How It Works
This calculator projects your retirement balance the same way the Compound Interest Calculator does — monthly compounding, with monthly contributions — but uses your current and target retirement age to determine the time period instead of asking for a raw number of years.
It also shows what that projected balance could support annually using the 4% rule, a commonly cited starting point from retirement research (not personalized advice, and not a guarantee that any balance will last a specific number of years).
Formula
- P — Current retirement savings
- C — Monthly contribution
- r — Monthly interest rate (annual return ÷ 12)
- n — Months until retirement (years × 12)
Example
Example inputs: Current age 30, retirement age 65, $15,000 current savings, $400/month contribution, 7% expected annual return.
Result: Projected balance at retirement: $893,014.12. Estimated annual income (4% rule): $35,720.56.
Frequently Asked Questions
What is the 4% rule?
It's a widely referenced guideline from retirement research suggesting that withdrawing about 4% of a portfolio in the first year of retirement, then adjusting for inflation each year after, has historically had a reasonable chance of lasting 30 years. It's a starting point for discussion, not a guarantee or personalized advice — actual sustainable withdrawal rates depend on markets, spending, and how long retirement lasts.
Does this include Social Security?
No. This calculator only projects your own contributions and savings growth. Social Security, pensions, or other income sources would be additional.
What if I don't know what return to expect?
This calculator doesn't recommend a rate — try a few different assumptions to see how sensitive your projection is to the return you use.
This calculator provides estimates for informational purposes only and should not be considered financial, tax, or legal advice.