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Coast FIRE calculator

Coast FIRE is the point where what you've already invested could grow into enough for retirement on its own. Past it, saving more is optional. Answer a few questions to see whether you're there, or the age you'd get there.

Coast FIRE estimate

Example numbers. Change them to yours.

Your 401(k), IRA, and other investments, added up.

In today's dollars. What you spend in a year now is a fair start.

Assumptions

Nobody knows these for sure. They start at common values. Change them and watch the answer move.

How much your investments grow a year, after inflation. In past US data, a mix of 60% stocks and 40% bonds grew about 5% a year. Lower is more cautious.

The share of your savings you would spend each year in retirement. 4% is the common rule of thumb. At 4%, your target is 25 times your yearly spending.

You reach coast FIRE at

Age 51

Adding $1,500 a month, you reach your coast number at 51. If you stopped adding then, at 5% growth a year, what you have could reach $1,500,000 by 65.

Your coast number today
$347,066
What you would need saved right now to stop adding
Your target at 65
$1,500,000
Enough to spend $60,000 a year at a 4% withdrawal rate
If you stopped adding today
$648,291
What $150,000 could grow to by 65

Your savings from 35 to 65

How it works: your target is yearly spending ÷ withdrawal rate. Your coast number is that target ÷ (1 + growth rate)^years until you retire. Figures are in today's dollars because growth is after inflation. Social Security and pensions are not counted. This is an estimate, not advice.

See it with your actual numbers.

These are numbers you typed. With Candor, the AI you already use, like Claude or ChatGPT, builds this page from your real retirement accounts and keeps it up to date as they grow.

What you ask your agent, and the page it builds in Candor

You

Could I stop saving for retirement and still be okay?

Your agent

Not yet. Your 401(k) and Roth IRA hold $296,840, and your coast number today is $452,699. At the $1,850 a month you have been adding, you reach it at 47. I saved a page in Candor where you can move the growth rate, since that is the assumption this depends on most.

Written by ChatGPT

Coast FIRE

Live · Figures as of Sep 21, 6:12 AM

Whether what you have invested could grow into enough.

You reach coast FIRE at

Age 47

401(k) and Roth IRA today
$296,840
Coast number today
$452,699
Target at 62
$1,460,000

Candor with sample data.

What your agent needs
Investment and retirement balances, your age, when you want to retire, and what you expect to spend.
What you get back
A live page showing whether your investments coast to your target, and the gap if not.
When to use it
A focused review when this question comes up.

The prompt: Could I stop saving for retirement and still be okay?

Copy the prompt into the AI agent you use with Candor. It works from your Candor records and asks for anything it's missing. New to Candor? Connect your agent first.

Your prompt

Help me check whether I could stop adding to retirement savings and still be okay, the idea people call coast FIRE. Use my investment and retirement balances in Candor, and ask my age, when I want to retire, and what I expect to spend each year then. Build a live page in Candor that shows what my current investments could grow to by then, the target that spending implies, and the gap or surplus. Let me change the growth rate, retirement age, and spending on the page, and label them as assumptions. If something the page depends on is missing, say so on the page instead of counting it as zero. Tell me in our conversation which assumption the answer depends on most.

Nothing runs until you send the prompt to your agent.

New to Candor? Set up and start in one message

Paste this into Claude, ChatGPT, or the agent you use. It sets up Candor and walks you through approving its access and connecting your accounts, then runs the prompt from your records.

Set up Candor from https://candor.money/START.md and walk me through connecting it here. Help me check whether I could stop adding to retirement savings and still be okay, the idea people call coast FIRE. Use my investment and retirement balances in Candor, and ask my age, when I want to retire, and what I expect to spend each year then. Build a live page in Candor that shows what my current investments could grow to by then, the target that spending implies, and the gap or surplus. Let me change the growth rate, retirement age, and spending on the page, and label them as assumptions. If something the page depends on is missing, say so on the page instead of counting it as zero. Tell me in our conversation which assumption the answer depends on most.

