Selecting the Right 3D Printer

Discover how to choose the right 3D printer for your needs and the key performance attributes to consider.

STEM Career Outlook

Wages, employment opportunities, and growth projections for STEM jobs.

Injection Molding Design Guide

Guide for high quality and cost-effective plastic injection molding.

Salary Expectation

8 things to know about the interview question "What's your salary expectation"?

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Scenario 1: Find the Amount of Payment

Loan Amount (C)

Interest Rate % (R)

Compound Frequency (m)

No. of Payments (N)

Payment Frequency (q)

Payment Amount (P): 
Interest rate R% is always a yearly figure. However, in most loan situations it is compounded monthly. In this calculator the Payment Amount P is calculated by the following formula
where r is the adjusted equivalent interest rate
For most loans, interests are compounded monthly and payments are also made monthly (m=q=12). r is then simplified to R/1200:
Note that the number 100 is to convert the percentage value R% to decimal.
Scenario 2: Find the Interest Rate

Loan Amount (C)

Payment Amount (P)

No. of Payments (N)

Payment Frequency (q)

Compound Frequency (m)

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:
The annual interest rate R% is
Scenario 3: Find the Number of Payments

Loan Amount (C)

Interest Rate % (R)

Compound Frequency (m)

Payment Amount (P)

Payment Frequency (q)

No. of Payments (N): 
This calculator figures out the Number of Payments N by the following closed-form expression:
Notice that N has to be an integer, so the Payment Amount P might be slightly adjusted to satisfy this condition.
Selecting the Right 3D Printer

Discover how to choose the right 3D printer for your needs and the key performance attributes to consider.

STEM Career Outlook

Wages, employment opportunities, and growth projections for STEM jobs.

Injection Molding Design Guide

Guide for high quality and cost-effective plastic injection molding.

Salary Expectation

8 things to know about the interview question "What's your salary expectation"?