Util Hub.io
← Back to Tools

Compound Interest Calculator

See how your investment grows with compound interest and monthly contributions.

Enter values to see your investment grow

🔒 All calculations happen in your browser — no data is sent to any server. Results are estimates and do not account for inflation or taxes.

Related Tools

Personal Loan CalculatorCalculate personal loan payments, interest, and credit score impacts.Age CalculatorCalculate your exact age in years, months, days, hours and minutes.Percentage CalculatorCalculate percentages — find X% of Y, percentage change, increase and decrease.Random Number GeneratorGenerate cryptographically secure random numbers, roll dice, flip coins.BMI CalculatorCalculate your BMI with metric or imperial units and see your category.Tip CalculatorCalculate tips and split bills instantly. Choose tip percentage, divide among friends, see per-person totals with round up option.

Compound Interest Calculator

Compound interest is interest earned on both your initial deposit and previously earned interest — creating a snowball effect that accelerates your savings growth. Our free calculator shows you exactly how your money will grow over any time period with customizable compounding frequency and monthly contributions. Enter your starting amount, monthly contribution, interest rate, and time horizon to see a detailed breakdown with a year-by-year balance table.

How to use Compound Interest Calculator

  • Enter your initial deposit amount.
  • Add a monthly contribution (optional).
  • Set the annual interest rate and compounding frequency.
  • Choose your investment period in years to see the growth breakdown.

Features

  • Initial deposit and monthly contributions — Model realistic savings scenarios.
  • Compounding frequency — Daily, monthly, quarterly, or annually.
  • Year-by-year balance table — See your balance grow year by year.
  • Contributions vs interest breakdown — See how much comes from deposits vs earned interest.
  • Adjustable investment period — From 1 to 50 years.
  • 100% browser-based — No data sent to any server.

Frequently Asked Questions

How does compound interest differ from simple interest?

Simple interest is calculated only on the principal amount. Compound interest is calculated on the principal plus all accumulated interest. Over time, compound interest produces significantly larger returns because you earn interest on your interest.

How often should interest be compounded?

More frequent compounding produces slightly higher returns. Daily compounding yields more than monthly, which yields more than annually. The difference becomes more significant with larger amounts and longer time periods. Our calculator lets you compare all options.

How much will $10,000 grow in 10 years?

It depends on the interest rate and compounding frequency. At 7% annual return compounded monthly, $10,000 grows to approximately $20,097 in 10 years. Add monthly contributions of $200 and it reaches approximately $54,696. Use our calculator to model your specific scenario.