Free Online Calculators

Simple Interest Calculator

Calculate simple interest — solve for Interest, Principal, Rate, or Time.

Calculate Simple Interest
Result
—
Principal—
Rate—
Time—
Simple Interest—
Total Amount—

Simple Interest Formula

I = P × R × T / 100 | where I = Interest, P = Principal, R = Rate (%), T = Time (years).

Simple vs Compound Interest

Simple interest is calculated only on the principal. Compound interest is calculated on principal + accumulated interest. For long-term loans/investments, compound interest makes a significant difference.

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