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Robot Mowers

How robot lawn mowers work, wire vs wire-free navigation, how to size one for your lawn and slopes, what they really cost and whether one is worth it. Plain-English guides with maker specs.

Read our robot mowers guide · 4 min read

All robot mowers guides

BestThe Best Budget Robot Lawn MowersCheap robot lawn mowers that are still worth buying: wire-free Segway Navimow i-series, Worx Vision Cloud, Eufy E15, Mammotion Yuka mini 2 and a wired Worx pick.

The short version

A robot mower cuts a little grass every day or two and drives itself back to its dock to charge. On the right lawn it takes mowing off your weekly list. Getting a good one comes down to three decisions:

  1. Size it with margin. Makers rate robots by lawn area. Buy a model rated above your actual grass area, because complex layouts, slopes and fast spring growth eat into real coverage.
  2. Pick the navigation. Perimeter wire is cheaper and proven. Wire-free models using RTK satellite positioning, cameras or LiDAR skip the wire and let you draw the map in an app.
  3. Check the slope rating. Measure your steepest section and compare it with the maker's figure.

The guides in this section go deeper into each part. Specific picks come from maker specs and long-term owner reports, not from claims I can't back up.

Start here

Wire or wire-free?

Perimeter wire models follow a low-voltage wire you peg down or bury around the lawn edge and around beds. The wire is cheap and the technology is mature. The downsides, as long-time owners describe in Horticulture magazine: laying wire around a large lawn is a real job, rodents can chew it, a break is hard to find, and boundary wire can conflict with an electronic pet fence.

Wire-free models locate themselves with RTK (a base station corrects GPS signals down to centimeter level), with cameras (vision), with LiDAR, or with a mix. You walk or drive the mower around the edge once, or let it map the lawn itself, and edit the boundary in an app. Tall trees, a house wall or a tight side yard can weaken satellite signals, which is why many newer models add cameras or LiDAR as a backup.

Segway's Navimow X430, for example, combines network RTK with 360-degree vision and needs no boundary wire, according to the maker. Full comparison and picks in Best robot mowers without perimeter wire.

Sizing a robot for your lawn

Measure your actual grass area, not your lot size. Then look at how the lawn is laid out: one open rectangle is easy, several small sections linked by narrow paths are not.

Makers' rated areas give you a starting point. On Segway's US store, for example, the line-up runs from about 1/8 acre (Navimow i105) to 1 acre (X430) and 2.5 acres (X390). The X430 is listed at up to 9,600 sq ft per charge and up to 1 acre in a day.

My rule: if your lawn is near a model's rated limit, buy one size up. Bigger lawns have their own guide: Best robot mower for 1 acre.

Slopes

Slope ratings vary a lot between models. They're usually given in percent: 100% is a 45-degree slope, and 50% is about 27 degrees. Segway rates the all-wheel-drive Navimow X430 for slopes up to 84%, about 40 degrees, which is high for a robot. Many two-wheel-drive models are rated far lower.

Wet grass reduces grip, so a robot that manages a slope in July may slip on it in April. Measure the steepest part of your lawn with a phone level app on a straight board, and leave yourself some margin. Picks in Best robot mowers for hills and slopes.

What robot mowers do well and badly

Good at:

  • A lawn that always looks freshly mowed, because the robot cuts a little at a time.
  • Tiny clippings that break down quickly and return nutrients to the soil.
  • Low noise. Segway lists the X430 at under 68 dB(A) under lab conditions.
  • Working while you're out.

Not so good at:

  • Edges. Most robots leave a strip along walls and fences, so you still need a string trimmer.
  • Rough, bumpy lawns with roots and holes.
  • Separate lawns split by a driveway or sidewalk, unless the model supports multiple zones.
  • Stripes. Robots mow in a random pattern or in lanes.

Brand comparisons and reviews

Which robot is right for you?

Your lawnStart with
Small, flat, simple shapeA budget model, wired or wire-free
Up to about half an acre, some treesA wire-free model with vision or LiDAR backup
Around an acre, openAn RTK model rated above your area
Steep sectionsAn AWD model with a high slope rating
Several separate lawnsA model that supports multiple zones
Lots of tall trees near the houseAvoid RTK-only models, look for vision or LiDAR

All robot mower guides

FAQ

Do robot mowers need a perimeter wire?

Not all of them. Many newer models navigate with RTK satellite positioning, cameras or LiDAR and use a boundary drawn in an app. Budget models and some established brands still use wire.

How big a lawn can a robot mower handle?

It depends on the model. Ratings range from about 1/8 acre for small models to several acres for large ones. Buy a model rated above your actual grass area.

Can robot mowers handle hills?

Some can. Check the maker's slope rating in percent and compare it with your steepest section. All-wheel-drive models usually handle the steepest slopes.

Do I still need a regular mower?

Usually you'll still need a string trimmer for edges. Many owners keep a push mower for areas the robot can't reach, or for the first cut of the season if the grass grew tall.

Can a robot mower be stolen?

It can, since it sits outside on its own. Before buying, check which anti-theft features the maker lists, such as a PIN code, an alarm or app tracking.

How much do robot mowers cost?

From several hundred dollars for small-lawn models to $2,000 and more for wire-free models rated for an acre or more. Installation for wired models can add to that if you pay someone.