# Retire at 40 Calculator

> How much you need to retire at 40, why coasting rarely works for a 40 finish, and how to reach your money in the 19½ years before 59½.

Source: https://mycoastfire.com/retire-at-40
Last updated: 2026-09-26

A retirement that starts at 40 can last 55 years, and the tax rules keep most retirement accounts closed for the first 19½ of them. The calculator starts at a 3.25% withdrawal rate for that reason.

To retire at 40 spending $50,000 a year, you need about $1,538,462 invested. That uses a 3.25% withdrawal rate, because money you start drawing at 40 may need to last until you’re 95; the familiar 4% rule gives $1,250,000, but it was built around 30-year retirements.

## How much do you need to retire at 40?

Divide what you’ll spend each year by the withdrawal rate. In today’s dollars:

| Yearly spending | At 4% | At 3.25% | At 3% |
| --- | --- | --- | --- |
| $35,000 | $875,000 | $1,076,923 | $1,166,667 |
| $45,000 | $1,125,000 | $1,384,615 | $1,500,000 |
| $50,000 | $1,250,000 | $1,538,462 | $1,666,667 |
| $60,000 | $1,500,000 | $1,846,154 | $2,000,000 |
| $75,000 | $1,875,000 | $2,307,692 | $2,500,000 |

[William Bengen’s 1994 paper](https://www.financialplanningassociation.org/sites/default/files/2021-04/MAR04%20Determining%20Withdrawal%20Rates%20Using%20Historical%20Data.pdf) is where 4% comes from. With a portfolio split evenly between stocks and bonds, a 4% first-year withdrawal raised for inflation never ran out in under 33 years of U.S. history. Retire at 40 and 33 years gets you to 73. The same paper found rates up to about 3.5% lasted at least 50 years, which still stops at 90 for you.

Karsten Jeske’s [safe withdrawal rate study](https://earlyretirementnow.com/2016/12/07/the-ultimate-guide-to-safe-withdrawal-rates-part-1-intro/) at Early Retirement Now goes further out, testing horizons of up to 60 years against market data back to 1871. A 4% rate with a 50/50 portfolio worked about 95% of the time over 30 years and only about 65% of the time over 60. His rule of thumb is that 3.5% is the new 4%. I go a notch lower for a 40-year-old because the horizon is longer than anything Bengen tested, and on $50,000 of spending that caution costs $109,890 more than planning at 3.5%.

## Can you coast to 40 instead?

Rarely. Coast FIRE means having enough invested that growth alone carries you to your number, and a 40 deadline leaves growth very little time. At $50,000 of spending, 7% returns and 3% inflation, here is what you’d need today to stop contributing and still retire at 40:

| Your age now | Coast FIRE number | Share of the full $1,538,462 |
| --- | --- | --- |
| 22 | $774,905 | 50% |
| 25 | $868,737 | 56% |
| 28 | $973,931 | 63% |
| 30 | $1,051,045 | 68% |
| 35 | $1,271,610 | 83% |

Very few 25-year-olds have $868,737 invested. For almost everyone, retiring at 40 is a full FIRE plan: you save hard until the whole number is there, then stop. Coast FIRE earns its place as the fallback. If 40 slips, the money you built chasing it can coast you to [45](https://mycoastfire.com/retire-at-45) or [50](https://mycoastfire.com/retire-at-50) with no further saving.

## Diego and Mei: the full number by 39

Diego and Mei are both 27. They have $90,000 invested between them, put in $7,000 a month and spend $46,000 a year. That’s $84,000 of investing a year, which for most couples means living on one salary and investing the other. You can check your own split with the [savings rate calculator](https://mycoastfire.com/savings-rate-calculator).

