NPS Calculator: Net Promoter Score, CSAT and Satisfaction

Calculate Net Promoter Score (% Promoters - % Detractors), CSAT %, average rating out of 5, and interpretation benchmarks.

Calculating NPS and CSAT scores: formulas and example

Net Promoter Score is the percentage of promoters (scores of 9 and 10 out of 10) minus the percentage of detractors (0 to 6); it runs from −100 to +100. The CSAT score is the share of customers giving 4 or 5 on a 1-to-5 scale. With 140 promoters, 45 passives and 25 detractors, NPS is +55.

The two formulas

  • NPS = % promoters − % detractors, rounded to a whole number. Passives (7 and 8) count in total responses but neither for nor against. The question is "How likely are you to recommend us to a friend or colleague?", scored from 0 to 10.
  • CSAT = (4 responses + 5 responses) ÷ total responses × 100, to one decimal. The tool also shows the average rating out of 5, to two decimals.

Example (default values)

NPS: 140 + 45 + 25 = 210 responses; 66.7% promoters, 21.4% passives, 11.9% detractors; 66.67 − 11.90 = 54.76, shown as +55. CSAT: 110 ratings of 5, 60 of 4, 20 of 3, 12 of 2 and 8 of 1, i.e. 210 responses of which 170 positive: 81.0%, average 882 ÷ 210 = 4.20/5.

Reading the result

The grid beside the score (above +50 "world class", +20 to +50 "very good B2B/SaaS level", negative "alert") is a benchmark of the tool, not a scale published by the creators of NPS: compare yourself first with your own earlier surveys and your industry. On a small sample the score moves a lot; the tool shows neither a margin of error nor a customer effort score (CES). As a rough guide, computed outside the tool with the usual NPS variance formula, 210 responses give a margin of about ±9 points at 95%.

Limits

  • CSAT follows the "top 2 box" definition (ratings 4 and 5); some survey tools use the average or the share of 5s only.

Sources and dates: NPS categories and formula (promoters 9-10, passives 7-8, detractors 0-6) from Bain & Company's "Measuring your Net Promoter Score" page; Net Promoter Score is a mark of Bain & Company, Fred Reichheld and NICE Systems. Thresholds in the evaluation grid are indicative, unverified values (checked 14/10/2026).

Frequently Asked Questions

How do I calculate Net Promoter Score?

Group the answers to the 0-to-10 recommendation question: promoters (9 and 10), passives (7 and 8), detractors (0 to 6). NPS is the percentage of promoters minus the percentage of detractors: out of 100 responses with 50 promoters and 20 detractors, it is +30.

Why don't passives count in NPS?

They count neither for nor against, but they stay in the total number of responses used as the denominator. The more passives there are, the lower both the promoter and detractor percentages, which pulls the score towards zero.

What is the difference between NPS and CSAT?

NPS measures the intention to recommend the company on a 0-to-10 scale and runs from −100 to +100. CSAT measures satisfaction with an interaction or product, here the share of ratings 4 and 5 out of 5: 170 positive answers out of 210 give 81.0%.

How many responses do I need for a reliable NPS?

The smaller the sample, the wider the margin of error. With the usual NPS variance formula, 210 responses give about ±9 points at 95% for a score of +55; you need roughly four times as many responses to halve that margin. The tool itself does not display a margin of error.

Is this tool really free?

Yes, all tools on Kristools are 100% free and accessible without registration.

Is my data protected?

Yes. All processing is performed directly and securely inside your browser. No personal data is sent to our servers.