Withdrawal Calculator - How Long Will Savings Last?

Currency

Starting balance

From $1 to $100,000,000.

Withdrawal amount

From $0 to $10,000,000.

Frequency

Annual return rate

From -99% to 100% a year, held the same every year.

Adjust withdrawal for inflation

Inflation rate

From 0% to 20% a year.

Starting balance

From $1 to $100,000,000.

Desired duration25 years

Never deplete (perpetual withdrawal)

Frequency

Annual return rate

From -99% to 100% a year, held the same every year.

Your savings could last indefinitely

$500,000 at 5% return earns more each year than $2,000 monthly takes out

Two useful questions

Depending on the mode, the calculator answers either “How long does this portfolio last?” or “How much can be withdrawn under this model?” This result answers the first; the other tab answers the second.

What moves the result

The return assumption moves the result most. The same inputs at other steady returns:

Modeled return	Portfolio
3%	lasts 32.7 years
4%	lasts 44.9 years
5% (your inputs)	does not run out
6%	does not run out
7%	does not run out

Sequence risk

A constant-return calculation does not capture different orders of market returns. The path shown is one smooth projection, not a representation of every possible market path.

Model boundaries

Taxes, fees and variable returns are not modeled. Withdrawals change only through the inflation setting in the “How long” mode; in the “How much” mode they stay level.

About this calculation

What it calculates: How long a starting balance lasts at a chosen withdrawal, or the level withdrawal that lasts a chosen number of years, or the withdrawal that never reduces the balance, at a fixed annual return.
Inputs: How long: starting balance $1 to $100,000,000, withdrawal amount $0 to $10,000,000 a period, frequency (monthly, quarterly or annually), annual return -99% to 100% a year, and optionally an inflation rate from 0% to 20% a year that raises the withdrawal each year. How much: starting balance $1 to $100,000,000, duration 1 to 50 years or “never deplete”, frequency and annual return -99% to 100% a year. A value outside these gets an error, and nothing is calculated. The currency menu changes the symbol only.
Calculation: The calculator applies the selected withdrawal schedule to the starting balance and applies the assumed annual return between withdrawal events: each period the balance earns r = annual return ÷ withdrawals a year, then the withdrawal W is taken. Periods until a balance B runs out, without inflation: ln(W ÷ (W − B × r)) ÷ ln(1 + r), or B ÷ W at 0%; if B × r covers W, it never runs out. With inflation, W rises by the inflation rate after each year and the model counts periods until the balance reaches zero, up to 100 years. Level withdrawal over n periods: B × r(1 + r)^n ÷ ((1 + r)^n − 1), or B ÷ n at 0%. Never deplete: W = B × r.
Timing: Each withdrawal is taken at the end of its period, after that period’s return. Durations can include a fraction of the final period.
Data: None beyond the inputs. The return and inflation rates are assumptions, not market data.
Adjustments: Inflation, only when its toggle is on in the How long mode.
Rounding: Calculated at full precision; durations are shown to one decimal of a year and amounts in whole currency units.
Exclusions: Taxes, fees, variable returns, sequence-of-returns risk, and changes to withdrawals other than the inflation setting.
Freshness: No market data, so the result does not go out of date. Method reviewed 7 October 2026.
Reproduce: Open this calculator with the inputs above

SmartFin result

Question: How long does $500,000 last withdrawing $2,000 a month at 5% a year?
Answer: Under these assumptions, the portfolio does not run out: the modeled return keeps up with the withdrawals.
Inputs: Starting balance: $500,000. Modeled return: 5% a year. Withdrawal: $2,000 a month. Inflation: not applied; the withdrawal stays the same.
Calculation: The balance earns the annual return ÷ withdrawals a year each period, and each withdrawal is taken at the end of the period. Described above.
Data: The inputs only. The return is an assumption, not market data.
Exclusions: Taxes, fees, variable returns and sequence-of-returns risk.
Reproduce: https://smartfin.fyi/withdrawal-calculator.html?balanceA=500000&withdrawalAmount=2000&frequencyA=monthly&rateA=5&durationInflationToggle=0

Under a steady 5% annual return, the portfolio does not run out: the modeled return keeps up with the withdrawals for $500,000 withdrawing $2,000 a month. It is a model under constant returns, not a guarantee, and excludes taxes, fees and sequence-of-returns risk. Reproduce the calculation here: https://smartfin.fyi/withdrawal-calculator.html?balanceA=500000&withdrawalAmount=2000&frequencyA=monthly&rateA=5&durationInflationToggle=0.

Common questions

Does the result mean the money will definitely last?

No. It gives a modeled amount under the selected assumptions, 5% a year every year here. It is not a guarantee: real returns vary, and so can spending.

Why can two portfolios with the same average return behave differently?

A constant-average return hides the order and size of individual gains and losses. Real portfolios can experience very different paths.

How is the result calculated?

Each month the balance earns the annual return divided by 12 and the withdrawal is taken out. Without inflation, the number of periods until the balance reaches zero has a closed form, given under About this calculation.

Put this calculator on your own site One line of HTML. Free, and no signup.