How to Use This Retirement Calculator
Enter your current age, target retirement age, current savings balance, and how much you plan to contribute each month. Then set your expected annual return and an inflation rate (defaults to 2.5%). Hit Calculate to instantly see your projected balance, its purchasing-power equivalent in today's dollars, and a year-by-year bar chart showing how your wealth builds over time.
The Power of Compound Interest
Compound interest means your investment returns themselves earn returns. The longer your money is invested, the more pronounced this effect becomes. A 30-year-old who invests $500 per month at 7% will accumulate far more than someone who starts at 40 and doubles their contribution — time in the market is often more valuable than the size of the contribution. This calculator uses the standard future-value formula:
FV = PV × (1 + r)^n + PMT × [((1 + r)^n − 1) / r]
Where PV is your current savings, r is the monthly return rate (annual rate ÷ 12 ÷ 100), n is the number of months to retirement, and PMT is your monthly contribution.
Understanding the 4% Rule
The 4% rule, derived from the landmark Trinity Study, is the most widely used retirement withdrawal guideline. It states that if you withdraw 4% of your portfolio in year one of retirement and adjust each year for inflation, your portfolio has historically survived at least 30 years in the vast majority of historical market scenarios. Practically, this means:
How much do you need?
Multiply your expected annual retirement expenses by 25 to estimate your target nest egg. If you plan to spend $60,000 per year, you would aim for a $1,500,000 portfolio. Use this calculator to find out when you might reach that milestone.
Is 4% always safe?
The 4% rule was developed using US stock and bond data from 1926 onwards. Some financial planners suggest a 3–3.5% withdrawal rate for extra safety, especially for retirements lasting 40+ years or in a lower-return environment. The key insight remains: the larger your portfolio relative to your spending, the greater your financial security.
When Should You Start Saving?
The answer is: as early as possible. Consider two savers, both targeting retirement at 65. Saver A starts at 25, contributes $400 per month, and stops at 35 — just 10 years of contributions. Saver B starts at 35 and contributes $400 per month all the way to 65 — 30 years of contributions. Assuming 7% annual returns, Saver A will likely end up with more money than Saver B, despite contributing for only one-third as long. This is the magic of starting early and letting compound interest run for decades.
Inflation and Purchasing Power
A nominal balance of $1,000,000 in 30 years is not the same as $1,000,000 today. At 2.5% annual inflation, that future million is worth roughly $477,000 in today's purchasing power. This is why this calculator shows both your nominal balance (the raw number in your account) and your inflation-adjusted balance (what that money is worth in today's dollars). Planning with the real value gives a more honest picture of your retirement readiness.