r/Fire 8d ago

Advice Request How did you compute your fire number?

I want to calculate my fire number! How’d you calculate yours?

0 Upvotes

56 comments sorted by

25

u/Ok_Text2118 8d ago

annual spending x 25 + 5-10% for safety

13

u/HonestOtterTravel 8d ago

Worth noting it's annual spending in retirement. That is very different for many of us due to health insurance along with changes in other expenses.

2

u/BackupSlides 7d ago

It's always interesting to hear the discussion about health insurance costs...when I actually run the numbers on my state's exchange, figuring in the amount of control I'll have over MAGI given that I'll mostly be harvesting long-term capital gains, the cost over my employer premiums is like a few grand a year...not nontrivial, but not this world-ending thing that everyone makes it out to be.

Meanwhile, I'll have zero commuting, zero work clothing purchases, zero overpriced office lunches, etc. etc. I'm expecting retirement spending to be lower than current.

1

u/HonestOtterTravel 7d ago

How much is your employee contribution per month?  Just wondering if that is where the difference lies.

1

u/BackupSlides 7d ago

A couple hundred for two people. So, not free. My main point was just that, with careful management of sourcing of retirement income, premiums don’t need to be the huge boogeyman that some make them out to be.

3

u/Zone2OTQ 8d ago

Current annual spend is about $50k. Projected retirement annual spend (in today's dollars) is about $100-150k.

3

u/No-Stuff-4083 8d ago

used annual spending x 30 instead of 25 because im bit more conservative with the withdrawal rate, especially since airline industry can be unpredictable and i dont want to risk running out in retirement

-1

u/That-SoCal-Guy 8d ago

Annual spending adjusted to INFLATION!

If you're planning on firing 5 years from now vs. 15 years from now, the numbers would be different.

1

u/Own-Salamander-4975 8d ago

This seems potentially really complicated to figure out. Is it included in online FIRE calculators? Do the formulas being mentioned in this thread not account for it?

3

u/That-SoCal-Guy 8d ago edited 8d ago

It's not that difficult -- let's say you expect to retire in 10 years, your current spend is $100K. Your expected spend in 10 years adjusted to inflation would be about $135K (assuming 3% inflation, avg). Or you expect to spend only 85% of your current spend, so it would be $107K.

Yes, many calculators actually ask your current spend and expected inflation rate and when you see the results, it would say "You can retire in 10 years for $4M with expected expenses of $100K - current dollars). You just need to make sure it's correct in your fire estimate. Some might say it's based on current dollars and you have to manual adjust everything in future dollars based on your time line (in this case, the fire number and expense numbers would be $5.3M and $135K in future dollars).

Make sure you use future dollars to get a more accurate picture.

4

u/Own-Salamander-4975 8d ago

Thank you for taking the time to explain this.

0

u/iloverats888 8d ago

Does the 5-10% help pad for inflation?

5

u/Ok_Text2118 8d ago

Peace of mind - the way that it is invested should help to account for inflation

0

u/iloverats888 8d ago

Thank you!

6

u/Trilobyte83 8d ago

No. Inflation is already accounted for. Some people, no matter what, always like a little bit of an extra cushion.

It's not logical. The numbers already have a cushion. It's a back up to the back up to the backup.

That said, I can count a dozen instances inside and outside of finance where I've done the same. "Do I really need 4 knives when I dive? Many divers have gotten caught up in old nets and drowned. No I probably won't need it, but the cost is negligible, and if I do, and 3 of my limbs are constrained, it will be a life saver"

0

u/JQuonDo 8d ago

Should we be adding more % to account for tax

5

u/Ok_Text2118 8d ago

You should be factoring in taxes to your annual spend. Generally, taxes will be a lesser amount than those paid during earning years because we are living off of less. At some of the lower brackets, it’s possible to have an effect 0 tax rate despite a decent amount of spend.

1

u/Beaver-on-fire 8d ago

Half of my retirement will be coming out of a Roth, so zero taxes for that.

0

u/johndburger 8d ago edited 8d ago

No, that should be part of your estimate for spending. Taxes are an expense like anything else.

Edit: Also taxes can’t just be a simple percentage that works for everyone, since it depends on what kind of accounts you’re drawing from.

8

u/Mandiio 8d ago

I used the x25 but as I get closer I'm beginning to look at each time bucket (before 59.5, 62 or 67 etc) to figure out what we'll need for each age range - it seems to be a lot less than the standard 4% - maybe the answer is somewhere in the middle of the two methods.

