How many ACD agents do I need?

The rule of thumb for calculating the number of agents needed in an inbound call centre is:

The required number of agents is roughly (the number of calls expected per hour) multiplied by (the average number of seconds it takes to handle each call) divided by 3200

But this rule of thumb makes significant assumptions:

  • The average number of seconds it takes to handle each call includes the time spent talking and the time it takes to complete any after-conversation administrative tasks.
  • Your call centre will be of average or above average size – 25 agents or more – if our approximation gives an answer below 25 then you should recalculate replacing 3200 with 2400.
  • Your call centre is delivering a good level of service – the rule of thumb assumes that you are answering callers promptly (for example answering 80% of calls within 20 seconds or better). If your call centre is not answering calls effectively then you need slightly fewer agents.

This looks a bit too complicated! Isn’t there an easier way?

There are quick, easy tools that take account of the many variables in the agent calculation.

A free tool for calculating the number of ACD agents is available  in the Call Centre & Resource Planning section of our web site.

Call Centre Calculator app

rostrvm Call Centre CalculatorAlternatively our  inbound call centre calculator app for mobile phones is available to calculate the number of staff needed to deal effectively with calls.

The calculator provides an instant indication of the number of people needed to man call centre phones whilst meeting the required service level targets.

Download on the App Store




Android app on Google Play



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You can read more about our inbound contact management software here. Or why not contact us to get more help with your plans?


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Please note that this website is not offering specific advice based on your circumstances. We aim to provide you with information based upon our general contact and process management experience. If you are unsure about any information provided here please contact us for advice.