Every robot mower gets a score from 0 to 100% built from six factors, which maps onto the 5-point rating shown on the site (a 0% score would be 1.5 stars; a perfect score, 5). Each factor is scored against fixed reference points, not against the other products in the list, so adding a new model never moves another model’s rating. Mowers are ranked within their lawn size, set by the largest lawn the maker rates them for.
| Factor | Measures | Weight |
|---|---|---|
| Value | price per rated acre | 30% |
| Navigation | how it finds its way | 20% |
| Slopes | steepest rated slope | 20% |
| Features | zones, obstacles, edges, rain, 4G, theft | 15% |
| Warranty | years of cover | 10% |
| Noise | rated sound level | 5% |
Reference points by size
| Lawn size | Price per rated acre scoring 0 → 100 |
|---|---|
| Up to 1/4 acre | $12,000 → $3,000 |
| 1/4 to 1 acre | $6,000 → $1,500 |
| 1 acre and up | $4,000 → $1,200 |
The factors
Value is the current lowest checked price divided by the lawn area the maker rates the mower for. Prices are checked by hand and dated on every page; a mower with no current price gets the neutral middle score. Small mowers always cost more per acre, so each size has its own scale.
Navigation scores how the mower knows where it is:
| Navigation | Score |
|---|---|
| LiDAR + RTK + vision | 100 |
| LiDAR + vision | 85 |
| RTK + vision | 80 |
| LiDAR | 70 |
| RTK | 60 |
| Vision (cameras only) | 45 |
| Boundary wire | 10 |
RTK is satellite positioning corrected by a base station or a network service, accurate to an inch or two in the open but prone to losing its fix under trees and beside walls. LiDAR maps the yard with a laser scanner and works in shade and at night. Cameras recognize obstacles and lawn edges, but on their own they struggle in low light and on lawns without clear borders. Each combination covers the other’s weak spots. A boundary wire works reliably but has to be laid around every lawn and repaired when it’s cut.
Slopes is the steepest slope the maker rates the mower for, as a percentage grade: 25% (14°) scores zero and 80% (39°) full marks. All-wheel-drive models are listed as such, and are usually the ones near the top.
Features is the share of these the mower has: multiple zone maps, no-go zones, obstacle avoidance, an edge-mowing mode, a rain sensor, built-in 4G, anti-theft protection and cutting height set from the app. A feature the maker doesn’t say either way about is left out of the share, and the factor is marked estimated.
Warranty is the length of the standard warranty: 1 year scores zero and 4 years full marks.
Noise is the rated sound level: 70 dB(A) scores zero and 55 dB(A) full marks. Makers don’t all measure it the same way (some publish sound power, some sound pressure at a distance), so it carries only a small weight.
What isn’t scored
Independent tests are listed on each product page where they exist, but robot mowers are tested in reviewers’ own yards, on different grass and with different settings, so the results aren’t comparable enough to score yet. Cutting width and run time are listed but not scored either, because the rated lawn area already reflects them.
Missing data
If a figure isn’t published, that factor gets the neutral middle score (50) and the product page marks it as estimated.
Ties and discontinued models
Products are ranked by score within each size. Discontinued models stay listed but rank below every current model and can be hidden with the “Hide discontinued” filter.