Compound Interest Calculator
Compound interest is one of the most powerful concepts in personal finance. Unlike simple interest, which is calculated only on the principal, compound interest is calculated on the principal plus all previously earned interest. Over time, this creates a snowball effect that can dramatically grow your savings or investments.
This free compound interest calculator shows you exactly how much your money will grow over any time period, at any interest rate, with any compounding frequency — monthly, quarterly, semi-annually, annually, or daily.
How to use it: enter your initial investment amount, the annual interest rate, the number of years, and how frequently the interest compounds. Click Calculate Growth to see your final balance, total interest earned, and how much of the final amount is your original investment versus the interest it generated.
The formula used is: A = P × (1 + r/n)^(n×t), where P is the principal, r is the annual rate, n is the compounding frequency, and t is the time in years.
Common uses include projecting savings account growth, estimating investment returns, comparing different compounding frequencies, planning for long-term financial goals, and understanding the real cost of compound interest on debt.
Frequently Asked Questions About Compound Interest Calculator:
Q: What is the difference between simple and compound interest?
A: Simple interest is calculated only on the original principal. Compound interest is calculated on the principal plus accumulated interest, causing the balance to grow faster over time.
Q: Which compounding frequency is best?
A: More frequent compounding means slightly higher returns. Daily compounding produces marginally more than monthly, which produces more than annual. The difference becomes significant over long periods.
Q: Can I use this for savings accounts?
A: Yes. Enter your deposit as the initial investment, the account’s annual interest rate, and select the compounding frequency your bank uses (usually monthly or daily).
Q: Does this include additional monthly contributions?
A: This calculator covers a single lump sum investment. For calculations with regular monthly contributions, use a dedicated savings or retirement calculator.
Related tools: Retirement Savings Calculator — Loan Repayment Calculator — Salary After Tax Calculator
For more on how age is calculated across different calendar systems, see this overview from Wikipedia.