What is net promoter score?
Net promoter score (NPS) answers one question: how likely are you to recommend us to a friend or colleague? Scores run 0–10. You sort respondents into promoters (9–10), passives (7–8), and detractors (0–6), then subtract the detractor share from the promoter share. The result is a single number between −100 and +100 — your net promoter score — that tracks loyalty the way revenue alone cannot.
How to read every box in the NPS calculator
Picture a small online plant shop. After each delivery, owner Riley asks customers the standard NPS question. One hundred people answered last quarter. Riley uses this calculator to turn those answers into a score — no spreadsheet required.
Riley's plant shop survey
55 promoters (scores 9–10) — they post unboxing videos. 25 passives (7–8) — plants arrived fine, nothing special. 20 detractors (0–6) — late tracking, wrong pot size, slow email replies. Total: 100 responses. NPS = 55% − 20% = 35.
Inputs — what you type in
- Promoters (9–10)
- People who would actively recommend you. Riley has 55. They drive referrals and usually tolerate small mistakes.
- Passives (7–8)
- Satisfied but quiet. Riley counts 25. They are not in the NPS formula, but they are in the total when you calculate percentages — and they are often convertible with one great support moment.
- Detractors (0–6)
- Unhappy customers. Riley has 20. Bain notes detractors account for more than 80% of negative word of mouth (Net Promoter System). Each one subtracts from your score.
- By score (0–10) tab
- Enter exact counts per score if you exported raw survey data. The calculator auto-groups them into promoters, passives, and detractors.
- What-if: convert detractors to promoters
- Models recovery — e.g. if Riley fixes tracking alerts and 25% of detractors (5 people) become promoters, NPS moves from 35 → 45 (+10 points). Use this to size the payoff from support investments.
Outputs — what you get back
- Net Promoter Score
- The headline integer: % promoters minus % detractors. Riley's 35 means more advocates than critics, but 20 unhappy customers still hurt.
- Projected NPS
- Score after your what-if conversion. At 25% recovery, Riley sees 45 — a concrete before/after for a support sprint.
- Charts
- Score distribution (where responses cluster), group mix (% in each bucket), and sensitivity (how NPS rises as you win back detractors).
The problem: you cannot fix what you do not measure
CSAT tells you if the last ticket felt okay. NPS tells you if customers will stake their reputation on you. Fred Reichheld introduced the metric in The One Number You Need to Grow (Harvard Business Review, 2003) because “would you recommend?” predicted repeat business and referrals better than generic satisfaction questions.
Detractors are expensive in ways accounting misses. Promoters refer friends; detractors warn them away. If your net promoter score is flat while ad spend climbs, you may be buying awareness while word of mouth works against you.
The net promoter score formula (and how to use it)
Ask: “How likely are you to recommend [brand] to a friend or colleague?” on a 0–10 scale. Then:
NPS = (% Promoters) − (% Detractors)
Passives count in the total respondents but not in the subtraction (Qualtrics). Example: 70% promoters and 10% detractors → NPS = 60. Range: −100 (everyone is a detractor) to +100 (everyone is a promoter).
“Your Net Promoter Score is simply the percentage of customers who are promoters … minus the percentage who are detractors.”
Bain's analysis links higher NPS to durable growth: value creators tend to run at roughly 2× the average NPS, and Net Promoter System leaders grow more than twice as fast as competitors (Bain). Medallia-related research cited in industry roundups connects a 10-point NPS increase to roughly 6–7% revenue growth (Desk365 customer service statistics roundup) — directionally useful when pitching support budget.
What research says about service moments and NPS
McKinsey surveyed 25,000 customers and found that deliberate “moments of delight” lifted NPS by 15–28 points depending on sector — including +15 in banking and +28 in tourism (McKinsey, 2023). Bain's banking loyalty work found that improving a handful of high-impact interactions could raise a bank's NPS by 10–15 percentage points (Bain, Guide to Loyalty in Banking). Those are not abstract CX slides — they are the same-sized moves Riley models with the what-if slider when detractors become promoters.
How AI customer service moves NPS — with numbers
Most detractors are not philosophically opposed to your brand. They hit a slow reply, a wrong answer, or a chat that said “call us during business hours.” That is exactly where an AI customer service agent earns its keep: instant, accurate answers trained on your policies and catalog.
Real deployments report measurable NPS lifts:
- Vodafone +20% NPS after augmenting its virtual agent with Microsoft GenAI; first-time resolution on critical billing issues improved up to 50%, and average handle time dropped by at least one minute (CX Today, 2024).
- Bank contact center: NPS 3 → 39 (twelvefold) after AI quality and coaching bots (Verint case summary) — extreme, but shows the lever when support quality was the bottleneck.
- Zendesk reports AI agents can automate up to 80% of incoming inquiries, freeing humans for the complex tickets that decide whether a passive becomes a promoter (Zendesk NPS guide).
Map that to Riley's shop: 20 detractors → recover 25% (5 people) → NPS +10 points in the calculator. Vodafone's +20% relative lift would take Riley from 35 toward ~42 on the same scale. You will not copy telecom numbers exactly, but you can run the same before/after survey and watch your bar chart shift.
How ChatInCart helps you raise net promoter score
ChatInCart is an AI customer service agent you train on your website and docs, then embed on your store or app. It answers the questions that create detractors — order status, returns, sizing, billing — in seconds instead of hours, 24/7.
That hits NPS drivers directly:
- Fewer detractors — Bain ties detractors to churn and negative word of mouth; cutting response time removes a common trigger.
- Passives → promoters — McKinsey's delight research shows +15–28 NPS points when key moments exceed expectations; a correct answer on the first message is one of those moments.
- Measurable before/after — run the same NPS survey pre- and post-launch, plug counts into this calculator, and quantify the delta for your team.
Pair it with our Lifetime Value of a Customer calculator to connect loyalty scores to dollars — promoters stay longer and spend more. Start on the free plan, embed the widget, fix the support moments that show up in your detractor column, and re-run the survey next quarter.
Common questions
It varies by industry. Bain notes that sustained value creators often have NPS roughly twice the average. Above 0 means more promoters than detractors; above 50 is strong in many B2C categories. Compare against your sector, then track your own trend.
Passives (7–8) are satisfied but rarely refer others or buy much more. NPS focuses on the gap between enthusiastic promoters and harmful detractors. Passives still count in the denominator when calculating percentages.
Many teams survey after key support or purchase interactions (transactional NPS) and run a broader relationship survey quarterly or twice a year. The goal is enough responses to see trends, not survey fatigue.
Case studies suggest yes when bots resolve issues faster and more accurately — Vodafone reported a 20% NPS lift after GenAI upgrades, and Bain found fixing key service moments can raise NPS 10–15 points. Measure before and after on the same survey cadence.