Calculators / Coast FIRE
Coast FIRE calculator
Coast FIRE is the point where you can stop adding money and still retire on time. Your existing balance does the rest of the work by itself. This works out that number, and when you get there.
401(k), IRA, HSA and taxable brokerage. Not home equity.
In today's dollars. What the year costs, not what you earn.
Everything going in, including the employer match.
Real means inflation is already taken out, so every figure below stays in today's money.
4% is the common starting point. Lower is more cautious.
How Coast FIRE is worked out
Two steps. First the target: the pot you need on the day you retire, which is your annual spending divided by your withdrawal rate. At 4%, $60,000 a year needs $1.5M.
Then discount that target back to today at your real return. If you are 32, retiring at 65, and you assume 5% real, you have 33 years of compounding to do the work: $1.5M ÷ 1.0533, which is about $299,000. Hold that much and you can stop contributing tomorrow and still land on $1.5M in today's money at 65.
The date is the year your current balance plus your contributions crosses that same discounted line. The line falls every year you get closer to retirement, which is why the two curves meet sooner than most people expect.
Why people run this number
Almost nobody who reaches Coast FIRE actually stops saving. What changes is the pressure. Coast FIRE is what lets someone take the job that pays less and is better, drop to four days, or take a year out, without wrecking the plan. It converts a retirement date into leverage you can use now, which is the thing people are usually after when they say they want to retire early.
The assumption that moves the answer most
Your real return. Between 4% and 6% real, the Coast FIRE number for a 33-year runway moves by roughly a third. Nobody knows which is right. Run it at 4% and at 6% and treat the gap as the honest answer, rather than picking the number that makes the date look good.
Annual spending is the second one, and it is the input most people are guessing at. If you have never tracked it, your estimate is probably low. Try the calculation again with 15% more spending and see how far the date slides.
Keep the answer, then change one number
This page forgets everything when you close it. NestEgg saves the plan, runs both partners' incomes and ages against one shared date, and models the bit this calculator skips: which account you draw first, and what health insurance costs before 65.