Almost every customer service team measures its agents with a handful of numbers, usually called KPIs (key performance indicators). They come up in interviews ("How would you improve your CSAT?"), in your weekly reviews and in decisions about raises. Knowing what they mean, and how they fit together, makes you a better agent and a stronger candidate.
No single number tells the whole story. Teams that push one metric too hard, like call speed, usually see others get worse, like customer satisfaction.
CSAT: customer satisfaction
What it is: How happy customers are with a conversation, usually from a short survey after the chat, call or email: "How satisfied were you with our service today?" on a scale of 1 to 5.
How it's worked out: The share of responses that are positive (usually 4 or 5 out of 5).
CSAT = positive responses ÷ total responses × 100
How to improve it:
- Solve the actual problem, not just the question as it was asked.
- Use the customer's name and acknowledge how they feel before jumping to the fix.
- Set clear expectations: what happens next, and when.
- Close the loop: "Is there anything else I can help with?"
FCR: first contact resolution
What it is: How often a customer's issue is fully solved in the first conversation, without them having to come back.
How it's worked out: Issues solved on first contact ÷ all issues × 100. Each team decides exactly what counts as "solved", often by checking whether the same customer contacts them again within a few days.
Why it matters: Customers hate repeating themselves. High FCR usually goes hand in hand with high CSAT.
How to improve it:
- Ask one more question to find the real cause.
- Check the knowledge base before answering from memory.
- Before closing, confirm the fix worked.
AHT: average handle time
What it is: The average time you spend on one customer contact.
How it's worked out: (Talk or chat time + hold time + after-contact work) ÷ number of contacts. After-contact work is the notes and follow-ups you do once the customer has gone.
Why it matters: It helps teams plan how many people they need. But it's easy to misuse: rushing customers to lower AHT tends to hurt CSAT and FCR, because people come back.
How to improve it without rushing:
- Learn the tools and shortcuts until you don't have to think about them.
- Use saved replies (macros) for common questions, then personalise them.
- Write notes during the conversation, not after.
- Put customers on hold only when you need to, and say why and for how long.
NPS: net promoter score
What it is: How likely customers are to recommend the company, on a scale of 0 to 10. People who answer 9–10 are "promoters", 0–6 are "detractors".
How it's worked out: % of promoters − % of detractors. It ranges from −100 to +100.
What it means for you: NPS measures the whole company (product, price, delivery), not just support. You influence it, but you're rarely judged on it alone.
QA score: quality assurance
What it is: A team lead or QA specialist reviews a sample of your conversations against a checklist, for example: greeting, empathy, accuracy, following the process, tone, spelling and closing.
Why it matters: It's the metric you control most directly, and many companies tie bonuses to it.
How to improve it: Ask for the QA checklist on your first day and use it as your own guide. Read the feedback on every review and ask for examples of a "perfect" score.
Other numbers you'll hear
| Metric | What it measures |
|---|---|
| First response time | How long customers wait for the first reply (key for email and chat) |
| Resolution time | How long it takes to fully solve an issue |
| Adherence | How closely you follow your scheduled shifts and breaks |
| Occupancy | How much of your logged-in time you spend handling customers |
| Concurrency | How many chats you handle at once (chat roles) |
| Backlog | How many tickets are waiting |
How the numbers fit together
Good teams look at speed and quality together. A useful way to think about it:
- 1.Be right first (FCR, QA).
- 2.Be kind (CSAT).
- 3.Be efficient (AHT, first response time).
If you focus in that order, your numbers usually improve together.
Using KPIs in interviews
Interviewers love candidates who speak about results. If you have experience, use numbers: "I kept a CSAT of 95% over six months while handling 60 chats a day." If you don't, show you understand them: "I'd focus on solving issues on the first contact, because that's what drives satisfaction." See our interview questions guide for more.
What to do next
Our certifications are hands-on desk simulations that score you on the same things employers measure. Then browse remote customer service jobs.