The main question when setting up a call center is how many agents you need. But how do you calculate that number? Let’s look at a few simple approaches that will help you determine the optimal number of agents with almost no complex formulas, in a clear and engaging way.
How do you calculate the required number of agents?
One of the most common tools is the Erlang calculator. It uses formulas and algorithms to calculate the workload on a call center agent and determine the optimal number of agents.
The Erlang calculator makes it possible to determine the required number of agents more accurately to ensure optimal productivity and service level.
To use the Erlang calculator, you should consider several key parameters:
- Call volume (Traffic intensity): This is the number of calls received by the call center over a certain period of time. Call volume can be expressed as the number of calls per hour, minute, or second.
- Average Call Duration: This is the average time agents spend handling one call. It is measured in seconds or minutes.
- Service Level: This is the percentage of calls that must be handled within a certain time. For example, if the service level is 80%, that means 80% of calls must be handled within a certain time.
With the Erlang calculator, you can experiment with different parameter values and see how changes affect the number of agents needed. This helps you make an informed decision about staffing levels to ensure efficient customer service.
In Oki-Toki, you can tell that a call center is short on agents by using the summary report or the “Call Log”, which shows the reasons for failed calls. For example, if many calls are marked “Dropped: no available agent,” you can conclude that there are not enough staff on the line.
A detailed step-by-step calculation of the number of agents for a call center, along with common mistakes, is covered in a separate blog post.
“«Erlang-C Formula»”
To calculate the number of agents in a call center, a formula known as the “«Erlang-C Formula»” is used, based on probability theory and calculating call traffic intensity.
«Erlang-C Formula»: N = A * T / 3600, where:
- N — number of agents,
- A — number of calls per hour
- T — average talk time in seconds,
This formula will help determine how many staff members are needed to handle a certain number of calls, taking into account only the average call duration and total call volume.
Example 1: Calculating the number of contact center agents on outsourcing:
Conditions:
- Calls per day: 1000;
- Average talk time: 5 minutes;
- Workday: 8 hours.
Calculation of the number of agents:
- Calls per hour: 1000 / 8 hours = 125 calls;
- Average talk time in seconds: 5 min * 60 = 300 sec;
- Number of agents: 125 * 300 / 3600 ≈ 10 (using the formula N = A * T / 3600);
As a result, using the Erlang formula, we calculated that this call center needs at least 10 agents.
Another way to calculate:
- Determine the number of calls per hour per 1 agent: 60 minutes / 5 minutes = 12;
- Divide the total number of calls per hour by the number of calls per hour per 1 agent: 125 / 12 ≈ 10.
This calculation method also showed that approximately 10 agents would be enough for this contact center.
Important! Please note that this is an approximate number, since employees need lunch, breaks, maybe training with a supervisor, sick leave, or vacation, so for a better result you can add 2-3 more agents. You should also take into account whether these are only inbound calls, whether a dialer will be used (where there is a chance of failing to reach the customer), and whether call volume changes throughout the day.
Example 2: Calculating the number of call center agents in the finance sector:
- Calls per day: 2500 (dialer, inbound and outbound)
- Average talk time: 8 minutes (including time to connect with the customer and post-call processing)
- Working time per day: 9 hours
Calculation of the number of agents:
- Calls per hour: 2500 / 9 hours ≈ 278;
- Average talk time in seconds: 8 min * 60 = 480 sec;
- Number of agents: 278 * 480 / 3600 ≈ 37 (using the formula N = A * T / 3600);
As a result, using the Erlang formula, we calculated that this call center needs at least 37 agents.
You can calculate it manually: 60 minutes / 8 minutes ≈ 7.5 calls per hour per 1 agent, then 278 / 7.5 ≈ 37.
Important! These are approximate figures, without taking into account breaks, failed calls, and so on. The example is based on simplified calculations and factors, and each specific case may have its own characteristics and requirements.
These examples use simplified calculations and assumptions to illustrate the application of the formula. For more accurate results, we recommend conducting a more detailed analysis and taking into account the specifics of your call center.
You can also use special programs to calculate the number of agents based on the Erlang-C formula, which will show the approximate customer wait time in the queue, the connection success rate, and more.
How many calls should a call center agent make?
In a call center, it is important to determine how many calls an agent should make, taking into account the workload and such factors as:
- The first factor — the number of customers. The more customers there are, the more calls may be needed to handle all requests.
- The second factor — the types of requests. An agent should be ready for different customer questions and issues, which may require different amounts of time to handle.
- The third factor — the tasks agents perform in addition to calls, such as replying to emails or chats.
Taking all these factors into account, you can find the right balance and ensure efficient service for every customer.
You can learn how many outbound calls an agent should make in a separate blog post.
How do you calculate the number of calls per agent?
To calculate the number of calls per agent, you need to:
- Determine the average handling time for one call. This is the time an agent spends talking to a customer, including resolving issues or providing information.
- Determine the time an agent spends on breaks, lunch, training, or other non-productive tasks. This is the time when the agent cannot handle calls.
Example:
- Average handling time for one call: 2 minutes
- Time during the hour when the agent can handle calls: 50 minutes
Use the formula: number of calls per agent = time available for the agent to work / average handling time
So: 50 minutes / 2 minutes = 25 calls per hour per agent
Important! This calculation is approximate and can be supplemented by other factors such as call complexity or peak activity periods during the day. Every call center has its own characteristics and requirements. Therefore, it is recommended to use this calculation method together with an analysis of the specific conditions and needs of your call center.
Read about how to improve contact center agent performance, increase productivity, and optimize processes in a separate blog post.
