Many contractors want to be able to measure the productivity of a zero-turn riding mower by calculating how many square feet (or sometimes acres) it can mow per hour. Seems straightforward, right? Kind of ... but here are some things to keep in mind.
It's important to use mowing speeds as opposed to transport speeds, since riding mowers can't effectively cut as fast as they can travel.
From there you have to do some good old-fashioned arithmetic. Here's an example:
- Mower can cut at 8.5 mph
- Since there are 5,280 feet in a mile, the mower can cover 44,880 feet per hour
Then you can multiply the width of cut in feet, giving you square feet per hour:
- If you have a 60-inch (5-foot) deck, you take 44,880 x 5 = 224,400 feet per hour
You know that it is not likely that you are going to get 100% cutting for the full width all of the time due to overlap and trimming. Thus, it's a good idea to calculate your mowing productivity rates at 80%. So multiply by 0.8 to get your actual productivity in terms of square feet per hour.
- 224,400 feet per hour x 0.8 = 179,520 square feet per hour
You can then use that square feet per hour number to calculate acres per hour:
- There are 43,560 square feet in an acre, so ......
- 179,520 / 43,560 = 4.12 acres per hour.
WHOA!! That seems like a lot, doesn't it? Well, site conditions always vary, as do operator skills. So keep in mind that this 4.12 acre/hour rating means the mower is cutting full bore at 8.5 mph with just 20% overlap. This is important to remember when bidding jobs.