How to Reach Coast FIRE (and When You Can Expect To)

1. Find your number

Start with the Coast FIRE calculator. The input people get wrong most often is retirement spending, and they almost always guess low. Every $10,000 of yearly spending adds $250,000 to your FIRE number at a 4% withdrawal rate, so it’s worth ten honest minutes with your bank statements.

To keep things concrete, the rest of this post follows one example. You’re 30, you have $50,000 invested, you expect to spend $60,000 a year in retirement and you’d like to be done at 65. Your Coast FIRE number is $395,332.

2. Pick a monthly amount and see your date

Your Coast FIRE number tells you where the line is. Your monthly contribution decides when you cross it.

Look at the jump between $1,500 and $2,000. Below a certain amount your contributions barely keep pace with the target, which keeps rising as you get older. A little above it, every few hundred dollars buys you years.

So when can you reach Coast FIRE? Use the age the calculator shows for an amount you can keep up for years, not the one you could manage for three good months. A plan you stick with at $2,000 beats a plan you abandon at $3,000.

3. Lower the target where it’s painless

Spending is the other half of the equation. Here’s the same person contributing $2,500 a month with different retirement budgets:

In this example, $10,000 a year of retirement spending is worth about four years of contributions. You don’t have to plan a bare-bones retirement to use that. Just decide now which of today’s costs will actually still exist. A paid-off house, grown kids and no commute can take a surprising amount off.

Retirement age matters too, in the other direction. Moving the target from 65 to 60 pushes this person’s Coast FIRE age from 45 to 50, because the money has five fewer years to grow.

4. Put the money in the right accounts

For most people in the US, this order works well:

1. Contribute enough to your 401(k) to get the full employer match. Nothing else gives you an instant return like that.
2. Pay off high-interest debt such as credit cards. No investment reliably beats 20% interest.
3. If you have a high-deductible health plan, fund your HSA. It’s the only account that’s tax-advantaged going in, while it grows and coming out for medical costs.
4. Fund a Roth or traditional IRA.
5. Go back and put more into your 401(k).
6. Use a regular brokerage account for anything beyond that.

Contribution limits change every year, so check the current ones on irs.gov before you set your monthly amounts. Inside those accounts, a low-cost total market or target-date index fund is enough for most people. Fees matter more than fund choice: a 1% fee does far more damage over 30 years than picking a slightly different broad index fund, and the catch section of our Coast FIRE guide shows how much it moves the number.

5. Protect the plan

Coast FIRE plans rarely fail because of bad math. They fail because people stop contributing too early or have to pull money out at a bad time.

Keep an emergency fund in cash, separate from your investments. Three to six months of expenses is the usual range, and closer to six makes sense if you’re planning a move into less stable work. When the market drops, leave the investments alone, because every number in the calculator assumes your money stays invested through the bad years. And once a year, update your balance and spending in the calculator to see whether your date moved.

6. Decide what happens when you cross the line

This is the part people skip, and it’s the whole point of the exercise. Once your balance passes your Coast FIRE number, you can keep contributing the same amount and move your full retirement earlier. You can cut contributions to something small and spend the difference now. Or you can take a job you like more that pays less, or go part-time. If your portfolio ends up covering some of your costs, that’s Barista FIRE.

My own bias is to keep putting in something, even $300 or $500 a month. It’s cheap insurance against a bad decade in the market, and it means a later setback costs you months instead of years.