Free tool
NPS calculator
Enter how many promoters, passives and detractors you have, or paste raw 0–10 scores. You get the score, the breakdown and how much it could move by chance.
Net Promoter Score
+30
±7.7 points at 95% confidence (n = 400), so the true score is likely between 22 and 38.
- Promoters
- 50% (200)
- Passives
- 30% (120)
- Detractors
- 20% (80)
Two scores whose ranges overlap may not differ in reality. Compare like with like: same question wording, channel and customer type.
How to calculate Net Promoter Score
Ask the standard question
“How likely are you to recommend [company] to a friend or colleague?” on a 0–10 scale.
Group the answers
9–10 are promoters, 7–8 passives and 0–6 detractors.
Work out the percentages
Divide each group by the total number of responses.
Subtract
NPS = % promoters − % detractors. Passives count towards the total but not the score, so NPS ranges from −100 to +100.
Check the margin of error
Before reporting a change between two periods, check whether the difference is larger than the margin of error.
The margin of error for NPS
Because each answer scores +1, 0 or −1, NPS has its own variance: (pp + pd − (pp − pd)²) / n, where pp and pd are the promoter and detractor shares. The 95% margin of error is 1.96 times the square root of that, expressed in points.
With 400 responses split 50% promoters, 30% passives and 20% detractors, NPS is +30 with a margin of about ±7.7 points. A move from +30 to +34 next quarter is within that range and may be noise.
Reading the score
Benchmarks vary widely by industry, channel and country, so the most useful comparison is with your own previous score using the same wording and audience. Always read the follow-up comments: the score tells you whether loyalty is moving, the reasons tell you why.
Frequently asked questions
What is a good NPS?
Any score above 0 means more promoters than detractors. Beyond that, compare with your own history and, if you have them, published benchmarks for your industry and region, since typical scores differ a lot between sectors.
Why don't passives count?
They are included in the total, so a large share of passives pulls the score towards zero, but they do not add or subtract directly. Turning passives into promoters is often the cheapest way to raise NPS.
How many responses do I need for NPS?
At 400 responses the margin of error is typically ±6 to ±8 points for common splits, and never more than ±9.8. With 100 responses it is typically ±13 to ±15 points, which is too wide to track small changes.
Is my data sent anywhere?
No. The calculation runs in your browser and nothing you type is stored.