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Investment Calculators

From compound growth and inflation-adjusted returns to retirement savings and portfolio analysis — our free investment calculators help you model the future value of your money.

Investment Glossary — Key Terms Explained

CAGR
Compound Annual Growth Rate — the rate at which an investment grows from start to end value assuming it grew at a steady compounded rate each year. CAGR = (End Value ÷ Start Value)^(1/years) − 1.
Real Return
Investment return adjusted for inflation. If your portfolio grows 8% but inflation is 3%, your real return is approximately 5%. Real return = (1 + nominal return) ÷ (1 + inflation rate) − 1.
Dollar-Cost Averaging (DCA)
Investing a fixed amount at regular intervals regardless of price. Buys more shares when prices are low, fewer when high, reducing the impact of volatility on the average purchase price.
Compound Annual Growth Rate
CAGR — see above. The most useful single number for comparing investment performance across different time periods.
Time Value of Money
The principle that a dollar today is worth more than a dollar in the future because today's dollar can be invested and grow. The foundation of all investment return calculations.

Frequently Asked Questions

What is a good annual investment return?

The US S&P 500 has historically returned approximately 10% per year nominally (7% inflation-adjusted). A diversified global portfolio typically returns 6–9% nominally. Individual stocks and alternative investments vary enormously. Past performance does not guarantee future results.

How does compound interest grow investments?

Compound interest means your returns earn returns. $10,000 at 8% annually: after 10 years = $21,589; after 20 years = $46,610; after 30 years = $100,627. The doubling happens every 9 years at 8% (use the Rule of 72: 72 ÷ rate = doubling years).

What is the Rule of 72?

A quick estimate of how long it takes to double your money: doubling years = 72 ÷ annual return %. At 6% return, money doubles in 12 years. At 9%, in 8 years. At 12%, in 6 years. It's an approximation — the compound interest calculator gives exact figures.

How much should I save for retirement?

A common guideline: save 15% of income from age 25 and aim for 25× your annual expenses at retirement (the 4% withdrawal rule). If you need $40,000/year in retirement, target a $1,000,000 portfolio. Starting later requires a higher savings rate — use the retirement calculator for your specific situation.