Coast FIRE: saving early and stopping

In short

A friend of mine once told me he felt behind at thirty, because every retirement chart on the internet seemed to ask for more than he had. If you are holding some savings in your twenties or thirties and wondering whether it still counts, this guide is for you. Coast FIRE is the idea that a person saves hard early, then stops adding to retirement accounts. The saved money grows on its own while paychecks only cover today's bills. The idea works only if the growth rate assumed holds up, and no one can promise that. It also leaves out taxes, inflation, and health costs unless the planner adds them. So the sound way to use it is to run your own numbers, test them against a weaker market, and check the official limits for your accounts, which the site fills in below. Start small. Start soon.

The whole of it

What it is

I once watched a neighbor plant a pecan tree and then go back to his ordinary chores for years. He did not water it every hour. He just gave it a good start and trusted the soil. Coast FIRE works a bit like that. FIRE stands for financial independence, retire early. The coast part means a person builds a pile of savings early enough that it can grow to a full retirement sum by a normal retirement age, even with no new deposits.

After that point, the saver no longer adds to retirement accounts. Paychecks only have to cover living now. That might open the door to a lower paying job, part time work, or something a person loves. Notice what it does not mean. It does not mean quitting work at thirty. The money stays locked in the account until the owner is older, so income is still needed for the years in between.

How it works

If you have ever set money aside and forgotten about it, you have seen the engine here. Compound growth means your earnings start earning too. The math runs backward from the goal. First a person picks a target sum for retirement. Then comes a growth rate and a number of years. Then the question is how much is needed today so the pile reaches the target on its own.

The rule is simple. The amount needed today equals the target divided by one plus the growth rate, raised to the power of the number of years. That is a mouthful, so here is the plain version. A dollar growing at 5 percent a year for 30 years becomes about $4.32. So a target of $1,000,000 in 30 years at 5 percent means $1,000,000 divided by 4.32 today. That is about $231,500.

A careful reader will ask where the target comes from. A common shortcut takes the yearly spending wanted in retirement and multiplies it by 25. That comes from a 4 percent withdrawal idea, and it is a rough guide, not a law. Someone who wants $40,000 a year would aim for $1,000,000 by that shortcut. I would not bet my porch swing on it being exact, so treat it as a starting point.

The numbers, and where to find yours

Plenty of folks like to know what the government actually says, and that is a fair way to be. Retirement accounts have yearly limits set by law. For a 401(k), the most an employee can put in this year is the current figure, which the official source publishes each year. For an IRA, the yearly limit is $7,500 for 2026 (source, checked 10/4/2026). Older savers get a bit more room, and the amount of that catch up is the current figure, which the official source publishes each year. The age when money can come out without a penalty is the current figure, which the official source publishes each year. Withdrawals before that age can bring a tax and a penalty, and the penalty percent is 10 for 2025 (source, checked 9/27/2026). The IRS publishes these figures each year, and the site fills in the checked numbers with the source and date.

Your own numbers are the ones that matter most, though. Gather your current balance, your yearly spending now, the retirement age you have in mind, and a growth rate you are willing to test. Your plan's statement shows the balance. Your bank records show the spending. The rest is a choice, so make it on the cautious side.

A worked example

Let me tell you about a woman named Maria. She is 30, and she has saved $60,000 across a 401(k) and an IRA. She plans to stop adding to them. She wants to reach age 60, which is 30 years away. She hopes to spend $40,000 a year in retirement, so her target by the 25 times shortcut is $40,000 times 25, which is $1,000,000.

Now she tests the growth. At 5 percent a year, $1 becomes about $4.32 over 30 years. So her $60,000 grows to about $60,000 times 4.32, which is $259,200. That is far short of $1,000,000. Her coast number at 5 percent is $1,000,000 divided by 4.32, which is about $231,500. She has $60,000, so she is not there yet.

She asks a fair question. How big is the gap? It is $231,500 minus $60,000, which is $171,500 in today's terms. Suppose she saves $15,000 a year. With growth, those deposits add up faster than the plain sum. The exact timing depends on the real returns, so she would check her balance against her coast number each year. Once the balance meets it, she could stop adding.

Now she runs it at a weaker 3 percent. A dollar over 30 years becomes about $2.43. Her coast number jumps to $1,000,000 divided by 2.43, which is about $411,500. The same plan now asks for much more. That swing is the honest lesson. A small change in the growth rate moves the finish line a long way.

Where it goes wrong

Nobody likes hearing this part, but I would rather say it now than let you find out later. The biggest trap is the growth rate. Markets do not give a smooth 5 percent each year. Some years are bad, and a bad stretch early can hurt a plan that has no new savings coming in.

Inflation is the quiet thief. A million dollars thirty years from now buys less than a million today. A plan built on today's prices works best with a growth rate after inflation, because otherwise the target comes out too small. Taxes matter too. Money in a traditional 401(k) is taxed when it comes out, so the spendable amount is smaller than the balance.

Then there is the gap. A person who coasts from age 35 to 60 still has bills in those years. Rent, food, and insurance do not stop. Health insurance before Medicare can cost a great deal, and that is a number worth pricing for your own state. A lower paying job may also come with no employer match and no benefits. A match is extra pay from an employer, so giving it up is a real cost.

Early withdrawals are a last trap. Taking money out before the age set by law can bring a tax and a penalty. Coast FIRE does not solve the years before that age. It only covers the later ones.

Questions to answer before you leave this page

What yearly spending do you honestly want in retirement, and have you checked it against what you spend now? Which growth rate are you using, and would your plan still stand if it came in two points lower? Have you counted inflation and taxes, or only the bare balance? How would bills and health insurance get paid between the day saving stops and the day the accounts can be tapped? Are you giving up an employer match by stopping, and what is that worth each year? Do you know the current limits for your 401(k) and IRA, and where the IRS lists them? And when you picture the life you want, does a lower paying job make you glad, or does it only make you nervous?