If you are wondering how long will my money last the answer depends on more than your current savings balance. Your monthly withdrawals, investment return, inflation, taxes, fees and the length of time you need the money to support you can all change the result.
A how long will my money last calculator helps turn those variables into a practical estimate. You enter your starting balance,expected withdrawals and an assumed rate of return and the calculation projects how long the money may last under those assumptions.
The result is not a guarantee. Investment returns are uncertain inflation changes purchasing power and actual taxes and fees can reduce the amount available for spending. But a properly structured calculator can help you understand the relationship between savings withdrawals investment growth and time.
This guide explains how the calculation works which inputs matter most how to interpret the result why inflation and investment volatility matter and how to use the ExpoVault calculator for practical financial planning.
Table of Contents
What Is a How Long Will My Money Last Calculator?
A how long will my money last calculator estimates how many months or years a savings or investment balance could support withdrawals before the balance reaches zero under specified assumptions.
The basic calculation considers three major variables:
| Input | What it represents |
| Starting balance | Money available at the beginning of the projection |
| Withdrawal amount | Money removed regularly for spending |
| Expected return | Assumed growth of the remaining balance |
More advanced calculations can also account for:
- Inflation
- Increasing withdrawals
- Taxes
- Investment fees
- Other income
- Retirement age
- Onetime expenses
- Different withdrawal schedules
The central idea is straightforward:
Starting money + investment growth − withdrawals = remaining balance
If withdrawals consistently exceed the amount generated by the portfolio the balance can eventually reach zero. If investment growth is sufficient to cover withdrawals the money may last much longer or potentially remain positive throughout the modeled period.
The result therefore depends heavily on the assumptions you enter.
How Does the Calculator Work?
A How Long Will My Money Last Calculator starts with your current balance and then projects the balance forward through time based on withdrawals, investment returns, and other assumptions.
Suppose for example that you have $500,000 and plan to withdraw $2,500 per month. If the money remains completely uninvested, the simplest calculation would be:
$500,000 ÷ $2,500 = 200 months
That equals approximately 16.7 years.
However, this simple division ignores investment growth and inflation.
If the remaining balance earns a return while you withdraw money, the portfolio may last longer than the simple calculation suggests. On the other hand if your withdrawals increase because of inflation the portfolio may be depleted sooner.
A calculator can therefore model the balance repeatedly:
New balance = Previous balance + investment growth − withdrawal
For monthly calculations the annual return can be converted into an approximate monthly rate. A simplified model may use:
Monthly rate = Annual rate ÷ 12
A more precise effective monthly conversion can use:
Monthly rate = (1 + annual return)^(1/12) − 1
The exact method depends on the calculator’s methodology.
This distinction matters because a result is only meaningful when you understand how the calculator treats investment returns, withdrawals, inflation, taxes and fees.
What Information Do You Need?
To use a How Long Will My Money Last Calculator, you generally need several pieces of information, including your starting balance, withdrawals, expected return, and inflation assumptions.
Starting balance
This is the amount you currently have available for the calculation.
It could represent:
- Retirement savings
- Investment accounts
- Cash savings
- A lump sum amount
- A portfolio
- Proceeds from selling an asset
If you have multiple accounts decide whether you want to calculate them together or separately.
Monthly or annual withdrawal
This represents how much money you expect to take from the balance.
For example:
- $2,000 per month
- $3,500 per month
- $50,000 per year
Be consistent. If the calculator asks for a monthly withdrawal convert annual spending into a monthly figure rather than entering an annual amount into the wrong field.
Expected annual return
This is the assumed rate at which the remaining balance grows.
It is important to understand that this is an assumption not a guaranteed investment return.
A calculator using a 5% annual return does not mean your portfolio will actually earn 5% every year.
Real investments can experience:
- Positive returns
- Negative returns
- Flat periods
- Large market declines
- Uneven yearly performance
Investor.gov notes that investment risk includes market volatility and that inflation can reduce purchasing power.
Inflation rate
Inflation matters because the same amount of money may buy fewer goods and services in the future.
For example if your current monthly spending is $3,000 you may eventually need more than $3,000 to purchase the same basket of goods and services.
The Bank of England explains that inflation reduces the purchasing power of money: when prices rise a unit of currency buys less.
A calculator can model this by increasing your withdrawals over time.
