Enter any two values to calculate the missing variable among Loan Balance ($), Annual Interest Rate (%), and Monthly Interest ($).

Monthly Interest Calculator

Calculate monthly interest charges from a balance and annual rate, or convert an annual rate into a monthly rate.

Monthly Interest
APR to Monthly
Loan / Mortgage Style
Credit Card Daily Method

Use this for an estimated daily-interest billing cycle calculation.

Loan / mortgage style uses a simple monthly estimate based on APR ÷ 12.

APR ÷ 12
Equivalent Monthly Rate

This mode gives the nominal monthly rate by dividing the annual rate by 12.

Monthly Interest Formula

The following formula is used by the calculator above to determine the monthly interest of a loan or mortgage.

MI = LB X AIR / 1200
  • Where MI is the monthly interest ($)
  • LB is the loan balance ($)
  • AIR is the annual interest rate (%)
  • 1200 is derived from 12 months multiplied by 100 (for percentage conversion)

To calculate monthly interest, multiply the loan balance by the annual interest rate, then divide by 1200.

This formula calculates the total monthly interest you would pay on a loan. Actual payments may vary based on the terms of the loan agreement.

Monthly Interest Definition

Monthly interest is the amount of interest accrued on a loan each month, calculated based on the loan balance and the annual interest rate.

How to calculate monthly interest?

1. First, determine the loan balance.

2. Next, determine the annual interest rate.

3. Finally, compute the monthly interest using the formula: (Loan Balance × Annual Interest Rate) / 1200. Ensure that you leave one field empty for the calculation.

FAQ

What is monthly interest?
Monthly interest is the amount of interest accrued on a loan each month, calculated by multiplying the loan balance by the annual interest rate and dividing by 1200.