Mowers

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Two numbers decide a battery mower. Deck width sets how long you spend walking; watt-hours set whether you finish at all. Everything else on the spec sheet is secondary to those two, and most listings lead with neither.

The category has settled into a narrow band: nearly every flagship is a 21-inch brushless self-propelled machine, and they differ mainly in how much energy they carry and how fast they spend it. The spread we measured across six current mowers runs from 4.0 to 9.7 watt-hours per minute — a factor of more than two, entirely invisible in the marketing.

Below: how to size a mower to your lawn, what the published runtime claims actually mean once you convert them, and where the honest gaps are — including the fact that three of six manufacturers will not tell you what their mower weighs.

Sizing a mower, in one calculation

Time one mow with whatever you own now. Multiply the minutes by 7.5 watt-hours for a 21-inch self-propelled deck (or 4.0 for a 20-inch push mower), then add 30% for the weeks when the grass is wet or has got ahead of you.

That single number eliminates most of the market before you read a review. Full tables by lawn area are in what size mower do I need.

Why the same deck size uses different energy

The push mower uses less than half the energy per minute of the hungriest self-propelled machine. Some of that is the drive motor and some is the deck — a 4-in-1 deck with turbo leaf pickup legitimately draws more than a simple one. What matters practically is that a small deck on a small lawn is not a compromise; it is the correct specification.

The gaps in this category

We transcribed thirteen specifications across four flagship mowers for the brand comparison. Seventeen of the fifty-two cells came back "not published". Three of six brands do not publish the weight of a mower you have to steer, and not one of the six publishes a decibel figure.

That is why every other comparison in this category is written in adjectives — frequently there is no number to write about. Where a manufacturer has not published something, we leave the cell empty and say so, including on a page about the quietest mower where the honest finding was that nobody publishes the number at all.

What else decides a mower

• Slope, not lawn size, decides self-propel. On flat ground a drive motor is weight and battery draw you cannot use — the reasoning is here.
• Cut height range matters more than people expect. EGO publishes 1 to 4 inches across eight positions, the widest here. Most cool-season lawns want the top half of that range.
• Recharge time is a published spec on only three of six. Greenworks says 40 minutes, Greenworks 40V says 120, Toro says 150. That is a real difference in how you use the tool.
• The battery is most of the price. Which makes the mower a platform decision as much as a machine one — start there if you own nothing yet.