Investment Growth Calculator
Calculate how your investments will grow over time with compound interest. See your future value, wealth milestones, and compare different scenarios to understand the power of consistent investing.
Investment Details
Future Value
In today's dollars: $447,876
Contributions vs Earnings
Wealth Milestones
Growth Over Time
What If Scenarios
| Scenario | Future Value | Difference |
|---|---|---|
| Your Plan | $854,537 | — |
| +$100/month | $1,003,573 | +$149,036 |
| +1% Return | $1,062,678 | +$208,140 |
| Start with $10k more | $963,894 | +$109,357 |
The Power of Compound Interest
Rule of 72
Divide 72 by your annual return to estimate how many years it takes to double your money. At 8% return, money doubles every 9 years. At 10%, every 7.2 years.
Time is Your Greatest Asset
Starting 10 years earlier can more than double your final wealth. The earlier you start, the more time compound interest has to work. Even small amounts grow significantly over decades.
Consistency Beats Timing
Regular monthly contributions through market ups and downs (dollar cost averaging) often outperforms trying to time the market. Automate your investments and stay consistent.
Frequently Asked Questions
What is a realistic rate of return to expect?
- S&P 500 (stocks): ~10% nominal, ~7% real (after inflation)
- Balanced portfolio (60/40): ~7-8% nominal
- Bonds: ~4-5% nominal
- High-yield savings: ~4-5% (currently)
Be conservative in projections—it's better to be pleasantly surprised than disappointed.
What is the Rule of 72?
The Rule of 72 estimates how long it takes to double your money:
Years to Double = 72 ÷ Annual Return Rate
- At 6% return: 72 ÷ 6 = 12 years to double
- At 8% return: 72 ÷ 8 = 9 years to double
- At 10% return: 72 ÷ 10 = 7.2 years to double
Should I account for inflation?
Yes! Inflation erodes purchasing power over time. A million dollars in 30 years won't buy what it does today. Use "real" (inflation-adjusted) returns for more accurate planning:
Real Return ≈ Nominal Return - Inflation Rate
If you expect 8% returns and 3% inflation, your real return is about 5%.
How does compounding frequency affect returns?
More frequent compounding slightly increases returns, but the difference is small:
- Annual: $10,000 at 8% for 30 years = $100,627
- Monthly: $10,000 at 8% for 30 years = $109,357
- Daily: $10,000 at 8% for 30 years = $110,232
The bigger impact comes from the rate of return and time invested.