Quality Magazine

Techniques to improve quality on the shop floor and in manufacturing planning.

Autonomous Vehicle Engineering

The No. 1 media source for those developing the next generation mobility solutions.

Desktop Engineering

Design, simulation, test, prototyping and high performance computing.

Laser Focus World

Semiconductors, medical equipment, lasers, optics and aviation and aerospace.

more free magazines
Scenario 1: Find the Monthly Payment

Loan Amount (C)

Interest Rate % (R)

Number of Months (N)

Monthly Payment (P): 
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

Loan Amount (C)

Monthly Payment (P)

Number of Months (N)

Interest Rate % (R): 
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 Newton-Raphson method with an educated initial guess:
Scenario 3: Find the Number of Payments

Loan Amount (C)

Interest Rate % (R)

Monthly Payment (P)

Number of Months (N): 
This calculator figures out the number of months N by the following closed-form expression:
Notice that N has to be an integer, so the monthly payment P might be slightly adjusted to satisfy this condition.
Glossary