Per Acre GuideGrade in percent · Area in acres · US models

Segway

Navimow X450

Rated for 1.5 acres and 84% grade — that is 40°, not 84°. On a real lawn, once you allow for borders and travel paths, plan on about 1.2 acres.

Rated area1.5 acres
Max grade84% · 40°
Drive4WD
NavigationEFLS 3.0 RTK + VSLAM
Sold viaOnline retail

What it handles

All four wheels drive, which is what buys the steeper rating. That puts it in the small group that can work genuinely steep ground.

Navigation is satellite-based without vision or LiDAR, so heavy tree cover is a real risk — it loses its fix under canopy.

If your ground is steeper

These are rated for a similar area but hold more grade than the Navimow X450’s 84%.

Lymow One Plus1.73 ac · 100% · Tracked

Cross-shopped with

Rated for a similar area, at the same grade or less.

Mammotion LUBA 3 AWD 50001.25 ac · 80% · AWD
Mammotion LUBA 3 AWD 5000H1.25 ac · 80% · AWD
Mammotion LUBA 2 AWD1.25 ac · 80% · AWD

How confident we are

Cross-checked against the manufacturer and at least one other source.

Slope corrected from 50% to 84%: 50% is the X3 series rating (X330/X350/X390), merged into this row by mistake. X4 series has no separate traction-control slope figure, so 84% is the only applicable number. US rated area 1.5 acres; the EU X450 is 5000 sq m (1.24 ac) - genuinely different, do not equate.

Match your own acreage and grade → · Why 84% is not 84° →