How to Calculate and Improve Service Level in Your Call Center

When a customer calls your support line, how long are they willing to wait? And how quickly can your team answer?

Service level is one of the most important metrics in any call center. It measures the percentage of calls answered within a target time — typically 20 or 30 seconds — and helps teams balance speed, staffing, and customer experience.

Improving service level requires a mix of smart staffing, efficient call handling, and — increasingly — real-time agent tools like Balto that help teams stay ahead of demand as it happens.

The standard call center service level formula is: Service Level = (Calls Answered Within Threshold ÷ Total Calls) × 100

So if your team receives 500 calls and answers 425 of them within 20 seconds, your service level is 85%.

An 80/20 target (80% of calls answered within 20 seconds) is the most common benchmark, but expectations vary by industry.

In this article, we’ll break down how to calculate service level, why it matters, and seven best practices to improve service level in your call center:

1. Forecast accurately and staff accordingly: Use historical data to predict demand and avoid under- or overstaffing.
2. Reduce average handle time (AHT): Help agents resolve calls faster through better training, tools, and workflows.
3. Prioritize schedule adherence: Ensure agents are logged in on time and available when needed to avoid coverage gaps.
4. Implement skills-based routing: Direct calls to the most qualified agents to reduce transfers and shorten resolution time.
5. Monitor queues in real time: Use dashboards to identify issues as they happen and make quick adjustments.
6. Cross-train agents for flexibility: Train agents across topics so you can shift resources as demand changes.
7. Leverage automation and self-service tools: Free up agent time by letting customers handle common requests on their own.

What is Service Level in a Call Center?

Service level is a key call center performance metric that measures how quickly customer calls are answered within a defined threshold, usually expressed as a percentage.

At its core, service level reflects your ability to meet customer demand in a timely manner. It helps call centers balance staffing, customer satisfaction, and operational efficiency.

Service level directly impacts:

• Customer satisfaction: Longer wait times = higher frustration and abandonment.
• Agent workload: Poor service levels can lead to overburdened teams and burnout.
• Operational costs: Understaffing or overstaffing both carry risks. Service level helps optimize scheduling.
• Reputation & retention: Consistent service shows customers they can rely on you.

While service level shouldn’t be the only performance metric you track, it’s a strong signal of how well your contact center is delivering on its promise to customers.

Why Does Service Level Matter?

Service level isn’t just a number on a dashboard — it’s a direct reflection of your contact center’s ability to meet customer expectations.

When the service level drops, the ripple effects are immediate:

• Customers wait longer, increasing frustration and abandonment rates.
• Agents feel overwhelmed, leading to stress, reduced performance, and burnout.
• Supervisors lose control, struggling to manage queues and meet SLAs.

Conversely, a healthy service level helps your team:

• Provide fast, consistent customer support
• Maintain productivity during high-volume periods
• Optimize staffing without overspending
• Build trust with customers and leadership alike

Service level is also one of the first metrics executives look at when evaluating contact center performance, because it links directly to customer experience, operational efficiency, and business continuity.

Call Center Service Level Formula

The standard call center service level formula is:

Service Level (%) = (Calls Answered Within Threshold ÷ Total Calls Offered) × 100

This formula helps you measure the percentage of incoming calls answered within a target timeframe — most often 20 or 30 seconds.

Service Level Formula Example:

Let’s say that your contact center receives 600 calls in a day. You answer 480 of them within 20 seconds.

(480 ÷ 600) × 100 = 80% service level

In this case, you’re hitting the widely used 80/20 benchmark — answering 80% of calls within 20 seconds.

What is a Service Level Threshold?

A service level threshold is the maximum acceptable wait time, commonly:

• 20 seconds (standard across many industries)
• 30 seconds for more complex interactions
• 10 seconds or less for high-priority lines or VIP service levels

Some contact centers also include calls abandoned after the threshold in the denominator to give a more complete picture of service performance.

How to Calculate Service Level in a Call Center

Calculating your call center’s service level is straightforward, but understanding what to include (and what not to) can make a big difference in accuracy and reporting.

