Interest Rate Calculator

Effective Interest Rate Estimation Calculator

Input Fields

Principal (P)

P

$

Enter the loan principal amount

Annuity Payment (A)

A

$

Enter the annuity (regular) payment amount

Number of Periods (q)

q

periods

Enter the number of payment periods

CalculateReset

Calculate automaticallyIf enabled, the result will update automatically when you change any value.

Your Results

Approximate Interest Rate

Leave a Comment

How did this result make you feel?

0😀 Like 0💡 Helpful 0😕 Confused 0😞 Disappointed 0❌ Inaccurate

Interest Rate Approximation Formula

$$i \approx \left[ \left( 1 + \frac{P}{A} \right)^{\frac{1}{q}} – 1 \right] q – 1$$

Where:

• $$i$$ = Approximate periodic interest rate
• $$P$$ = Principal amount (initial investment or loan)
• $$A$$ = Payment amount per period
• $$q$$ = Number of periods per year

The Interest Rate Calculator helps in approximating the periodic interest rate when you know the payment, principal, and frequency of compounding. It’s useful for financial analysis, loan structuring, and investment planning when interest rates are not directly provided.