Once the answers are in
NPS calculator
Calculate Net Promoter Score from promoter, passive and detractor counts, with a confidence interval to show sampling uncertainty.
No login required. Calculations run in your browser.
Count people who answered the recommend question. Leave out anyone who skipped it rather than counting them as passive.
Net Promoter Score
+36
from 220 answers
- Promoters, 9-10
- 54.5%
- Passives, 7-8
- 27.3%
- Detractors, 0-6
- 18.2%
At 95% confidence the score sits somewhere between 26 and 47, a span of 20 points.
This interval is wide. Treat changes between periods cautiously and report the promoter, passive, and detractor shares alongside the score.
Passives contribute to the response total but not to the promoter-minus-detractor numerator. Report all three shares and describe who answered, especially if the survey only reached current users.
How this tool works
Net Promoter Score is the share of promoters (scoring 9 or 10) minus the share of detractors (scoring 0 to 6), in percentage points, with passives (7 and 8) counted in the denominator but nowhere else. The range runs from −100 to +100 and the result is conventionally reported as a whole number without a percent sign.
The interval uses the standard error √((p + d − (p − d)²) ÷ n), where p and d are the promoter and detractor proportions. With 120 promoters, 60 passives, and 40 detractors, n = 220 and the rounded score is +36. The approximate 95% confidence interval runs from 26 to 47.
Small samples can produce large score changes when a few respondents move between categories. Report the promoter, passive, and detractor shares with the score and its uncertainty. When comparing periods, account for uncertainty in both samples.
Describe who was invited and who answered. A survey limited to current users or recent support contacts may not represent all customers. Keep wording, scale, recruitment, and timing consistent when tracking NPS. Interpret benchmarks in the context of the product and audience.
Also once the answers are in
System Usability Scale calculator
Score ten-item SUS responses and inspect individual scores.
Kano model classifier
Classify paired feature reactions and calculate coefficients.
Van Westendorp price sensitivity calculator
Plot pricing curves and inspect the acceptable-range crossings.
Margin of error calculator
Estimate the margin of error around a survey percentage.
Survey significance test calculator
Compare two groups using their response counts.
A useful next step
The standard question with a follow-up that explains the score.
Why a few people moving from 8 to 9 swings a small sample by several points.
The interval around each percentage behind the score.
Start
Put it into practice in your next survey.
100 responses a month on Free, and no credit card. Pro is $15 a month for 10,000 responses.