To calculate Net Promoter Score (NPS), subtract the percentage of detractors from the percentage of promoters. Promoters give a rating of 9–10, passives 7–8, and detractors 0–6. Include all three groups when calculating the total number of valid responses.
For example, 60% promoters minus 20% detractors gives an NPS of +40. This guide explains the formula through worked examples, an Excel calculation and guidance on combining team scores. All numerical examples are hypothetical.
Want to calculate NPS from your own survey results? Use our free NPS Calculator to enter promoter, passive and detractor counts, combine comparable groups and download your results.
What is Net Promoter Score?
NPS groups answers to a recommendation question on a 0–10 scale. The categories are promoters (9–10), passives (7–8) and detractors (0–6). It summarises recommendation sentiment among the customers who responded, rather than directly counting repeat purchases or referrals. See Bain’s explanation of NPS scoring.
Net promoter score formula
NPS = % promoters − % detractors
NPS = ((promoter responses − detractor responses) ÷ total valid responses) × 100Total valid responses include promoters, passives and detractors. Report the result as a score between −100 and +100, for example +40, rather than 40%. Passives affect the denominator even though they are not subtracted or added in the numerator.
Worked NPS calculation example
| Response group | Count | Share of valid responses |
|---|---|---|
| Promoters: 9–10 | 120 | 60% |
| Passives: 7–8 | 40 | 20% |
| Detractors: 0–6 | 40 | 20% |
| Total | 200 | 100% |
First calculate the total: 120 + 40 + 40 = 200. Promoters are 120 ÷ 200 × 100 = 60%. Detractors are 40 ÷ 200 × 100 = 20%. Therefore, NPS = 60 − 20 = +40.
If you incorrectly exclude the 40 passives, you would calculate (120 − 40) ÷ 160 × 100 = +50. That inflates the score by 10 points without any change in customer responses.
How to calculate NPS in Excel
Use A2 for promoter count, B2 for passive count and C2 for detractor count. Enter non-negative whole-number counts, including an explicit zero for a category with no responses. Put this formula in D2:
=IF(COUNT(A2:C2)<>3,"Enter all 3 counts",IF(OR(MIN(A2:C2)<0,SUMPRODUCT(--(MOD(A2:C2,1)<>0))>0),"Use non-negative whole numbers",IF(SUM(A2:C2)=0,"N/A",(A2-C2)/SUM(A2:C2)*100)))With 120, 40 and 40 in A2:C2, D2 returns 40. Format D2 as Number, with one or two decimal places; do not apply Percentage formatting because the formula already multiplies by 100. For a signed display, use the custom number format +0.00;-0.00;0.00. Some regional Excel settings require semicolons instead of commas.
The formula flags missing or nonnumeric counts, negative numbers and fractions. An all-zero row returns N/A: no valid responses means no score, rather than a score of zero. Fix any underlying spreadsheet error values before calculating.
How to combine NPS across teams or channels
Combine the underlying counts for comparable, non-overlapping groups. Do not take an unweighted average of team scores when response volumes differ.
| Group | Promoters | Passives | Detractors | Responses | NPS |
|---|---|---|---|---|---|
| Team A | 80 | 10 | 10 | 100 | +70 |
| Team B | 120 | 90 | 90 | 300 | +10 |
| Combined | 200 | 100 | 100 | 400 | +25 |
The combined score is (200 − 100) ÷ 400 × 100 = +25. Averaging +70 and +10 produces +40, which gives the smaller team too much influence. Equivalently, weight each unrounded group score by its response count.
Before combining groups, confirm that they use the same survey purpose, question, scale and period. If a customer appears in multiple exports, apply your documented deduplication rule before calculating. Do not blend relationship surveys and post-interaction surveys simply because both use NPS.
Set measurement rules before comparing scores
Bain distinguishes relationship, experience and competitive forms of NPS and stresses consistent measurement and sound sampling. Its measurement overview explains why the survey type matters.
- Define the scope. Record whether the survey concerns the business relationship, a product or a recent experience.
- Keep collection consistent. Document eligibility, survey timing, channel, language and reminder rules.
- Count valid ratings. Keep only valid integer ratings from 0 to 10; distinguish a genuine rating of zero from an unanswered question.
- Record coverage. Show response count and, where measurable, response rate using a documented invitation base.
- Use comparable periods. Note changes in the customer mix, survey delivery or service conditions alongside the score.
What does a positive or negative NPS mean?
A positive score means promoter responses outnumber detractor responses. A negative score means the reverse. Zero means equal promoter and detractor counts; it does not mean there were no responses.
There is no single target that fits every business. Compare against your own consistently measured history and suitably matched benchmarks. A score from ten responses deserves a different level of confidence from one based on thousands. Neither sample size alone nor a high response rate guarantees that respondents represent all customers.
NPS also hides part of the distribution. For example, 50 promoters and 50 detractors produce zero, as do 100 passives. These groups need different follow-up actions despite having the same score. Always retain the category counts and customer comments.
NPS, CSAT and FCR measure different things
CSAT summarises satisfaction using your chosen survey scale and favourable-response rule. First contact resolution measures whether eligible issues were resolved on the initial contact. NPS summarises recommendation sentiment. Review them together, but do not treat one as a substitute for another.
For a BPO team, recommendation feedback may reflect product quality, pricing, delivery or policy as well as the service interaction. Review the reason for a rating before attributing it to an individual advisor. An accurate calculation does not establish who caused the outcome.
Turn NPS feedback into practical improvements
- Read comments alongside the rating and identify the customer’s specific concern.
- Group repeated themes such as billing clarity, repeat contacts or missed commitments.
- Assign an owner to the underlying process issue and agree on an observable correction.
- Follow up appropriately where the customer has consented and your process permits it.
- Track whether the issue recurs after the change, using operational and quality evidence alongside subsequent survey results.
Keep survey invitations neutral. Selectively inviting only satisfied customers or asking people to choose a particular rating undermines the usefulness of the result. The objective is reliable feedback that helps improve the experience.
Frequently asked questions
Do passives count in NPS?
Yes. Ratings of 7 or 8 count toward total valid responses. They do not enter the promoter-minus-detractor numerator.
Is a rating of 8 a promoter?
No. On the standard 0–10 NPS scale, 8 is passive. Only 9 and 10 are promoters.
Is NPS an average customer rating?
No. Averaging the raw ratings gives a different statistic. NPS uses the shares of promoters and detractors.
Can NPS be negative?
Yes. For example, 20 promoters, 20 passives and 60 detractors produce (20 − 60) ÷ 100 × 100 = −40.
How much does one changed response affect NPS?
With the total fixed at 200 responses, changing one detractor to a promoter increases the score by 2 ÷ 200 × 100 = 1 point. A detractor-to-passive change increases it by 0.5 point. This is arithmetic, not a recommendation to influence ratings.
Should I round before combining results?
No. Combine counts first and round only the final displayed score to avoid avoidable rounding differences.
Related CX tools and guides
Explore our free CX and quality calculators, including the CSAT Calculator and FCR Calculator, to review satisfaction and resolution alongside recommendation feedback.
References
- Bain & Company: Measuring Your Net Promoter Score — category definitions and calculation.
- Bain & Company: The Net Promoter Score — survey types and consistent measurement.
This is an independent educational guide. CX Metric Works is not affiliated with or endorsed by the owners of the Net Promoter marks.