD/BTC exchange rate assumption you can calculate the BTC you need to save.