Money Last Calculator
If you stopped earning income today, how long would your money last?
The Money Last Calculator helps you estimate:
- Your net monthly burn rate
- How many months and years your savings will last
- Your projected depletion date
- Total interest earned before funds run out
This tool is ideal for retirement planning, career breaks, emergency funds, or financial independence planning.
How the Money Last Calculator Works
The calculator simulates your finances month by month, accounting for:
- Monthly expenses
- Optional monthly income
- Interest earned on remaining savings
- Inflation increasing expenses over time
It continues calculating until your balance reaches zero.
Step-by-Step Breakdown
1️⃣ Net Monthly Burn Rate
Burn Rate = Monthly Expenses − Monthly Income
If income covers expenses, your money will not run out.
If expenses exceed income, savings are used to cover the difference.
2️⃣ Monthly Interest Calculation
Interest is compounded monthly:
Monthly Interest = Balance × (Annual Interest Rate ÷ 12)
Higher interest helps your savings last longer.
3️⃣ Inflation Adjustment
Expenses increase monthly based on inflation:
New Expenses = Current Expenses × (1 + Monthly Inflation Rate)
Even small inflation rates significantly shorten how long savings last.
Inflation data is commonly tracked by the U.S. Bureau of Labor Statistics.
4️⃣ Monthly Simulation
Each month the calculator:
- Adds interest
- Subtracts net expenses
- Adjusts expenses for inflation
- Repeats until savings reach zero
It then calculates:
- Total months
- Total years
- Estimated depletion date
Example Calculation
Let’s assume:
- Total Savings: $250,000
- Monthly Expenses: $4,000
- Monthly Income: $1,000
- Interest Rate: 4%
- Inflation Rate: 3%
Net Burn Rate
$3,000 per month
Result
Savings may last approximately 7–9 years depending on inflation impact.
Without inflation, savings would last longer. Inflation steadily increases your withdrawal amount over time.
Why Inflation Matters
Inflation reduces purchasing power over time.
For example:
- 3% annual inflation doubles expenses in about 24 years
- Even 2% inflation compounds significantly
This is why long-term financial planning must factor inflation.
How to Use the Calculator
1. Enter Total Savings
Your current available cash or investment balance.
2. Enter Monthly Expenses
Include housing, food, insurance, utilities, and discretionary spending.
3. Enter Monthly Income (Optional)
Include Social Security, rental income, pensions, or part-time work.
4. Enter Annual Interest Rate
Estimate expected investment return.
5. Enter Annual Inflation Rate
Default is 3%.
6. Click “Calculate”
The calculator instantly shows your timeline and depletion date.
When Should You Use This Tool?
This calculator is helpful if you are:
- Planning early retirement
- Considering a career break
- Living off savings
- Evaluating emergency funds
- Modeling FIRE (Financial Independence, Retire Early) scenarios
- Assessing risk tolerance
Important Considerations
✔ Assumes constant interest rate
✔ Assumes constant inflation rate
✔ Does not include taxes
✔ Does not include market volatility
✔ Assumes expenses inflate steadily
✔ Stops calculation after 100 years (1,200 months max)
For long-term retirement planning, consider consulting a financial professional.
How to Make Your Money Last Longer
Here are strategies that significantly extend savings:
Reduce Burn Rate
Even a $500 reduction in expenses can add years.
Increase Income
Part-time work or passive income reduces withdrawals.
Improve Returns
Higher investment returns compound growth.
Manage Inflation Risk
Diversify assets to hedge inflation impact.
Delay Major Purchases
Large withdrawals dramatically shorten timelines.
Quick Rule of Thumb (No Inflation)
If you ignore inflation and interest:
Months Money Lasts = Total Savings ÷ Net Monthly Burn
Example:
$120,000 ÷ $3,000 = 40 months (~3.3 years)
But real-world results differ due to compounding and inflation.
Frequently Asked Questions (FAQs)
1. Does this include investment volatility?
No, it assumes steady returns.
2. What if income exceeds expenses?
Your money won’t run out under current assumptions.
3. Is inflation really that important?
Yes, especially for long time horizons.
4. What’s a realistic interest rate?
Depends on your investment allocation.
5. Should I use nominal or real returns?
This calculator uses nominal returns and separate inflation.
6. Can I use this for retirement?
Yes, it’s commonly used for retirement planning.
7. Does it include Social Security?
Only if you enter it as monthly income.
8. What if I underestimate expenses?
Your money may run out sooner than projected.
9. Can this model safe withdrawal rates?
It approximates them but is not a full SWR calculator.
10. Is this better than the 4% rule?
It’s more customizable than simple rules of thumb.
Final Thoughts
The Money Last Calculator gives you a realistic projection of how long your savings can support your lifestyle. By factoring in inflation and interest, it provides a clearer picture than simple division.
Understanding your burn rate and compounding effects can help you make smarter decisions, adjust spending, and improve long-term financial security.