Call Centre Calculator
Calls per hour
Call duration (s)
Average delay (s)
Important: Decimal separator is '.' not ','
Brief instructions

Here is a brief introduction to the calculator.  For a running record of the results calculated, press the Results button.  This function open new browser window on your desktop.

  • This calculator, which is based on the Erlang C traffic model, can tell you how many agents you need in your call centre during an hour. To work this out, you need to know how many calls you receive during that hour, the average duration of those calls and the average delay you will tolerate in answering all your calls.
  • This calculator can also used to establish the number of switchboard operators required.
  • To use the calculator, enter the figures for the number of calls, average duration of calls and average delay to calls in the edit boxes. Remember that call duration should include any wrap up times (see help system for more information). When you press the Calc. button, the required number of agents will be displayed in a message box.
  • You can display a running total of calculation results by pressing the Results button.
  • It is important to understand that there is a bare minimum of agents you will need, regardless of the call answering delays which you are prepared to tolerate. The calculator will not display a number of agents below this minimum as this would result in an unstable situation in which the number of calls queued would constantly increase, leading to abandoned calls. For more information, refer to the help system.