At 3.25%, their target is $1,415,385. They reach it at 39. Their Coast FIRE age for a 40 finish is 38, only about 7 months before they’d have the whole amount anyway, which is what coasting to 40 usually looks like.

| What changes | Age they reach the full number | Coast FIRE age for 40 |
| --- | --- | --- |
| Nothing: $7,000 a month, $46,000, 3.25% | 39 | 38 |
| They invest $6,000 a month | 41 | Not before 40 |
| They spend $52,000 a year | 41 | Not before 40 |
| They plan on a 4% withdrawal rate | 37 | 35 |

One missed promotion or one more child’s worth of spending pushes them past 40. The more useful number for them is their Coast FIRE age for 45, which is 35. If they burn out at that point, they can take lower-paid jobs that cover their $46,000 and still retire at 45 without saving another dollar.

Diego and Mei, aiming at 45 instead

Same savings, five more years. Watch how early the coasting line gets crossed.

[Open the calculator with these numbers](https://mycoastfire.com/?age=27&ret=45&spend=46000&assets=90000&contrib=7000&swr=3.25)

## Nineteen and a half years before 59½

Withdrawals from a 401(k) or IRA before 59½ generally come with a [10% additional tax](https://www.irs.gov/retirement-plans/plan-participant-employee/retirement-topics-exceptions-to-tax-on-early-distributions) on top of income tax. At $46,000 a year, the stretch from 40 to 59½ costs $897,000, about 63% of their whole target. Where the money sits matters as much as how much there is.

I’d plan the bridge in this order. The [retire at 50 page](https://mycoastfire.com/retire-at-50) covers the mechanics of each.

A taxable brokerage account comes first, because it has no age rules. Roth IRA contributions come next: [IRS Publication 590-B](https://www.irs.gov/publications/p590b) treats regular contributions as the first money out, with no tax and no 10% charge. If Diego and Mei each put $7,500 a year into a Roth IRA from 27 to 40, that’s $195,000 of contributions they can take back, roughly four years of spending. That assumes their income stays under the Roth IRA limits.

The Roth conversion ladder is the backbone at 40. Each year you move money from a traditional IRA into a Roth and pay income tax on it. Each conversion has its own five-year clock, starting January 1 of the year you convert, before it can come out free of the 10%. Convert in the year you turn 40 and that money is available in the year you turn 45. After that, one rung opens every year, and the brokerage and Roth money only has to cover the first five.

[72(t) payments](https://www.irs.gov/retirement-plans/substantially-equal-periodic-payments) are the other route, and I’d treat them as a backup at this age. They must continue until five years have passed or you reach 59½, whichever is later, so a 40-year-old is committing to 19½ years. Change the amount early and you owe the 10% on every past payment, plus interest.

## Twenty-five years of buying your own health insurance

[Medicare starts at 65](https://www.medicare.gov/basics/get-started-with-medicare), so retiring at 40 means a quarter-century of paying for coverage yourself. COBRA can keep your employer’s plan for up to [18 months](https://www.dol.gov/agencies/ebsa/about-ebsa/our-activities/resource-center/faqs/cobra-continuation-health-coverage-workers) at the full premium plus 2%. After that you’re on a Marketplace plan, and [premiums can be up to three times higher](https://www.healthcare.gov/how-plans-set-your-premiums/) for older enrollees than for younger ones, so the bill will climb through your 50s.

The subsidy rules create a conflict with the ladder. Marketplace help depends on income, and [HealthCare.gov counts most IRA and 401(k) withdrawals](https://www.healthcare.gov/income-and-household-information/income/) as income. A Roth conversion is taxable income in the year you make it, so every rung you convert can shrink your subsidy. Early retirees end up choosing each year between converting more and paying less for insurance. Our [guide to health insurance before 65](https://mycoastfire.com/blog/coast-fire-health-insurance-before-65) explains how the subsidy is figured. Over 25 years the rules will change more than once, so I’d make sure the plan still works at full price.

## What stopping at 40 does to Social Security

You’ll almost certainly qualify. Retirement benefits need [40 credits](https://www.ssa.gov/pubs/EN-05-10072.pdf), and in 2026 you earn one for every $1,890 of covered pay, up to four a year. Ten years of full-time work does it.

