Garden & outdoor
Which robot mower fits your lawn size and slope?
Rated capacity your robot mower needs based on lawn area, slope and garden complexity — wire or GPS navigation.
Quick answer
Robot mower capacity ratings are written for a lawn that barely exists: perfectly flat, wide open, mowed almost every day. Add slopes and the motor works harder and covers less; add flower beds, trees and narrow passages and the robot spends time navigating instead of cutting. That’s why matching your raw square metres to the box rating is the classic mistake — the calculator inflates your area by up to 40% for slope and up to 40% for layout complexity before suggesting a rated class, which is exactly the margin dealers apply informally.
Rated capacity to look for
≥ 600 m²
- Minimum slope spec
- ≥ 25%
- Navigation type suggested
- Perimeter wire is fine
Manufacturers rate robots for ideal conditions: flat, open, mowing almost daily. Slopes and complex layouts eat into effective coverage, so the calculator inflates your area before matching a rated class. Check the slope spec on the exact model — it’s the first thing that disqualifies cheap robots — and for multiple zones connected by narrow passages, modern GPS/RTK robots without perimeter wire handle transfers far better.
How it works
The second spec that disqualifies models is maximum slope, printed in percent: budget robots stop at 25%, mid-range handles 35-45%, and only specialized models with all-wheel drive go beyond. Measure your steepest passage, not the average. Finally, navigation: classic perimeter-wire robots are reliable and cheaper, but if your garden is split into zones connected by narrow corridors, the new GPS/RTK generation without wire transfers between zones on its own and is worth the premium — burying wire across a driveway is nobody’s favourite weekend.
Frequently asked questions
What size robot mower do I need for 500 m²?+
For a flat, reasonably open 500 m² lawn, a 600 m²-rated model fits. With obstacles and some slope, step up to 800 m²; with multiple zones or steep sections, 1,000 m². The price difference between adjacent classes is usually modest, and a robot working below its limit mows less hours per day, makes less noise and its blades and battery last longer.
Perimeter wire or GPS robot mower?+
Wire robots are mature, cheaper and unaffected by tree cover blocking satellite signal — still the right choice for a single open lawn. GPS/RTK robots skip the wire installation entirely, handle multiple zones, and let you redraw boundaries from an app, but want decent sky view and cost more. If your lawn has heavy tree canopy, check that the specific GPS model supports it (some add vision navigation exactly for this).
Can a robot mower handle my slope?+
Convert to percent first: 10 cm of rise over a metre is 10%. Entry robots manage 25% (14°), mid-range 35-45%, specialist AWD models up to 70-80%. Two traps: the rated slope applies to open lawn, not near the boundary where the robot must turn (there it drops to roughly half), and wet grass on a slope cuts grip drastically — schedule mowing away from irrigation and rain.
How much maintenance does a robot mower need?+
Little but regular: flip it and replace the small pivoting blades every 1-3 months (a €10-15 kit, 5 minutes with a screwdriver), brush off grass buildup monthly, and store it indoors over winter with the battery around half charge. Batteries last 3-6 seasons depending on hours. The one accessory worth having from day one is a garage — sun and rain age the plastics and electronics faster than the mowing does.
As an Amazon Associate I earn from qualifying purchases — the price does not change for you.