Subject: Need to estimate how much time will be needed for job. My situation is this: I'm a contractor and need to estimate how much time it will take me to do a specific job. A previous job I did was 6,480.16 Square Feet and I was able to paint it in 31.5 hours. In estimating my next job, how many hours will it take me to paint 11,000 Sqare Feet. Please show me the formula for figuring out my future jobs. Thank you very much. I'm Jack Hook a Painting Contractor. Hi Jack, The previous job was was 6,480.16 square feet and you was able to paint it in 31.5 hours. Thus you did the job at the rate of 31.5/6,480.16 = 0.00486 hours/square foot If you perform the new job at the same rate, 0.00486 hours per square foot, then it will take you 0.00486 x 11,000 = 53.47 hours Just as a mental check, this looks correct to me. The first job too about 30 hours and the second job is a little less than twice as large, so I expect that it will take a little less than 2 x 30 = 60 hours. Cheers, Penny Go to Math Central