NPS Calculator

NPS deliberately ignores passives, which is why it can look harsh: a company where most customers are mildly satisfied scores near zero. The score is a relative measure, not an absolute one — a +30 might be excellent in an industry people rarely enjoy dealing with and mediocre in one where switching is easy, so your own trend over time is far more informative than any published benchmark. Sample size matters more than most teams acknowledge. With 100 responses the 95% confidence interval is around ±10 points, so a move from +45 to +49 is noise, not improvement. The follow-up question — asking why someone gave that score — routinely produces more value than the number itself.

NPS = %promoters − %detractors. Promoters score 9 or 10, passives score 7 or 8 and detractors score 0 to 6. Passives count towards the total number of responses but contribute nothing to the score, and the result is rounded to a whole number between −100 and +100.

NPS summarises sentiment into a single number and deliberately ignores passives, so it hides a great deal of nuance. The confidence interval assumes a random, representative sample; surveying only engaged or recently-helped customers inflates the result regardless of the arithmetic.

From 100 responses — 62 promoters, 25 passives and 13 detractors — the score is 62% − 13% = +49, with a 95% confidence interval of roughly ±10 points.

1. Choose whether you have group counts or raw scores.
2. Enter the counts, or paste every 0–10 response.
3. Read the score, which runs from −100 to +100.
4. Check the confidence interval before comparing with a previous survey.

• Reading a small movement as a real change when the sample is small.
• Treating passives as neutral-positive; they simply do not count.
• Comparing your score with a benchmark from a different industry.
• Surveying only happy customers, which inflates the result.

The NPS Calculator works out your Net Promoter Score either from the number of promoters, passives and detractors, or straight from a list of raw 0–10 survey responses. It shows the percentage split, the score, a rating and the confidence interval for your sample size.

Product managers, customer-success teams and business owners tracking customer sentiment.

• Accepts raw 0–10 responses and buckets them for you.
• Shows the confidence interval, so you know whether a change is real.
• Gauge and donut charts make the promoter-to-detractor balance obvious.
• Flags responses outside the 0–10 range instead of silently including them.

• Calculating NPS from a customer survey export.
• Tracking sentiment quarter over quarter.
• Checking whether a score change is statistically meaningful.
• Reporting customer satisfaction to a board or investor.