Contractor Refuses to Share Square Footage

[James Sloan]

I am in the process of collecting bids for a pine paneling project, and have found only a couple of contractors to do the job. One is ready to start right away, but refuses to tell me the square footage that he calculated for the job. 

With no bids yet to compare his with, I can only go by the average cost per square foot in my area to determine whether his price is reasonable. 

Am I in the wrong for requesting this? I am a bit confused as to why he would outright refuse to share it, unless he is hiding something, or if he did not actually perform the measurements.

Thanks for any feedback.