How to Calculate Your Score

NPS is based on the fundamental perspective that every company's customers
can be divided into three categories: Promoters, Passives, and Detractors.

By asking one simple question — How likely is it that you would you recommend
[Company X] to a friend or colleague? — you can track these groups and get a
clear measure of your company's performance through its customers' eyes.

Customers respond on a 0-to-10 point rating scale and are categorized as
follows:

Promoters (score 9-10) are loyal enthusiasts who will keep buying and refer
others, fueling growth.

Passives (score 7-8) are satisfied but unenthusiastic customers who are
vulnerable to competitive offerings.

Detractors (score 0-6) are unhappy customers who can damage your brand and
impede growth through negative word-of-mouth.

To calculate your company's Net Promoter Score (NPS), take the percentage of
customers who are Promoters and subtract the percentage who are Detractors.

詳細圖表
請至此LINK
http://www.netpromoter.com/np/calculate.jsp