calculator
FIRE number calculator
Set a spending target and withdrawal rate, then test how returns and monthly contributions change a simple accumulation estimate.
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- FIRE Aggregator editorial process
Estimate a planning target
Before using this calculator
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Formula: annual spending ÷ withdrawal rate = planning target. The projection compounds the current portfolio monthly and adds the selected monthly contribution. It ignores taxes, fees, inflation, and return sequence.
Worked example without JavaScript: $60,000 ÷ 4% = $1,500,000. Change the inputs and select Calculate estimate for a projection.
Calculate the target from annual spending
The familiar target is annual portfolio-funded spending divided by a chosen starting withdrawal rate. At 4%, each $1 of annual spending implies $25 of invested assets; $60,000 implies $1.5 million. At 3.5%, the same spending implies about $1.71 million.
Count spending the portfolio must cover after reliable income such as a pension or Social Security. Include taxes and health costs. The result is a planning scenario, not a prediction or guarantee.
Read the projection as a sensitivity check
The projection assumes a constant monthly return and end-of-month contributions. Markets do not behave that way: returns arrive unevenly, fees and taxes cut balances, inflation raises future spending, and poor returns early in retirement can do lasting damage.
- Recalculate with lower returns, a lower withdrawal rate, and higher spending.
- Compare the result with the SEC calculators; neither tool gives individualized advice.
- Revisit Social Security, pension, insurance, and tax assumptions before acting on it.
Limits
This estimate omits inflation, taxes, fees, asset allocation, Social Security rules, longevity, market volatility, and sequence-of-returns risk. It is for exploring scenarios, not investment advice.
Sources
- SEC Investor.gov Compound Interest Calculator
- SEC Investor.gov Savings Goal Calculator
- Morningstar State of Retirement Income 2025 report
The source-check date records editorial review. Routine builds do not advance it.
Revision history
- — Published after checking the cited SEC calculators and retirement-income research.