How to Calculate Net Promoter Score (NPS) - The Easy… | CustomerGauge How to Calculate Net Promoter Score (NPS) - The Easy Way

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How to Calculate Net Promoter Score (NPS) - The Easy Way

How can you discover the health of your customer experience? The Net Promoter Score® (NPS) and its expanded version the Net Promoter System are metrics proven to measure customer loyalty. The Net Promoter Score gauges how loyal your customers are, by conducting short 2-minute surveys.

How to calculate your Net Promoter Score is based on a single question (although pros ask more than one question, we will come to that later).

“On a scale of 0-10, how likely is it that you would recommend [company name] to your friends, family or business associates?”

Customers that give you a 6 or below are Detractors, a score of 7 or 8 are called Passives, and a 9 or 10 are Promoters.

To calculate your Net Promoter Score, subtract the percentage of Detractors from the percentage of Promoters. It is that simple. So, if 50% of respondents were Promoters and 10% were Detractors, your Net Promoter is a score of 40.

The importance of the Net Promoter Score is that it gives you insights into your customer loyalty spectrum. As you move up the scoring scale, from 0 to 10, customers defect at lower rates, will spend more and will move from negative word of mouth to positive.

By measuring customer loyalty you can identify customer experience weak points that need improving, but to do this, you need to know how to conduct Net Promoter surveys. As the Net Promoter’s strength isn’t its ability to measure customer loyalty (there are many arduous ways to do this already), but it is how easy it is to measure loyalty that is crucial.

With close to a decade of experience at CustomerGauge helping clients design and conduct Net Promoter surveys, this guide will show you how to create a reliable Net Promoter Score by asking the right questions, to the right people, at the right time.

The State of B2B Account Experience

1) How to Begin a Net Promoter Survey

Many choose to start a survey program by conducting a long planning period to decide the type of surveys, how many different surveys need to be created, and what is to go into each one.

Implementing a survey program in this way, means investing a lot of time and resources before you have a single survey out there. Net Promoter is about being fast and easy to implement.

Are you wasting time planning? Get your first relationship survey out there, and plan as you go!

Instead, roll out NPS in stages. Start with the core of NPS, the relationship survey. As you master your first round of surveying, you will learn how to expand the program with new surveys, and surveying larger numbers or different company segments.

2) Relationship and transactional surveys: What are they?

Relationship Surveys

Relationship surveys seek to investigate a customer’s loyalty to a company/brand. These types of surveys ask customers to consider the overall experience and satisfaction they have with a company. They are typically carried out at regular intervals (e.g., quarterly, half-yearly); however, there are exceptions (learn more in the ebook).

Transactional Surveys

Transactional surveys investigate the experience a customer has in a specific transaction/interaction (touchpoint). This survey is designed, not to measure customer loyalty, but to measure satisfaction with a particular company segment to improve it.

We recommend that you begin your NPS program with a relationship survey to investigate customer loyalty and brand perception, and uncover which touchpoints are affecting it - be it good or bad. Not all companies need transactional surveys, but if you feel they are needed, only begin once you have identified the touchpoints that are the most important to the customer experience.

3 - How long should a Net Promoter survey be?

The Net Promoter Score is about uncovering customer loyalty and what most affects it. But as I mentioned in the opening, Net Promoter surveys need to ask more than just the “how likely are you to recommend” question.

The Net Promoter question needs other questions to give it meaning (these will be discussed shortly), but you need to keep your Net Promoter survey short. The Net Promoter’s strength is not only that it measures customer loyalty, but because it is short and receives high response rates it gives you a bigger picture of your customer loyalty.

Keep your survey to a maximum of four or five questions. This will also help you avoid survey fatigue resulting in inaccurate answers and ensure that your data is still immediately actionable.

Our best results have always occurred with just three questions. Shorter than this may produce higher response rates, but asking just the NPS question will produce data that has limited actionability. With just three questions, you can gather all the data you need to create actionable insights and still receive high response rates (40% - 60%). In the following chapter, I will explain just what these three questions are.

4 - What questions should I ask?

A score alone only tells you how you are performing not why. It is now generally agreed that asking customers what drove their score, is necessary.

The easiest way is to ask customers to identify only the most important reasons (drivers) for their score and present customers with a predefined list of touchpoints.

