Hi Joe,
Last time I checked they used a BTU rating for Window AC units. They may also use them for Mini split systems but I am not sure.
I believe if you search on google you can find that a one ton AC unit is rated @ 12,000 Btu per hour.
Forgive me but I don't know about permitting in California, but Who is asking for this information?
When I'm submitting for permits I sometimes use the IC3 compliance calculator https://esl.tamu.edu/terp/code-compliance-calculator/
When I have issues like this come up when i don't have enough information I consult with my HVAC contractor and HERs rater.
You might also post your question on an HVAC forum like HVAC-Talk.com.