Nest Egg Duration Calculator

About the Nest Egg Duration Calculator

The Nest Egg Duration Calculator answers the most anxiety-inducing retirement question: how long will my money last? Enter your portfolio balance, planned withdrawals, expected returns, and inflation to see the exact year your savings would run out — or confirm they'll last a lifetime.

This calculator plots a year-by-year depletion curve showing your balance declining and highlights the critical crossover point. It also runs sensitivity analysis across different return and withdrawal assumptions so you can stress-test your plan.

Knowing your portfolio's runway empowers you to make confident decisions about spending, part-time work, and risk tolerance in retirement. For instance, a $1 million portfolio with $50,000 annual withdrawals and 6% returns might last 30 years in theory, but adjusting for 3% inflation cuts that runway to roughly 22 years — a gap that surprises many retirees. Running multiple scenarios with different assumptions is the only way to build a robust plan that accounts for market downturns, inflation spikes, and unexpected expenses.

When This Page Helps

Running out of money is retirees' #1 fear. This calculator turns that vague fear into a specific number — how many years your savings will last under various scenarios. Armed with this data, you can adjust withdrawals, returns, or spending to extend your runway as needed. Seeing the year-by-year depletion curve also helps you identify the inflection point where small changes have the greatest impact.

How to Use the Inputs

1. Enter your total portfolio/nest egg balance.
2. Enter your planned annual withdrawal amount.
3. Enter an expected annual return rate.
4. Enter the expected inflation rate.
5. View how many years your nest egg will last.
6. Examine the year-by-year balance table.
7. Check the sensitivity grid for best and worst cases.

Example Calculation

Tips & Best Practices

• A withdrawal rate of 4% or lower with balanced returns typically sustains a portfolio for 30+ years.
• Even a 1% difference in returns (5% vs 6%) can change duration by 5-10 years.
• Factor in Social Security and pension income to reduce the withdrawal needed from your portfolio.
• Consider a declining withdrawal strategy in later years when spending naturally decreases.
• Holding 1-2 years of cash buffers avoids selling investments in a down market.
• Review this calculation annually and adjust withdrawals if returns fall below expectations.

The Depletion Curve

Every portfolio follows a depletion curve shaped by three forces: returns pulling the balance up, withdrawals pulling it down, and inflation eroding purchasing power. When withdrawals plus inflation exceed returns, the curve bends downward. Understanding this curve helps you recognize warning signs early and take corrective action.

Extending Your Runway

The two most effective levers are reducing withdrawals and maintaining growth. Reducing withdrawals by $5,000 per year can extend duration by 5-7 years. Maintaining even modest equity exposure (40-50%) provides growth that bonds alone cannot deliver. Guard against the temptation to go all-bonds for safety — longevity risk is the bigger threat.

The "Perpetual" Withdrawal Rate

Historically, a 3-3.5% withdrawal rate from a balanced portfolio has been sustainable indefinitely. This means a $1 million portfolio can support $30,000-$35,000 in annual spending forever. Planning for a perpetual rate also builds in an inheritance or emergency buffer.

Frequently Asked Questions

• What rate of return should I assume?

  A balanced portfolio (60% stocks / 40% bonds) has historically returned about 7-8% nominal. For conservative planning, use 5-6% nominal. Subtract inflation (2-3%) to get real returns. Each percentage point matters significantly for duration.

• Does this account for inflation?

  Yes. The calculator uses real (inflation-adjusted) returns. This means the annual withdrawal maintains its purchasing power over time. A $50,000 withdrawal in year 1 has the same real value in year 20.

• What if my nest egg shows "indefinite"?

  If your withdrawal rate is below the real return rate, your portfolio never depletes — it actually grows. This is the ideal scenario and means your spending is sustainable. Consider this a minimum withdrawal; you could safely spend more.

• How does sequence of returns risk affect this?

  This calculator uses a constant return assumption. In reality, if markets drop heavily early in retirement, your nest egg depletes much faster. This is called sequence of returns risk. To mitigate it, keep 2-3 years of cash, reduce withdrawals in down years, and maintain a diversified portfolio.

• What's the biggest factor in nest egg duration?

  The withdrawal rate (withdrawal ÷ portfolio) is the dominant factor. At 3% withdrawal rate, most portfolios last 40+ years. At 5%, many run out within 25-30 years. At 7%, depletion often occurs within 15-20 years. Controlling spending is the most reliable strategy.

• Should I use fixed or inflation-adjusted withdrawals?

  This calculator assumes inflation-adjusted withdrawals, which is the more conservative and realistic approach. Fixed nominal withdrawals would make your money last longer but your purchasing power would decrease every year.