How Long Will Your Money Last?
Use this savings depletion calculator to estimate how many years and months your portfolio can support your lifestyle.
What this “how long will money last” calculator helps you answer
Most people don’t wonder whether they can retire in theory. They ask a much more practical question: “If I stop earning a full paycheck, how long can my money support my life?” That’s exactly what this calculator is for.
It blends five real-world forces that determine portfolio longevity:
- Starting savings balance
- Monthly spending
- Reliable monthly income sources (Social Security, pension, rental cash flow)
- Investment growth rate
- Inflation pressure on future spending
Whether you’re planning retirement, testing a FIRE withdrawal strategy, or simply stress-testing your emergency runway, this retirement withdrawal calculator gives you a fast projection in years and months.
How the calculation works (simple version)
Each month, the model runs through the same sequence:
- Your portfolio grows by the expected monthly return.
- Monthly income is added.
- Monthly expenses are deducted.
- Expenses are increased gradually for inflation over time.
This repeats until your balance reaches zero or your selected projection window ends. The result gives you either:
- A depletion horizon (for example, 27 years and 4 months), or
- A message that your money did not run out within the selected period.
How to use the calculator effectively
1) Start with your current reality
Use your true liquid portfolio amount and realistic monthly expenses. Be careful not to underestimate spending—many plans fail because budgets were optimistic.
2) Separate income from withdrawals
If you expect pension income, Social Security, annuity payments, or rental net income, include that in monthly income. This lowers your required draw from savings and can dramatically extend portfolio life.
3) Be conservative on returns
Using an 8% return assumption may look nice on paper but can produce misleading confidence. A moderate assumption often gives a better planning baseline. You can always run multiple scenarios afterward.
4) Don’t ignore inflation
Inflation is one of the biggest hidden risks in retirement. Even if your spending looks stable now, costs tend to rise over long horizons. This calculator adjusts expenses upward automatically.
Example scenarios you should test
Base case
Use your best estimate for spending, return, and inflation.
Conservative case
Lower investment returns by 1–2%, increase inflation by 1%, and see how quickly longevity changes.
High-spending case
Add travel, healthcare, home repairs, and family support costs. Many households spend more in the first decade of retirement than expected.
Sequence-of-returns stress test
While this tool uses a steady average return, real markets are volatile. If poor returns happen early in retirement, sustainability can drop sharply. Use lower return assumptions to approximate this risk.
What makes money run out faster?
- High withdrawal rate: Taking too much too early is the biggest driver of depletion.
- Low or negative returns: Weak market periods reduce compounding power.
- Persistent inflation: Rising expenses increase monthly draw over time.
- Unplanned one-time costs: Medical events, family emergencies, and major repairs can reduce future runway.
- No spending flexibility: A rigid spending plan can force large withdrawals during bad market years.
How to make money last longer
Cut fixed expenses first
Reducing recurring housing, insurance, or debt payments has lasting impact because the savings repeat every month.
Delay major discretionary spending
Postponing large optional expenses for a few years can improve long-term portfolio survival.
Increase dependable income streams
Part-time work, consulting, or rental optimization can offset withdrawals and reduce pressure on your nest egg.
Use dynamic withdrawals
Instead of withdrawing a fixed inflation-adjusted amount every year, consider reducing spending after poor market performance and increasing it after strong years.
Frequently asked questions
Is this a safe withdrawal rate calculator?
It overlaps with that concept, but this tool is broader. A safe withdrawal rate calculator starts with a percentage rule (like 4%). This tool starts with your actual monthly budget and income gap.
Does it include taxes?
Not directly. To account for taxes, increase your monthly expense figure or reduce your expected net return to reflect after-tax results.
Can this model predict market crashes?
No. It uses a constant average return assumption. For better risk awareness, run multiple cases with lower returns and higher inflation.
Should I rely on one output?
No. Think in ranges, not single-point forecasts. Run at least three scenarios (optimistic, base, conservative) before making big decisions.
Bottom line
A good savings longevity calculator won’t remove uncertainty, but it can make uncertainty manageable. It shows the trade-offs between spending, returns, inflation, and time—so you can make better decisions before money stress becomes urgent.
Use the calculator above regularly as your numbers change. Small course corrections today can add years of financial confidence tomorrow.
Educational use only. This is not financial, tax, or legal advice.