What Is NPS? A Simple Guide to Calculation, Promoter/Detractor Categories, and Benchmarks

NPS (Net Promoter Score) shows up constantly in customer surveys and service-improvement work. It is widely used as a measure of customer loyalty, yet many people are unsure exactly how to calculate it or what counts as a good score.

This article explains how to calculate NPS step by step, starting from a single question and the classification into Promoters, Passives, and Detractors. We cover a worked example, score benchmarks, and tips for putting it to use, at a level that even first-timers can apply in practice.

What Is NPS?

NPS (Net Promoter Score) is a metric that measures customer loyalty (attachment to and trust in a company or brand) through how strongly customers would recommend a product or service to others.

Whereas traditional "satisfaction" measures how satisfied someone was at a given moment, NPS goes a step further into future behavior and intent to recommend, asking whether the customer will keep using the product and recommend it to others. Because of this, it is adopted by many companies as a metric that correlates well with business performance.

NPS Is Measured with a Single Question

An NPS survey is, in essence, complete with just one question.

"How likely are you to recommend this product (service / company) to a friend or colleague?"

Respondents rate this question on an 11-point scale from 0 to 10, where 0 means "not at all likely" and 10 means "extremely likely." Calculating NPS begins by sorting these 11-point scores into three groups.

Categorizing Promoters, Passives, and Detractors

The responses obtained on the 0-10 scale are divided into the following three groups based on their score. This classification is the foundation of the NPS calculation.

• Promoters: those who give a 9 or 10. Enthusiastic fans who have strong attachment to the service and actively recommend it to others.
• Passives: those who give a 7 or 8. Satisfied but not highly enthusiastic, and still likely to switch to a competitor.
• Detractors: those who give a 0 to 6. Dissatisfied customers who may spread negative word of mouth or churn.

Something to watch out for here is that the 7-8 "Passives" are not included in the NPS calculation. Also, since everything 6 and below is treated as a "Detractor," a score of 6—which might seem "not bad" at first glance—is also classified as a Detractor. This strict cutoff is part of why NPS is good at picking up signals for improvement.

How to Calculate NPS

Once the classification is done, NPS is found with the following simple formula.

NPS = % of Promoters − % of Detractors

The key point is that you calculate using percentages of all respondents, not the raw number of people. Passives do not appear in the formula, but they must always be included in the denominator (the total number of respondents) when calculating the percentages.

Organized into steps, the calculation has three parts.

• 1. Classify: sort all responses into Promoters (9-10), Passives (7-8), and Detractors (0-6).
• 2. Find the percentages: calculate the percentage of Promoters and of Detractors, each as "number in group ÷ total respondents × 100."
• 3. Subtract: subtract the percentage of Detractors from the percentage of Promoters. That value is the NPS.

Because NPS is a subtraction of percentages, the result ranges from −100 to +100. If everyone is a Promoter it is +100; if everyone is a Detractor it is −100. Unlike many metrics, it can take negative values. By convention, the number is not written with a "%" sign—you simply say "NPS is +20."

A Worked Example

Let's calculate with concrete numbers. Suppose a service surveys 100 people and the responses break down as follows.

• Promoters (9-10): 40 people
• Passives (7-8): 35 people
• Detractors (0-6): 25 people

First, find the percentages. Promoters are 40 ÷ 100 × 100 = 40%, and Detractors are 25 ÷ 100 × 100 = 25%. Plugging these into the formula gives NPS = 40% − 25% = +15.

Here, the 35 Passives do not appear in the formula itself, but they are properly included in the denominator of 100 people used to compute the percentages. If you exclude Passives from the denominator, the percentages change and you will not get the correct NPS, so be careful.

NPS Score Benchmarks

Let's cover rough benchmarks for how to evaluate the NPS you have calculated. As a premise, though, there is no single universal standard for the absolute value of NPS.

As a general rule, a positive NPS means Promoters outnumber Detractors—a healthy state—while a negative NPS means there are many Detractors and improvement is needed. A range of +30 to +50 is often considered strong, and above +50 is considered very high, but these are only rough guides.

Especially important is that average values differ greatly by industry and country. For example, people in Japan tend to choose mid-range scores (7-8), so NPS is said to come out lower there than in Western countries. For that reason, rather than simply comparing your numbers with other companies or other industries, it is more practical to look at the trend compared with your own past scores.

Tips for Putting NPS to Use

To make sure NPS does not end as just a "score" but actually drives improvement, here are points to keep in mind.

• Ask for the reason (free text) as a set: by asking not only for the score but also "the reason you gave that score," you get concrete hints about what to improve.
• Track the trend over time: rather than a one-off number, measure regularly and watch changes as a time series to judge whether your initiatives are working.
• Break it down by segment: splitting NPS by plan, length of use, or customer attributes reveals which segments have issues.
• Act on Detractors and Promoters separately: follow up with Detractors to resolve dissatisfaction, and encourage Promoters to refer and spread word of mouth—changing your tactics by group.

Measuring NPS is not the goal in itself; it has value only when you read the customer voices behind the score and connect them to your next improvement action.

Summary

NPS is a customer loyalty metric that asks "how likely you are to recommend to a friend or colleague" with a single question on an 11-point 0-10 scale, then classifies responses into Promoters (9-10), Passives (7-8), and Detractors (0-6). The formula is simply "% of Promoters − % of Detractors"; Passives are not part of the formula but must always be included in the denominator when computing the percentages.

The score ranges from −100 to +100, with positive read as healthy and negative as needing improvement; but because differences by industry and country are large, the basic approach is to track your own trend rather than compare with other companies. Rather than stopping at producing a number, combine it with free-text reasons and segment analysis to turn customer voices into improvement actions.