Thoughts on 4% rule

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StayPuft
Posts: 24
Joined: Sun Nov 10, 2019 2:29 am

Thoughts on 4% rule

Post by StayPuft »

How does FRP compare to the 4% rules that's commonly used for retirement calculations?

When I plug in my annual expenses into FRP and how much I'll need saved when I hit retirement, I get a median portfolio value that's about twice the amount needed compared to when I use the 4% rule to calculate how much I'll need. Seems to be a pretty big gap.
StayPuft
Posts: 24
Joined: Sun Nov 10, 2019 2:29 am

Re: Thoughts on 4% rule

Post by StayPuft »

Anyone have any thoughts on this? I'd just like an idea of if FRP is ultra-conservative, or if 4% rule is not conservative enough. With such a large difference in the numbers pumped out, I'm struggling to figure out which "retirement model" to follow.
FRPJunkie
Posts: 42
Joined: Wed Feb 24, 2016 8:17 am

Re: Thoughts on 4% rule

Post by FRPJunkie »

Did you plug in all your income streams? Social Security, pensions, etc. And an accurate # for annual expense? Average tax rate? What return rate and inflation rate did you enter?

Lot of moving parts here. The "Goal Seek" Function (which I assume you're referring to, since that's the only setting that will show you how much the planner things you will need) is not super reliable in my experience.
StayPuft
Posts: 24
Joined: Sun Nov 10, 2019 2:29 am

Re: Thoughts on 4% rule

Post by StayPuft »

Yup, plugged in all of that. What do you mean by "goal seek" function?

All I did was input all that info, zero out the inflation to get a rough idea of future dollar amounts, then hit "RUN".
Then I look at "detailed view" and see how much the median portfolio needs to be at my retirement age to support my lifestyle.

When I compare this number with the 4% rule (adjusted to future dollars, as well), FRP tells me I need to save roughly double of what the 4% rule tells me to live the same lifestyle.

The numbers aren't close at all.

FRPJunkie wrote: Thu Feb 13, 2025 5:00 pm Did you plug in all your income streams? Social Security, pensions, etc. And an accurate # for annual expense? Average tax rate? What return rate and inflation rate did you enter?

Lot of moving parts here. The "Goal Seek" Function (which I assume you're referring to, since that's the only setting that will show you how much the planner things you will need) is not super reliable in my experience.
FRPJunkie
Posts: 42
Joined: Wed Feb 24, 2016 8:17 am

Re: Thoughts on 4% rule

Post by FRPJunkie »

StayPuft wrote: Fri Feb 14, 2025 3:12 am Yup, plugged in all of that. What do you mean by "goal seek" function?

All I did was input all that info, zero out the inflation to get a rough idea of future dollar amounts, then hit "RUN".
Then I look at "detailed view" and see how much the median portfolio needs to be at my retirement age to support my lifestyle.

When I compare this number with the 4% rule (adjusted to future dollars, as well), FRP tells me I need to save roughly double of what the 4% rule tells me to live the same lifestyle.

The numbers aren't close at all.

FRPJunkie wrote: Thu Feb 13, 2025 5:00 pm Did you plug in all your income streams? Social Security, pensions, etc. And an accurate # for annual expense? Average tax rate? What return rate and inflation rate did you enter?

Lot of moving parts here. The "Goal Seek" Function (which I assume you're referring to, since that's the only setting that will show you how much the planner things you will need) is not super reliable in my experience.
Settings>Activate Goal Seek Parameters>Use Goal Seek to Find retirement portfolio value...

When you say "adjusted to future dollars are well..." ? FRP reports in current dollars, not future dollars.

Also can you provide some numbers? The 4% "rule" is simply a calculation. If my portfolio balance is $1m and my expenses are $80k, well, that means the "4% rule" is only going to give me half as much money as I need (i.e. $40k). In this example you'd either need lower expenses or a higher portfolio balance (or a higher withdrawal rate) in order for 4% to work.
Last edited by FRPJunkie on Fri Feb 14, 2025 9:18 am, edited 1 time in total.
StayPuft
Posts: 24
Joined: Sun Nov 10, 2019 2:29 am

Re: Thoughts on 4% rule

Post by StayPuft »

Ah! Very interesting! I've never even used the goal-seek function. Thank you! Is there somewhere I can learn more about what the goal-seek function does so I can understand it?

As far as numbers, when I use the 4% rule to multiply my expenses, it tells me I need $800k saved up in future dollars to pull it off. However, if I use the same expenses in FRP, delete the inflation rate to roughly predict future dollars, it tells me I need about $1.6 million...so double. I must be doing something wrong because why would it be double?

Maybe I should look more into this goal-seek function. I looked online, but can't find a more in-depth explanation of goal-seek.
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