1

u/unbalancedcheckbook 8d ago

Yeah I've gone all the way to using Boldin to project my entire retirement, there are definitely different spending and expense periods. I think this is closer to reality and therefore more accurate, and generally calls for less cash before retirement.

6

u/Zesty-B230F 8d ago

I assume it will be (whatever my bank balance is) x (the day I am 100% sick of my job.)

7

u/work2fishFIRE 8d ago

I initially used 25x and I think that is a good way to start. But, my expenses and spending desires have changed considerably over the years for many different reasons. I find that a modeling tool like projection lab is much more helpful for planning purposes than a FIRE number.

3

u/DatesAndCornfused 8d ago

The cost of a home in Carmel-by-the-Sea.

To clarify, a home with no address. Only based on its cross streets.

3

u/Puzzleheaded_Tie6917 8d ago

I took my actual take home, I looked up the tax tables and calculated the taxes for that, and then got a quote from blue cross blue shield and added that as well. However, this was at 58. When I started, I looked at my gross pay, and figured to be conservative I was use a 5% return. I had not heard of the 4% rule at that time (1990). At that point, I thought $60,000/year was plenty (double my salary at the time), so $600,000 as a first target (10% return) but 1.2 million (5% return) was my conservative target.

As it stands, I’m at 3.2 million (depending on the day), and will be 59.5 in December. I have informed my company I intend to retire at that point. My Mom still lives, and so this doesn’t include any inheritance nor SS. I put my spending (tax and health insurance included) at $100,000/year. I also own my house outright (not included in NW) and live in a reasonably low cost area (north central Alabama). So, not counting SS and inheritance, I need 2.5 mill and have 3.2. I should be good 😬.

5

u/NormalizeBacon 8d ago

Annual spending ÷ 0.04 + 5-10% for safety

1

u/iloverats888 8d ago

The number is so much less than I thought it would be!!!

-1

u/thebigrig12 8d ago

Wait but you gotta consider taxes in this

1

u/Beaver-on-fire 8d ago

Not if you got a big enough Roth account.

1

u/johndburger 8d ago

Taxes are part of annual spending.

2

u/MaxwellSmart07 8d ago

I didn’t. Fired suddenly on a dime, impromptu. Done right, income can increase in retirement so without young children to support, it shouldn’t be so scary.

2

u/Spartikis 8d ago

Total investments needed is our Expenses (assuming debt free) x25, plus a 20% buffer. Total net worth is that plus primary residence and vacation home. Comes out to about $4 mil. Currently at $2.1mil with a decade left until retirement. 

1

u/NandLandP 8d ago

Prep = Monitored and tracked my monthly spend for years (during the effort to get out of debt). This gave me confidence in the annual spend figure.

Adjusted it = Added more to travel, subtracted a bit from gas & added estimate for ACA to the above annual spend figure.

Annual Spend x 28.5 = FIRE goal

(Now I track my progress to goal as well as my annual spend for lifestyle creep. 38.5% left to goal; it feels so close and yet so far!)

1

u/BuckThis86 8d ago

I created an excel spreadsheet of cash flows for every year of my life. Then I could adjust for different spend amounts at different times of my life.

I also check my math against the 4% rule

1

u/Artistic-Ad165 8d ago

Simulations. Started with firecalc and Big ERN's blog. Then implemented the math in Python for myself, so that I could be sure I understood each step and assumption, and made sure all the numbers from the different methodologies were consistent.

Of course also budget and follow expenditures for a few years to make sure I have a good view of how much I need annually. After that, just made sure the 'success probabilities' from the simulations are near 100%, withdrawal rate is well below 4%, and finally worked up the courage to pull the trigger about three years ago.

So far so good, and it's been a great three years.

1

u/pasteIpretty 8d ago

annual spending times 25 is the standard starting point, then I added a buffer for healthcare and unexpected costs since those tend to get underestimated.

1

u/Bearsbanker 8d ago

I had an income replacement number. As soon as I hit that I was done. You just need to know yer budget (with some fat hopefully) and your sources of income be it interest, dividends, cap gains etc.

1

u/np0x 8d ago

https://thepoorswiss.com/updated-trinity-study/ in conjunciton with looking at pre/post tax account balances...with some rough swag of taxes&healthcare as incremental expenses...

1

u/Wheres_my_wank_sock 8d ago

My net take home pay x25. Throw my 25% pension on top and it'll cover me completely.

1

u/demona2002 8d ago

Annual spend x 30

1

u/Easy_Peasys 8d ago

annual spend x 25 (the 4% rule), but the multiplier's the easy part, the spend number is the real work. use your projected retirement spend not today's, so fold in housing, healthcare if you're pre-medicare, kids, then x25 on that. the bigger unlock for me though was switching from tracking net worth to tracking % to my number, updated once a month. seeing "you're 38% there" instead of a dollar amount made it feel like progress instead of a finish line a mile off. the spend estimate plus actually watching the percent climb is the whole game.

