tooloctopus.

Fire calculator

Translate a spending gap into a portfolio target using your chosen withdrawal-rate assumption.

On your device · No account
Privacy details

Fire calculator processes your input in this browser. Inputs and results are excluded from analytics. Recent tools save tool names, visit counts and last-visit times. Saved tools store only their names. Draft saving is optional and stays on this device; delete saved text with the draft controls. Loading text from a URL is optional and contacts that server; its URL and your IP address are visible to the server. An optional “Use in” action keeps a handoff in this tab. The next tool removes it on arrival and ignores it if more than a minute has passed.

Copy link includes the inputs you choose to share in the address. Anyone with that link can reopen them. Files and generated results are excluded. Password and key tools share settings only.

More inputs and assumptions

Answer

…

Translate a spending gap into a portfolio target using your chosen withdrawal-rate assumption.

More results
Precision and calculation record
Rounding changes displayed numbers, not the calculation. Text, fractions, matrices and CSV schedules keep their own formatting. Automatic keeps up to 12 significant digits, with money shown to cents where applicable.
Saved scenario
Save the current answer, then change an input to compare. This clears when you leave.
Formula and assumptions
Target = max(0, spending − other income) ÷ withdrawal rate. The example rate is a scenario, not an endorsed safe rate. No success probability, inflation, tax, longevity or market-risk simulation. Fixed assumptions only: no taxes, fees, changing returns, guarantees or product eligibility. Amounts share one currency.
Automatic precision shows numbers to 12 significant digits. Thousands separators such as 1,000 are accepted; use a dot for decimals.
Scratch calculator
Use +, −, ×, ÷, parentheses and %. A percentage is divided by 100. This does not change the main tool.
Reset reloads the tool with its starting values and releases open files and device controls. Saved drafts stay on this device until you delete them.
Links include your inputs and settings. Anyone with the link can see them, so leave out private text. Files and generated results are left out; random draws run again.
Keyboard shortcuts
Updated 
Using Fire calculator
Translate a spending gap into a portfolio target using your chosen withdrawal-rate assumption.
Target = max(0, spending − other income) ÷ withdrawal rate. The example rate is a scenario, not an endorsed safe rate. No success probability, inflation, tax, longevity or market-risk simulation. Fixed assumptions only: no taxes, fees, changing returns, guarantees or product eligibility. Amounts share one currency.
Next: Retirement calculator
A worked example
Example inputs: annual spending to fund = 40000, your assumed annual withdrawal rate (%) = 4, annual income from other sources = 10000. Portfolio target = 750000.
Before you use the result
Target = max(0, spending − other income) ÷ withdrawal rate. The example rate is a scenario, not an endorsed safe rate. No success probability, inflation, tax, longevity or market-risk simulation. Fixed assumptions only: no taxes, fees, changing returns, guarantees or product eligibility. Amounts share one currency.
Example results for annual spending to fund
These examples use Your assumed annual withdrawal rate (%): 4; Annual income from other sources: 10000. They are reference calculations, not recommended settings.
Annual spending to fundPortfolio target
20000250000
40000750000
800001750000
Cite this page
ToolOctopus. “Fire calculator.” Updated 2026-09-26. https://tooloctopus.com/fire-calculator.
Add an access date if your instructions require one.
Citation formatting uses citeproc-js by Frank Bennett and Citation Style Language styles. Licence and source code.
Find a tool
Search by task. Use ↓ and ↑ to choose, Enter to open.