You calculate the Net Promoter Score by subtracting the percentage of detractors from the percentage of promoters. For example, if 60% of your respondents give a 9 or 10, and 15% give a 6 or lower, then your NPS is 60 minus 15 = 45. The NPS scale ranges from -100 to +100. In this article, we answer the most frequently asked questions about NPS, from the basic formula to using NPS data to systematically improve your customer experience.
What are promoters, passives, and detractors in NPS?
In the Net Promoter Score, you divide all respondents into three groups based on their answer to the question: “How likely are you to recommend us to others?” Promoters give a 9 or 10, passives a 7 or 8, and detractors a score of 0 through 6. Only promoters and detractors are included in the calculation.
The distinction between these three groups was made deliberately. Promoters are enthusiastic customers who actively talk about you and bring in new customers. They are loyal and are relatively quick to forgive the occasional mistake. Passives are satisfied, but not enthusiastic. They’ll switch to a competitor’s better offer fairly quickly. Critics are dissatisfied customers who spread negative word-of-mouth and can damage your reputation.
Passive customers are intentionally excluded from the formula because they do not have a significant impact on your growth or reputation. By excluding them, the NPS provides a clearer picture of the actual polarization within your customer base.
What is the formula for the Net Promoter Score?
The formula for the Net Promoter Score is: NPS = % of promoters minus % of detractors. Count the number of respondents who gave a 9 or 10, divide that by the total number of respondents, and multiply by 100. Do the same for detractors (scores 0 through 6). The difference between those two percentages is your NPS.
A concrete example makes this immediately clear:
- 100 respondents answered the NPS question
- 55 gave a 9 or 10 (advisors) = 55%
- 20 gave a 7 or 8 (passive) = 20%
- 25 gave a score of 0 to 6 (critics) = 25%
- NPS = 55 minus 25 = 30
The result is always a whole number between -100 and +100. A score of 0 means you have an equal number of promoters and detractors. Any score above 0 is technically positive, but whether that’s a good thing depends heavily on your industry.
What is a good NPS score for your industry?
A good NPS is relative and depends heavily on the industry in which you operate. In industries with naturally high customer satisfaction, such as technology or e-commerce, average scores are higher than in industries like telecommunications, government, or utilities. An NPS of 30 can be excellent in one industry and below average in another.
As a general guideline, the following applies:
- Below 0: More critics than supporters. Action required.
- 0 to 30: Acceptable. There is room for improvement.
- 30 to 70: Good. Your customers are generally satisfied and loyal.
- Above 70: Excellent. You rank among the very best in your industry.
Benchmarking within your own sector is more valuable than comparing yourself to the overall average. For organizations in the public sector, healthcare, or housing cooperatives, an NPS of 20 to 40 is already a strong performance, partly because customers have limited choices and expectations have historically been lower. What really matters is the trend over time: if your score is rising, you’re doing something right.
How often should you measure the NPS?
The frequency of NPS measurements depends on your volume of customer interactions and your objective. For organizations with a high volume of customer interactions, a transactional NPS works best: you measure it immediately after an interaction, such as a phone call or a completed request. For strategic insights, a relational NPS measured two to four times a year is sufficient.
Both measurement methods serve a specific purpose:
- Transactional NPS: Measured immediately after a customer touchpoint. Provides insight into the quality of specific interactions, such as a phone call with customer service or a resolved complaint.
- Relational NPS: Measured periodically, independent of any specific interaction. Provides insight into overall loyalty and brand perception over a longer period of time.
Measuring too frequently can lead to respondent fatigue, which lowers the response rate and makes the data less reliable. If you measure too infrequently, you’ll miss trends before they become apparent. A combination of both methods provides the most complete picture: transactional for operational management, relational for strategic direction.
What factors influence the reliability of your NPS?
The reliability of your NPS is determined by sample size, timing, channel, and representativeness. An NPS based on ten respondents is not very meaningful. Only with a sufficiently large sample—representatively distributed across your customer base—does the score become statistically meaningful.
Factors that reduce reliability include:
- Sample size too small: Fewer than 30 to 50 respondents makes the results too susceptible to outliers.
- Selection bias: If only satisfied or, conversely, dissatisfied customers respond, the score will be skewed.
- Timing: A measurement taken immediately after a negative event (malfunction, error) yields a temporarily lower score that is not representative of the overall experience.
- Channel bias: Customers who are invited via email respond differently than customers who are asked immediately after a phone call.
- Lack of follow-up questions: Without an open-ended follow-up question, you don’t know why someone gave a particular score, which makes it difficult to translate the data into action.
Always include an open-ended text field in your NPS survey. That qualitative feedback is just as valuable as the number itself.
How can you use NPS data to improve customer engagement?
NPS data only becomes valuable when you link it to specific improvement actions in your customer interactions. Analyze the open-ended responses from critics for recurring themes, link scores to specific touchpoints or channels, and use the insights to implement targeted improvements in routing, handling time, or information provision.
An effective approach consists of three steps:
- Segment your data: Break down NPS results by channel (phone, chat, email), by department, or by type of inquiry. This way, you can see where the pain points are—not just that there are pain points.
- Analyze the open-ended responses: Group the qualitative feedback from critics into themes. Do customers repeatedly mention wait times, being transferred, or unclear information? If so, you’ll know where to start.
- Link NPS to operational KPIs: Tie your NPS score to measurable metrics such as first-call resolution, average wait time, or the number of transfers. This will help you see whether operational improvements also lead to higher customer satisfaction.
A common mistake is treating NPS as a reporting metric rather than a management tool. The score itself doesn’t change anything, but the actions you take based on it do. Organizations that systematically integrate NPS into their customer engagement strategy and share the insights with both operational management and frontline staff see the greatest improvements.
