How to calculate net promoter score (NPS)
Net promoter score (NPS) is the most widely used loyalty metric, prized for its simplicity: one question, one number. It correlates with retention and word-of-mouth growth, which is why it shows up in board decks.
The scoring is unusual. NPS is not an average; it is the net of promoters minus detractors, which is why it ranges from negative 100 to positive 100 and can feel harsh.
- % promoters - % detractors The formula
- -100 to +100 The range
- Promoters 9-10 Detractors 0-6
Short answer
Net promoter score measures customer loyalty from one question: how likely are you to recommend us, on a 0 to 10 scale. Subtract the percentage of detractors (0 to 6) from the percentage of promoters (9 to 10). Passives (7 to 8) are ignored. If 60 percent are promoters and 15 percent detractors, NPS is 45. Scores run from negative 100 to positive 100.
Step by step
Ask the recommendation question
Survey customers with the standard question: how likely are you to recommend us to a friend or colleague, on a 0 to 10 scale.
Bucket the responses
Promoters score 9 to 10, passives 7 to 8, detractors 0 to 6. Passives are counted in the total but do not affect the score directly.
Compute the percentages
Calculate the percentage of respondents who are promoters and the percentage who are detractors.
Subtract detractors from promoters
NPS equals percent promoters minus percent detractors. The result is a whole number from negative 100 to positive 100.
Worked example
You survey 200 customers. 120 score 9 to 10 (promoters, 60 percent), 50 score 7 to 8 (passives, 25 percent), and 30 score 0 to 6 (detractors, 15 percent).
NPS = 60 percent minus 15 percent = 45. The 25 percent passives do not enter the calculation directly but do dilute your promoter percentage. Moving passives to promoters is often the fastest way to lift NPS.
How Ardovo handles it
Ardovo can track NPS by segment and tie it to retention and expansion, so the score connects to revenue rather than sitting alone. Rook flags detractor clusters in a segment, turning a survey number into a targeted retention action.
Frequently asked questions
What is the NPS formula?
Percent of promoters (scoring 9 to 10) minus percent of detractors (scoring 0 to 6). Passives (7 to 8) are excluded from the subtraction. The result ranges from negative 100 to positive 100.
What is a good NPS score?
Any positive score means more promoters than detractors. Above 30 is good, above 50 is excellent, and above 70 is world-class. Benchmarks vary by industry, so compare within your sector and track your trend.
Why isn't NPS just an average?
Because it deliberately weights the extremes. By counting only promoters and detractors and ignoring passives, NPS emphasizes strong loyalty and strong dissatisfaction, which correlate with word-of-mouth and churn better than a simple average would.