Effective Annual Rate (EAR)

Effective Annual Rate (EAR)

The Problem with APR

  • The Annual Percentage Rate (APR) does not account for the impact of compounding.
  • The frequency of compounding influences the future value or present value of a cash flow.

Comparing Interest Rate Quotes

  • Consider these interest rate quotes:
    • 10.8% compounded annually
    • 10.5% compounded quarterly
    • 10.2% compounded monthly
    • 10% compounded daily
  • Although the APR varies, the lowest APR isn't necessarily the best option when borrowing.
  • The compounding rate affects the ultimate value of a cash flow.

Effective Annual Rate (EAR) Defined

  • EAR is the actual rate of interest, accounting for compounding effects.
  • It allows for a true comparison between different interest rate quotes.

EAR Formula

  • The formula for calculating the Effective Annual Rate (EAR) is: EAR=(1+APR/m)m1EAR = (1 + APR/m)^m - 1 Where:
    • EAREAR = Effective Annual Rate
    • APRAPR = Annual Percentage Rate
    • mm = Number of compounding periods per year