Unfortunately that is not enough information. Is it built with 2x4 walls? 2x6? 2x8? 16 inch on centers? 24 inch on centers? Is there an attic? Trusses, flat roof with 2x10 rafters? If there is an attic you will be well insulated if you use blown-in cellulose. You will need about 300 cubic feet of blown in cellulose for an attic. If it's 2x10 rafters you will need about 336 square feet of 2x10 insulation blankets that are the width of the space between your rafters. If it's 24 inch on center rafters, you will need 24 inch blankets. You will need about 660 square feet of insulation for the walls, less the area of the doors and windows. Again, if it's 24 inch on center 2x6 walls, get the appropriate insulation blankets.
Your cieling appears to be a volume rather than an area. This is confusing. 408 inches.
Five feet six inches !
12 feet, 6 inches
681 inches = 56.75 feet (56 feet 9 inches).
5 feet 4 inches
125 inches is equal to 10.4167 Feet.
5 feet 3 inches
12 feet 8 inches
Multiply the height of the wall space by the length. This will give you the square footage. Rolls of faced and unfaced insulation are generally sold by square footage. Make sure you take out for windows and doors (especially the overhead garage door).
There are 6 feet in 72 inches.
10,284 inches in 857 feet.
180 inches in fifteen feet