Coast FIRE Calculator
Find out if your current savings will grow to cover retirement without any additional contributions.
Coast FIRE number
$93,663
Save this much today and stop contributing — it grows to your FIRE target by age 65.
FIRE target at retirement
$1,000,000
Portfolio needed to cover $40,000/yr at 4% withdrawal.
Status
$13,663 to go
Keep saving until you hit your Coast FIRE number.
Projected at retirement
Your savings will grow to: $854,127
Falls short of FIRE target by $145,873
Start: Today
Latest: Year 35
Final value: $920,492
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Understanding the calculator
How it works
Coast FIRE is a milestone on the path to financial independence that asks a different question: how much do I need to save right now so that I can stop contributing and still retire comfortably at a normal age? Once you reach your Coast FIRE number, compound growth alone carries your existing savings to your full retirement target. You still need to earn enough to cover current expenses, but the pressure to maximize savings disappears.
The calculation works backward from your FIRE target. It takes the portfolio you will need at retirement and discounts it to today using your expected annual return and the years remaining. The result is your Coast FIRE number — a present-value figure. If your current savings exceed it, you have already reached Coast FIRE.
The math behind it
Key formulas
Coast FIRE Number = FIRE Target / (1 + r)^n
If your FIRE target is $1,000,000, expected return is 7%, and you have 25 years: $1,000,000 / 1.07^25 = $184,249.
Real-world scenarios
Practical examples
Age 30, needs $1.2M by 65, expects 7% returns
Coast FIRE number: $1,200,000 / 1.07^35 = $111,982. If current savings exceed $112,000, compound growth alone will do the rest.
Age 40, same target and return
Coast FIRE number: $1,200,000 / 1.07^25 = $220,949. Starting 10 years later nearly doubles the amount you need today.
What Coast FIRE enables
A 35-year-old who has reached Coast FIRE with $180,000 saved can take a lower-paying dream job, work part-time, or start a business without jeopardizing retirement security.
Getting the most value
When to use this calculator
Use a Coast FIRE calculator when you want to know whether you have already saved enough for retirement to "handle itself." This is especially relevant if you are considering a career change, going back to school, or reducing work hours.
If the idea of full FIRE feels overwhelming, Coast FIRE provides a more achievable intermediate target. Knowing that your retirement is secured — even if you still need to cover current expenses — removes a significant source of financial anxiety.
Young professionals who have been saving aggressively may already be closer to Coast FIRE than they realize. Running the calculator can reveal that compound growth has already done much of the heavy lifting.
Expert guidance
Tips and best practices
- Coast FIRE is the most achievable FIRE milestone for most people. It does not require early retirement — just front-loading enough savings to let compounding finish the job.
- The younger you are, the lower your Coast FIRE number, because time gives compound growth more room to work.
- Use conservative return assumptions (6-7% nominal) rather than optimistic ones. Overestimating returns can lead to a false sense of security.
- Coast FIRE does not account for inflation. Make sure your FIRE target is expressed in future dollars or use a real (inflation-adjusted) return rate.
Summary
Key takeaways
- Coast FIRE means your current savings, left alone, will grow to cover retirement through compound growth alone.
- It is the most achievable FIRE milestone because it does not require early retirement — just enough savings to let time work.
- The younger you reach Coast FIRE, the lower the number, because compound growth has more years to multiply.
- Once at Coast FIRE, you only need to earn enough to cover current expenses — opening the door to career flexibility.
- Conservative return assumptions are important; overestimating growth can create a false sense of security.
Common questions
Frequently asked questions
What is Coast FIRE?
Coast FIRE means you have saved enough that compound growth alone will carry your portfolio to your retirement target. You no longer need to save — just cover your current living expenses.
How is Coast FIRE different from regular FIRE?
Regular FIRE means you can stop working entirely. Coast FIRE means you can stop saving for retirement but still need income for current expenses. It is a milestone on the way to full FIRE.
What assumptions matter most?
The expected rate of return and years until retirement have the biggest impact. Higher returns or a longer timeline lower your Coast FIRE number significantly.
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