As only the most important reasons are provided, it removes the need for lengthy surveys and the complicated statistical approaches needed to make sense of the data.

How you ask customers what affects their score should be different for promoters than detractors and passives. Take a look at the two survey examples below of a travel company, to see how you can discover with just a single question what is most impacting the customer experience.

Constructing the survey this way keeps it short and simple for the respondent, as they only need to think about what is most important to them, which leads to higher response rates. When constructing the question in this way, we have found that 82% of respondents answer this question.  

Finally, it is also important not to restrict the customer to selecting only one reason; customers should be able to choose as many reasons as they deem important.

What touchpoints do I use?


Discover where you and your customers interact.

For your first relationship survey, start by mapping out the customer journey to find customer touchpoints, and select those that have the highest customer traffic.

Look back at the example above, the touchpoints you choose will be your first tier of answers. The drop down answers under each touchpoint is its strengths and weaknesses.

Pay attention, though, the first set of answers in your transactional survey will cover a much narrower group of touchpoints than your relationship survey. For the travel company example above, a transactional survey after a trip could expand the relationship touchpoint “your holiday experience” to become:

  • Your flight
  • Your hotel
  • Your guided tour
  • Holiday arrangements and information

Add a comment box

Your survey will never be able to cover all touchpoints nor all its strengths and weaknesses. Going back to our example above, you can see the option: “Other (please elaborate in the comment box below).” For this reason, always remember to add a comment box.

In our experience, 44% of survey respondents leave a comment. Frame the question as voluntary, to ensure the survey appears as short as possible and convey that you do care about their feedback, like so:

Comments are also an invaluable source of direct information from your customers, which is hard to argue against. A score can be argued against, but when a customer says, “your product is great, but each time I need to ring customer support it takes forever,” it is clear and inarguable how the customer perceives the company.

Analyzing free text is always a challenge, even with advanced text analytics. Use an Net Promoter survey tool that can, in real-time, identify keywords to be submitted as they are or changed by the customer. Customer comments can then act as an additional means to identify key drivers of loyalty.

Give customers the option to be contacted

Add a simple tick-box asking customers “may we contact you to discuss your experience in more detail?” Doing this conveys to customers that you really are listening and willing to act on their feedback.

5 - How many should I survey?

What is a good sample size, what error of margin or confidence level should I aim for with NPS? These questions unnecessarily plague many who first start out with NPS, and who can blame them as it has been drilled into everyone doing surveys.


Don't worry about numbers too much at the start.

Sample size and statistical significance are important in NPS, but not for your first surveys. While part of NPS is about aggregating feedback to drive organizational change ( meaning certain statistical standards), its biggest strength is as a voice of the customer program. It is a program designed to raise loyalty by resolving individual customer issues.

Release your survey to your customers over weeks and months (depending on the size of your base) and you will over time create the sample size you need, as NPS surveying is a continual process.

6 - What’s the best day of the week or hour to send surveys?

We felt compelled to answer this question because it is commonly asked about improving response rates. However, for those just starting out, our answer is: It doesn’t matter!

Experimenting with timing is only something you should attempt when you have an operationalized your Net Promoter program, where you have the time and skills to test which days or hours work better. However, as we have found, there isn’t much to be gained by focusing energy on this.

7 - Through what channels should I send Net Promoter surveys?

There are many ways to send Net Promoter surveys to customers, but deciding which channel to use is about convenience for your customers and what will receive the best response rate.

Two of the most common methods are to send survey links by email or SMS. This is particularly useful for relationship surveys, where the customer has not had any recent contact with a company.

The many ways to send transactional surveys

Transactional surveys offer a lot of options for sending, as surveys can be presented to customers immediately after a transaction. Think about the industry you are in, and how you can “grab” a customer straight after a transaction.

Retail stores often put survey links at the bottom of receipts while others ask customers if they would like to complete the survey via dedicated in-store tablets.

Even in single purchase industries you can still survey the customer.

Online, many companies present a Net Promoter survey link on the final screen of a transaction, while in the software industry some present it during the use of an app or software tool.

However, we strongly recommend using email over all other channels, as it is not a dead channel of communication (as some claim). As it gives you the space to construct a proper invitation and is the best way to conduct relationship surveys.

Are you mobile friendly?

