Retirement Savings Calculator
What this calculator does
This calculator projects how much your retirement savings could grow over time based on your current balance, monthly contributions, expected rate of return, and years until retirement. It helps you see whether you are on track to meet your retirement income goals or need to adjust your savings rate.
Retirement planning is one of the most consequential financial decisions you will make, yet many people postpone it because the numbers feel abstract. By plugging in a few inputs—your current age, target retirement age, existing savings, and monthly contribution—you can see a concrete projection of your nest egg at retirement and the monthly income it could support.
Whether you contribute to a 401(k), IRA, Roth IRA, or a taxable brokerage account, the math of compound growth applies equally. The earlier you start and the more consistently you contribute, the more dramatically compounding works in your favor.
How to use it
- Enter your current retirement savings balance (e.g. $45,000).
- Enter your monthly contribution (e.g. $500).
- Enter the expected annual return as a percentage (e.g. 7% for a diversified stock portfolio).
- Enter your current age and target retirement age.
- Review the projected total savings at retirement and estimated monthly retirement income (based on a 4% withdrawal rate).
Formulas used
Future value with regular contributions: FV = P × (1 + r)^n + C × [((1 + r)^n − 1) / r] where P = current balance, r = monthly rate (annual rate / 12), n = total months, C = monthly contribution.
Estimated monthly income (4% rule): Annual withdrawal = FV × 0.04; Monthly income = Annual withdrawal / 12. The 4% rule is a guideline from retirement research suggesting you can withdraw 4% of your portfolio annually with low risk of running out over 30 years.
Examples
Example 1 — Starting early: Age 25, retire at 65, current savings $10,000, contributing $400/month at 7% return. FV ≈ $1,065,000. Estimated monthly income ≈ $3,550.
Example 2 — Mid-career catch-up: Age 40, retire at 65, current savings $120,000, contributing $800/month at 7%. FV ≈ $930,000. Estimated monthly income ≈ $3,100.
Example 3 — Aggressive saver: Age 30, retire at 55, current savings $50,000, contributing $1,500/month at 8%. FV ≈ $1,230,000. Estimated monthly income ≈ $4,100.
Tips and common mistakes
- Start as early as possible. A 25-year-old investing $300/month will likely accumulate more than a 35-year-old investing $600/month, thanks to an extra decade of compounding.
- Maximize employer match. If your employer matches 401(k) contributions, contribute at least enough to get the full match—it is an immediate 50–100% return on your money.
- Account for inflation. A 7% nominal return might be roughly 4–5% in real (inflation-adjusted) terms. Use real returns for a more conservative projection.
- Don't forget taxes. Traditional 401(k)/IRA withdrawals are taxed as income. Roth accounts grow tax-free. Factor this into your income estimates.
- Increase contributions over time. Even small annual increases (1–2% of salary) compound significantly over decades.
- The 4% rule is a guideline, not a guarantee. Actual safe withdrawal rates depend on market conditions, retirement length, and spending flexibility.