We know that the basic formula is Service Level (%) = (Calls Answered Within Threshold ÷ Total Calls Offered) × 100

But some contact centers refine this by adjusting the denominator to exclude or include:

• Abandoned calls (especially those abandoned after the threshold)
• Short abandons (e.g., calls abandoned within 5–10 seconds)

Adjusted Service Level Formula Example

Let’s say you receive 800 calls in a day:

• 640 are answered within 20 seconds
• 120 are answered after 20 seconds
• 40 are abandoned (15 of them after 20 seconds)

Your adjusted formula would be: Service Level = (640 ÷ (640 + 120 + 15)) × 100 = 81.5%

Some centers may exclude short abandons entirely, so it’s important to clarify your calculation method when reporting or comparing benchmarks.

Try it: Call Center Service Level Calculator

Use this calculator to plug in your own numbers and get an instant snapshot of your team’s performance:

This interactive calculator is great for workforce managers, QA leads, and team supervisors looking to benchmark performance and spot opportunities for improvement.

Call Center Service Level Standards

While every contact center is different, most organizations follow industry-wide benchmarks to set service-level goals. These standards help align expectations across teams, define staffing needs, and establish SLAs (service level agreements).

Common Call Center Service Level Standards

Keep in mind that what’s considered “good” depends on context. 

A perfect service level isn’t always realistic — or necessary. The right target depends on:

• Your industry and customer expectations
• The complexity of inquiries
• Call volume patterns
• Your available staffing and technology

It’s also important to balance service level with other KPIs like abandonment rate, average handle time (AHT), and first call resolution (FCR) to get the full picture

💡 Pro Tip: Before you commit to 80/20, run the numbers on what staffing levels you’ll need to hit that goal during peak hours – it’s often more resource-intensive than expected.

7 Factors that Influence Service Level

Your service level doesn’t live in a vacuum. It’s shaped by a combination of people, processes, and systems, and even small changes can cause noticeable shifts in performance.

Here are the key factors that impact your call center’s ability to meet service level targets:

Understanding these factors is the first step toward controlling them. 

In the next section, we’ll explore the metrics you should track alongside service level to get a full picture of performance.

6 Call Center Service Level Metrics to Track

Tracking service level alone won’t tell you everything you need to know. 

To truly understand your call center’s performance — and where to improve — it’s important to monitor supporting metrics that influence or are influenced by service level.

Here are the most critical ones:

1. Average Speed of Answer (ASA)

How quickly, on average, do your agents answer calls?

Why it matters: A rising ASA usually signals staffing or routing issues that will eventually impact service level.

2. Abandonment Rate

The percentage of callers who hang up before reaching an agent.

Why it matters: High abandonment often correlates with long wait times and low service level, especially if not excluded from your calculations.

3. Average Handle Time (AHT)

The total time agents spend per call, including talk time and after-call work.

Why it matters: Longer AHT reduces call capacity, making it harder to meet service level targets, especially during peaks.

4. First Call Resolution (FCR)

The percentage of calls resolved without follow-up.

Why it matters: A high service level is great, but if customers have to call back, the overall experience still suffers. FCR helps ensure efficiency doesn’t come at the cost of quality.

5. Agent Utilization Rate

The percentage of time agents spend actively handling calls or post-call work.

Why it matters: Overworked agents may hit service level targets but burn out quickly. Underutilized agents may signal scheduling or volume misalignment.

6. Real-Time Queue Metrics

Live dashboards showing wait times, queue length, and agent availability.

Why it matters: Service level is a dynamic metric, and having real-time visibility helps supervisors act before problems escalate.

💡 Pro Tip: Consider building a composite scorecard that includes service level, AHT, FCR, CES, and CSAT. This gives a more holistic view of performance and helps avoid tunnel vision on a single metric.

Bonus Reading

If you’re looking to improve your contact center performance more generally, read our guide with proven techniques to improve contact center customer service. 

In this guide, we cover: 

• Strategies to improve overall call center customer service
• Ways to nurture customer service skills in agents
• Strategies to improve overall agent performance 
• Techniques to improve overall contact center performance 
• Best practices for speaking with customers

7 Best Practices to Improve Service Level

Improving service level is rarely about one big fix — it’s the result of small, strategic changes across staffing, processes, training, and tools.

Here are 7 proven ways to boost your service level without burning out your team or inflating your budget:

1. Forecast Accurately and Staff Accordingly

Use historical data, seasonal patterns, and real-time trends to predict call volume and schedule agents based on actual need, not guesswork.

2. Reduce Average Handle Time (AHT)

Equip agents with better scripts, real-time assist tools (like Balto), and system shortcuts to help them resolve calls faster, without rushing the customer.

