What is Simple Interest? Formula, Examples & Calculation

What is Simple Interest?

Simple Interest (SI) is the interest calculated only on the original principal amount for the entire loan or investment period. It does not include interest on previously earned interest.

📌 Simple Interest Definition

Simple interest is a quick and easy method of calculating interest where the interest amount remains the same every year.

📐 Simple Interest Formula

The formula used to calculate simple interest is:

Simple Interest (SI) = (P × R × T) / 100
  • P = Principal amount
  • R = Rate of interest per year (%)
  • T = Time (in years)

🧮 Simple Interest Example

Suppose you invest ₹10,000 at an interest rate of 5% per year for 3 years.

SI = (10,000 × 5 × 3) / 100
Simple Interest = ₹1,500

The total amount received after 3 years will be: ₹11,500

🏦 Where is Simple Interest Used?

  • Personal loans (short-term)
  • Car loans (some cases)
  • Education loans (initial period)
  • Fixed short-term investments

📊 Simple Interest vs Compound Interest

Unlike compound interest, simple interest does not earn interest on accumulated interest. Compound interest grows faster over time.

🧠 Advantages of Simple Interest

  • Easy to calculate
  • Transparent interest amount
  • Lower total interest cost

⚠️ Disadvantages of Simple Interest

  • No growth on earned interest
  • Not suitable for long-term investments

🛠️ Calculate Simple Interest Online

Use our free calculator to instantly calculate simple interest.

About this Calculator

Learn what simple interest is, its formula, how to calculate it with examples, and when simple interest is used.

Related Calculators
Learn More