Interest Calculator
Calculate simple or compound interest on any principal amount.
How this is calculated
Simple: I = P x r x t
Compound: A = P(1 + r)t
Frequently Asked Questions About Interest Calculator
An interest calculator computes how much interest you earn on a principal amount using either simple or compound interest methods. Use it to understand savings growth and compare interest calculations.
What is the difference between simple and compound interest?
Simple interest is calculated only on your principal (initial amount) and doesn't compound. Compound interest is calculated on both your principal and accumulated interest from previous periods, leading to exponential growth. For most savings accounts and investments, compound interest applies.
When is simple interest used?
Simple interest is primarily used for short-term loans, bonds, and some specific types of savings accounts. Most modern savings accounts, investments, and loans use compound interest, which results in higher returns or costs depending on whether you're saving or borrowing.
How often is interest compounded?
Compounding frequency varies by account type: daily (savings accounts), monthly (some CDs), quarterly (bonds), or annually. More frequent compounding produces higher returns. This calculator assumes annual compounding for simplicity; actual results may vary based on your account's compounding frequency.
How much interest will I earn in a year?
Using this calculator, enter your principal, annual interest rate, and time period (1 year). The result shows your interest earned and total amount. Actual results depend on the compounding frequency used by your bank or investment firm.
Can this calculator help me plan my savings?
Yes, use this calculator to estimate how much interest you'll earn on a specific amount over time. This helps you compare different savings accounts, understand growth potential, and plan long-term financial goals. For more advanced planning with regular contributions, use the compound interest calculator.
What rate should I use?
Use the annual percentage yield (APY) or annual percentage rate (APR) your bank or investment offers. Current savings account rates typically range from 4-5%. Investment returns vary widely based on the type of investment and market conditions.