Net Promoter Score (NPS) Calculator
% promoters − % detractors, with the margin of error and what it takes to improve.
Promoters, passives and detractors
Answers by score
Show as a table
How this was calculated
About the Net Promoter Score (NPS) Calculator
The Net Promoter Score comes from one question — how likely are you to recommend us to a friend or colleague? — answered from 0 to 10. People who answer 9 or 10 are promoters, 7 or 8 passives and 0 to 6 detractors, and the score is % promoters − % detractors, from −100 to +100. Enter the number in each group, the number of answers for each score, or paste the raw scores from your survey export, and the calculator gives the NPS with its margin of error, a chart of the answers and what it would take to reach a target.
eNPS does the same for employee surveys — How likely would you recommend this company as a place to work? — and narrows the margin of error when you know how many people were asked. The CSAT tab works out a customer satisfaction score: the share of answers in the top boxes of a 1–5, 1–7 or 1–10 rating.
How to use it
- Choose NPS, eNPS (employees) or CSAT.
- Enter the answers the way you have them: the number of promoters, passives and detractors, the number of answers for each score from 0 to 10, or paste the scores from a spreadsheet column or survey export — one per line or separated by commas. A heading line and anything that is not a score are left out and listed. Paste a whole table with its heading row and the column headed “Score”, “NPS”, “Rating” or “How likely…” is read.
- Read the score, the share of each group and the margin of error; choose 90%, 95% or 99% confidence.
- For eNPS, enter how many employees were asked, for the response rate and a tighter margin.
- Optionally enter a target score to see how many detractors or passives would have to become promoters.
Examples
NPS = 60% − 15% = 45 ±14.5 at 95% confidence (30.5 to 59.5)
Turn 3 detractors into promoters, or 5 passives into promoters, or win 10 new promoters
The margin narrows to ±11.3 with the finite-population correction
CSAT 80% · 95% interval 71.1% to 86.7% · average rating 4.05
How the Net Promoter Score works
Fred Reichheld introduced the score in the Harvard Business Review article The One Number You Need to Grow: group the answers to the recommend question into promoters (9–10), passives (7–8) and detractors (0–6), then subtract the share of detractors from the share of promoters.
Passives count in the total but in neither group. So turning a detractor into a passive raises the score as much as turning a passive into a promoter — by 100 ÷ the number of answers — and turning a detractor into a promoter raises it twice as much.
Margin of error
A score from a sample is an estimate. Count each answer as +1 (promoter), 0 (passive) or −1 (detractor): the NPS is 100 × the average, and its standard error is 100 × √((p₊ + p₋ − (p₊ − p₋)²) ÷ n), where p₊ and p₋ are the shares of promoters and detractors. The margin of error is z times that — 1.96 for 95% confidence. With 100 answers and a score of 45 it is about ±14.5 points, so a move from 45 to 50 in the next survey may be noise.
This normal approximation is rough for small samples and for scores near ±100. The statistics of NPS intervals are discussed in Brendan Rocks’ paper Interval Estimation for the “Net Promoter Score” in The American Statistician.
eNPS for employee surveys
Employee NPS asks how likely someone would be to recommend the company as a place to work, and is worked out the same way. An employee survey usually goes to everyone in a known group, so the calculator can apply the finite-population correction √((N − n) ÷ (N − 1)): when 100 of 250 employees answer, the margin of error shrinks by about 22%, and when everyone answers there is no sampling error left at all.
CSAT
A customer satisfaction score is the share of answers that count as satisfied. A common definition is the top two boxes — 4 and 5 on a 1–5 scale — and some teams count only the top box; choose the scale and the lowest rating that counts. The interval uses the Wilson score method, which stays sensible for small samples and for scores near 0% or 100%. The average rating is shown too.
Limitations
- One survey at a time: segment breakdowns and trends over time are not included.
- The margin of error covers sampling only — not who chose to answer, how the question was asked or when.
- Net Promoter®, NPS® and Net Promoter System® are registered trademarks, and Net Promoter Score℠ is a service mark, of Bain & Company, Inc., NICE Systems, Inc. and Fred Reichheld; the names are used here only to describe the calculation.
Privacy
Everything happens in your browser. What you enter or open here is not uploaded or stored by MySmartCoPilot.
Frequently asked questions
How do I calculate NPS?
Subtract the percentage of detractors (0–6) from the percentage of promoters (9–10). With 60 promoters, 25 passives and 15 detractors out of 100 answers, NPS = 60 − 15 = 45.
Why do passives not count?
They do count in the total number of answers, which lowers both percentages, but they are in neither group. 50 promoters and 50 passives give an NPS of 50; 50 promoters, 25 passives and 25 detractors give 25.
Is NPS a percentage?
No — it is the difference between two percentages: a number from −100 (everyone a detractor) to +100 (everyone a promoter), usually written without a % sign.
How many responses do I need?
It depends on the precision you want. The margin of error falls with the square root of the number of answers, so four times as many answers halve it: with 60% promoters and 15% detractors, 100 answers give ±14.5 points at 95% confidence and 400 give ±7.3.
What is the difference between NPS and CSAT?
NPS asks whether people would recommend you, a sign of loyalty; CSAT asks how satisfied they were, usually with one purchase or contact. They answer different questions, and this calculator works out both.