The Coast FIRE Calculator is a free, web-based financial tool that determines whether your current investments can grow to your retirement goal without additional contributions, using compound growth. It takes inputs like current age, retirement age, current assets, annual spending, and assumed rates, and outputs the Coast FIRE number, projected assets at retirement, and any shortfall. The tool is hosted at coastfirecalc.org and is developed by an independent creator (no specific name on page, but site is about Coast FIRE).
What is the Coast FIRE Calculator?
The Coast FIRE Calculator is a specialized financial tool designed to help individuals plan their path to financial independence by calculating the amount needed to coast to retirement. It takes user inputs such as current age, retirement age, current invested assets, annual spending in retirement, and assumptions for growth rate, inflation, fees, and safe withdrawal rate. The calculator then outputs the Coast FIRE number (the amount needed today), projected assets at retirement, and a detailed breakdown of any shortfall, including months needed and required monthly contribution. The tool is 100% free and requires no signup.
Key Features
- Instant calculation without signup — Enter your data and get results immediately; no account creation required.
- Comprehensive financial inputs — Adjust current age, retirement age, monthly contribution, current assets, annual spending, investment growth rate, fee rate, inflation rate, and safe withdrawal rate.
- Real-time output display — See Coast FIRE number, projected assets at retirement, shortfall amount, months needed to reach target, and required monthly contribution.
- Interactive investment growth projection chart — Visualize your portfolio's growth over time and the point where it meets your target.
- Multi-language support — Available in English, Chinese, Spanish, French, Japanese, Korean, German, and Russian.
- Share results — Easily share your Coast FIRE calculation with others via a shareable link.
- Related calculator links — Access other FIRE calculators like FIRE Calculator, Coast FIRE Number, With Social Security, With Inflation, Barista FIRE, UK Calculator (£), and For Couples.
Who is it for?
- Individuals planning early retirement — Use the calculator to see if you can stop saving for retirement and let your investments grow on their own.
- Personal finance enthusiasts — Experiment with different assumptions to understand how changes in growth rate, spending, or timeline affect your Coast FIRE number.
- Followers of the FIRE movement — A free, quick check to see if you've hit the Coast FIRE milestone on your path to financial independence.
What can you do with the Coast FIRE Calculator?
- Determine Coast FIRE status — Enter your current financial situation to see if your savings are enough to coast to your retirement goal.
- Scenario planning — Adjust one input at a time (e.g., retirement age, spending) to see how it impacts your required Coast FIRE number.
- Compare strategies — Test different safe withdrawal rates or growth assumptions to build a more robust retirement plan.
How does it work?
The calculator computes your full FIRE number by dividing annual retirement spending by your safe withdrawal rate. Then it discounts that figure back to today using your expected real return (growth rate minus fees and inflation) and the number of years until retirement: Coast FIRE Number = FIRE Number ÷ (1 + Real Return)^Years. The result updates automatically as you adjust inputs, and a chart shows the projected growth of your portfolio versus the target.
FAQ
What is Coast FIRE?
Coast FIRE is the moment your invested savings are large enough that, even without additional contributions, compound growth will carry the balance to your full retirement target by your planned retirement age.
How is the Coast FIRE number calculated?
First, your full FIRE number is annual spending divided by your safe withdrawal rate. Then that amount is discounted to today using your expected real return over the years until retirement.
What rate of return should I use?
Historically, the S&P 500 has returned ~7% after inflation, but a conservative real return of 5% is recommended for planning. Lower assumptions increase your Coast FIRE number.
Is my data private?
Yes, the calculator runs entirely in your browser. No data is collected or stored, and no signup is required.
