Simple Interest Calculator
Calculate simple interest using the formula: I = P × r × t where I = Interest, P = Principal, r = Rate, t = Time
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Advanced Interest Calculator
Model daily, monthly, and annual compounding, generate growth charts, and compare multiple rate scenarios side by side.
Frequently Asked Questions
What is the difference between simple and compound interest?
Simple interest applies only to the original principal (I = P × r × t). Compound interest applies to the growing balance, so interest earns interest over time using A = P(1 + r/n)^(nt).
How often does compound interest compound?
Interest can compound annually, semi-annually, quarterly, monthly, or daily. More frequent compounding leads to a higher effective annual yield.
What is the Rule of 72?
The Rule of 72 is a quick way to estimate how long it takes an investment to double: divide 72 by the annual interest rate. At 6%, money doubles in roughly 12 years.