Simple Call and Trunk Calculator


This calculator will allow you to calculate the number of trunks needed in a call center to answer calls. This is the simple version, I also made a much more involved one that will determine the number of IVR's (Interactive Voice Response Units) and the number of Agents as well as make allowances for multiple inbound/outbound routes. Explanation on this one would require a book of instructions, so E Mail me your interests and I will come out of retirement for you. If your call center is outside of Los Angeles County (California, USA) then be prepared to send me an airline ticket and pay for the hotel for two weeks, and I am yours. If you are in the big call center city of Bangalore, I like lunch and dinner at "The Only Place" or in the food court of the Forum Mall.

Here is the the Blank Page:

Here is how it is used:

Insert the Number of Calls you expect, and for the % of calls in the busy hour put in 17. This is the "standard".

Put in the length of the average call in seconds. If sometimes the calls are longer, use a compromise figure.

That's it!

The form fills in and you get results. Here are the results of a typical calculation:

In the example these values were chosen:

Number of Calls in one 24 hour period - 15,000

Percentage of Calls arriving in the Busy Hour - 17

Average Length of the Call - 45 (Includes actual call time and other times)

SCTC calculated you needed 32 Telephone Lines or 1.5 T1's. It is that simple. All basic math. If you need more information or the Excel file, please contact me. I give it out freely, I just like to know who is using it and for what. If you do not fully understand trunking and call centers it may not give you the results you need. There are 24 Circuits on a T1.

Remember, I did a traffic study of my local Central Office in the 1950's when I was 15. I not no dummy!