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Learn more about call centers and related technology

  • Writer's pictureContaqt

Determine the Number of Call Center Agents You Need

Call center staffing is not the easiest to calculate when attempting to hire the perfect amount of people to keep your customers satisfied. When you are deciding on a number, you want to make sure that your organization is not understaffed or overstaffed since that can lead to an increase in costs or employee dissatisfaction.

Thankfully, there are methods you can use to decide on the appropriate number of agents for your contact center.

The Erlang C Formula

The Erlang C is a standard formula used in call centers to determine how many call center agents are needed to meet demand and maintain customer satisfaction. This formula requires valuable information that includes call volumes, Average Handle Time, and customer service goals.

Call Volumes

To begin calculating the number of agents you need for your call center, you first need to measure how many calls your organization receives. The information you gather on your call volumes will depend on the measuring method you use. Typically, established call centers can derive call volumes data from their Automated Call Distribution (ACD) system.

If you do not have an ACD system, there are still other ways you can determine your call volumes. You can find this information by searching through your call-logging system, requiring your employees to log all calls, or estimating through knowledge of your customer base size or average times a customer calls in a year.

Average Handle Time

Average Handle Time (AHT) is more difficult to calculate than call volumes. You have to be careful to not use the wrong numbers as well as recognize that AHT can fluctuate depending on the time of day or day of the week.

To calculate Average Handle Time, use the formula below:

(Total Talk Time + Total Hold Time + Total After Call Time)


Number of Calls Handled

It may be instinctual to want to greatly reduce AHT for the purpose of minimizing the number of agents you have to hire, however, this is not a great idea. A higher average handle time does not necessarily mean that your sales are low and your customers are dissatisfied. Reducing average handle time results in shorter phone calls which in turn can result in lower First Call Resolution and customer loyalty.

Customer Service Goals

Before completing the final step in your formula, you need to decide on what goals your customer service team will strive for. To do this, you have to know the service level at which you want to answer calls and the target answer time at which calls will be answered.

For example, your customer service goal could be that 75% of calls will be answered within 15 seconds. Once you have determined your customer service goals, complete your Erlang C formula online by plugging in all the numbers to find out how many call center agents you need.


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