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Having hand rolled my own retirement calculator (excel) with a lot of other variables that seem like overkill at first, I think this is very misleading if you d

Having hand rolled my own retirement calculator (excel) with a lot of other variables that seem like overkill at first, I think this is very misleading if you don't at least account for inflation. It gets complicated real quick when you start realizing that if you need amount X and it takes Y years to get that X amount, the goalposts have moved by the time you actually save up to X, and now may need 1.2X. Not to mention that the passive income buying power will go down each year, so you actually need to have passive income growing at the same rate of inflation. Yes, this complicates and it would be nice to have a simple calculator, but the reality is there is no real utility for this other than to highlight the principle of "gotta have money to make money".

bemmu 9y ago
Exactly; $1000 / month might be nice now, but 30 years later could be equivalent to $500.
- andruby 9y ago
  If you assume 3% inflation, it only takes 23.44 years for the value of money to halve
froindt 9y ago
Have you looked into engineering economics? The formulas you'd need are already developed depending on the scope you're building. Present value calculations will handle most of the hard work, letting you talk about everything in "today" dollars.
- adjkant 9y ago
  I've taken a macro course and am more or less using those formulas (and translating them into basic examples in the grandparent). Present value only does so much lifting though, as my scope is a lot wider. Life is more complicated than that. You can't forget about different taxation treatment when comparing Roth/Traditional savings, savings outside of retirement accounts when applicable, etc. Excel also acts as a wrapper to allow for me to change my annual budget easily, my expected salary over time, expected inflation, etc and see the results. I'm not reinventing the wheel here, just making my own instance of the wheel. But the point remains: it's a heck of a lot more complex than this calculator. One of my "ideas to do if I had time" it to take that and make it into a "simpler" service that could actually be useful to people. I know most retirement helper companies try to do this but wow are they bad in my experience. The problem they are fighting of course is balancing the simplicity with the customization though, which I suspect is the crux. Still, to whoever finds that solution first, a pot of gold will follow.
anotheryou 9y ago
Would you share you excel sheets? I'm curious. But currently I'm rather searching for a path towards part-time work. Sadly that's challenging as a project manager, maybe slightly less as a product manager (I always filled both roles in smaller startups, so I'm flexible here).
- adjkant 9y ago
  I'd be happy to, though I suspect it's too specific to be of use to a wider audience, and certainly could be improved as they were made out of need, not designed perfectly.

bemmu 9y ago

Exactly; $1000 / month might be nice now, but 30 years later could be equivalent to $500.

andruby 9y ago
If you assume 3% inflation, it only takes 23.44 years for the value of money to halve

froindt 9y ago

Have you looked into engineering economics? The formulas you'd need are already developed depending on the scope you're building. Present value calculations will handle most of the hard work, letting you talk about everything in "today" dollars.

adjkant 9y ago
I've taken a macro course and am more or less using those formulas (and translating them into basic examples in the grandparent). Present value only does so much lifting though, as my scope is a lot wider. Life is more complicated than that. You can't forget about different taxation treatment when comparing Roth/Traditional savings, savings outside of retirement accounts when applicable, etc. Excel also acts as a wrapper to allow for me to change my annual budget easily, my expected salary over time, expected inflation, etc and see the results. I'm not reinventing the wheel here, just making my own instance of the wheel. But the point remains: it's a heck of a lot more complex than this calculator. One of my "ideas to do if I had time" it to take that and make it into a "simpler" service that could actually be useful to people. I know most retirement helper companies try to do this but wow are they bad in my experience. The problem they are fighting of course is balancing the simplicity with the customization though, which I suspect is the crux. Still, to whoever finds that solution first, a pot of gold will follow.

anotheryou 9y ago

Would you share you excel sheets? I'm curious. But currently I'm rather searching for a path towards part-time work. Sadly that's challenging as a project manager, maybe slightly less as a product manager (I always filled both roles in smaller startups, so I'm flexible here).

adjkant 9y ago
I'd be happy to, though I suspect it's too specific to be of use to a wider audience, and certainly could be improved as they were made out of need, not designed perfectly.