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Simple Interest Calculator

Calculate simple interest on your principal: interest earned, total amount, and monthly breakdown

What is Simple Interest?

Simple interest is a financial calculation method where interest is generated only on the original principal, without considering accumulated interest from previous periods.

Simple Interest Formula

The formula is: I = P × r × t

Where:

  • I = Interest earned
  • P = Principal (initial amount)
  • r = Annual interest rate (as decimal)
  • t = Time in years

Example: If you invest $10,000 at 5% annual for 2 years:

  • I = $10,000 × 0.05 × 2 = $1,000
  • Total amount: $10,000 + $1,000 = $11,000

Simple vs Compound Interest

| Feature | Simple | Compound | |---|---|---| | Calculation base | Original principal only | Principal + accumulated interest | | Growth | Linear | Exponential | | Returns | Lower long-term | Higher long-term |

When is Simple Interest Used?

  • Short-term loans
  • Promissory notes
  • Some savings accounts
  • Fixed-term investments
  • Legal interest calculations