Compound Interest Calculator

Calculate compound interest growth on investments over time.

Calculator Inputs

Enter your details and click "Calculate" to see your results

About This Calculator

Calculate compound interest growth on investments over time. This calculator helps you make informed financial decisions by providing accurate calculations and detailed breakdowns.

Use this tool to plan your finances, compare options, and understand the long-term impact of your financial decisions.

Compound Interest Formulas & Equations

Basic Compound Interest Formula

A = P(1 + r/n)^(nt)
  • A = Final amount (principal + interest)
  • P = Principal (initial investment)
  • r = Annual interest rate (decimal)
  • n = Number of times interest compounds per year
  • t = Time in years

With Regular Contributions

A = P(1 + r/n)^(nt) + PMT × [((1 + r/n)^(nt) - 1) / (r/n)]
  • PMT = Regular contribution amount
  • Second term calculates the future value of regular payments

Continuous Compounding

A = P × e^(rt)

When interest compounds continuously (n → ∞), we use Euler's number (e ≈ 2.71828).

Example: The Power of Compounding

$10,000 invested at 7% for 30 years:

  • • Monthly compounding: A = $10,000 × (1 + 0.07/12)^(12×30) = $81,164.97
  • • Total interest earned: $71,164.97
  • • Your money grew 8.1× without adding a penny!

Frequently Asked Questions

How accurate are these calculations?

Our calculators use industry-standard formulas and are designed to provide accurate estimates. However, actual results may vary based on your specific situation and lender terms.

Can I trust these results?

Yes, our calculations are based on proven financial formulas. However, always consult with a financial advisor for personalized advice.