FIRE Number Calculator
Calculate an expense-based asset target and the first modeled whole year when annual saving reaches it.
YOUR CALCULATION
Result
—
Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Divide annual spending by the entered withdrawal fraction. Start the projection from current assets. Apply annual real growth before the year-end contribution. Find the first whole year reaching the target.
Target=annual spending/withdrawal fraction; A(n+1)=A(n)(1+r)+saving
Worked example
Spending 40000 with an entered 4% withdrawal fraction gives an asset target of 1000000.
Assumptions and input details
The withdrawal fraction is a scenario input, not a safe-rate recommendation. Constant real growth and end-of-year saving are assumed for at most one thousand years. Taxes and investment risk are not modeled.
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
Model an initial deposit plus equal periodic contributions. Compare beginning/end contributions, nominal/effective annual rates, total deposits and before-tax growth.
Compare the original and reversed order of the same annual returns with fixed annual withdrawals.
Add balances in different currencies, including debts. Convert the total and compare a table and currency chart.
Reserved advertising space.