How to use the net promoter score (nps) calculator
- Choose whether you have counts for each group or a list of scores.
- For counts, enter the number of promoters (scores 9 and 10), passives (7 and 8) and detractors (0 to 6). For a list, paste the scores separated by spaces, commas or new lines.
- Read the Net Promoter Score, the share of each group and the total number of responses.
- Check the sample size note. A score from a small number of responses can swing widely.
Formula
Promoters = scores of 9 or 10; passives = 7 or 8; detractors = 0 to 6
% promoters = promoters / total responses x 100
% detractors = detractors / total responses x 100
NPS = % promoters - % detractors
The score runs from minus 100 (everyone is a detractor) to plus 100 (everyone is a promoter). Passives count in the total but not in the score. By convention the result is written as a whole or decimal number without a percent sign.
Worked example
A survey has 120 promoters, 60 passives and 20 detractors, 200 responses in total. Promoters are 60% and detractors are 10%, so NPS = 60 - 10 = +50. Passives are 30% of responses.
Ten scores of 10, 9, 9, 8, 7, 10, 6, 3, 9 and 10 give 6 promoters, 2 passives and 2 detractors. NPS = 60 - 20 = +40.
If all responses are detractors the score is -100, and if all are promoters it is +100.
The question behind the score
NPS comes from a single survey question: how likely are you to recommend us to a friend or colleague, from 0 to 10? The groups are a way of sorting the answers. Promoters are likely to recommend you, passives are satisfied but not enthusiastic, and detractors may speak badly of you.
The score is useful as a simple trend line, and the real value usually comes from the comments people add. Ask why, and read the answers from detractors first.
Using NPS well
A few habits make the number far more reliable.
- Ask the same question the same way each time and survey a mix of customers, not only the happy ones.
- Track the score over time and by segment instead of comparing it with other companies. Industries differ widely.
- Look at the sample size. With 20 responses, a single answer changes the score by 5 points.
- Pair the score with a follow-up question and act on what you learn.
Assumptions and limits
- Scores must be whole numbers from 0 to 10. Decimal or out of range values are rejected.
- The calculator uses the standard grouping of 0 to 6, 7 to 8 and 9 to 10.
- Percentages are shown to one decimal place and the score to one decimal place.
- There is no confidence interval or significance test. Treat scores from small samples as rough.
Frequently asked questions
How do you calculate NPS?
Subtract the percentage of detractors from the percentage of promoters. With 60% promoters and 10% detractors the score is plus 50. Passives are ignored in the subtraction.
What is a good Net Promoter Score?
Anything above zero means more promoters than detractors, and scores vary a lot by industry. The best comparison is your own score over time and between customer groups.
Why do passives not count in the score?
Passives are satisfied but not likely to promote or criticize you, so the method leaves them out of the subtraction. They still count in the total, which is why they pull the score toward zero.
How many responses do I need?
More is better. With small samples a few answers can move the score by several points, so look at the trend across surveys and the written comments as well.