How Pegamento Helps Improve NPS Through Better Customer Engagement Technology
A low NPS is rarely the result of a single problem. Often, the causes run deeper: fragmented systems, poor routing, employees who lack context, or customers who have to repeat their story over and over again. We help organizations resolve these bottlenecks systematically through our contact center platform.
What we offer specifically:
- Omnichannel customer contact: Phone, chat, WhatsApp, and email all in one view, so employees always have the full context without having to switch between systems.
- Intelligent call routing: Customers are routed directly to the right agent or department, which minimizes transfers and repeat calls.
- Agentic AI assistants: Self-thinking assistants that not only follow instructions but also take the initiative on their own. They handle repetitive questions outside of business hours, freeing up employees to focus on more complex conversations.
- Reporting and Insights: A central dashboard with customer engagement KPIs across all channels, allowing you to correlate NPS trends with operational data.
- Everything under one roof: From implementation to management and support, without the complexity of supplier management.
Would you like to know which improvements to your customer interactions have the greatest impact on your NPS? Contact us, and we’ll explore the possibilities together.
Frequently Asked Questions
Kan ik de NPS combineren met andere klanttevredenheidsmetingen zoals CSAT of CES?
Ja, en dat is zelfs aan te raden. De NPS meet loyaliteit op de lange termijn, terwijl de Customer Satisfaction Score (CSAT) de tevredenheid over een specifieke interactie meet en de Customer Effort Score (CES) inzicht geeft in hoeveel moeite een klant moest doen. Door deze drie metrics te combineren, krijg je een completer beeld: de NPS vertelt je wát de algehele beleving is, de CSAT en CES helpen verklaren waaróm. Gebruik NPS als strategisch kompas en CSAT of CES als operationele bijsturing.
Hoe ga ik om met een plotselinge daling in mijn NPS-score?
Ga eerst na of de daling structureel of tijdelijk is. Een plotselinge dip kan veroorzaakt worden door een eenmalige gebeurtenis, zoals een systeemstoring of een mediabericht, en is dan niet representatief voor je structurele klantbeleving. Analyseer de open antwoorden uit die meetperiode op terugkerende klachten en vergelijk de score met voorgaande periodes. Als de daling aanhoudt over meerdere meetmomenten, is er sprake van een structureel probleem dat om gerichte actie vraagt.
Wat is de minimale respons die ik nodig heb voor een betrouwbare NPS-meting?
Als vuistregel geldt dat je minimaal 30 tot 50 volledige responsen nodig hebt om een statistisch zinvolle NPS te berekenen, maar voor betrouwbare segmentatie per kanaal of afdeling heb je per segment bij voorkeur minimaal 30 responsen. Hoe groter en representatiever de steekproef, hoe kleiner de foutmarge. Bij een te kleine steekproef kan één ontevreden klant je score al met meerdere punten doen dalen, wat een vertekend beeld geeft van de werkelijkheid.
Moet ik criticasters altijd persoonlijk opvolgen na een NPS-meting?
Het is sterk aan te raden om criticasters, waar mogelijk, persoonlijk op te volgen. Een snelle en oprechte reactie kan een ontevreden klant omzetten in een loyale klant en voorkomt dat negatieve ervaringen zich verspreiden via mond-tot-mondreclame. Stel een intern proces in waarbij criticasters binnen 24 tot 48 uur worden gecontacteerd door een medewerker die bevoegd is om het probleem daadwerkelijk op te lossen. Zorg er wel voor dat je toestemming hebt om contact op te nemen, in lijn met de AVG-wetgeving.
Hoe betrek ik mijn medewerkers bij de NPS-resultaten zonder dat het als bedreiging wordt ervaren?
Presenteer NPS-resultaten als een gezamenlijk verbeterinstrument, niet als een beoordelingssysteem voor individuele medewerkers. Deel inzichten op teamniveau en koppel ze aan concrete verbeterpunten die medewerkers zelf kunnen beïnvloeden, zoals doorverbindprocedures of informatieverstrekking. Betrek medewerkers actief bij het interpreteren van klantfeedback en het bedenken van oplossingen; zij kennen de praktijk het beste en voelen zich meer eigenaar van de verbetering als ze er zelf aan bijdragen.
Wat doe ik als mijn NPS hoog is, maar mijn klantenservice toch klachten blijft ontvangen?
Een hoge gemiddelde NPS kan individuele pijnpunten maskeren, zeker als een grote groep zeer tevreden klanten de score omhoog trekt terwijl een kleinere groep structureel negatieve ervaringen heeft. Segmenteer je NPS-data op klantsegment, kanaal of type vraag om te zien of er specifieke groepen zijn die achterblijven. Combineer de NPS met kwalitatieve klachtanalyse en operationele KPI’s zoals First Call Resolution om een vollediger beeld te krijgen van waar het schuurt.
Hoe lang duurt het voordat verbeteringen in klantcontact zichtbaar worden in de NPS?
Dat hangt af van de aard van de verbetering en de meetmethode die je gebruikt. Operationele verbeteringen, zoals snellere routing of kortere wachttijden, kunnen bij een transactionele NPS al binnen enkele weken zichtbaar worden. Structurele veranderingen in klantbeleving, zoals een cultuuromslag of een nieuw omnichannel platform, vergen doorgaans drie tot zes maanden voordat ze consistent doorwerken in de relationele NPS. Meet daarom regelmatig en koppel NPS-trends expliciet aan de verbeteringen die je hebt doorgevoerd, zodat je de impact kunt aantonen.
