Portfolio Drawdown Calculator
How long savings last at a given spend rate.
Calculate how long a portfolio will last at a specified annual withdrawal rate and expected return. Enter portfolio value to see years the portfolio sustains.
What this tool does
This calculator estimates how many years a portfolio lasts given a starting balance, a fixed annual withdrawal amount, and an expected annual return rate. The result shows the time horizon before the portfolio is fully depleted, assuming withdrawals occur at the end of each year and returns compound annually. The calculation is most sensitive to the initial portfolio value and the annual withdrawal amount—larger withdrawals or smaller starting balances shorten the timeline significantly. A typical use case might involve modelling a savings drawdown over retirement or during a career break. The calculator assumes constant real withdrawals, a steady return rate, and no additional contributions or unexpected expenses. Results are for educational illustration and do not account for inflation adjustments, tax implications, or market volatility.
Quick answer: with the default values, the result is 37.0 years (Portfolio Lasts). Adjust the values below for your own figures.
Enter Values
People also use
Investing
Safe Withdrawal Rate Calculator — Retirement Income
Estimate how much can be withdrawn from a retirement portfolio each year at a chosen withdrawal rate, with the monthly income it implies.
Savings
Bucket Retirement Strategy Calculator
Allocate retirement savings across three buckets — immediate cash, medium-term income, and long-term growth. Enter retirement pot to see each bucket's amount.
Savings
Bucket Strategy Calculator
Split a portfolio into near-term cash, medium-term bonds, and long-term growth buckets based on target allocations across each band.
Formula Used
Disclaimer
Results are estimates for educational purposes only. They do not constitute financial advice. Consult a qualified professional before making financial decisions.
500,000 portfolio with 30,000/year withdrawal at 5% return lasts 37 years. At 6% return, it can last indefinitely. At 4% return, about 23 years. The gap between 4% and 6% is decades — return assumptions matter enormously for retirement sustainability.
Quick example
With portfolio value of 500,000 and annual withdrawal of 30,000 (plus expected return of 5%), the result is 37.0 years.
Which inputs matter most
You enter Portfolio Value, Annual Withdrawal, and Expected Return.
What's happening under the hood
Solve for n when portfolio equals zero after n annual withdrawals compounding at return rate. Annual compounding, withdrawals at year end.
Where to go next
This calculation rarely sits alone in a planning exercise. If you're running these numbers, related tools include the safe withdrawal rate calculator, the maximum savings rate calculator, and the pension drawdown sustainability calculator — each one answers a different question in the same territory.
Why the return assumption dominates
How long a portfolio lasts is far more sensitive to the return assumption than to the size of the pot. At the defaults, 500,000 supporting 30,000 a year at 5% lasts about 37 years. At 6% the withdrawal is covered by growth and the balance does not deplete on this model. At 4% it runs to roughly 23 years. A two-point swing in an assumption nobody can verify in advance moves the answer by decades.
What a flat withdrawal misses
The model withdraws a flat amount and grows the remainder at a constant rate, which is a smoother world than the one portfolios live in. It does not vary the withdrawal with inflation, and it does not model sequence risk, where poor returns early in retirement do more damage than the same returns later, because the withdrawals come out of a smaller base. Running the calculation across a range of returns gives a span rather than a single date, which is closer to what the arithmetic can honestly support.
A portfolio of £500,000 with £30,000 annual withdrawals at 5% return lasts 37.0 years.
Inputs
| Withdrawal Rate | 6.00% |
|---|---|
| Expected Return | 5.00% |
| Initial Portfolio | $500,000.00 |
| Annual Withdrawal | $30,000.00 |
This example uses typical values for illustration. Adjust the inputs above to match a specific situation and see how the result changes.
Sources & Methodology
Methodology
This calculator computes how many years a portfolio sustains a given annual withdrawal amount. It solves for the number of periods (n) at which portfolio value reaches zero, using the standard drawdown formula that accounts for both investment returns and regular withdrawals. The model assumes a constant annual return rate applied to the remaining balance, with withdrawals occurring at the end of each year. It treats returns as compounding annually and does not account for fees, taxes, inflation adjustment of withdrawals, market volatility, or variation in actual returns over time. The calculation also assumes withdrawals continue at a fixed amount regardless of market performance or portfolio balance.
References
Frequently Asked Questions
Is this the 4% rule?
Return assumption sensitivity?
Sequence of returns risk?
What if withdrawal is flexible?
Related Calculators
Safe Withdrawal Rate Calculator — Retirement Income
Estimate how much can be withdrawn from a retirement portfolio each year at a chosen withdrawal rate, with the monthly income it implies.
Bucket Retirement Strategy Calculator
Allocate retirement savings across three buckets — immediate cash, medium-term income, and long-term growth. Enter retirement pot to see each bucket's amount.
Bucket Strategy Calculator
Split a portfolio into near-term cash, medium-term bonds, and long-term growth buckets based on target allocations across each band.
More Savings Calculators
Savings
Bucket Retirement Strategy Calculator
Allocate retirement savings across three buckets — immediate cash, medium-term income, and long-term growth. Enter retirement pot to see each bucket's amount.
Savings
Bucket Strategy Calculator
Split a portfolio into near-term cash, medium-term bonds, and long-term growth buckets based on target allocations across each band.
Savings
Cash vs Invest Calculator
Compare long-term value of holding cash vs investing the same amount at expected market returns. Enter cash rate and investment return to see opportunity cost.
Savings
CD Calculator — Certificate of Deposit Growth
CD calculator for certificates of deposit. Enter principal, APY, and term to see maturity value, interest earned, and effective yield.
Savings
CD Early Withdrawal Penalty Calculator
Calculate CD early withdrawal penalty cost and net amount received. Enter CD principal and CD APY to see penalty amount and interest earned.
Savings
College Savings Calculator
Calculate required monthly savings for future college costs using inflation-adjusted tuition and investment growth projections.
Explore Other Financial Tools
Psychology & Behavioral
Charity Compound Impact Calculator
Calculate total lifetime charitable giving at a consistent monthly amount. Enter uplift and years to see total nominal lifetime giving.
Utilities
Split Bill Calculator
Split any bill among multiple people including tax and tip. Calculate per-person amounts accurately for restaurants, rent, utilities, or shared costs.
Cloud & Tech
App Development Cost Calculator
Estimate total app development cost from team hours, hourly rates, platform complexity, and a 15% project-management buffer.
Spotted something off?
Calculations or display — let us know.