NPS is one of the simplest metrics in business, and one of the most misread. The math takes a minute. The interpretation takes some restraint. Let's walk through both.
The one question
Net Promoter Score comes from a single question: "On a scale of 0 to 10, how likely are you to recommend us to a friend or colleague?" That is the whole instrument. No other questions are required to compute the score. Most teams add one open-ended follow-up to capture context, and that is a good idea, but the score itself only needs the number.
You send this question to your customers, you collect answers, you do a small amount of arithmetic.
The three buckets
Sort your responses into three groups based on the score.
Anyone who gave you a 9 or a 10 is a promoter. They are loyal, and most of them will recommend you without being asked.
Anyone who gave you a 7 or an 8 is a passive. They are satisfied but not enthusiastic. The next interesting offer from a competitor will get their attention.
Anyone who gave you a 0 through 6 is a detractor. The bottom of that range is genuinely unhappy. The top of that range, the 5s and 6s, is often more disappointed than angry, which is the easiest group to win back.
Notice that 6 is a detractor, not a passive. People miss this constantly. The Net Promoter scale is not a normal 1-to-10 rating where 6 is "above average." A 6 means the customer would not recommend you. That is the whole point of the metric.
The calculation
The formula is one line:
NPS = % Promoters − % Detractors
Passives are worth nothing. They do not appear in the calculation. They sit there as a reminder that "fine" is not a growth strategy.
Run the percentages on the same response set. If 200 customers respond and 90 are promoters and 30 are detractors, you have 45% promoters and 15% detractors. Your NPS is 30.
The score can run from -100 to +100. Negative numbers are possible and not unusual for businesses that are losing the room.
Doing it in a spreadsheet
Drop your responses in column A, one score per row. Then in any empty cells:
Promoters: =COUNTIF(A:A, ">=9")
Passives: =COUNTIF(A:A, ">=7") - COUNTIF(A:A, ">=9")
Detractors: =COUNTIF(A:A, "<=6")
Total: =COUNTA(A:A)
% Promoters: = (Promoters / Total) * 100
% Detractors: = (Detractors / Total) * 100
NPS: = % Promoters - % Detractors
Or if you want it in a single cell:
=((COUNTIF(A:A,">=9")/COUNTA(A:A)) - (COUNTIF(A:A,"<=6")/COUNTA(A:A))) * 100
That is it. You now have your NPS.
What the number actually means
Public benchmarks for NPS are messy because the metric varies wildly across industries. A 40 in airline travel is heroic. A 40 in a high-touch B2B service relationship is mediocre. Compare yourself to peers in your category, not to a generic chart.
That said, here are useful rough markers for most businesses:
Above 50 is strong. You have a customer base that is actively pulling new customers in. Lean into referrals.
Between 0 and 50 is normal. Most companies live here. The work is to figure out which segments are pulling you down and which are pulling you up.
Below 0 is a warning. You have more detractors than promoters. Word-of-mouth is working against you. This usually shows up in churn and acquisition cost before you notice it in NPS.
A few honest caveats
The score is one number. One number cannot run a customer experience program. Anyone who tells you to manage to NPS is going to lead you into bad decisions.
Treat NPS as a coarse temperature reading. It tells you whether the relationship is warming up or cooling down. The interesting work is in the open-ended responses, the segment cuts, and the trend over time.
Also, be careful comparing your NPS to other companies' NPS unless you know how they collected it. Sample size, timing, channel, and survey design all move the number. Two companies with "an NPS of 35" can have very different realities.
Cadence and segmentation
Run NPS on a steady cadence. Quarterly is enough for most businesses. Some companies do "relationship NPS" once or twice a year and "transactional NPS" after specific events like a purchase, a support interaction, or a milestone.
When you have enough responses, slice the data. NPS by acquisition channel often reveals which marketing source is bringing in the right customers. NPS by tenure tells you whether you have a honeymoon problem or a retention problem. NPS by product line, plan tier, or geography often shows you exactly where to focus.
Get the calculation right, then put the calculator away
The math is the easy part. The harder part is acting on what the score is telling you. That is where most NPS programs fall apart, and that is where outsourced support can carry a lot of the load.
Our agents run NPS programs for businesses across software, ecommerce, subscription services, and professional services. The work is the same in every case. Send the surveys. Read every response. Follow up with detractors within 48 hours. Tag the patterns. Report monthly.
If you are doing all of that yourself and would rather not, that is exactly the kind of work we cover at $3,900 a month, fully managed.
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If running an NPS program in-house has become more work than insight, let's chat about what a senior CS agent could take off your plate.
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