Key Factors You Need to Consider When Estimating Agent Headcount

Key Factors You Need to Consider When Estimating Agent Headcount

Calculating the number of agents, you need in your contact center in order to offer an excellent service for your customer is not an easy task. You probably have a contact center which by now has grown steadily agent by agent.

That might trigger the feeling of being under or overstaffed or maybe your company will have a big change in department headcount growth, and you need to accurately define how many agents you will need. Well, let me tell you that a simple multiplication will not be enough, and you need to look closer to your numbers to make a correct estimation. Probably you already have heard about the Erlang calculator, but you just don’t know what those required numbers are. Here is what you need to consider.

Volume of Calls

It’s clear that in order to know how many agents you will need, you will have to know the number of calls you have, it can be inbound calls our outbound calls, for outbound calls you will need to review the number of contacts you have and your goals. You can get this information from your telephone system, it can tell you the number of calls per day, an hour or 30 minutes, depending on what you need. If what you have is contacts for outbound calls, you can check your CRM to estimate this metric.


Average Handle Time (AHT)

This is Key, AHT is the amount of time an agent spends in a call. There’s a discussion of whether you should use this metric or not, to evaluate your agents. You can choose not to use this metric in order to have a better customer experience, but you need to keep a track of it because you will need it to estimate the number of agents you need. An Automated Call Distribution (ACD) system or other similar systems you might have in place should give you the AHT. If you don’t manage these metrics, reach to your QA or analytics department, they might have this information.


Service Level

The service level is used to see if the calls are being answered before a specific time, this will avoid making the customers wait in line for someone to answer because this can cause call abandonment and dissatisfaction. Its expressed in a percentage and time, for example, 80% of the calls should be answered within 20 seconds. The most used service level is 80/20 but it can be 75/35 or any other percentage and time. What you need to consider is how much are the customers able to wait, keep in mind that this is not the only metric that matters for customer satisfaction.

If you want to estimate your current Service Level, you need to divide the number of calls answered within the desired time by the number of calls offered, that multiplied by 100 to get the percentage.



Shrinkage is the paid time where the agent cannot answer the phone. Things like breaks, meetings, training, vacations, holidays, make up the time that the agent is getting paid but not actively working. This metric should be considered to estimate the number of agents you need, extract this time in order to have a more accurate number. If you don’t consider this unproductive time, you might be understaffed. Generally, shrinkage is about 35% however do your math. Take note of all the inactive hours like absenteeism, tardiness, sick days, special projects and all those mentioned before, Sum the shrinkage hours, divide it by the total hours available and multiply it by 100.


Maximum Occupancy

This represents the time an agent spends on call-related activities during a specific time. It is normal and healthy for an agent to take some time between calls. The average occupancy rate is between 85% to 90%, a lot of time depends on how performance-driven the agents are. Not to be confused with shrinkage, occupancy percentage doesn’t consider absenteeism and lateness for example.


Erlang Calculator

There is an elaborate mathematic formula you can use, but others have made our job easier and there are several Erlang Calculators online and downloadable templates for excel. Now you just need to worry about calculating correctly the metrics mentioned above and add them in the calculator to find out the number of agents needed. Please keep in mind that it will give you the number per hour of 30 minutes. With that information, you can map the numbers and see the pattern. With that, you will be able to take a wiser decision on how many agents you need for your contact center.


Now that you know the number of agents you need; the challenge will be to recruit those agents and justify the budget of getting those agents. Or you can choose to outsource, depending on the number you need. This will help you reduce cost and sometimes add extra value, like a bilingual service.

With CCSI you can expand your operation in Mexico, with bilingual & performance-driven agents. Contact us and tell us how many agents you need, and we can send you a proposal with no compromise.

Print   Email