1 acre is about 43,500 square feet. If I'm interpreting your question correctly, you are looking to convert to amount per 1000 square feet. You would divide the amount per acre by 44. This is further explained in the link below which discusses how to interpret fertilizer recommendations. The University of Minnesota recommends soil testing prior to fertilizing. http://www.extension.umn.edu/garden/yard-garden/soils/soil-test-interpretations-and-fertilizer-management/#soil-test-interpretations Your product label probably shows an amount for a.i. per acre which you would also divide by 44 to determine amount per 1000 square feet. Or I believe this is the same as .0019 x 4.02 lbs per 1000 square feet. I've also included the university information about control of turf grass weeds and the available options. http://www.extension.umn.edu/garden/yard-garden/lawns/weed-control-in-lawns/