Skip to content

Free tool · Surveys

Net Promoter Score (NPS) calculator

Work out your Net Promoter Score from response counts or a pasted list of 0 to 10 answers, with the margin of error and a check for whether a change is real.

Runs in your browser. Nothing you enter is uploaded, and there's no sign-up.

Responses

Answers of 9 or 10

Answers of 7 or 8

Answers of 0 to 6

Net Promoter Score

45±10 points at 95% confidence

Likely range 35 to 55, from 200 responses.

  • Promoters60%
  • Passives25%
  • Detractors15%

More of your respondents are promoters than detractors.

NPS 45, plus or minus 10 points, from 200 responses.

Share links carry these numbers after the # sign, which never reaches a server.

How NPS is calculated

Net Promoter Score is the percentage of promoters minus the percentage of detractors. Everyone answers one question, usually "How likely are you to recommend us to a friend or colleague?", on a scale from 0 to 10, and each answer falls into one of three groups.

  • Promoters answer 9 or 10.
  • Passives answer 7 or 8. They count toward the total but don't add or subtract.
  • Detractors answer 0 to 6.
NPS = % promoters - % detractors

Example: 200 people answer. 120 are promoters (60%), 50 are passives (25%), and 30 are detractors (15%). The score is 60 - 15 = 45. Scores run from -100, when everyone is a detractor, to 100, when everyone is a promoter.

What the margin of error tells you

A score from a sample is an estimate. The margin of error is how far the true score could plausibly sit from the one you measured, at 95% confidence. The calculator works it out from the share of promoters (P), the share of detractors (D), and the number of responses (n):

margin of error = 1.96 × √((P + D - (P - D)²) ÷ n) × 100

In the example above that comes to about 10 points, so a score of 45 from 200 answers is consistent with anything from roughly 35 to 55. Collecting four times as many answers roughly halves the margin.

Is a change between two periods real?

Scores move from month to month even when nothing changed, because each month is a different sample. The Compare two periods tab checks whether a change is bigger than that noise. It combines the standard error of each period and treats a change as real when it is larger than 1.96 times the combined figure, a standard two-sided test at 95% confidence.

The default example goes from 23 to 45, with 200 answers in each period. The change of 22 points is larger than the combined margin of about 15 points, so it is unlikely to be chance.

The test assumes the two groups of respondents are independent and were reached the same way. If you changed who you ask, or when, the comparison tells you less.

Getting NPS answers you can trust

A precise calculation can't fix a biased sample. A few habits make scores comparable from one period to the next:

  • Ask at the same moment each time, such as a set number of days after sign-up.
  • Keep the question wording identical between periods.
  • Ask inside your product, where active users already are, instead of relying only on email.
  • Add one open follow-up question, so each score comes with a reason.
  • Cap how often anyone sees the survey, so the same people aren't asked again and again.

Last reviewed

Questions about the NPS calculator

nps-calculator.md
What is a good NPS?

Any score above 0 means more of your respondents are promoters than detractors. Beyond that, the most useful comparison is your own score over time, measured the same way. Scores vary a lot by industry, audience, and when you ask, so another company's number tells you little about yours.

Why don't passives count in the formula?

They do count toward the total number of responses, which lowers both percentages. They just don't add to the promoter share or the detractor share. Turning a passive into a promoter raises your score, and turning one into a detractor lowers it.

How many responses do I need?

It depends on how precise you need the score to be. With 100 responses the margin of error is usually somewhere between 10 and 20 points, and with 400 it is roughly half that. The calculator shows the margin for your own numbers and flags samples under 30 as too small to rely on.

Can NPS be negative?

Yes. NPS runs from -100 to 100. A negative score means you have more detractors than promoters.

Can I paste answers from a spreadsheet or CSV export?

Yes. Paste a column of scores into the Paste scores tab. Commas, tabs, spaces, and line breaks all work as separators. Anything that isn't a whole number from 0 to 10, such as a header row, is skipped, and the calculator tells you how many entries it left out.

Is anything I enter sent to ReleaseDock?

No. The calculator runs entirely in your browser and nothing you type or paste is uploaded. If you copy a share link, the numbers live in the part of the link after the # sign, which browsers never send to a server.

markdown6 entries

More free tools

All free tools