Coast FIRE Calculator

Coast FIRE means you have invested enough that, without adding another dollar, your investments are on track to reach your full FIRE number by your target age. From that point you only need to earn enough to cover today's bills. You can keep your job, take a lower-paying one you like more, work fewer hours or take a long break, while compound growth does the rest.

The idea sits between saving hard and full financial independence. You are not free to stop working yet, but the pressure to save is gone, because your future FIRE number is already taken care of if returns are close to what you assumed.

That last part matters. Coast FIRE is a projection, not a finish line. A few weak years early on can push your Coast FIRE age back, so many people keep investing a little after they coast, and check their number once a year.

Start with your FIRE number: your yearly spending at your target age divided by your withdrawal rate. At 4%, $40,000 a year needs $1,000,000. Then work out how much money today would grow into that amount by your target age, with no more saving. The formula is your FIRE number divided by (1 + real return) to the power of the years until your target age.

The real return is your expected return after inflation: (1 + 7%) divided by (1 + 3%), minus 1, is about 3.9% a year. Using it keeps every number in today's dollars, so your Coast FIRE number compares directly with what you have invested now. A 30-year-old with a target age of 65 has 35 years of growth, and $1,000,000 divided by about 3.79 is $263,555.

How much you need to coast also depends on your assumptions. With a 3.5% withdrawal rate, the same plan needs about $301,205 today. With an 8% return it needs about $190,314, and with a 5% return about $510,126. Try a few returns to see the range.

See growth without a target in the compound interest calculator with inflation.

Say you are 30, want your FIRE number ready by 65, plan to spend $40,000 a year, have $100,000 invested and save $1,500 a month, raised 3% a year for inflation, while your investments earn 7% a year.

Your FIRE number is $1,000,000 in today's dollars and your Coast FIRE number today is $263,555, so you need $163,555 more. Saving $1,500 a month, you reach Coast FIRE in about 11 years and 5 months, at age 41. After that, with no more saving, growth alone carries your balance to about $1,000,910 in today's dollars by 65.

If you stopped saving today, your $100,000 would grow to about $379,428 in today's dollars by 65. To coast by 40 instead, save about $1,668 a month, and to coast by 35, about $3,047 a month.

How much you need invested at each age so that growth alone reaches your FIRE number by 65, with a 7% return and 3% inflation, in today's dollars.

The younger you are, the less you need, because growth has more years to work. A $1,000,000 FIRE number needs about $263,555 at 30 but about $683,179 at 55. Use the calculator above for your own age, target and spending.

They mean the same thing. Coast FIRE, CoastFIRE, Coast FI and CoastFI all describe the point where your investments can coast to financial independence without new money. FI stands for financial independence, and FIRE adds the option to stop working early.

Some people say Coast FI because they plan to keep working by choice, and others say Coast FIRE because they hope to stop sooner. The math is identical, so this Coast FI calculator, also called a CoastFIRE calculator, works the same way whichever name you use.

FIRE means your investments already cover all of your spending, so work is optional now. Coast FIRE means your investments will cover your spending later, by your target age, as long as you earn enough to pay today's bills and leave your investments alone. Barista FIRE sits in between: your investments already cover part of your spending, and part-time work covers the rest.

With the same $40,000 budget, a 4% withdrawal rate and a 7% return with 3% inflation, a 30-year-old needs about $263,555 invested to coast to a $1,000,000 FIRE number at 65, $500,000 for Barista FIRE with $20,000 a year of part-time income, and $1,000,000 for full FIRE.

Coast FIRE needs the least invested of the three, but you keep working longer. Full FIRE takes the most money and gives the most freedom. To see your FIRE number, years to FI and Barista FIRE number, use the FIRE calculator.

Want full FI sooner? Try the FIRE calculator.

For part-time income, open the Barista FIRE calculator mode.

You can count Social Security or a pension you expect by your target age. Enter it as other income, in today's dollars. It lowers the spending your investments must cover, so it lowers your FIRE number and your Coast FIRE number.

If you expect $15,000 a year, a $40,000 budget leaves $25,000 for your investments, your FIRE number falls to $625,000, and your Coast FIRE number today falls to about $164,722. In the example you would reach it at 34 instead of 41.

Use an estimate you trust and keep it in today's dollars, or leave the field at $0 to plan without it. Your Social Security statement shows estimated benefits at different ages, and counting only part of it builds in a cushion.

For a couple, enter your combined spending, savings and investments. If your ages differ, run it once for each age to see the range.

The calculator finds your FIRE number from your yearly spending at your target age, minus any other income, divided by your withdrawal rate. It divides that number by your real return compounded over the years to your target age to get your Coast FIRE number for today, and repeats that for each later age to draw the line on the chart.

Your saving is added at the end of each month and rises once a year with inflation, and the yearly return is converted to a monthly rate. You reach Coast FIRE in the first month your balance in today's dollars meets the Coast FIRE number for that age. Everything is in today's dollars, the same method as our compound interest calculator. Results are before taxes and fees, and real returns change from year to year.

The FIRE and Coast FIRE calculators open with the compound interest calculator's example, a 7% return with 3% inflation. The withdrawal calculator's example uses 5% for money you are already spending. All three are inputs, so set them to your own mix.

The growth left after inflation is the real rate of return: (1 + return) / (1 + inflation) - 1. A 7% return with 3% inflation is a real return of about 3.9% a year.

To see how long your FIRE number could last, use the How Long Will My Money Last Calculator.

If your target is within 10 years, try a Monte Carlo simulation for a portfolio. Free with a GNG account, for forecasts from one week to 10 years.

Track your portfolio and its income in the dividend portfolio tracker with a free GNG account.

Read what expected return means.