Simple Interest Calculator

Calculate simple interest on loans or deposits with our free online SI calculator. Get instant results with principal, rate, and time inputs.

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Enter Loan/Deposit Details
₹1,00,000
₹1,000₹1 Crore
8%
1%30%
5 years
Principal vs Interest
Total₹1,40,000
Principal Amount
₹1,00,000
Interest Earned
₹40,000

Principal Amount

₹1,00,000

Total Interest

₹40,000

Total Amount

₹1,40,000

Monthly Interest

₹667
Simple Interest Formula

SI = (P × R × T) / 100

= (₹1,00,000 × 8% × 5.00 years) / 100 = ₹40,000

Interest as % of Principal40.0%
Principal
Interest

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What is Simple Interest?

Simple Interest (SI) is a method of calculating interest where the interest is computed only on the principal amount for the entire tenure. Unlike compound interest, the interest does not earn interest on itself. Simple interest is commonly used in short-term loans, car loans, and some savings accounts.

The formula is straightforward and easy to calculate, making it popular for quick financial calculations and understanding basic interest concepts.

Simple Interest Formula

SI = (P × R × T) / 100

  • SI = Simple Interest
  • P = Principal (Initial Amount)
  • R = Rate of Interest (per annum)
  • T = Time Period (in years)

Total Amount (A) = P + SI = P × (1 + R×T/100)

Example Calculation

Problem: Calculate simple interest on ₹50,000 at 10% p.a. for 3 years

  • Principal (P): ₹50,000
  • Rate (R): 10%
  • Time (T): 3 years
  • SI: (50,000 × 10 × 3) / 100 = ₹15,000
  • Total Amount: ₹50,000 + ₹15,000 = ₹65,000

Simple Interest vs Compound Interest

FeatureSimple InterestCompound Interest
Interest CalculationOn principal onlyOn principal + accumulated interest
Interest GrowthLinearExponential
Total InterestLowerHigher
Common UsesShort-term loans, car loansFDs, savings, investments

Where Simple Interest is Used

  • Personal Loans: Some personal loans use simple interest calculation
  • Car Loans: Many auto loans in India use simple interest
  • Short-term Deposits: Some short-term bank deposits
  • Consumer Credit: Store credit and consumer financing
  • Education Loans: During the moratorium period

Frequently Asked Questions

In simple interest, interest is calculated only on the original principal throughout the tenure. In compound interest, interest is calculated on principal plus previously accumulated interest. Compound interest results in higher returns/payments over time.

Convert months to years by dividing by 12. For example, for 6 months, use T = 6/12 = 0.5 years. Then apply the formula SI = (P × R × 0.5) / 100. Our calculator handles this conversion automatically.

Yes, simple interest is generally better for borrowers as you pay less total interest compared to compound interest. For lenders/investors, compound interest is more beneficial as earnings grow exponentially.

Most banks use compound interest for savings accounts and fixed deposits. Simple interest is more common in personal loans, car loans, and some short-term lending products. Always check the loan terms.

Rearrange the formula: R = (SI × 100) / (P × T). For example, if ₹10,000 earns ₹2,000 interest in 2 years, Rate = (2000 × 100) / (10000 × 2) = 10% per annum.
Disclaimer

This calculator is provided for informational purposes only. The results are estimates and should not be considered as financial advice. Actual values may vary based on various factors. Please consult a certified financial advisor before making any financial decisions.

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