Simple Interest Calculator

Use this Simple Interest Calculator to calculate the interest on loans, savings, or deposits. Enter the principal amount, interest rate, and time period to find total interest and the final amount. Perfect for quick financial calculations and comparisons with compound interest.

Calculate Interest
Find interest earned or paid
Starting amount or loan principal
Calculate Principal
Find required initial amount
Calculate Interest Rate
Find required rate
Calculate Time Period
Find required duration
Simple Interest Formula & Information
Formula

Interest = Principal × Rate × Time

Final Amount = Principal + Interest

  • Principal (P) = Initial amount
  • Rate (R) = Annual interest rate (%)
  • Time (T) = Time period in years
Simple vs Compound Interest
  • Simple Interest: Calculated only on principal
  • Compound Interest: Calculated on principal + accumulated interest
  • Use Simple Interest for: Short-term loans, basic calculations
  • Use Compound Interest for: Long-term investments, savings accounts

FAQ – Simple Interest Calculator

What is a Simple Interest Calculator?

A Simple Interest Calculator helps you calculate the interest earned or paid on a fixed principal amount over a specific time period at a given rate of interest. It’s useful for quick financial estimations in loans, deposits, and savings.

How does simple interest work?

Simple interest is calculated only on the principal amount. The interest remains the same every year because it does not compound on the previous interest earned.

What is the formula for simple interest?

The formula used is:

SI = (P × R × T) / 100

where:
SI = Simple Interest, P = Principal Amount, R = Annual Interest Rate, T = Time (in years).

What inputs are needed for the Simple Interest Calculator?

You need to enter the principal amount, annual interest rate, and time period in years. The calculator will then compute the interest amount and total value.

How do I find the total amount after interest?

You can find the total amount using the formula:

Total Amount = Principal + Simple Interest

When should I use simple interest instead of compound interest?

Simple interest is suitable for short-term loans, car loans, or fixed deposits where interest does not compound. It’s also commonly used in educational and personal finance calculations.

Can I calculate simple interest for months or days?

Yes. You can adjust the time period accordingly. For months, use T = months ÷ 12; for days, use T = days ÷ 365.

What are the benefits of using a Simple Interest Calculator?
  • Instant and accurate interest calculation
  • Useful for quick financial planning
  • Shows clear separation of principal and interest
  • Helps compare different loan or investment options
Is the calculation result 100% accurate?

Yes. The Simple Interest Calculator gives an exact result based on your inputs. However, actual interest may differ slightly if your bank or lender uses a different time basis (e.g., 360 vs. 365 days per year).