The overall Which? test score is made up of the following star ratings, all determined by our rigorous lab tests.
How we test grass cutting ability
We assess how good robot mowers are at cutting grass on multiple test lawns of different types over a period of four weeks. These include standard, wet, and long grass. We also see how the mowers fare on slopes and uneven ground, and if they're able to navigate obstacles they're likely to encounter in gardens like trees, fences and patios.
How we test ease of use
Our testers assess the robot mower's ease of use by rating how straightforward it is to adjust the cutting height, get the mower set up and installed, load up and use any accompanying apps, and keep it clean.
How we test quietness
Running a robot mower every day that makes a racket won't make you very popular with your neighbours. A high rating for this means the robot mower is quiet enough not to disturb anybody.
How we test battery life
We measure and rate how good the battery life and charging time of the robot mower is regardless of how long the manufacturer says it runs or charges for.
