


LoanIQ for iPhone is now available.
efunda's iPhone version of its online loan, lease, and APR calculators. Choose any variable (loan amount, payment, interest rate, etc.) as the unknown and calculate the result in realtime as other variables are entered. App Store

Scenario 1: Find the Monthly Payment 


Interest rate R% is always a yearly figure. However, in most loan situations it is compounded monthly. In this calculator
the monthly payment is calculated by the following formula where r = R/1200:

Scenario 2: Find the Interest Rate 


For given C, P and N, one can only solve the following equation for r by numerical means.
Given the rather smooth behavior of this equation, this calculator employs the NewtonRaphson method with an educated initial guess:

Scenario 3: Find the Number of Payments 


This calculator figures out the number of months N by the following closedform expression:
Notice that N has to be an integer, so the monthly payment P might be slightly adjusted to satisfy this condition.