How Do You Calculate How Long Your Money Will Last?
There are several approaches depending on how sophisticated the calculation needs to be.
Simple calculation with no investment growth
The simplest method is:
Years = Starting balance ÷ Annual withdrawals
For example:
Hypothetical example:
Starting balance: $300,000
Monthly withdrawal: $2,000
Annual withdrawals:
$2,000 × 12 = $24,000
Estimated duration:
$300,000 ÷ $24,000 = 12.5 years
This is easy to understand but it assumes no investment return and no change in withdrawals.
Calculation with investment growth
When the remaining balance earns a return the calculation becomes more complex.
A simplified periodic model can be represented as:
Balance at next period = Current balance × (1 + return) − withdrawal
The process is repeated until the balance reaches zero.
If withdrawals increase with inflation the withdrawal amount changes during the projection.
For example:
Year 1 withdrawal: $30,000
Annual inflation assumption: 3%
Year 2 withdrawal:
$30,000 × 1.03 = $30,900
Year 3:
$30,900 × 1.03 = $31,827
This illustrates why inflation can materially affect long term spending plans.
Why Your Withdrawal Rate Matters
One of the most useful figures to calculate is your initial withdrawal rate.
The basic formula is:
Withdrawal rate = Annual withdrawal ÷ Starting balance × 100
For example suppose you have $500,000 and withdraw $25,000 during the first year.
$25,000 ÷ $500,000 × 100 = 5%
Your initial withdrawal rate is therefore 5%.
A higher withdrawal rate generally puts greater pressure on the portfolio because more money is leaving relative to the starting balance.
A lower withdrawal rate leaves more capital available to potentially compound.
Historical retirement research has often examined withdrawal rates over specific periods including the widely discussed 4% rule. However that rule is a historical planning framework rather than a guarantee that a portfolio will last for every person or market environment. NerdWallet’s 2026 retirement guidance also notes that changing market conditions can affect how useful a fixed withdrawal strategy is.
The important point is not to treat a particular percentage as universally “safe.” Instead use the withdrawal rate as one way to understand the relationship between your spending and available assets.
How Inflation Changes How Long Your Money Lasts
Inflation is one of the easiest factors to overlook.
Imagine that you currently spend $3,000 each month. If prices rise over time maintaining the same lifestyle may require a larger withdrawal.
A projection that keeps your withdrawal permanently at $3,000 could therefore make your money appear to last longer than a projection that increases withdrawals with inflation.
Consider this hypothetical example:
Starting balance: $500,000
Initial monthly withdrawal: $2,500
Annual inflation assumption: 3%
The first year’s annual withdrawal is:
$2,500 × 12 = $30,000
If withdrawals increase by 3% each year the spending requirement grows over time.
This does not mean inflation will actually be exactly 3%. It simply demonstrates how an assumption affects the calculation.
For planning purposes it can be useful to run multiple scenarios rather than relying on one inflation estimate.
For example:
- 0% inflation
- 2% inflation
- 3% inflation
- A higher stress test assumption
Comparing the outputs shows how sensitive your money’s longevity is to rising expenses.
How Investment Returns Affect the Result
Investment return can significantly change the projection.
Consider two hypothetical calculations using the same starting balance and withdrawals but different assumed returns.
| Starting balance | Monthly withdrawal | Assumed return | Inflation | Purpose |
| $500,000 | $2,500 | 0% | 0% | Simple baseline |
| $500,000 | $2,500 | 3% | 0% | Moderate growth illustration |
| $500,000 | $2,500 | 5% | 0% | Higher growth illustration |
| $500,000 | $2,500 | 5% | 3% | Inflation adjusted illustration |
These are hypothetical scenarios not forecasts.
The important lesson is that a small change in an assumed return can produce a large difference over a long period.
However assuming a higher return simply to make the result look better can create a misleading projection.
Investment returns are uncertain. A portfolio might earn considerably more than an assumed average in one year and lose money in another.
Why Sequence of Returns Matters
A major limitation of a simple calculator is that it may use an average or constant annual return.
Real markets do not normally behave that way.
Imagine two portfolios that both average 5% over a long period. One experiences several strong years early in retirement. The other experiences a significant market decline shortly after withdrawals begin.
The final average return might look similar but the retirement outcomes can be very different.
This is known as sequence of returns risk.
