Savings Longevity Calculator
Use this tool to estimate how many years and months your savings can support your lifestyle, based on spending, income, investment return, and inflation.
Tip: You can type values with commas or dollar signs, like $250,000.
What this calculator tells you
The how long will savings last calculator estimates how long your current money can sustain your spending habits. It is helpful for retirement planning, career breaks, emergency planning, or any period where you need your savings to bridge a gap.
Instead of doing rough math in your head, this calculator runs a month-by-month projection and accounts for:
- Your starting balance
- Monthly spending
- Monthly income from other sources (pension, rental income, part-time work, etc.)
- Investment growth (or decline) on remaining savings
- Inflation that gradually increases your expenses
How the savings duration math works
Core monthly projection
Each month, your balance is updated using this sequence:
- Your savings grow by the monthly equivalent of your annual return
- Your monthly income is added
- Your monthly expenses are subtracted
- Next month’s expenses are increased by inflation
That process repeats until your balance reaches zero, or until the end of your chosen projection horizon.
Why inflation matters so much
A lot of people underestimate how strongly inflation affects long-term plans. If your monthly expenses are $4,000 today and inflation averages 3%, those expenses rise to about $5,375 in 10 years. That means your annual draw from savings keeps rising over time, even if your lifestyle does not change.
How to use this calculator effectively
1) Start with realistic expenses
Use your real monthly cash outflow, not an optimistic guess. Include housing, food, healthcare, transportation, subscriptions, taxes, and irregular costs averaged over a year.
2) Be conservative on returns
If this model is for serious planning, use a moderate expected return (for example, 3% to 6% depending on your portfolio). Avoid relying on best-case market performance.
3) Stress test multiple scenarios
Run at least three versions:
- Base case: reasonable assumptions
- Conservative case: lower returns + higher inflation
- Best case: stronger returns + controlled spending
Good planning means your finances still work in the conservative case.
Example scenario
Suppose you have $250,000 in savings, spend $4,000/month, earn $1,500/month from other sources, expect a 4.5% annual return, and assume 2.5% inflation. The calculator may show that your savings last for many years, but not indefinitely, because inflation gradually increases the gap between income and spending.
If you reduce spending by just $300/month or increase income by $300/month, your timeline can improve dramatically. Small monthly changes compound into major long-term impact.
Ways to make savings last longer
Lower your burn rate
- Renegotiate fixed bills (insurance, internet, mobile plans)
- Downsize high-cost recurring expenses
- Adopt a target budget and track variance monthly
Increase recurring income
- Part-time consulting or freelance work
- Rental or licensing income
- Delayed retirement for a few extra earning years
Improve after-fee investment returns
- Review portfolio fees and tax drag
- Maintain an allocation aligned with your risk tolerance
- Avoid panic selling during downturns
Common mistakes people make
- Ignoring inflation: leads to overestimating how long money lasts
- Using gross income instead of net income: taxes and deductions matter
- Forgetting irregular expenses: car repairs, travel, medical deductibles, home maintenance
- Assuming fixed investment returns: real markets are volatile
Important limitations
This calculator is a planning tool, not financial advice. It does not model every real-world factor, such as taxes on withdrawals, sequence-of-returns risk, changing healthcare costs, pension timing rules, or unexpected life events.
Use it as a clear first-pass estimate, then refine your plan with a qualified advisor if the decision is significant.
Quick FAQ
Can this be used for retirement planning?
Yes. It is especially useful for early retirement and bridge periods before pension or Social Security starts.
What if my income is higher than my expenses?
If your monthly income consistently exceeds expenses, your savings can continue growing. The calculator will show that funds are not depleted within your chosen horizon.
Should I use nominal or real returns?
This calculator uses nominal return and separately applies inflation to expenses. That keeps assumptions transparent and intuitive.
Bottom line
The best time to test your financial runway is before you need it. A clear estimate of savings duration helps you make better decisions now: spending adjustments, income planning, and investment strategy. Use the calculator above, test multiple scenarios, and build a plan that is resilient under conservative assumptions.