What is Net Promoter Score (NPS)? Definition, Formula & Benchmarks

Definition

Net Promoter Score (NPS) is a customer-loyalty metric that measures how willing customers are to recommend a company, product, or service to others. It is calculated from a single survey question — "How likely are you to recommend [organisation] to a friend or colleague?" — answered on a 0-10 scale. The result is a single number between -100 and +100.

The NPS formula

NPS = % Promoters − % Detractors

Respondents are classified by their score:

Promoters — score 9-10 (loyal enthusiasts who actively recommend)
Passives — score 7-8 (satisfied but unenthusiastic)
Detractors — score 0-6 (unhappy customers who may spread negative word-of-mouth)

Passives are deliberately excluded from the formula — they appear in the total but do not add to or subtract from the score. Calculate your NPS or see the step-by-step guide.

History

NPS was introduced by Fred Reichheld of Bain & Company in 2003, in the Harvard Business Review article "The One Number You Need to Grow." Reichheld argued that the recommendation question — easier to answer and more predictive than complex multi-question surveys — correlates strongly with subsequent revenue growth. The metric was developed in collaboration with Satmetrix and is now used by a majority of Fortune 1000 companies.

The 1-100 scale variant

Some platforms (including kazva.bg) use an extended 1-100 scale with proportionally adjusted cutoffs:

Promoters: 80-100
Passives: 50-79
Detractors: 1-49

The wider range reduces the "ceiling effect" common in 0-10 surveys and reveals nuances in sentiment that a coarser scale would miss. The final NPS is still expressed in the -100 to +100 range and is comparable across scales.

What is a good NPS?

The headline rule: any positive NPS means more promoters than detractors. But the absolute number must be benchmarked against industry, not against an absolute target.

Above +70 — world-class. Rare even among loved consumer brands.
+50 to +70 — excellent.
+30 to +50 — good. The bulk of healthy organisations sit here.
0 to +30 — adequate. Room to improve customer experience.
Below 0 — critical. More detractors than promoters.

Published industry averages (Bain & Company, Retently, ACSI):

Hospitality and education: +35 to +55
Retail: +30 to +45
Financial services: +25 to +40
Airlines: +20 to +35
Municipal services: +15 to +30

NPS vs CSAT vs CES

NPS is one of three widely-used CX metrics, each answering a different question:

NPS — "How likely are you to recommend us?" Measures long-term loyalty and brand health.
CSAT — "How satisfied are you?" Measures satisfaction with a specific interaction.
CES — "How easy was it?" Measures friction and effort in resolving an issue.

Mature feedback programmes use all three together: CSAT for operational quality control, NPS for strategic loyalty tracking, CES for process optimisation.

How NPS is collected

NPS can be collected via any channel — email after a transaction, in-app prompt, SMS, paper survey, QR code at a physical location. Best practice is to survey within hours of the interaction, before the memory fades. Response rate above 20% is generally needed for statistical reliability; aim for 100+ responses before drawing firm conclusions.

Common mistakes

Including passives in the formula. The formula is % Promoters − % Detractors. Passives appear in the denominator but do not get added or subtracted.
Mixing scales. A 1-100 score of 90 ≠ a 0-10 score of 9. Pick one scale per survey and stay consistent.
Calculating NPS from a single-digit sample. An NPS computed from 20 responses can swing 20 points just from one or two people. Always report sample size.
Reporting NPS without trend data. A single number is less useful than the month-on-month or quarter-on-quarter trajectory.

Net Promoter Score (NPS) — Glossary | kazva.bg