It matters because withdrawals force an investor to remove money from the portfolio. If the portfolio falls sharply while withdrawals continue fewer assets remain available to participate in a later recovery.
This is one reason a calculator result should be viewed as a projection rather than a promise.
A more sophisticated retirement analysis may use multiple market scenarios or simulations rather than assuming the same return every year.
How Taxes and Fees Can Reduce the Result
The amount you withdraw from an account is not always the same as the amount available for spending.
Taxes may reduce the amount you actually receive from certain retirement or investment accounts.
For U.S. users tax treatment depends on the account type and circumstances. For example the IRS states that distributions from many retirement plans are generally included in income subject to applicable exceptions and rules. The IRS also has specific required minimum distribution rules for many traditional retirement accounts.
Fees can also reduce investment growth.
Potential costs may include:
- Fund expenses
- Advisory fees
- Trading costs
- Account fees
- Tax costs
- Withdrawal related charges
The exact treatment varies by country account provider and investment.
For this reason your calculator assumptions should be clear about whether the expected return is:
- Before fees
- After fees
- Before taxes
- After taxes
Do not mix these figures without adjusting the model.
How to Use the ExpoVault Calculator
The ExpoVault how long will my money last calculator can be used as a practical starting point for estimating the lifespan of your savings.
Begin with your current financial position rather than an idealized target.
Enter:
- Starting balance — the amount available for the projection.
- Withdrawal amount — how much you expect to take out regularly.
- Expected annual return — a hypothetical investment growth assumption.
- Inflation rate if the calculator provides the option.
- Time horizon if applicable.
Then review the projected result.
Do not stop at the headline number.
Also consider what happens when you change the assumptions.
For example run one calculation using your expected spending and then test:
- Lower investment returns
- Higher inflation
- Higher monthly withdrawals
- Lower monthly withdrawals
- A longer retirement period
- Additional income
This approach helps you understand how sensitive your plan is to changing circumstances.
Practical Example: Estimating the Lifespan of $500,000
Hypothetical example:
Suppose someone has:
- Starting savings: $500,000
- Monthly withdrawal: $2,500
- Annual return assumption: 5%
- Annual inflation assumption: 3%
A monthly projection using these assumptions produces an illustrative result of roughly 20.6 years before depletion, depending on the exact timing and methodology used.
This figure is not a prediction of what will happen to a real portfolio.
It assumes a smooth return pattern and a particular withdrawal schedule. Real investment returns can fluctuate significantly and taxes, fees changes in spending and unexpected expenses could alter the result.
The value of the example is therefore the relationship between the variables.
If the monthly withdrawal increases the projected lifespan generally decreases.
If the starting balance increases the projected lifespan generally increases.
If the assumed return increases the mathematical projection may last longer—but taking a higher return assumption also introduces greater uncertainty if that return requires higher investment risk.
How Different Users Can Apply the Calculator
A How Long Will My Money Last Calculator is not limited to retirees.
Retirees
Someone already withdrawing from investments can estimate how long existing savings could support current spending.
People planning retirement
Someone who has not retired yet can test different combinations of savings spending and investment assumptions.
Freelancers
A freelancer with irregular income can estimate how long a financial reserve may last during a period with reduced earnings.
Business owners
A business owner can model how long a personal reserve could support household expenses while business income fluctuates.
Families
A household can examine whether savings may cover expenses during a planned career break, relocation, education period, or other temporary reduction in income.
Investors
An investor can use the calculation to understand how withdrawal rates affect portfolio longevity rather than focusing only on the size of the portfolio.
Common Mistakes When Estimating How Long Money Will Last
Several mistakes can make a projection misleading.
Ignoring inflation
A fixed withdrawal may not maintain the same purchasing power over decades.
Using an unrealistically high return
A higher assumed return can make the mathematical result look attractive but may not reflect the risk associated with achieving it.
Ignoring taxes
Your gross withdrawal may not equal your spendable income.
Ignoring fees
Investment expenses reduce the amount available for compounding.
Medical costs home repairs, education, travel, vehicle replacement and other large expenses can disrupt a smooth monthly spending pattern.
Forgetting irregular expenses
Treating the result as guaranteed
A calculator produces an estimate based on assumptions. It cannot predict future markets.
Using one scenario
One projection is less informative than testing several reasonable scenarios.
Confusing nominal and real returns
A return stated before inflation is different from a return measured after inflation.
