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Measurement changes convert valid existing quantities. Incomplete entries stay as typed; finish them using the units shown. Other units stay as labeled. Enter numbers as 1,234.56; a decimal comma is not supported.

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Coast FIRE Calculator

Estimate the Coast FIRE amount needed today, with optional pension or ongoing retirement income. Adjust spending, return, inflation, and retirement age.

Live resultUSD 187,315.53Coast amount todayView results ↑

Your inputs

Estimate the Coast FIRE amount needed today, with optional pension or ongoing retirement income. Adjust spending, return, inflation, and retirement age.

USD amounts; no exchange conversion. Use 1,234.56 number format.

years
Whole years, 18–99.
years
Must be later than current age, at most 100.
$/year
Full spending before deducting retirement income, in today’s purchasing power.
$/year
Pension or other income from your retirement age onward, in today’s purchasing power.
%
A modeling assumption, not a guaranteed safe rate.
%
Hypothetical average return before inflation.
%
Constant assumption used to derive real growth.
$
Assets available for this modeled retirement target.

Change any input to see the result immediately. Start with your own measurements and assumptions.

Results

Live
Coast amount todayUSD 187,315.53needed now under the entered assumptions
Retirement targetUSD 1,000,000.00USD 40,000.00 annual spending funded by the portfolio
Gap to coast amountUSD 87,315.53current coast amount less investments, floored at zero
Projected investmentsUSD 533,858.56after 35 years with no new contributions
Real annual growth4.9%nominal return adjusted for inflation
Growth period35 yearsuntil the entered retirement age

Display values are rounded. The calculation method and limits are explained below.

What this result includes

Retirement income is assumed to start at the selected retirement age and maintain its purchasing power throughout retirement. Use an after-tax amount consistent with spending. Income that starts later, fixed nominal pensions without inflation adjustment, benefit eligibility, and survivor changes are not modeled. A zero spending gap is a model result, not a readiness verdict. Returns, inflation, taxes, fees, longevity, and spending vary. The withdrawal rate is an assumption, and investment losses or sequence risk are not modeled.

Reference formulas and worked examples below keep their stated units. Monetary examples use USD; dimensional examples use US customary units unless labeled otherwise. Metric calculator inputs are converted to these reference units before calculation. Choosing another currency does not convert example amounts or exchange money.

How to use this coast fire calculator

Estimate the Coast FIRE amount needed today, with optional pension or ongoing retirement income. Adjust spending, return, inflation, and retirement age.

How the calculation works

Annual portfolio-funded spending = the greater of zero and annual spending minus annual retirement income. Target portfolio in today’s dollars = that spending gap ÷ assumed withdrawal rate.

Real growth = (1 + nominal return) ÷ (1 + inflation) − 1. Coast amount today = target ÷ (1 + real growth)^(retirement age − current age).

The gap compares the coast amount with current investments. Projected retirement assets assume no new contributions or withdrawals before retirement.

Worked example

With $40,000 annual spending, no other retirement income, and a 4% assumed withdrawal rate, the target is $1,000,000 in today’s dollars. With $12,000 of qualifying annual retirement income, the spending gap is $28,000 and the target becomes $700,000. With zero real growth, that entire $1,000,000 would be needed today.

Limits and assumptions

Retirement income is assumed to start at the selected retirement age and maintain its purchasing power throughout retirement. Use an after-tax amount consistent with spending. Income that starts later, fixed nominal pensions without inflation adjustment, benefit eligibility, and survivor changes are not modeled. A zero spending gap is a model result, not a readiness verdict. Returns, inflation, taxes, fees, longevity, and spending vary. The withdrawal rate is an assumption, and investment losses or sequence risk are not modeled.

Frequently asked questions

Can I include a pension or other retirement income?

Yes, if it begins by the selected retirement age and continues at the entered real purchasing power. Enter the annual amount consistently with your spending. Later-starting or fixed nominal benefits need a more detailed model.

What does Coast FIRE mean here?

Enough invested now that modeled growth reaches a retirement target without additional contributions. Living expenses before retirement are funded separately.

Are results adjusted for inflation?

Yes. The model converts nominal return to real growth and expresses the target and projected balance in today’s dollars.

Does reaching the number guarantee retirement income?

No. It is conditional on assumptions; it does not model uncertainty or guarantee a withdrawal rate.