NPS vs CSAT: Differences, Formulas, and When to Use Each

NPS and CSAT are the two most common customer feedback scores, and they're often treated as interchangeable. They aren't. They ask different questions, use different scales, and tell you different things about your product. Here's how each one works, how to calculate it, and when to use which.

NPS vs CSAT at a glance

What is NPS?

Net Promoter Score was introduced by Fred Reichheld of Bain & Company in a 2003 Harvard Business Review article. It asks a single question: "On a scale of 0 to 10, how likely are you to recommend product to a friend or colleague?"

Every response falls into one of three groups:

• Promoters (9–10): enthusiastic customers who are likely to stay and to recommend you.
• Passives (7–8): satisfied, but not enthusiastic enough to promote you.
• Detractors (0–6): unhappy customers who may churn or discourage others.

How to calculate NPS

NPS = % of promoters − % of detractors

Say you get 200 responses: 110 promoters, 50 passives, and 40 detractors. Promoters are 55% of responses and detractors are 20%, so your NPS is 55 − 20 = 35.

Passives don't appear in the formula, but they still count toward the total, which is why a lot of lukewarm answers pull the score toward zero. NPS is written as a plain number, not a percentage, and it ranges from −100 (every respondent a detractor) to +100 (every respondent a promoter).

What is CSAT?

Customer Satisfaction Score asks how satisfied someone was with a specific experience, usually on a 1–5 scale from "very unsatisfied" to "very satisfied." Some teams use 1–3, 1–7, or 1–10 instead. Any scale works, as long as you keep it the same so scores stay comparable over time.

How to calculate CSAT

CSAT = (satisfied responses ÷ total responses) × 100

On a 1–5 scale, "satisfied" means a 4 or a 5. If 160 of 200 responses are 4s or 5s, your CSAT is 160 ÷ 200 × 100 = 80%.

Some tools report CSAT as an average rating instead, such as 4.2 out of 5. Both methods are valid, but they aren't comparable, so pick one and stick with it.

When to use NPS and when to use CSAT

Use NPS to track the relationship. It measures how customers feel about your product as a whole, so ask it on a regular cadence rather than right after a particular event. A falling NPS is worth investigating before it shows up in renewals.

Use CSAT to measure moments. Ask it right after a support ticket closes, at the end of onboarding, or after someone uses a new feature for the first time. Because it's tied to one event, it tells you which part of the experience is working and which isn't.

Many teams run both: NPS every quarter for the big picture, and CSAT continuously at the touchpoints they care most about.

What about CES?

Customer Effort Score asks how easy it was to get something done, such as "How easy was it to resolve your issue?", usually on a 1–7 scale. It was introduced by the Corporate Executive Board (now part of Gartner) in 2010. CES is most useful for support and self-serve flows, where removing friction matters more than delighting anyone.

Common mistakes

• Comparing your NPS with other companies' scores. Scores vary widely by industry and by how and when you ask. Your own trend over time is the useful comparison.
• Surveying too often. Survey fatigue lowers response rates and skews results toward your most engaged, or most annoyed, customers.
• Treating the score as the goal. The number is a symptom. The follow-up question is where the useful information is.
• Mixing methods. Switching CSAT between a percentage and an average, or changing scales between surveys, makes the trend meaningless.

What neither score tells you

Both scores tell you how customers feel, not what to build. A detractor who gives you a 4 might want a missing integration, a bug fixed, or a cheaper plan, and the number alone can't tell you which. Always follow up with an open question: "What's the main reason for your score?"

For product decisions, pair your scores with a place where customers can say what they want and see whether others agree: a feedback board with feature voting. Feevox doesn't run NPS or CSAT surveys. It covers the next step: collecting the specific requests behind the scores and ranking them by demand. See NPS vs feature voting for how the two fit together, and how to collect customer feedback for the wider picture.

FAQ

Can NPS be negative? Yes. If more respondents are detractors than promoters, the score is below zero. The full range is −100 to +100.

What is a good NPS? Anything above zero means you have more promoters than detractors. Beyond that, compare against your own past scores rather than industry averages, which vary widely by industry and survey method.

What is a good CSAT score? As with NPS, your own trend matters more than a benchmark. Watch for drops at specific touchpoints, since that's what CSAT is designed to catch.

How many responses do I need? Enough that a few answers don't swing the result. With 30 responses, a single person moving from detractor to promoter changes your NPS by almost 7 points.

Should I use NPS or CSAT? Use NPS for overall loyalty on a regular schedule, and CSAT for specific moments in the customer journey. Most teams that run both get a clearer picture than either score gives alone.

Turn scores into a roadmap

Scores tell you something needs attention. A feedback board tells you what. Feevox gives customers a place to post requests and vote on them, free for 1 board and up to 100 ideas.

Create a free board and start collecting the "what" behind your scores.