For example a 5% nominal return does not mean your purchasing power increases by exactly 5%.
Forgetting other income
Pensions, Social Security, rental income, business income or other reliable sources may reduce the amount that must come from savings.
How Can You Make Your Money Last Longer?
There is no single strategy that guarantees that savings will last for a particular period. However the calculation highlights several variables that can be examined.
You can test the effect of:
- Reducing withdrawals
- Increasing savings before withdrawals begin
- Delaying withdrawals
- Accounting for other income
- Adjusting spending during weak market periods
- Reviewing investment assumptions
- Considering taxes and fees
- Maintaining an emergency reserve
- Testing longer time horizons
The purpose of these adjustments is not to promise a particular outcome. It is to understand how different assumptions affect the mathematical projection.
For example reducing annual withdrawals from $40,000 to $35,000 may have a meaningful effect on a portfolio’s longevity. The exact effect depends on the starting balance, return, inflation, taxes and withdrawal schedule.
What the Calculator Cannot Tell You
A How Long Will My Money Last Calculator is useful for estimating savings longevity, but it cannot answer every retirement or financial planning question.
It cannot reliably predict:
- Future stock market returns
- Future inflation
- Unexpected expenses
- Future tax legislation
- Your future spending habits
- Major health or family expenses
- Changes in employment
- Currency movements
- Individual investment performance
It also cannot determine whether a particular investment is appropriate for you.
For U.S. retirement accounts specific withdrawal and tax rules can apply. For example the IRS generally requires minimum distributions from many traditional IRAs and retirement plans beginning at age 73, subject to the applicable rules and exceptions.
Other countries have different systems. U.K. and Pakistani retirement, tax, pension and investment rules should not be assumed to follow U.S. rules.
FAQs
How does a how long will my money last calculator work?
It projects your starting balance forward while accounting for withdrawals and depending on the calculator, investment returns and inflation. The calculation continues until the modeled balance reaches zero or the selected projection period ends.
What information do I need?
Most calculators require your starting savings balance, withdrawal amount and expected investment return. More detailed calculators may also ask for inflation, taxes, fees, other income, age or a planned retirement period.
Does inflation affect how long my money lasts?
Yes. If withdrawals increase to maintain purchasing power, more money is withdrawn over time. This can cause savings to run out sooner than a calculation using a fixed withdrawal amount.
Is the calculator result guaranteed?
No. The result is an estimate based on assumptions. Actual investment returns, inflation, taxes, fees, spending and unexpected expenses can produce a different outcome.
What is a withdrawal rate?
A withdrawal rate measures annual withdrawals as a percentage of the starting balance. For example withdrawing $20,000 from $500,000 represents a 4% initial withdrawal rate.
Should I include investment returns?
If the money will remain invested while you withdraw it including an assumed return can make the projection more representative of the intended scenario. However the return should be treated as an assumption rather than a guaranteed result.
Should I include Social Security or pension income?
If you receive reliable income from another source you can generally account for it by reducing the amount your savings need to provide. The exact treatment depends on the calculator and the nature of that income.
Does the calculator include taxes?
Not necessarily. Some calculators include a tax input while simpler models do not. If taxes materially affect your available income the tax treatment should be considered separately or incorporated into the assumptions.
Can my money last indefinitely?
Mathematically a portfolio may remain positive if investment growth consistently offsets withdrawals. However real world investment returns fluctuate so indefinitely in a calculator should not be interpreted as a guarantee that the money can never run out.
How often should I recalculate?
Recalculate when an important assumption changes such as your savings balance, spending level, expected retirement date, other income, investment assumptions or inflation outlook. Periodic reviews can help you understand whether the original projection still reflects your circumstances.
Conclusion
Knowing how long will my money last is fundamentally a question of balancing available capital against spending over time.
A How Long Will My Money Last Calculator makes that relationship easier to understand by combining your starting balance, withdrawals, investment-growth assumptions, and, when supported, inflation and other variables.
The most useful approach is to treat the result as a planning estimate not a prediction. Start with realistic assumptions, examine different scenarios and pay attention to withdrawal rates, inflation, investment volatility, taxes, fees and unexpected expenses.
Use the ExpoVault calculator to test your numbers compare scenarios and understand how changes in spending or assumptions affect the projected lifespan of your savings.
