Calcyuncle EMI Calculator

Simple Interest Calculator

Simple interest is charged only on the original amount, never on interest already earned. Enter the principal, rate and time to get the interest and the total amount instantly.

Details

Use decimals for part years, e.g. 2.5.

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Year-by-year

Year-by-Year Interest

How the value builds up at the end of each year.

Growth over time

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Amounts are rounded to the nearest rupee for display; calculations use full precision.

Simple interest assumes interest is never added to the principal. Most bank deposits and loans compound interest — use the compound interest or EMI calculators for those. Read our disclaimer.

What is Simple Interest?

Simple interest is calculated only on the original principal. The interest for every year is the same, and interest already earned never earns more interest. That makes it easy to calculate and easy to compare.

Simple Interest Formula

SI = P × R × T ÷ 100    Amount = P + SI
  • P — principal
  • R — annual interest rate in percent
  • T — time in years (use 1.5 for 18 months)

Worked examples

₹2,00,000 at 9% for 4 years: SI = 2,00,000 × 9 × 4 ÷ 100 = ₹72,000, so the total amount is ₹2,72,000. The interest is ₹18,000 every year.

₹50,000 at 10% for 2.5 years: SI = 50,000 × 10 × 2.5 ÷ 100 = ₹12,500.

Simple vs Compound Interest

For short periods the difference is small; for long periods it is large. The same ₹2,00,000 at 9% for 4 years earns ₹72,000 as simple interest but ₹82,316 with yearly compounding. Over 20 years, ₹1,00,000 at 10% gives ₹3,00,000 with simple interest and ₹6,72,750 with compounding.

Finding the Rate or Time

  • Rate: R = SI × 100 ÷ (P × T)
  • Time: T = SI × 100 ÷ (P × R)
  • Principal: P = SI × 100 ÷ (R × T)

Frequently Asked Questions

What is the simple interest formula?

SI = P × R × T ÷ 100, where P is the principal, R the annual rate in percent and T the time in years. The total amount is P + SI. ₹2,00,000 at 9% for 4 years earns ₹72,000, for a total of ₹2,72,000.

Where is simple interest used?

In some short-term personal lending, certain bonds that pay interest out rather than reinvesting it, and in school and exam problems. Bank FDs, savings accounts and EMI loans generally use compound or reducing-balance interest instead.

How do I calculate simple interest for months?

Convert months to years: 18 months = 1.5 years. ₹50,000 at 10% for 18 months earns 50,000 × 10 × 1.5 ÷ 100 = ₹7,500.

Does the calculator store my numbers?

No. All calculations run inside your browser. The amounts you enter are not sent to our server or saved anywhere.