NPS
Net Promoter Score
Quick definition
Net Promoter Score (NPS) is calculated from a single 0–10 recommendation question. It is the percentage of promoters (9–10) minus the percentage of detractors (0–6).
Formula
NPS = % Promoters − % Detractors
Formula variables
- % Promoters
- Share of respondents who answered 9 or 10.
- % Detractors
- Share of respondents who answered 0 to 6. Passives (7 or 8) count in the total but not in either percentage.
Worked example
- Responses
- 200
- Promoters (9–10)
- 100
- Passives (7–8)
- 60
- Detractors (0–6)
- 40
50% − 20%
Result: 30
Half the respondents are promoters and a fifth are detractors, giving a score of 30. The result is a number between −100 and +100, not a percentage. The figures are illustrative.
How to interpret it
NPS summarises relationship loyalty on a scale from −100 to +100. It is most useful as a trend measured the same way over time, together with the reasons customers give.
The score alone does not say why customers feel as they do. Follow-up questions and segment breakdowns provide the actionable insight.
When it is useful
- Tracking customer loyalty over time on a consistent question.
- Comparing segments, products or regions measured with the same method.
- Identifying detractors for follow-up.
Limitations
- Response rates and survey timing change the result.
- The score hides the mix of promoters and detractors behind it.
- Cultural and channel differences in how people use rating scales make comparisons unreliable.
- Net Promoter®, NPS®, NPS Prism® and Net Promoter System® are registered trademarks, and Net Promoter Score℠ is a service mark, of Bain & Company, Inc., NICE Systems, Inc. and Fred Reichheld.
Common mistakes
- Comparing scores from surveys with different wording or timing.
- Reporting NPS as a percentage.
- Reading the score without the reasons behind it.