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What "up to 1/2 acre" means on a robot mower
Updated
The area on the box is the most lawn the mower can keep up with in good conditions. Husqvarna's own buying guide lists every Automower's lawn size as plus or minus 20 percent, depending on the grass. Plan on your yard landing on the minus side if it has trees, beds, slopes or more than one zone.
What the number assumes
- One open lawn, not a front, back and side yard joined by paths.
- Few obstacles to steer around.
- Mostly flat ground.
- The mower runs on the schedule the maker planned for, often most days of the week.
What eats into it
| Your yard has | Why it costs capacity | Our calculator factor |
|---|---|---|
| Trees, beds, a play set | More turns, more edge passes, more time per square foot | 0.8, or 0.65 for a lot of them |
| Slopes | Climbing drains the battery faster and the mower slows down | 0.9, or 0.75 near the rating |
| More than one zone | Travel between zones is time spent not mowing | 5% less per extra zone |
| Fast spring growth | Grass grows faster than the mower's average pace | We plan to use 80% at most |
Measure the lawn, not the lot
A lot size includes the house, the driveway, the patio and the beds. The mower only cares about grass. A 1/4 acre lot is 10,890 sq ft, but the lawn on it is often well under 10,000 sq ft. Measure length times width for each grass area and add them up.
The box claims of our six picks
Box claimTypical yard estimate
- Husqvarna 410iQ21,780 sq ft14,800 sq ft
- ECOVACS GOAT A200021,780 sq ft14,800 sq ft
- WORX WR32021,780 sq ft14,800 sq ft
- Mammotion LUBA mini 216,117 sq ft11,000 sq ft
- Navimow i105N5,445 sq ft3,700 sq ft
- Gardena SILENO City2,700 sq ft1,800 sq ft
The accent bars use a lawn with some trees and beds, gentle slopes and two zones. For the half-acre models, that turns 21,780 sq ft into about 14,800 sq ft. For the Segway Navimow i105N, 5,445 sq ft turns into about 3,700 sq ft.
Per hour and per charge claims
- Segway Navimow i105N: Navimow's page gives 60 to 100 m2 per hour, about 646 to 1,076 sq ft, with 60 minutes of mowing per charge and a 90 minute recharge. That is one of the most useful numbers any maker publishes.
- ECOVACS GOAT A2000 LiDAR PRO: ECOVACS claims up to 400 m2 per hour, about 4,306 sq ft. "Up to" means best case.
- Mammotion LUBA mini 2 AWD 1500H: the listing claims 350 m2 per charge, about 3,767 sq ft.
- The other listings we read give no per-hour figure.
Navimow's fine print says its mowing time was measured on a flat lawn at 77 F, cutting 5 mm of grass. Real lawns are rarely that easy.
So which size do you buy?
Take your lawn area and run it through the calculator with your real layout. If the answer is over 80 percent, go up a size. It is also fine to go down a size if your lawn is open and flat.
Check your own yard with the capacity calculator, or compare all six picks on the best robot mowers page.