Mowing efficiency calculator
Acres per hour from deck width, speed and efficiency. The efficiency is not a guess: it comes from mowing routes the Mow Mapper planner laid out, for each size of deck on each kind of yard.
How efficient mowing really is
| Mower | Rated | Open lawn | Typical yard | Busy yard |
|---|---|---|---|---|
| 21" push at 1.7 mph | 0.36 | 0.31 85% | 0.30 83% | 0.30 83% |
| 36" walk-behind at 3.4 mph | 1.24 | 1.03 83% | 0.97 78% | 0.95 77% |
| 48" zero-turn at 5 mph | 2.42 | 1.97 81% | 1.83 75% | 1.63 67% |
| 60" zero-turn at 5.8 mph | 3.52 | 2.74 78% | 2.51 71% | 2.36 67% |
| 72" zero-turn at 6.3 mph | 4.58 | 3.47 76% | 2.91 64% | 2.86 62% |
Acres per hour by deck width and speed
Scroll sideways for the faster speeds.
| Deck | 2 mph | 3 mph | 4 mph | 5 mph | 6 mph | 7 mph | 8 mph |
|---|---|---|---|---|---|---|---|
| 21" | 0.30 | 0.45 | 0.59 | 0.74 | 0.89 | 1.04 | 1.19 |
| 30" | 0.42 | 0.64 | 0.85 | 1.06 | 1.27 | 1.48 | 1.70 |
| 36" | 0.51 | 0.76 | 1.02 | 1.27 | 1.53 | 1.78 | 2.04 |
| 42" | 0.59 | 0.89 | 1.19 | 1.48 | 1.78 | 2.08 | 2.38 |
| 48" | 0.68 | 1.02 | 1.36 | 1.70 | 2.04 | 2.38 | 2.72 |
| 52" | 0.74 | 1.10 | 1.47 | 1.84 | 2.21 | 2.57 | 2.94 |
| 54" | 0.76 | 1.15 | 1.53 | 1.91 | 2.29 | 2.67 | 3.05 |
| 60" | 0.85 | 1.27 | 1.70 | 2.12 | 2.55 | 2.97 | 3.39 |
| 61" | 0.86 | 1.29 | 1.73 | 2.16 | 2.59 | 3.02 | 3.45 |
| 66" | 0.93 | 1.40 | 1.87 | 2.33 | 2.80 | 3.27 | 3.73 |
| 72" | 1.02 | 1.53 | 2.04 | 2.55 | 3.05 | 3.56 | 4.07 |
| Deck | 2 mph | 3 mph | 4 mph | 5 mph | 6 mph | 7 mph | 8 mph |
|---|---|---|---|---|---|---|---|
| 21" | 0.34 | 0.51 | 0.68 | 0.85 | 1.02 | 1.19 | 1.36 |
| 30" | 0.48 | 0.73 | 0.97 | 1.21 | 1.45 | 1.70 | 1.94 |
| 36" | 0.58 | 0.87 | 1.16 | 1.45 | 1.75 | 2.04 | 2.33 |
| 42" | 0.68 | 1.02 | 1.36 | 1.70 | 2.04 | 2.38 | 2.72 |
| 48" | 0.78 | 1.16 | 1.55 | 1.94 | 2.33 | 2.72 | 3.10 |
| 52" | 0.84 | 1.26 | 1.68 | 2.10 | 2.52 | 2.94 | 3.36 |
| 54" | 0.87 | 1.31 | 1.75 | 2.18 | 2.62 | 3.05 | 3.49 |
| 60" | 0.97 | 1.45 | 1.94 | 2.42 | 2.91 | 3.39 | 3.88 |
| 61" | 0.99 | 1.48 | 1.97 | 2.46 | 2.96 | 3.45 | 3.94 |
| 66" | 1.07 | 1.60 | 2.13 | 2.67 | 3.20 | 3.73 | 4.27 |
| 72" | 1.16 | 1.75 | 2.33 | 2.91 | 3.49 | 4.07 | 4.65 |
| Deck | 2 mph | 3 mph | 4 mph | 5 mph | 6 mph | 7 mph | 8 mph |
|---|---|---|---|---|---|---|---|
| 21" | 0.38 | 0.57 | 0.76 | 0.95 | 1.15 | 1.34 | 1.53 |
| 30" | 0.55 | 0.82 | 1.09 | 1.36 | 1.64 | 1.91 | 2.18 |
| 36" | 0.65 | 0.98 | 1.31 | 1.64 | 1.96 | 2.29 | 2.62 |
| 42" | 0.76 | 1.15 | 1.53 | 1.91 | 2.29 | 2.67 | 3.05 |
| 48" | 0.87 | 1.31 | 1.75 | 2.18 | 2.62 | 3.05 | 3.49 |
| 52" | 0.95 | 1.42 | 1.89 | 2.36 | 2.84 | 3.31 | 3.78 |
