Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Years savings will last
6.3
Total months
76
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How to use this
- 1Enter starting savings balance ($).
- 2Enter monthly withdrawal ($).
- 3Enter annual interest/return rate (%).
- 4Read your years savings will last on the right — it updates as you type.
- 5Hit Share to keep the scenario or send it to someone.
About this calculator
When you draw down a balance faster than it earns interest, the account eventually hits zero; this calculator simulates monthly withdrawals against ongoing interest to find exactly how many months and years your savings will last at a given withdrawal rate and return.
Worked example
Using the values the calculator loads with:
Inputs
- Starting savings balance: 100000 $
- Monthly withdrawal: 1500 $
- Annual interest/return rate: 4 %
Results
- Years savings will last: 6.3
- Total months: 76
What each field means
Inputs
- Starting savings balance ($)
- The starting savings balance used in the calculation, measured in $. Starts at 100000 $ so you have a working example on load.
- Monthly withdrawal ($)
- The monthly withdrawal used in the calculation, measured in $. Starts at 1500 $ so you have a working example on load.
- Annual interest/return rate (%)
- The annual interest/return rate used in the calculation, measured in %. Starts at 4 % so you have a working example on load. Accepted range: 0–15 %.
Results
- Years savings will last
- Returned as a decimal number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Total months
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How long will my savings last?
$100,000 earning 4% annually while withdrawing $1,500/month lasts about 8 years and 5 months (101 months) before hitting zero.
What if my withdrawal is less than my interest earned?
Then your balance actually grows over time instead of depleting — you're living off interest only, and the principal never gets touched, meaning your savings technically last indefinitely.
Does inflation affect this calculation?
This model uses a nominal, fixed withdrawal amount; in reality your real purchasing power erodes with inflation, so many retirees increase withdrawals annually, which shortens how long the balance actually lasts in real terms.
How is this different from retirement withdrawal calculators?
This tool answers 'when does the money run out at this exact spending rate,' while a sustainable withdrawal rate calculator works backward to find a spending rate designed to never fully deplete the balance.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). How Long Will My Savings Last?. Retrieved from https://www.revenuelab.fyi/toolbox/how-long-will-my-savings-last
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/how-long-will-my-savings-last" target="_blank" rel="noopener">How Long Will My Savings Last? — RevenueLab</a> (2026).</p>
Source: [How Long Will My Savings Last? — RevenueLab](https://www.revenuelab.fyi/toolbox/how-long-will-my-savings-last) (2026).