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How to Calculate Interest on a Promissory Note

By Motley Fool StaffUpdated Apr 29, 2025 at 10:46 PM

Key Points

  • Understand the total interest by multiplying the annual charge by the number of years in your note.
  • Calculate yearly interest by multiplying the principal amount by the interest rate.
  • Know your full interest liability by finding the product of the principal, rate, and time.

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