Net Promoter Score, or NPS, is a customer loyalty measure calculated by subtracting the percentage of detractors from the percentage of promoters. It is based on responses to a recommendation question scored from 0 to 10.
How are responses classified?
- Promoters: scores of 9 or 10
- Passives: scores of 7 or 8
- Detractors: scores from 0 to 6
Passives remain in the total response count but are not added to either side of the formula.
How is NPS calculated?
NPS = percentage of promoters − percentage of detractors. The result ranges from −100 to +100 and is expressed as a score, not a percentage.
Illustrative NPS calculation
| Response group | Responses | Share |
|---|---|---|
| Promoters | 120 | 120 ÷ 200 = 60% |
| Passives | 50 | 50 ÷ 200 = 25% |
| Detractors | 30 | 30 ÷ 200 = 15% |
| Net Promoter Score | 60 − 15 = 45 | |
The illustrative NPS is 45. The calculation does not show why respondents selected their scores, so follow-up comments and operational data are needed for interpretation.
What can distort the result?
Sampling method, response rate, survey timing, customer segment and channel can materially change the score. Compare like-for-like cohorts and retain the question wording and collection method.
How should an outsourced operation use NPS?
NPS can support a broader customer-experience scorecard, but it should not replace service measures such as resolution, quality, complaints and retention. State which party owns survey delivery and corrective actions.
