I believe your mower has a top speed of 7 mph, or 36960 feet per hour. Breaking down the travel distance time even more you will go 616 feet per minute. Your total cutting width should be reduced to 48 inches from 50 for a one inch overlap per pass. So theoretically the maximum amount of lawn you could cut per minute is 2464 sq. ft.

In reality this won't be possible at a rate of 7 mph and can only be achieved in a clear path without obstacles or turns. Adding delays because of turns, and obstacles I would say your average square feet per minute would be half the maximum speed, or about 1200 sq. ft per minute or about 4 minutes for every 5000 sq. feet.

But this isn't how you do it! You want to make a living so expenses must all be added to the job above what you want to clear, net, take home or pocket in cash. Are you going to weed eat, edge, blow clippings and any other jobs involved cutting grass? What if there is only a 3 foot fence gate to enter the back yard? Expenses include prorating the value of your truck, trailer, mower, hand tools, gas, maintenance, insurance, taxes and the wife's rate of spending.

Look at the job site to make a determination and not just based on the size of the lot. I'll give you a few tips. If you charge twice the going rate for cutting the grass you'll get half the number of clients, but make the same amount of money. Just offer extra services that would take less time at the present job than traveling to the next job to just cut grass. Wash windows? Pressure wash sidewalks? Pick up dog poo? take out trash? ect...

I saw a guy cutting grass with big crude hand painted signs on his truck. "Grass cutting, small yards $40 - medium yards $50." I had to stop and ask how those signs have worked out because of the simplicity of his advertising. He laughed and said his business tripled, but no one so far has a small yard, and only half the people have a medium yard, so he will give them prices for large yards. He was getting multiple clients on the same block because of the inquisitive nature of his signage, less windshield time more money.

I have a Toro zero turn 52" time cutter. It takes me about 45 minutes to cut 32,000 square feet (3/4 acre) wide open at 7 mph with a lot of obstacles. If I want to weed eat it's more like 2 hours. I have a lot of trees so when I need to pick up sticks and branches it's more like 3 hours. I also rotate and cut sections of another 4 acres every two weeks and my 52 in mower is to small and slow. I don't bag, will never bag and no one should.

I have about a half an acre of grass on my 3/4 acre lot. For for about 10 years I had a mower with a 38" deck that I used to mow the grass. About three years ago I purchased a 42" mower as the old one died.

With a roughly 10% increase in the size of the mower, you would think that it would take less time to mow. It does not!

I still have the same building foot print, the same plantings and flower beds, the same trees, and the same contours. The increase mowing capacity (42" vs 38") is insignificant when compared to the time maneuvering around the objects in the yard. In fact the larger mower actually cause an increase in actual mowing time as the 42" mower will not go into the same areas as the 38" mower because it is too wide.