RTK robot mowers, compared on published specifications

RTK is satellite positioning corrected by a fixed reference antenna, and it is what lets a mower cut in straight parallel lines and stop at a boundary that exists only in software. It is the mainstream wire-free technology, and it needs a clear view of the sky.

We do not test robot mowers. The median RTK robot mower in this category is rated for 10,890 sq ft — the number worth carrying into any listing you read.

Every figure below is taken from the manufacturer’s published listing and measured against the rest of the category. A rated lawn area is published by 95% of the RTK robot mowers here; where a listing is silent, the page says not stated rather than filling the gap.

Where the data runs out. 4 lawn-size classes hold too few listings to support a median: under 1/8 acre (1 listing), 1/8 – 1/4 acre (7 listings), 1/2 – 1 acre (7 listings), 1 acre and above (6 listings). Below 8 a median describes the sample rather than the market, so the table prints the count and leaves the median blank rather than a number that would not survive one more listing.

What the numbers say about this category

Baselines for this category. A specification needs at least 8 listings stating it before a median is published.
Specification	Stated	Median	Middle half	Full range
Rated lawn area	38	10,890 sq ft	10,890 sq ft – 32,670 sq ft	5,382 sq ft – 6 acre
Claim density	37	543 sq ft/cm	493 sq ft/cm – 986 sq ft/cm	151 sq ft/cm – 5,145 sq ft/cm
Cutting width	39	8.7 in	7.9 in – 9.5 in	7.1 in – 20 in
Lowest cut	31	31 mm	30 mm – 41 mm	20 mm – 91 mm
Rated slope	18	45%	45% – 80%	35% – 100%
Weight	28	26 lb	22 lb – 46 lb	20 lb – 215 lb

The middle-half column is the more useful one. It spans the 25th to 75th percentile, so it describes where most of the category actually sits, and it is far less sensitive than the full range to a single unusually large or small machine.

Claim density is this site’s own figure: the rated lawn area divided by the cutting width, in square feet per centimetre of deck. It is not a specification any manufacturer publishes, and it is not a quality score. It says how much lawn a machine is claimed to cover for the width it actually cuts — and a figure well above the class median means the rating leans on run time and scheduling rather than on the machine cutting any faster.

How this category spreads across lawn sizes

Where this category’s 40 listings sit by rated lawn size.
Lawn size	Listings	Median rating	Range
under 1/8 acre	1	Too few for a median
1/8 – 1/4 acre	7	Too few for a median
1/4 – 1/2 acre	17	10,890 sq ft	10,890 sq ft – 16,117 sq ft
1/2 – 1 acre	7	Too few for a median
1 acre and above	6	Too few for a median
Not stated	2	The listing publishes no rated area

How to choose one

What the reference station is actually for

Ordinary GPS puts a receiver within a few metres, which is useless for a machine that must stop at a flower bed. RTK adds a second receiver at a known fixed point — the antenna you mount on the house or a pole — which sees the same satellite errors at the same moment and broadcasts the correction. The mower applies it and lands within a couple of centimetres. Everything RTK does well and badly follows from that: the correction is only as good as the reference station’s own sky view and its link to the mower.

Tree cover and tall buildings are the real constraint

Satellites are blocked by canopy and reflected by walls, and a reflected signal is worse than a missing one because it arrives late and looks valid. A garden with mature trees along one edge, or a wall on the north side, can leave a strip the mower cannot position itself in. This is why so many RTK mowers now carry a camera as well and fall back to it under cover — a listing that names both technologies is describing a genuine engineering answer to this problem, not padding the feature list.

What the coverage rating assumes

A rated area assumes an open expanse mowed on a full schedule. A lawn split into front, back and side sections costs time in travel and re-localisation that the rating does not account for. Where a garden is genuinely fragmented, size up rather than matching the rating exactly.

What the listings do and do not tell you

Specification coverage is uneven, and that unevenness is itself worth knowing before you shop. A missing figure is not a worse product — it is a less completely described one — but it does mean you cannot compare on that axis without contacting the manufacturer.

How many listings in this category publish each specification.
Specification	Stated	Share
Rated lawn area	38	95%
Cutting width	39	98%
Lowest cutting height	31	78%
Boundary system	31	78%
Rated slope	18	45%

Where a listing is silent, this site prints not stated. It never fills the gap with a plausible default, because a specification table that looks complete and is partly invented is worse than one with visible holes.

Sizing the mower to the lawn

Rated area is the specification buyers get wrong most often, and almost always in the same direction. The rating describes an open expanse mowed on a full schedule — not a garden divided into front, back and side sections, crossed by paths, and interrupted by beds and trees. Every one of those costs travel time the rating does not account for.

Measure the grass rather than the plot. A quarter-acre lot with a house, a drive and planting on it is often well under 5,000 square feet of actual lawn, and buyers who size from the deed rather than the turf spend for coverage they will never use.

Then leave headroom. An undersized robot mower does not fail in a way you notice immediately — it simply never finishes, and the shortfall shows up in the growing season when the grass is moving fastest and the machine is already running its longest schedule.

Mistakes this data makes visible

Reading a rated area as a promise

The rating is a manufacturer claim measured under conditions no listing describes. Two mowers with identical ratings and very different deck widths are making very different claims about how long they expect to run — which is exactly what the claim density figure above is for.

Treating a slope rating as a target

A slope stated as a percentage is rise over run, so 45% is a little over 24 degrees. The figure is measured on dry grass in a straight line. Wet grass, a bank at the very edge of the cutting area, and a turn taken across the fall line are all harder than the number implies, so read it as a ceiling.

Assuming wire-free means no setup

It means no trench. A wire-free mower still has to map the garden, which means a guided first run, and satellite models need their reference antenna sited where it can see sky. The saving is real and it is not the same as unpacking and walking away.

Find one that fits your lawn

The robot mower finder filters on lawn size, boundary system, cutting height and slope, and shows each result against the median for its own lawn-size class. Mowers that do not state a value are kept in your results rather than hidden, and labelled.

Narrower comparisons

Same data, scoped to the group people most often shop for:

RTK Robot Mowers for Large Lawns

Individual mowers in this class

One page each, with the distance it drives per cut and how it sits against the median above:

Related categories

LiDAR Robot Mowers — LiDAR builds a map by measuring distance with laser pulses rather than by inferring position from satellites.
Camera-Navigated Robot Mowers — These mowers navigate on cameras alone, without satellite correction or laser ranging.

Figures on this page were computed from the corpus on 2026-08-27. How we compile these figures.