A rough calculation is enough
Take the fully-loaded monthly cost of your support team, divide by the number of tickets handled that month. It is crude, it ignores complexity, and it is still more useful than not knowing.
Use it to price deflection
If a ticket costs you a certain amount and one knowledge-base article removes forty tickets a month, the article pays for the afternoon it took within weeks. This is the argument that gets documentation time approved.
Use it to price product fixes
A confusing checkout step generating two hundred tickets a month has a number attached to it. Product teams schedule numbers; they do not schedule complaints.
Do not use it to rank agents
Cost per ticket falls when agents close things prematurely. Paired with reopen rate it is informative; alone it is actively harmful.
PUT THIS INTO PRACTICE
Everything described here is configurable in EconomicalHelpDesk.com. Open the demo and try it, or ask us to configure it with you.