Simple Interest Calculator
Calculate interest earned or owed on a principal at a fixed annual rate.
Interest Calculation
📊 Interest Breakdown
📝 Examples
💡 Simple vs Compound Interest
Simple Interest: Interest calculated only on the principal. Used for short-term loans and bonds.
Compound Interest: Interest calculated on principal + accumulated interest. More common in savings accounts and investments.
📈 Typical Interest Rates
Formula
Simple Interest = Principal × Rate × Time
I = P × r × t
Total Amount = Principal + Interest
A = P + I
How it works
Simple Interest Formula: I = P × r × t Where: I = Interest amount P = Principal (initial amount) r = Annual interest rate (as decimal) t = Time period in years Total Amount = P + I Examples: $1,000 principal at 5% for 3 years: I = 1000 × 0.05 × 3 = $150 Total = $1,000 + $150 = $1,150
The simple interest calculator computes interest earnings or charges based on principal, rate, and time period. Simple interest is calculated only on the principal amount, not on accumulated interest. Used for short-term loans, bonds, and basic savings calculations.
Why this matters
Understanding interest calculations is essential for financial planning, loans, and savings. Simple interest is the foundation of financial math and helps you understand how money grows or shrinks over time. Compare simple vs compound interest to make informed financial decisions.
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Learn more
The complete guide to simple interest calculator
Formulas, examples, and tips explained in plain English