What is Net Promoter Score?
Net Promoter Score, or NPS, summarizes how likely surveyed customers are to recommend a product, service, or company. Respondents answer on a scale from zero to ten and are grouped into promoters, passives, and detractors. The final score is a directional relationship metric, not a percentage of satisfied customers.
How to calculate NPS
Use NPS = % promoters − % detractors. Count every response in the denominator, including passives. For example, 60 promoters, 25 passives, and 15 detractors produce an NPS of 45 because 60% minus 15% equals 45.
- Count ratings of 9–10 as promoters.
- Count ratings of 7–8 as passives.
- Count ratings of 0–6 as detractors.
- Divide each group by total responses, then subtract the detractor percentage from the promoter percentage.
How to interpret the result
A positive score means promoters outnumber detractors; a negative score means the opposite. The number becomes more useful when you follow its movement over time, retain a consistent survey method, and compare similar customer groups. Pair the score with open-text feedback to learn why respondents chose their rating.
Survey practices that protect signal quality
- Use the same wording, channel, audience, and timing when comparing periods.
- Avoid surveying only the most active or successful customers.
- Track response count and rate so a small sample is not mistaken for a broad trend.
- Segment carefully, but do not overinterpret groups with very few responses.
- Connect rating changes with qualitative feedback and behavioral data before acting.