Free tool
Paste the raw scores from your survey, separated by commas, spaces, or new lines, and get your Net Promoter Score or CSAT straight away. You also get the promoter, passive, and detractor breakdown and a 95% confidence interval, which tells you whether a change from last month is real or noise.
Net Promoter Score from 40 responses
95% confidence interval: -5 to +45 (± 25)
| Score | Responses | Share |
|---|---|---|
| 0 | 1 | 2.5% |
| 1 | 0 | 0% |
| 2 | 0 | 0% |
| 3 | 2 | 5% |
| 4 | 0 | 0% |
| 5 | 3 | 7.5% |
| 6 | 4 | 10% |
| 7 | 5 | 12.5% |
| 8 | 7 | 17.5% |
| 9 | 10 | 25% |
| 10 | 8 | 20% |
The formulas
Net Promoter Score comes from one question: “How likely are you to recommend us to a friend or colleague?”, answered from 0 to 10. Respondents fall into three groups:
NPS = % promoters − % detractors, so it runs from −100 to +100. With 45% promoters and 25% detractors, the NPS is +20.
CSAT (customer satisfaction) usually asks “How satisfied were you?” on a 1–5 scale. The common definition is the share of responses scoring 4 or 5. Some teams use the average score instead, but the share is easier to track and compare.
Read it correctly
An NPS from 40 responses is an estimate, not a fact. Survey a different 40 customers and you'd get a different number. The confidence interval shows how far the true score could plausibly be from what you measured.
For NPS, the calculator treats each promoter as +1, each passive as 0, and each detractor as −1, then takes the standard error of that average. For CSAT it uses the Wilson score interval, which stays accurate when nearly everyone is satisfied.
The practical rule: if this month's interval overlaps last month's a lot, the change is probably noise. Margins shrink as responses grow. Around 100 responses usually gives ±10 to 15 NPS points, and around 400 gives ±5 to 8.
FAQ
Anything above 0 means you have more promoters than detractors. Above +30 is generally strong and above +50 is excellent, but benchmarks vary widely by industry, so tracking your own trend is more useful than comparing with other companies.
You have more detractors (0–6) than promoters (9–10). Scores of 7 and 8 feel positive but don't count, so a survey full of 7s and 8s gives an NPS near zero.
There's no hard minimum, but below about 30 responses the margin of error is usually over ±25 points, so small changes mean nothing. Check the interval the calculator shows before you report a change.
No. The calculation runs in your browser and nothing you paste leaves your device.
Related
PulsePanda runs NPS and CSAT surveys inside your product and links every answer to the session replay behind it.
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