Not on Candor yet? Versions for ChatGPT and Claude.

Both versions work from the numbers you type, and the answer stays in that chat. With Candor, your agent reads your investment and retirement balances from your records and builds the page in Candor, with growth, retirement age, and spending as assumptions you can change. The page reads your balances each time you open it, so next year's answer starts from what you hold then.

For ChatGPT

Help me check whether I've reached coast FIRE: enough invested that it could grow into what I need by retirement with nothing more added. My retirement and investment balances total $[amount], I'm [age], I want to retire at [age], and I expect to spend $[amount] a year then in today's dollars. Use a growth rate after inflation and a withdrawal rate I can change, starting at 5% and 4%. Show the target, what my balance grows to with nothing added, the gap or surplus, and my coast number today. Then show the same at 4% growth, and tell me which assumption the answer depends on most. Don't count Social Security unless I give you an estimate.

Use ChatGPT with Candor

For Claude

I want to know whether I could stop adding to retirement savings and still be okay, the idea called coast FIRE. Here are my numbers: age [age], retirement age [age], invested for retirement $[amount], spending a year in retirement $[amount] in today's dollars, adding $[amount] a month. Work in today's dollars with a growth rate after inflation. Give me the target, my coast number today, whether I've reached it, and if not, the age I would reach it if I keep adding. Show how the answer changes at a growth rate one point lower and at a retirement age two years earlier. Ask before assuming anything I didn't give you.

Use Claude with Candor

What will the agent ask you?

A good agent asks before it answers. Expect questions like these, and answer the ones that matter to you.

  • When do you want to stop needing a paycheck?
  • What would a year in retirement cost, in today's dollars?
  • Which accounts count toward retirement: a 401(k), an IRA, a brokerage account, an HSA?
  • Will Social Security, a pension, or rental income cover part of that spending, and from what age?
  • What growth rate after inflation are you willing to assume, and how would a lower one change your plans?
  • Will your housing cost change by then, such as a mortgage paid off?

What does a good answer look like?

A worked example on sample data: one person, 38, with $260,000 across a 401(k) and an IRA, adding $1,800 a month, who wants to retire at 62 on $55,000 a year in today's dollars.

You

Could I stop putting money into retirement soon and still be fine?

Your agent

Your 401(k) and IRA hold $260,000. Spending $55,000 a year at a 4% withdrawal rate means a target of $1,375,000 at 62. At 5% a year after inflation, $260,000 grows to about $838,500 by then with nothing added, so you're not coasting yet. Your coast number today is about $426,300.

Your agent

If you keep adding $1,800 a month, you reach it by age 48. From then, the balance could grow to the target by 62 with nothing more added, if growth holds at 5%.

Your agent

Growth is the assumption that moves this most. At 4% instead of 5%, your coast number today is about $536,400, and you reach it by age 56 instead of 48. I built the page in Candor with growth, retirement age, and spending as assumptions you can change. Social Security isn't counted. If you share the estimate from your Social Security statement, I can show how much of the spending it might cover and from what age.

Illustrative example with sample data, not a customer result.

What does a weak answer look like?

Coast FIRE means you've saved enough that compound growth will carry you to retirement. A common rule is to have 25 times your expenses invested. Plug your numbers into a calculator with a 7% return to find out if you're there.
  • It never used your balances, age, or spending, so there's no answer.
  • A 7% return before inflation, set against spending in today's dollars, makes the target look closer than it is.
  • It doesn't say which assumption the answer depends on, or what a lower growth rate would change.
  • Nothing is saved, so next year you start over.

Coasting depends on growth you cannot know

The idea is simple: if what you have invested could grow into enough by retirement, new saving becomes optional. Candor supplies your investment and retirement balances. The growth rate, the age you retire, and what you will spend are assumptions, and the answer moves with each of them.

Check the answer

  • Try a lower growth rate than you expect. If the answer only works at the optimistic rate, it is not settled.
  • Check that spending in retirement reflects your life then, including housing costs that may change.