| 54" | 0.98 | 1.47 | 1.96 | 2.45 | 2.95 | 3.44 | 3.93 |
| 60" | 1.09 | 1.64 | 2.18 | 2.73 | 3.27 | 3.82 | 4.36 |
| 61" | 1.11 | 1.66 | 2.22 | 2.77 | 3.33 | 3.88 | 4.44 |
| 66" | 1.20 | 1.80 | 2.40 | 3.00 | 3.60 | 4.20 | 4.80 |
| 72" | 1.31 | 1.96 | 2.62 | 3.27 | 3.93 | 4.58 | 5.24 |
How to work out acres per hour
Acres per hour = deck width (inches) × speed (mph) × efficiency ÷ 99.
The 99 is what one inch of deck covers at one mile an hour, turned into acres: a mile is 5,280 feet, so a one-inch strip is 440 square feet an hour, and an acre is 43,560 square feet, which is 99 of those.
A 48-inch deck at 5 mph would cut 2.42 acres an hour if it never turned. At 75% efficiency it is 1.82.
Where the efficiency goes
Efficiency is everything that keeps a mower from cutting a full-width strip at full speed: the turn at the end of every pass, the overlap between passes, the lap round the edge, and slowing for beds, trees and the house.
Most calculators ask you to guess it. These yards' figures are measured: the Mow Mapper planner laid out every pass for each deck and timed it. The wider the deck and the busier the yard, the more of the rated pace goes to turning.
Questions
Anything else, see support or email support@mowmapper.com.
How do you calculate acres per hour?
Multiply the deck width in inches by the speed in miles per hour and by the efficiency, then divide by 99. A 48-inch deck at 5 mph and 75% efficiency: 48 × 5 × 0.75 ÷ 99 = 1.82 acres an hour.
How many acres per hour does a 60-inch zero-turn mow?
At 5.8 mph its rated pace is 3.52 acres an hour, as if it never turned. On planned routes it managed 2.74 on an open acre and 2.51 on a typical yard, mowing only.
How many acres per hour does a 48-inch mower cut?
A 48-inch zero-turn at 5 mph is rated at 2.42 acres an hour. On planned routes it cut 1.97 on an open acre and 1.83 on a typical yard, about 33 min an acre.
What is a good mowing efficiency?
On the routes Mow Mapper planned, mowers kept 76% to 85% of their rated pace on open ground, and 64% to 83% on typical yards with a house, a driveway, a bed and a couple of trees. Below that, look at the turns.
Why does a bigger deck lose more efficiency?
Every pass ends in a turn, and a turn takes about as long whatever the deck. A wide deck finishes each pass sooner, so turns are a bigger share of its time, and it has to slow down or stop short round more things. On a typical acre the 72-inch kept 64% of its rated pace; the 21-inch push mower kept 83%.
Measure the mowing, not the mower.
Mow Mapper plans the route on the actual yard and times it for the mower you run, turns and trimming included. $9.99 a month after a 7-day free trial.