No matter what channel you use to send your surveys, make sure your survey can open on mobile devices. Increasingly people are living by their phones, and although computers still dominate, a survey invite is often something a customer might leave for the bus ride home.

8 - What do I say in a survey invite?

How do you interest customers to click the link to your survey? What do you say to them in an email, SMS or post transaction screen?

In your invite, pay careful attention to each word you write and eliminate everything that isn’t necessary. Are you repeating yourself or communicating things that aren’t relevant or interesting to the customer?

Email subject lines

There are psychological triggers to get the attention of customers, such as using emotion or asking respondents a question. Your subject line should be brief, straightforward and friendly.

To learn more about this read our article “6 email subject lines strategies to increase your survey feedback.”

An effective invite

Whatever channel you use to invite customers, there will always be a body of text. To create an invite that gets the highest possible click-rates, follow these rules:

1 - Personalize the text with their name and maybe relevant transaction information. If you are sending the invite by email, there is no excuse for not doing this. For other channels, this can be tricky, but you should always try.

2 - Get straight to it and tell them what the email is about, why are you emailing them? Begin with something like:

“At CustomerGauge, we are constantly trying to improve our service and would like to hear your feedback on how we performed.”

3 - You know that one of the strengths of NPS is how quick the surveys are. Make sure the customer knows this too.

“The survey is short and will only take 2 minutes to complete.”

4 - Customers often think: “why respond, my issue will just end up as data on a spreadsheet rather than being fixed.” Convince them that this is not the case and let them know that you analyze feedback at an individual level.

“We promise to read every customer comment!”

5 - A well-designed button for a survey link isn’t as good an idea as you may think. If recipients’ email servers block images for security reasons or customers simply choose not to download images, then your button and survey link will be lost.

It is more important that the link to your survey is viewable by all. Use a nice hyperlinked phrase or set of words, and whatever format you use, make sure it is easy to find. Customers shouldn’t have to scroll down to find it.

6 - The invitation should be aesthetically pleasing, designed as well as the survey itself. Plain HTML won’t do much to capture the customer’s interest. Choose a nice font (classics that always work are Helvetica, Gothic or Arial), think about the alignment and layout of the text and consider adding a banner image to help remove the boredom of white backgrounds.

Send reminders

Sending survey invite reminders is a good way to improve your response rate. As many customers, particularly in email, may not see or be able to respond to your survey the first time around.

A standard waiting time for CustomerGauge clients is 3 - 7 days. You don’t want to remind the customer too soon after the first request, but if it is a transactional survey you don’t want to wait too long either.

How to avoid email spam filters

Various things may trigger spam filters. Avoid these common red flags in your invitation email:

  • All-caps subject lines
  • Exclamation marks in the subject line
  • Trigger words in the subject line or body of text, like 'free', 'urgent matter', 'act now', 'last chance'
  • An email with one big image and little to no text
  • Lots of different fonts, font sizes, and text colors

9 - How to test your Net Promoter survey

Before you send anything out to customers, test your survey internally. Send it to other employees within the company, to examine for technical problems.

Make sure your email engine is working, the emails open in the format and layout intended, links to the survey work and the survey itself runs smoothly for other employees.

Test your survey across different browsers. And although we think everyone uses Gmail or Outlook, make sure your email invitation works in all major email services.

Ask employees what they think of the survey and the process around it. Do they have any issues or ideas about such things as the invitation or the survey itself?

Testing NPS surveys isn’t difficult, and it will help ensure you create the most reliable data possible.

10 - Conclusion: Creating a reliable and actionable Net Promoter Score

Your Net Promoter Score is only as good as the survey it is based on. Question heavy surveys hamper response rates, confuse respondents and leave employees confused about how to interpret results.

Designing and conducting a Net Promoter survey does not require a long planning process. At just three questions long, the survey can be designed in a day and sent out the next.

Don’t worry about surveying all your customers or designing a survey for each division of your company. Start small, so that you get started fast.

Use a simple relationship survey on a select group of customers, to show upper management how fast it is to identify customer experience weaknesses and create a Net Promoter Score.

Want more Net Promoter Score best practices? Download our latest white paper, which includes best practices, stats and benchmarking information.

Next Up: How One B2B Organization is Getting 100% Response Rate

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