You have measured the steepest slope where your grass ends — at the property line, beside the driveway, at the top of a retaining wall — and you want to know which machines are still in the running.
This is a different question from “what slope can this mower handle”, and the number most product pages advertise will not answer it. If you want the background on why the two figures differ, read robot mower slope ratings. This page is the shortlist.
Why the headline figure misleads here
Manufacturers publish a slope rating for the interior of the mowing area. Several publish a separate, lower rating for the boundary — the perimeter the mower tracks along. On the same machine those two numbers can be far apart, and it is the boundary figure that usually decides whether a sloped-edge yard works.
A mower advertised at 70% inside the lawn may be rated far lower where the lawn ends. Compare on the interior figure alone and you will shortlist machines that cannot legally, per their own documentation, work your perimeter.
Models with a published boundary rating
Every model below publishes a boundary figure we have verified against the manufacturer’s own material. Sorted by boundary rating, highest first — find your measured edge slope and everything above it is a candidate.
Boundary slope rating against interior rating, as published
| Model | At the boundary | Inside the lawn | Needs a buried wire |
|---|---|---|---|
| Husqvarna Automower 435 iQ AWD | 50% | 70% | No |
| Husqvarna Automower 435X AWD | 50% | 70% | Yes |
| Mammotion LUBA 2 AWD 1000 | 45% | 80% | No |
| Mammotion LUBA 2 AWD 10000 | 45% | 80% | No |
| Mammotion LUBA 2 AWD 3000 | 45% | 80% | No |
| Mammotion LUBA 2 AWD 5000 | 45% | 80% | No |
| Segway Navimow X330 | 25% | 50% | No |
| Segway Navimow X350 | 25% | 50% | No |
| Segway Navimow X390 | 25% | 50% | No |
| Husqvarna Automower 410 iQ | 15% | 45% | No |
| Husqvarna Automower 415X | 15% | 40% | Yes |
| Husqvarna Automower 420 iQ | 15% | 45% | No |
| Husqvarna Automower 440 iQ | 15% | 45% | No |
| Husqvarna Automower 450X EPOS | 15% | 45% | No |
| Segway Navimow i105 | 10% | 30% | No |
| Segway Navimow i110 | 10% | 30% | No |
Figures come from each manufacturer's own published material. Follow a model link for the exact source and the date it was last checked.
Read the gap between the two columns rather than either number alone. Where a manufacturer qualifies its own figure, we record the qualifier with it:
The models that are missing from that table
16 of the 23 models we track publish a separate boundary slope rating.The rest are absent because no boundary figure is published, not because they perform badly. We will not estimate one from the interior rating: the whole point of this page is that the two are different numbers, so deriving one from the other would manufacture the very error it warns about.
If a model you want is missing here, that is a question for the seller, and a specific one: what slope is this rated for along the boundary, as opposed to inside the working area?
How to use this
Measure the edge separately. Not the middle of the lawn. The steepest patch of grass the mower must track along at the perimeter. There is a method in measure your yard before you shop.
Treat the rating as a ceiling, not a target. A machine rated at your exact measured slope is at the edge of its stated envelope, not comfortably inside it.
Check the boundary type too. The final column matters on a slope: a buried wire has to be laid along that perimeter, and some manufacturers publish a separate limit on how steep the ground under the wire may be.
Remember what a rating does not cover. Ground conditions, wet grass, and how abruptly the slope changes all affect real traction, and none of them appear on a spec sheet.
Check your yard against every constraint at once
Boundary slope is one input. Lawn size, interior slope, installation method and zone layout all rule models in or out as well, and a machine that clears your edge slope can still fail on something else.
The selector asks for the boundary slope directly, checks it against these verified figures, and tells you which models are ruled out and which it could not check because the figure is not published. If you want to put two specific machines side by side instead, use the comparison tool.