Sometimes...

…I just have to think that I am retarded. Did an inspection today, got the model and serial off of the furnace, but forgot to note BTU rating. Can anyone help?

Trane XL80

Model TDD080R936C1

Serial L094T0B2G

Natural Gas, Forced Air

80,000 input
64,000 output
Making it 80% eff

Thank you!