If you had a 48" walk behind mower. an acre is roughly 44,000 sq ft. so thats 11,000 lin feet of walking (actually more because you go around trees and do a few laps not he outside etc etc) at an average walking speed you would knock out 4 of those a day. 44000 lineal feet. That's a bit over 8 miles a day. 40 miles a week (this isn't counting trimming, blowing, etc) So it's safe to say a guy with a walk behind could be doing 50 miles a week. Dudes with 30" and 21" would probably be doing more, but would have to factor in more travel on the route because of smaller lawns, so it might average out. 50 miles per week, 200 miles per month, 1200-1400 miles in a typical season. I wonder what the "mileage average" on a vibram sole lug is? I vote 350 miles.