The amount is another matter. Your benefit is based on your [highest 35 years of indexed earnings](https://www.ssa.gov/benefits/retirement/planner/stopwork.html), with a zero for every missing year. Start full-time at 22 and stop at 40 and you have 18 years, so 17 zeros go into the average and cut it nearly in half. The check shrinks by less than that, because the [benefit formula](https://www.ssa.gov/oact/cola/piaformula.html) replaces 90% of the first slice of your average earnings, 32% of the next and 15% above that. Lower averages keep a bigger share.

Your statement won’t show any of this, because it [assumes you keep earning](https://www.ssa.gov/policy/docs/briefing-papers/bp2020-01.html) at your current pay until you claim. Claiming at 62 also cuts the check by [30% for anyone born in 1960 or later](https://www.ssa.gov/benefits/retirement/planner/agereduction.html). I’d leave Social Security out of a retire-at-40 plan entirely and treat whatever arrives as protection for your 80s.

## What a bad first decade does to a 55-year retirement

The calculator assumes a steady 7% a year. Markets don’t deliver that, and the order of returns matters most when you’re selling shares to live on. Run a 55-year retirement through the simulation behind our [4% rule calculator](https://mycoastfire.com/4-percent-rule-calculator), with its default 7% return, 3% inflation and 15% volatility, and a 4% start pays out in full in 50% of 2,000 simulated markets. At 3.25% it’s 66%, and at 3% it’s 71%.

Those defaults are harsher than U.S. history has been, so don’t read the figures as forecasts. The lesson is in the pattern. Over 55 years, lowering the rate helps less than people expect, because the failures come from a bad first ten years that no fixed rate fully protects against.

What does protect a 40-year-old is the ability to earn. Taking a few thousand dollars less out after a bad year, or some part-time income in your 40s, does more for the plan than another quarter point off the withdrawal rate, in my view. The [Barista FIRE calculator](https://mycoastfire.com/barista-fire-calculator) shows how much less the portfolio has to carry when you do. Before you stop, the [Monte Carlo calculator](https://mycoastfire.com/coast-fire-monte-carlo-calculator) shows how often a plan like Diego and Mei’s reaches its number on time when returns bounce around. This plan breaks down if you have no room to cut spending and no willingness to work again.

Planning a different age? [Retire at 45](https://mycoastfire.com/retire-at-45), [Retire at 50](https://mycoastfire.com/retire-at-50), [Retire at 55](https://mycoastfire.com/retire-at-55), [Retire at 60](https://mycoastfire.com/retire-at-60).For the years before 59½, see the [rule of 55 calculator](https://mycoastfire.com/rule-of-55-calculator).

## Questions people ask

### How much do I need to retire at 40 on $40,000 a year?

About $1.23 million at a 3.25% withdrawal rate, in today's dollars. The standard 4% rule would say $1 million, but it was built around 30-year retirements, and yours could run 55 years. The $40,000 has to cover health insurance and taxes as well.

### Can you retire at 40 with $1 million?

At 3.25%, $1 million supports about $32,500 a year. Some single people and a few frugal couples live on that. If you'd need more, the gap has to come from part-time income in your 40s, a lower budget or a few more years of work.

### How do I get money out of my 401(k) if I retire at 40?

Withdrawals before 59½ usually carry a 10% additional tax. The common workarounds are a Roth conversion ladder, where each converted amount becomes available five years after the start of the year you convert it, and 72(t) payments, which you'd have to keep taking until 59½. The rule of 55 doesn't apply if you leave at 40.

### Will I get Social Security if I retire at 40?

Almost certainly, as long as you have 40 work credits, which takes about ten years of covered earnings. The benefit will be smaller than your statement shows, because every year short of 35 counts as a zero in the average. The earliest you can claim is 62.

## Keep reading

-   [Retire at 45Five more working years and a shorter bridge.](https://mycoastfire.com/retire-at-45)
-   [Retire at 50The early-withdrawal workarounds in more detail.](https://mycoastfire.com/retire-at-50)
-   [4% rule calculatorTest a withdrawal rate over 50 or 55 years.](https://mycoastfire.com/4-percent-rule-calculator)