Net Promoter Score Calculator
Type how many people gave each score from 0 to 10, or paste the raw scores. You get the score, the three groups and how far you can trust it.
Worked examples
100 responses
60 promoters, 25 passives, 15 detractors
Score +45, margin 14.5 points
60% - 15% = 45. The margin comes from 1.96 x the square root of (0.60 + 0.15 - 0.45 squared) divided by 100.
200 responses
120 promoters, 50 passives, 30 detractors
Score +45, margin 10.3 points
The same score on twice the responses has a tighter margin, so it is more reliable.
40 responses
10 promoters, 20 passives, 10 detractors
Score 0, margin 21.9 points
With so few answers the true score could easily be anywhere from about minus 22 to plus 22.
About Net Promoter Score Calculator
The Net Promoter Score is built on one question: how likely are you to recommend us to a friend or colleague, from 0 to 10. People who answer 9 or 10 are promoters, 7 or 8 are passives and 0 to 6 are detractors. The score is the percentage of promoters minus the percentage of detractors, so it can run from minus 100 to plus 100. A score above zero means you have more promoters than detractors.
Type how many people gave each score, or paste the raw list of answers, and the calculator does the rest. It shows the three groups as numbers and percentages, and it adds something most calculators leave out: a 95% margin of error. A score based on 30 replies can move by 20 points or more through chance alone, so the margin tells you whether a change from last quarter is real. The result is a figure to track over time against your own history.
How to use Net Promoter Score Calculator
- Type the number of responses for each score from 0 to 10, or paste the raw scores and press the button.
- Read the score, the number of responses and the margin of error.
- Look at the three groups to see where most of your answers fall.
- Repeat each quarter with the same question, and compare changes with the margin.
Common uses
- Reporting customer satisfaction to a team or a board
- Comparing two branches or products on the same basis
- Checking whether a change in score is real
- Setting a target for the next survey
Sources
Last reviewed 18 October 2026.
Frequently asked questions
How is the Net Promoter Score calculated?
Take the percentage of respondents who scored 9 or 10 and subtract the percentage who scored 0 to 6. Passives, who scored 7 or 8, are counted in the total but not in either group.
What is a good score?
It depends on your industry, so compare yourself with your own past results first. Any score above zero means more promoters than detractors, and above 50 is regarded as excellent by most firms.
What does the margin of error mean?
It is a 95% range around the score. If the score is 45 with a margin of 14.5 points, the true score among all your customers is probably between 30.5 and 59.5.
How many responses do I need?
Aim for at least 100. Under about 50 responses the margin is very wide, so a rise or fall of a few points means little.
Can I use a different scale?
The method needs the 0 to 10 scale. Scores from a 1 to 5 scale cannot be converted directly, so ask the 0 to 10 question if you want a Net Promoter Score.