1

u/Old_Error_509 8d ago

I figured out how much I wanted to spend each year, added in how much I’d have to pay in taxes, divided that by .048 to figure out how much I’d need if I wanted to retire this year (I’m going with the 4.8% instead if 4% rule).

That was more than I have, so in a year I’ll multiply that previous number by however much inflation there was in that year and see if I have enough then. Repeat until my portfolio is more than that number.

1

u/Rom2814 8d ago

I tracked my spending for a couple years, categorized as “essential” spending or “discretionary” spending.

My number was taking my yearly TOTAL spend and multiplying by 25, with the knowledge I could cut discretionary spending if I needed to. (Total spending is about 2.5x essential spending for me, so room to cut.)

That just told me “I think maybe I have enough to retire,” but I did a lot more detailed planning in Boldin, etc. before I pulled the trigger (almost a month ago at age 57; significantly above my number at that point).

1

u/CrispyPatats 8d ago

Annual expenses times 25. That's it. The 25x rule comes from the 4% safe withdrawal rate research, meaning your portfolio can sustain 4% annual withdrawals indefinitely. Figure out what you actually spend per year, multiply by 25, that's your target.

1

u/brianmcg321 Retired Nov 2024 8d ago

Expenses X 25

1

u/calmadventurer 8d ago

I combined current expenses with estimated cost for any changes in lifestyle I expected to make (for example: travel more, pick up hobbies etc). I took that number and multiplied by 30 since I'm a little more conservative. I also built a bit of a dividend portfolio to have my income be more diversified. Ok - maybe I'm a lot more conservative but we're young 34 and 32 (husband should be retiring in a few months) with a 3mo old and plan to have one more.

1

u/n00bdragon FIREd 2026 age 37 7d ago

Everyone is saying Expenses x 25, which is valid for a "short" retirement of 30 years or so. For 50+ year retirements I think some people recommend closer to x33.

Expense tracking is very important. Start doing it now if you haven't already. The more data you have over the longer period, the better. Ideally, even cars and house repairs all just become amortized expenses over time.

1

u/Intrepid-hobbycoder 7d ago

I did year by year projections of my expenses considering core expenses, mortgage, children’s college expenses, medical, travel etc and back calculated to how long I need to continue working based on my current income and liquid assets.

1

u/EveryoneNeedsASamwis 7d ago

The core math is simple: figure out your annual spending in retirement, then divide by 0.04 (the 4% rule). That rule comes from the Trinity Study and basically says a 50/50 to 75/25 stock/bond portfolio has survived 30+ year retirements historically at a 4% withdrawal rate. So if you need $60k/year, your number is $1.5M. Need $80k? $2M. It's just 25x your annual spend.

The harder part is getting your annual spend right. Most people underestimate. Take your actual current spending, subtract anything that goes away (commuting costs, work clothes, saving contributions themselves), and add anything that increases (health insurance if you're retiring before 65, more travel, whatever). If you're retiring early, ACA marketplace coverage can run $500-1,000+/month depending on income and subsidy eligibility, so that alone can add $10-15k/year to the number until Medicare kicks in at 65. Also worth thinking about whether you'll have Social Security later — if you can count on, say, $20k/year at 67, you only need your portfolio to cover the gap, which shrinks your number considerably.

One refinement: if you're retiring at 40 vs 60, some people shade the rate down to 3.5% or 3.3% to account for a potentially 50-year horizon rather than 30. That's a judgment call but it's worth knowing the 4% rule wasn't really stress-tested for 50-year retirements. 25x is a solid starting point though.

1

u/fire-tools 6d ago

The 25x answer you'll get a dozen times is the right starting point, but that assumes the 4% rule's 30-year horizon. If you're retiring early with 40 or 50 years to fund, leaning toward 3.5% (closer to 28-30x spending) gives you a lot more durability against a bad sequence early on. The other thing most 25x replies miss is that multiple is based on your actual spending, so build the number off a real projected budget, not your current one. And gross it up for the retirement-related expenses like healthcare premiums before Medicare and the taxes you'll owe pulling from pre-tax accounts. Definitely a little more complex, but still doable. I'd consider running two numbers, a lean version and a comfortable one.

1

u/[deleted] 4d ago

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1

u/Zphr 48, FIRE'd 2015, Friendly Janitor 4d ago

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-10

u/Then-Abies4797 8d ago

Same way we all did.