Choose a next step

Use the gap or surplus to decide how much to keep saving. Your agent can look at the full retirement picture with you next.

Where Candor fits

Your agent works through the question with you, builds the plan, and keeps you on it. Candor gives it your real accounts, exact figures, and the goals, budget, notes, and decisions from earlier sessions, in whichever agent you use. Its review raises what's worth talking through and tells your agent why. Candor is not a licensed advisor and gives no advice; your agent does the advising, and the decisions are yours.

  • Candor connects to banks read-only and cannot move money.
  • Candor never sells your financial data or trains models on it, and you can export or delete it.
  • Every agent read and change is recorded with its reason.

Common questions

What is coast FIRE?
FIRE stands for financial independence, retire early. Coast FIRE is the point where what you have invested could grow, with no more contributions, into enough to retire at the age you choose. Your work still pays for today's spending, but saving more for retirement becomes optional.
How is the coast FIRE number calculated?
Start with the target: yearly spending in retirement divided by your withdrawal rate, so $60,000 at 4% is $1,500,000. Then divide the target by (1 + growth rate) raised to the years until retirement. At 5% for 30 years that factor is about 4.32, so the coast number is about $347,000. With a growth rate after inflation, the answer is in today's dollars.
What growth rate should I use for coast FIRE?
Use a rate after inflation, since the spending you type is in today's dollars. In the historical data William Bengen used for his 1994 study, a mix of 60% stocks and 40% intermediate-term Treasuries returned about 8.2% a year compounded, close to 5.1% after inflation. The Federal Reserve aims for 2% inflation over the longer run. Past returns are no promise, so try a lower rate and see whether the answer still holds.
What is the 4% rule, and what are its limits?
It comes from Bengen's 1994 study of US returns since 1926. With half stocks and half bonds, withdrawing 4% of the starting balance in the first year and raising the amount with inflation after that lasted at least about 35 years from every starting year he tested. He framed it for people retiring around 60 to 65. A 1998 study in the AAII Journal tested payout periods of 15 to 30 years, and an early retirement can run longer. Morningstar's 2021 research, using forward-looking return estimates, put the safe starting rate for a 50/50 portfolio at about 3.3%. A lower rate raises the target: $60,000 a year at 3.5% needs about $1,714,000.
What's the difference between coast FIRE and FIRE?
FIRE means having the whole target invested now, enough to stop working. Coast FIRE means having the coast number invested now, enough for growth to reach the target by your retirement age while your work pays for today. In the calculator's default example, FIRE at 35 takes $1,500,000 invested; coast FIRE takes about $347,000.
Does the calculator count Social Security?
No. It counts only the balance and monthly amount you type. Social Security, a pension, or rental income would pay part of your spending and lower the target. You can claim Social Security as early as 62, and the monthly benefit grows the longer you wait, up to 70. Social Security's own calculators estimate your benefit for each claiming age from 62 to 70.
Does Candor work this out from my accounts?
Your agent does, from your records in Candor. It reads your investment and retirement balances, asks what the records can't show, like when you want to retire, and builds this page in Candor with the assumptions labeled. Candor gives no advice; your agent works through it with you. Candor connects to banks read-only and cannot move money.

Sources

  1. Determining Withdrawal Rates Using Historical Data, William P. Bengen Journal of Financial Planning (Financial Planning Association)
  2. Retirement Savings: Choosing a Withdrawal Rate That Is Sustainable AAII Journal
  3. The State of Retirement Income: Safe Withdrawal Rates Morningstar, November 11, 2021
  4. Why does the Federal Reserve aim for inflation of 2 percent over the longer run? Board of Governors of the Federal Reserve System, August 22, 2025
  5. Planning your Social Security claiming age Consumer Financial Protection Bureau, January 29, 2026
  6. Use Social Security retirement calculators to estimate your benefits USAGov, January 16, 2026

Ask it with your own numbers.

Set up Candor, then send this to the agent you already use. It answers from your real records and keeps the plan for next time.