Investment Calculator

Calculate interest, depreciation, and investment growth.

The Power of Compound Interest

Compound interest is often called the "eighth wonder of the world." Unlike simple interest, where you earn money only on your initial principal, compound interest allows you to earn interest on your interest. Over long periods (10+ years), this exponential growth can turn modest monthly contributions into substantial wealth. This calculator helps you visualize that curve.

Investment Vehicles Explained

Mutual Funds & ETFs: Baskets of stocks that offer instant diversification. Historically, the S&P 500 has returned about 10% annually before inflation.

High-Yield Savings: These accounts pay higher interest rates than traditional checking accounts, making them ideal for emergency funds or short-term goals.

CDs (Certificate of Deposit): You lock your money away for a set term (e.g., 1 year) in exchange for a guaranteed interest rate. They are extremely safe but offer lower returns than stocks.

Inflation and Real Returns

When calculating long-term growth, it's important to remember inflation (the rising cost of goods). If your investment grows by 7% but inflation is 3%, your "real" return (purchasing power increase) is only about 4%. Our advanced modes help you account for depreciation and net present value (NPV) to make smarter decisions.

Start Early, Invest Consistently

Time is your biggest asset. Investing $500/month starting at age 25 yields significantly more at age 60 than starting at age 35, even if you invest double the amount later. Use the "Recurring Deposit" mode to see how consistent habits impact your financial future.

Measuring Investment Success: ROI vs. CAGR

Investing without measuring performance is like driving with your eyes closed. The UnitMaster Investment Calculator helps you translate raw numbers into actionable growth metrics.

ROI (Return on Investment)

ROI is the simplest metric. It answers: "For every dollar I put in, how many did I get back?"
Formula: (Net Profit / Total Investment) * 100

CAGR (Compound Annual Growth Rate)

ROI can be misleading for long-term investments. A 50% ROI looks great, but if it took 10 years to achieve, that's actually a terrible return (only ~4% per year).CAGR smooths out the volatility and tells you the annual growth rate you effectively earned.

Types of Investments

  • Fixed Deposits (CDs): Low risk, guaranteed returns, but often barely beat inflation.
  • Equities (Stocks): High risk, high potential return. Historically average 8-10% (S&P 500) over long periods.
  • Real Estate: Offers both rental yield (cash flow) and capital appreciation (growth).

The Rule of 72

Want to know how fast your money will double? Divide 72 by your interest rate.

  • At 6% return: 72 / 6 = 12 years to double.
  • At 12% return: 72 / 12 = 6 years to double.
Investment Calculator - Calculate Compound Interest & Growth | UnitMaster