Simple

Find the Sq. ft. divid by covrage rate. multiply that number by the cost of the dryfall. multiply Sq Ft. by hours. One guy can spray @ 400 Sq. Ft. pr. hr. add them together add 10 % to that number is your sub total. Then add 15% at the minmum and 30% at the max. this precentage is your profit. If you send me an email I will send you back a spread sheet to do all this for you. I will need th dryfall price from you that you will be using. Also the pay rate. I hope this helps. I estimate about 1 mill Sq Ft. of paint a month.Have a great day.