Lawn being measured with a tape across mown grass

Robot Lawn Mowers · Buying Guide

How to Choose a Robot Lawn Mower for Your Yard Size

Measure the grass, convert the units, add headroom. Most sizing mistakes come from skipping one of the three.

By TopPremiumPicks Editorial TeamPublished September 8, 20268 min read

Last updated September 8, 2026

Rated coverage is the number that decides whether a robot mower keeps up with your lawn or falls permanently behind. It is also the number buyers most often estimate rather than measure.

This guide covers measuring the mowable area properly, converting between the units manufacturers use, and deciding how much headroom to leave.

Measuring the mowable area

Break the lawn into rectangles and triangles, measure each, and add them up. For irregular shapes, an online map measuring tool traced around the grass is accurate enough for sizing.

Exclude everything the mower will never cut: beds, patios, drives, ponds, sheds and gravel. On many properties this removes a third of the apparent area.

Square metres, square feet and acres

One acre is 4,047 m² or 43,560 sq ft. A quarter acre is about 1,012 m², a half acre about 2,023 m².

Manufacturers publish in different units by region, so convert before comparing. A 1,000 m² rating is roughly a quarter acre, not a half.

How much headroom to leave

Aim to buy a mower rated at least 20-30% above your measured area. Rated figures assume good conditions, and spring growth is not a good condition.

Fragmented lawns need more headroom than open ones, because transit between zones consumes working time without cutting anything.

Matching measured area to a model class

Up to about 500 m²: an entry wire-free model such as the Segway Navimow i105N, or a budget wired mower.

Around 1,000-1,600 m²: the Segway Navimow i110N or eufy Robot Lawn Mower E15; up to an acre with no antenna to mount: the WORX Landroid Vision Cloud Robot Mower (WR340).

From 2,000 m² upward, and especially near an acre: the Segway Navimow X430 or Mammotion LUBA 2 AWD 5000, or the wired Husqvarna Automower 430X on shaded ground.

Frequently asked questions

Take the larger one. Running a mower permanently at its rated ceiling is the most common cause of disappointment.

Final verdict

Measure the grass rather than the property, convert everything into one unit, then choose a model rated comfortably above the total. Fragmented or fast-growing lawns need more margin than open, slow-growing ones.

TP

Editorial Team

TopPremiumPicks Editorial Team

The TopPremiumPicks Editorial Team researches and compares premium products across multiple categories using manufacturer specifications, professional reviews and customer feedback. Our guides are research-based and do not represent hands-on product testing.