Coast FIRE Calculator

Estimate capital needed now to reach an entered retirement target with no further contributions. Keep nominal returns, asset fees and inflation separate.

Your inputs

Use consistent units and periods. Defaults are examples.

Current age (whole years)Retirement age (whole years)Must not be before current age; the model uses the whole-year difference.Annual spending in today’s currencyUse an annual amount in the stated starting purchasing power. Include only the expense scope you intend to model.Annual other income in the same purchasing powerEntered other income is available from the start and uses the same inflation index as spending; no benefit entitlement is inferred.Initial withdrawal-rate assumption (%)Your initial spending-gap / portfolio ratio. This site does not certify a safe rate.Assumed gross nominal annual return (%)An entered gross effective annual scenario, not a rate supplied or predicted by AllMarkets.Annual asset fee after growth (%)Charged on assets after annual gross growth; no separate fixed account fees.Assumed annual inflation (%)A constant model assumption, not live CPI data.Current invested capital

Your result

Check the assumptions below before relying on a result.

Formula and method

Net nominal growth=(1+gross return)×(1−asset fee). Real growth=net nominal growth/(1+inflation). Required coast capital=real retirement target/(real growth^years).

Worked example

A zero-fee 10% nominal return, zero inflation,10 years, annual spending 40,000, zero other income and an assumed 4% withdrawal rate imply a 1,000,000 retirement target. Required capital now is 385,543.29. Starting with exactly that capital reaches 1,000,000 only along that fixed hypothetical path.

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How to use this result

Use one currency throughout. An annual spending input is not a monthly amount.
Read the timing, inflation and fee definitions before comparing scenarios.
Inspect the annual table and download CSV to retain the assumptions.
Use the second scenario on supported tools to vary one assumption at a time. No result proves that stopping work is prudent.

Questions about this calculation

Why does the fee multiply growth rather than simply subtract?

The model applies the stated percentage fee to assets after each year’s gross growth. For example,1.06×0.9975=1.05735. Your actual fees may use a different schedule.

What if real growth is negative?

Required capital now can exceed the retirement target. The calculator supports a bounded negative real-return scenario rather than silently forcing it to zero.

Why is there no automatic age when I become Coast FIRE?

With no new contributions and the same deterministic assumptions, both projected assets and the required coast path grow at the same real rate. A shortfall does not disappear just by moving along that path.

Continue your calculation

Compare, save and share assumptions

Scenario A uses the original inputs above. Scenario B has independent inputs below. Optional Save stores numeric inputs only in this browser. Links disclose the inputs you choose to include: use illustrative values.