The Math Behind Your Money
Figuring out how long your money will last is a race between two forces: your withdrawal rate (pulling money out) and your return on investment (putting money back in).
If your investments earn more in a month than you withdraw, your money lasts forever. But if you withdraw more than you earn, you begin eating into your "Principal" (your initial savings). Once you start eating into the principal, the remaining balance earns less interest next month, creating a compounding downward spiral until the account hits zero.
Principal
The lump sum you start with. Preserving this is the key to longevity.
Rate of Return
The percentage your money grows annually while sitting in the account.
The Famous "4% Rule"
In retirement planning, the 4% Rule is a rule of thumb used to determine a safe withdrawal rate. It states that you can comfortably withdraw 4% of your total portfolio value in your first year of retirement, and adjust that amount for inflation every subsequent year, without running out of money for 30 years.
| Total Savings | 4% Annual Withdrawal | Monthly Budget |
|---|---|---|
| $500,000 | $20,000 | $1,666 |
| $1,000,000 | $40,000 | $3,333 |
| $2,000,000 | $80,000 | $6,666 |
* The 4% rule assumes a balanced portfolio of 50% stocks and 50% bonds based on historical market data.
3 Ways to Make Your Money Last Longer
1. Lower Your Withdrawal Rate
Dropping your withdrawal rate from 5% to 4% can add decades to your portfolio's lifespan. Consider cutting discretionary spending during market downturns.
2. Optimize Asset Allocation
Keeping all your money in cash loses to inflation. A diversified portfolio of index funds and bonds provides the growth necessary to offset withdrawals.
3. Delay Social Security
Every year you delay claiming Social Security past your full retirement age, your benefit increases by roughly 8%. This drastically reduces the burden on your portfolio later in life.
How Long Will My Money Last Calculator
Use our free How Long Will My Money Last Calculator to estimate how long your savings, retirement funds, or investment portfolio can support your lifestyle based on your spending habits, inflation, investment growth, and additional income sources.
Whether you're planning for retirement, early financial independence, or simply managing your long-term savings, this calculator helps you understand how many years your money may last under different financial scenarios.
Unlike basic retirement calculators, our tool gives you a more realistic estimate by considering factors such as inflation, annual returns, monthly expenses, and withdrawal strategies.
Calculate How Long Your Savings Will Last
Enter your financial details below to estimate:
- How many years your money will last
- Your projected savings depletion date
- The impact of inflation on your savings
- How investment returns affect longevity
- Whether your retirement plan is sustainable
Calculator Inputs
Our calculator uses the following financial variables:
- Current savings balance
- Monthly living expenses
- Expected annual investment return
- Inflation rate
- Additional monthly income
- Retirement age
- Expected lifespan
Once entered, the calculator projects your future balance year by year to estimate how long your money can continue supporting your lifestyle.
How Does the Money Last Calculator Work?
The How Long Will My Savings Last Calculator estimates the duration of your savings by subtracting your projected expenses while factoring in investment growth and inflation over time.
The formula behind the calculator evaluates:
- Annual withdrawals
- Compound growth
- Inflation-adjusted expenses
- Additional retirement income
- Safe withdrawal assumptions
For example, if you have $500,000 in retirement savings and spend $3,500 per month, the calculator estimates how long your balance can sustain those withdrawals based on your expected investment returns and inflation rate.
This allows you to make smarter financial decisions before retirement and avoid outliving your savings.
What Factors Affect How Long Your Money Will Last?
Several financial variables can significantly impact the longevity of your retirement savings and investments.
1. Monthly Spending Habits
Your monthly expenses are one of the biggest factors in determining how long your savings will last. Higher spending reduces the lifespan of your portfolio, while lower spending increases sustainability.
Reducing discretionary expenses during retirement can dramatically improve long-term financial stability.
2. Inflation
Inflation gradually increases the cost of living over time. Even moderate inflation can significantly reduce purchasing power during retirement.
For example, with a 3% inflation rate, expenses may nearly double over 25 years.
Our calculator accounts for inflation to provide a more realistic long-term estimate.
3. Investment Returns
Investment performance can extend or shorten the life of your savings.
A diversified portfolio with steady annual returns may help offset inflation and withdrawals, allowing your money to last longer during retirement.
4. Retirement Age
Retiring earlier means your savings need to last longer.
Someone retiring at age 55 may need their investments to support them for 30–40 years, while retiring later reduces pressure on long-term savings.
5. Additional Income Sources
Income from pensions, Social Security, rental properties, or part-time work can significantly extend the life of your retirement savings.
Even small supplemental income streams can reduce withdrawal pressure from investments.
How Long Will Retirement Savings Last?
One of the most common retirement questions is:
“Will my savings last throughout retirement?”
The answer depends on your spending rate, investment returns, inflation, and withdrawal strategy.
Many retirees use the 4% rule, which suggests withdrawing 4% of your portfolio annually to improve the chances that savings will last for 30 years.
For example:
- $1,000,000 retirement portfolio
- 4% annual withdrawal
- $40,000 yearly income
However, market conditions, inflation, and healthcare costs can impact these estimates significantly.
Using a retirement savings longevity calculator helps create a more personalized projection based on your actual financial situation.
Example Retirement Scenarios
How Long Will $100,000 Last?
A $100,000 savings balance may last:
- Around 2–4 years with high monthly expenses
- 5–8 years with moderate spending
- Longer with investment growth and supplemental income
How Long Will $500,000 Last in Retirement?
Depending on spending and returns, $500,000 could last:
- 10–15 years with aggressive withdrawals
- 20+ years with controlled spending
- Even longer with investment growth
How Long Will $1 Million Last?
A $1 million retirement portfolio may support:
- $40,000–$60,000 annual spending
- 25–35 years under moderate market assumptions
- Longer with lower withdrawal rates
These are estimates only and should be adjusted based on your financial goals and lifestyle.
Why Use a Money Last Calculator?
A retirement savings calculator can help you:
- Plan retirement more confidently
- Avoid running out of money
- Understand future financial risks
- Create sustainable withdrawal strategies
- Prepare for inflation and market volatility
- Adjust spending before retirement
Financial planning becomes much easier when you can visualize how long your money may realistically last.
Plan Your Financial Future With Confidence
Understanding how long your money will last is one of the most important parts of retirement planning.
Use our free How Long Will My Money Last Calculator to estimate your financial future, test different retirement scenarios, and make smarter long-term financial decisions.
More Academic Tools
Explore our complete suite of free calculators and converters
Grade Tools
Frequently Asked Questions
Disclaimer: This calculator provides estimates for informational purposes only and does not constitute professional financial advice. Market returns fluctuate and past performance does not guarantee future results.