What is the total drivetrain tooth capacity of the SRAM RED eTap AXS 36T Max rear derailleur?

Drivetrain tooth capacity, or chain wrap capacity, for SRAM RED eTap AXS 36T Max rear derailleurs is 39T.

Drivetrain capacity is the amount of chain slack a derailleur is designed to manage, based on the number of teeth in the drivetrain. Drivetrain tooth capacity is calculated using the following formula: 

[Teeth on the large chainring - teeth on the small chainring] + [Teeth on the largest cassette cog - teeth on the smallest cassette cog].