Tool: How long will savings last · Embed · All how-we-calculate pages · Questions
Purpose
Estimate how many months a starting balance lasts when you withdraw a fixed amount each month, with an optional constant annual growth rate you type. Educational only.
Month model
- Start with the current balance.
- Add growth:
growth = balance × (annualRate / 100 / 12)(0 if rate is 0). - Subtract the monthly withdrawal (or remaining balance if smaller).
- Repeat until balance is effectively zero or 600 months (50 years) is reached.
“Does not run out”
If monthly growth on the starting balance is at least the withdrawal, the balance never falls under these constant assumptions. We report that as sustainable within the model—not a market or spending guarantee.
What we intentionally leave out
- Taxes, fees, inflation adjustment of withdrawals, and sequence-of-returns risk
- Social Security, pensions, and required minimum distributions
- Live investment returns or product recommendations
- Variable spending or one-time expenses
Related
Last reviewed: August 9, 2026.
YMYL notice: This site is for education only. It is not financial, tax, or investment advice. Nestfigure is not a bank, credit union, broker, investment adviser, or fiduciary. Product terms, rates, and penalties vary—always read your institution’s disclosures before acting. Calculator results are mathematical estimates, not bank quotes.