How to use this calculator
A savings-depletion projection compares the resources you start with against future withdrawals. Other income can reduce the amount you need from savings. This calculator models month-by-month cash flows and gives a small return-sensitivity comparison so one assumption is not presented as the only possible outcome.
The method
Enter the values in the labeled fields, check the units or selected mode, and choose Calculate. The result includes the applicable working and a breakdown or visual when useful. Change an input and calculate again to update the result.
Current savings ($): 250000 Monthly spending ($): 2500 Other monthly income ($): 1000 Assumed annual effective return (%): 4 Annual spending inflation (%): 2 Projection horizon (years): 40 Withdrawals and income timing: Start of month Other income over time: Fixed dollar amount
Estimated savings coverage: 14.72 years
Approximate funded duration under the assumptions below.
Scope and limitations
Hypothetical smooth returns, not a Monte Carlo retirement analysis. No taxes, fees, changing market returns, or sequence risk. Partial-month coverage is an approximation; reaching the horizon does not mean savings last forever.
Common questions
Is the projected date guaranteed?
No. Spending, returns, inflation, taxes, and life circumstances can differ from the assumptions.
What does "at least" the selected horizon mean?
The model did not exhaust the balance within the years you selected. It has not tested any period beyond that horizon.
References & further reading
External references provide background, not an endorsement of this implementation. See our methodology for numerical conventions and limitations.