Calculators

eNPS calculator

Enter how many promoters, passives and detractors you have, or paste the individual scores, and the calculator works out your eNPS along with your response rate and margin of error. Everything is calculated in your own browser: nothing you enter is sent anywhere.

Updated 3 min read

How the calculator works

eNPS is the percentage of promoters minus the percentage of detractors. Promoters scored 9 or 10, passives 7 or 8, and detractors anything from 0 to 6. Passives count towards the total, but not in the subtraction.

eNPS = % promoters − % detractorsRanges from −100 to +100, with no percentage sign

An example. Of 80 employees, 60 respond: 21 promoters, 24 passives and 15 detractors. That's 35% promoters and 25% detractors, so an eNPS of +10. The response rate is 60 out of 80, or 75%.

If you paste individual scores, the calculator sorts them into groups for you. Anything that isn't a whole number from 0 to 10 (an empty cell, a 7.5, a word) is skipped, and the calculator tells you how many values that was.

The margin of error

Unless you heard from everyone, your eNPS is an estimate. The margin of error shows how far the true value could plausibly be from it. The calculator uses the standard approximation for the difference between two shares of the same sample, at 95% confidence:

margin = 1.96 × √((P + D − (P − D)²) / n)P and D are the shares of promoters and detractors (as fractions), n is the number of responses

If you enter the number of employees you invited, the calculator also corrects for the size of your organisation (the finite population correction). The larger the share of your people who responded, the smaller the margin. In the example above, 60 responses out of 80, the margin is about ±10 points. Without that correction it would be close to ±20.

What the margin of error doesn't cover. It assumes the people who responded are like the people who didn't. If it's mainly the unhappy who drop out, or the happy, your eNPS will be off in a way no formula can see. And below 30 responses the approximation is rough.

What next?

eNPS tells you where you stand, not why. Compare the result above all with your own previous score, taken at the same time of year with the same question, and factor in the margin of error before you treat a shift as significant.

To find out what's behind the number, ask an open question after the score, or better still, follow up. How to go about that, and which pitfalls to avoid, is covered in What is eNPS?. Example questions for a broader survey are in our employee survey questions.

Sources

  1. Measuring Your Net Promoter Score, Bain & Company
  2. Employee NPS, Bain & Company

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Metrics explained What is eNPS? How to calculate and use the Employee Net Promoter Score The question, the calculation with a worked example, what counts as a good score, and why the number only becomes useful once you ask why. Calculators NPS calculator Your Net Promoter Score from counts or a pasted column of scores, with the margin of error alongside. Question sets Employee survey questions: examples you can use Example questions across ten themes, from workload to line managers, with tips on wording, length and anonymity.

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