FIRE Calculator: How Long Until Financial Independence?
Personal financeFreeNo sign-up
Your FIRE number is your yearly spending divided by your safe withdrawal rate. At $50,000 a year and a 4% rate you need $50,000 ÷ 0.04 = $1,250,000. The calculator then finds how long your savings take to reach it.
To live on $50,000 a year at a 4.0% withdrawal rate you need $1,250,000. Saving $40,000 a year (44% of your income) at a 7.0% return and 2.5% inflation gets you there in about 16 years 5 months, at age 51 and 5 months. All amounts are in today’s dollars.
What if you save more or less?
| Scenario | Saved per year | Time to FIRE | Age at FIRE |
|---|---|---|---|
| Save 50% less | $20,000 | 23 years 11 months | 59 |
| Save 25% less | $30,000 | 19 years 5 months | 55 |
| Your plan | $40,000 | 16 years 5 months | 52 |
| Save 25% more | $50,000 | 14 years 3 months | 50 |
| Save 50% more | $60,000 | 12 years 7 months | 48 |
| Save twice as much | $80,000 | 10 years 2 months | 46 |
Show the steps
- FIRE number = yearly spending ÷ withdrawal rate = $50,000 ÷ 4.00% = $1,250,000.00.
- Real return = (1 + 7.00%) ÷ (1 + 2.50%) − 1 = 4.390%. This keeps everything in today’s dollars.
- Monthly growth rate i = 0.3587%. Monthly saving = $40,000 ÷ 12 = $3,333.33.
- Solve for the number of months n: n = ln((FIRE × i + c) ÷ (savings × i + c)) ÷ ln(1 + i) = 196.3 months.
Months to reach the FIRE number
n = ln((F × i + c) ÷ (P × i + c)) ÷ ln(1 + i)
F = FIRE number, P = savings now, c = monthly saving, i = monthly real return
- Everything is in today’s dollars: savings contributions and spending rise with inflation.
- The 4% rule comes from historical U.S. data over 30-year periods. A longer retirement, such as 40 or 50 years, often calls for 3% to 3.5%.
- Does not include Social Security, taxes, health insurance before Medicare, or part-time income.
Estimates for planning and learning, not financial, tax, legal or medical advice. Check figures with your lender, tax preparer or doctor before you act.
About this calculator
FIRE stands for financial independence, retire early. The idea is to save and invest until your portfolio can pay for your living expenses without a paycheck. Once you reach that point, working becomes optional, even if you keep working at something you enjoy.
The math starts with your spending, not your income. If you spend $50,000 a year and plan to withdraw 4% of your portfolio each year, you need 25 times your spending, which is $1,250,000. The calculator works out that number, then uses your current savings, how much you save each year and the return you expect to find how many years it will take.
All the numbers are in today’s dollars. The calculator adjusts your return for inflation so you do not have to think about future prices. It also shows Lean FIRE, Fat FIRE and Coast FIRE targets, and a table that shows how much sooner you could retire if you saved more.
How to use it
- Enter your age, your take-home income and what you expect to spend each year in retirement.
- Enter your invested savings today and how much you will save each year.
- Set your expected return, inflation and safe withdrawal rate. The common starting point is 4%.
- Read your FIRE number, your savings rate and how many years you need.
- Use the what-if table to see how saving more or less changes your date. Open the Coast FIRE option to set your normal retirement age.
The flavors of FIRE
- Lean FIRE: a frugal retirement. This calculator shows 70% of your spending as the lean target.
- Fat FIRE: a more comfortable retirement. This calculator shows 150% of your spending.
- Coast FIRE: you have saved enough that growth alone will reach your FIRE number by a normal retirement age. After that you only need to earn enough to cover current expenses.
Worked example
You are 35 with $150,000 invested, you spend $50,000 a year and you save $40,000 a year. At a 7% return and 2.5% inflation, your real return is about 4.39%. Your FIRE number is $1,250,000 at a 4% withdrawal rate. Saving $40,000 a year with that real return takes about 16 years and 5 months, so you reach independence around age 51.
How safe is the 4% rule?
The 4% rule comes from studies of U.S. markets over 30-year retirements. An early retiree might need the money to last 40 to 60 years, so many people in the FIRE community use 3% to 3.5%. A lower rate means a bigger FIRE number and more years of saving, but a plan that is more likely to last.
What this calculator leaves out
- Taxes on withdrawals from retirement accounts and on investment gains.
- Health insurance before Medicare starts at 65, which can be a large cost.
- Early withdrawal rules. Most retirement accounts charge a 10% penalty before 59½, with exceptions, so early retirees often need taxable accounts to bridge the gap.
- Social Security and pensions, which lower the amount you need from savings.
Sources
Quick check: test yourself
You want to spend $30,000 a year in retirement. What is your FIRE number at a 4% withdrawal rate?
Correct answer: $750,000. $30,000 ÷ 0.04 = $750,000. That is 25 times your yearly spending.
What does Coast FIRE mean?
Correct answer: You have saved enough that growth alone reaches your FIRE number by normal retirement age. Once you reach the Coast number, you only need to earn enough to cover current expenses.
Which change gets you to financial independence sooner?
Correct answer: Raising your savings rate. Saving more raises your savings and spending less lowers your target at the same time.
Pick an answer for each question.
Common questions
What is a FIRE number?
It is the portfolio you need to live off your investments. Divide your yearly spending by your withdrawal rate. At 4%, multiply spending by 25.
How much do I need to retire early?
It depends on your spending. At $40,000 a year you need about $1,000,000. At $80,000 a year you need about $2,000,000, using a 4% withdrawal rate.
What savings rate do I need?
The higher your savings rate, the fewer years you need. Saving about 50% of your income reaches financial independence in roughly 17 years from zero at a 4.4% real return. A higher return shortens that and a lower one lengthens it.
What is Coast FIRE?
Coast FIRE means you have enough invested today that, with no more savings, growth alone will reach your full FIRE number by your normal retirement age.
Why does the calculator use today’s dollars?
Using a real return, the return after inflation, keeps your target and your savings in the same dollars, so you do not need to estimate future prices.
Does it include Social Security?
No. If you expect Social Security or a pension, subtract it from your spending to see how much your portfolio needs to provide.
More personal finance calculators
Related to This Article
More math articles
- How to Analyze and Understand Rational Functions: A Comprehensive Guide
- The Ultimate HSPT Math Formula Cheat Sheet
- The Best Grade 7 ELA Practice Tests for Missouri Students
- How to Find the Volume of Cones and Pyramids? (+FREE Worksheet!)
- Full-Length 6th Grade PSSA Math Practice Test
- ATI TEAS 7 Math Worksheets: FREE & Printable
- MPG Calculator
- Walking Calories Calculator
- The Best Grade 5 ELA Practice Tests for Vermont Students
- The Calvin Cycle Explained: Phases, ATP and G3P
What people say about "FIRE Calculator: How Long Until Financial Independence? - Effortless Math"?
No one replied yet.