3. Prioritize Schedule Adherence

Even small deviations (late logins, extended breaks) can tank service level. Set clear expectations and use real-time adherence tracking to keep shifts on track.

4. Implement Skills-Based Routing

Connect callers with the right agent the first time. Reducing transfers not only improves service level but also boosts customer satisfaction and FCR.

5. Monitor in Real Time and Adjust Fast

Use live dashboards to spot spikes, reassign available agents, and manage overflow queues. Don’t wait until the end of the shift to fix a backlog.

6. Cross-Train Agents for Flexibility

Train agents to handle multiple call types so you can shift resources as demand fluctuates. This adds agility without requiring new hires.

7. Leverage Automation and Self-Service

Use IVR, chatbots, and knowledge bases to handle common inquiries, freeing your agents to focus on higher-value calls that need a human touch.

7 Tools and Technologies to Boost Service Level

​​If you want to improve service level without increasing headcount, your tech stack matters. The right tools can help your agents work more efficiently, your supervisors respond faster, and your customers wait less.

Here are the most impactful technologies to consider:

1. Real-Time Agent Assist Tools

Platforms like Balto guide agents live during calls, offering prompts, checklists, and real-time feedback to reduce handle time and ensure consistency.

Impact: Faster resolutions, fewer escalations, better compliance

2. Workforce Management (WFM) Software

Forecast demand, schedule shifts, and monitor intraday adherence with precision.

Popular tools: Verint, Calabrio, NICE WFM

Impact: Better staffing alignment, fewer under-/overstaffing issues

3. Automated Call Distribution (ACD) Systems

ACD platforms route calls to the next available agent or the most qualified one.

Impact: Reduces wait time and improves first-call resolution

4. Interactive Voice Response (IVR) Systems

IVR lets customers self-navigate or get routed quickly to the right team.
Impact: Decreases queue times and deflects basic inquiries

5. Real-Time Performance Dashboards

Give supervisors live visibility into service level, queue status, and agent activity so they can adjust fast.

Impact: Prevents small delays from becoming major performance drops

6. Self-Service and AI Chatbots

Divert common questions to self-service portals, chatbots, or FAQs — especially outside business hours.

Impact: Lowers call volume and reduces pressure on live agents

7. Speech Analytics Tools

Analyze call patterns, agent performance, and customer sentiment to spot coaching and process improvement opportunities.
Impact: Boosts service quality and long-term efficiency

How to Balance Service Level with Customer Satisfaction

Improving service level is important — but not if it comes at the expense of customer satisfaction (CSAT). A high service level doesn’t automatically mean a great experience.

Here’s how to strike the right balance between speed and quality:

Don’t Rush the Call to Hit a Metric

Coaching agents to end calls faster just to meet AHT or service level targets can frustrate customers and reduce first call resolution (FCR). Prioritize issue resolution over speed alone.

Track CSAT and FCR Alongside Service Level

Use post-call surveys and QA reviews to ensure customers are satisfied, not just served quickly. Create a performance scorecard that weights quality and efficiency equally.

Offer Callback Options

Let customers keep their place in line without waiting on hold. This reduces perceived wait time and shows that you respect their time, even if your service level dips during volume surges.

Use Self-Service for Low-Stakes Inquiries

Not every call needs a live agent. Offer chatbots, IVR menus, and knowledge base articles for common issues, and reserve agents for high-value, high-emotion conversations.

Use Service Level Targets as a Guide, Not a Rule

It’s okay to adjust your SLA goals depending on volume, team maturity, or customer expectations. The best contact centers find the sweet spot where responsiveness and resolution quality meet.

💡 Pro Tip: Tools like Balto help agents stay efficient and customer-centric by surfacing live guidance, soft skill prompts, and checklist reminders that keep quality high without slowing them down.

Better Service, Smarter Strategy

Improving service level isn’t just about answering calls faster — it’s about creating a support system that’s responsive, efficient, and customer-focused.

By tracking the right metrics, fine-tuning your staffing strategy, and empowering agents with the right tools, you can consistently meet your service level goals without sacrificing quality.

And with Balto’s real-time AI tools, you don’t have to choose between efficiency and experience. 

Our call center platform helps agents perform better on every call, reduces handle time, and gives supervisors the visibility they need to stay ahead of the queue.

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