Do you not understand how to do the basic 4th grade math conversions? (Obviously not.) Do you not trust your builder to do the math that you cannot? Why are you second guessing this? What has eroded your trust here? Because youre setting yourself for major issues if you can’t do basic math, but don’t trust your builder to do it.

http://thompsonmahogany.com/board-feet-to-lineal-feet-converstion/

Ive asked my Builder (the project manager) for 3 weeks and she told me she does not know and confusd by it too. So hopefully you sympathize with my situation thank you for sending the link. i will look into it!

As a former math teacher I think you have a valid question. I would figure square footage as an area. I did find this table that shows that linear footage would be twice as much as the square footage for the 1 X 6.

@clt3 Yes the linear to sq feet conversion seems straightforward. It's the BF to SQ calculation that seems so confusing. appreciate you chiming in and trying to help

We estimate siding by the square foot of coverage, which considers overlap and waste. Its usually ordered and priced by the lineal foot. That should be your consistent go to & how you communicate with the supplier.

The BF number may be how they purchase it wholesale, how traders buy futures etc. Of little use to you as you're dealing with a highly processed specialty material, not a box car load.

144 cubic inches is a board foot. (1x12x12, 1x8x18, 2x6x12, etc)

A 1x8 board prior to milling is .667 BF. This is likely 3/4" x 7-1/2" less lap, so it might be 7" coverage.

Ask the supplier.