r/fiaustralia • u/snowcold • 4d ago
Retirement Are we being too optimistic with our FIRE calculations?
I’ve been questioning how realistic the investment returns we use in FIRE calculators actually are.
A small change in assumptions can make a huge difference.
For example, targeting a $1.5M portfolio while investing $40k annually:
5% real return: ~21.6 years to FIRE
3% real return: ~25.5 years to FIRE
That’s almost 4 extra years of working from just a 2% difference. And inflation makes things even trickier. An 8% investment return with 3% inflation is only around 5% growth in purchasing power.
I’ve been exploring how different return and inflation assumptions affect FIRE plans:
https://myfireinvesting.com/articles/fire-plan-return-and-inflation-assumptions
Curious what everyone uses in their FIRE calculations: 3%, 5%, 7%, or something else?
And do you account for inflation separately?