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Robot lawn mower size calculator
Enter your lawn area and steepest slope. The list shows which robot mowers are rated for both, cheapest first, and how much headroom each one has.
Count only the grass the robot mows, not the house, drive or beds. How to measure it.
Not sure? See the slope guide.
Robots for your lawn
A robot fits when its published maximum area is at least your lawn size and its slope rating covers your steepest section. Bars show how much of the rated area your lawn uses; above 85% we mark it a tight fit. Cheapest fits first.
How we match a mower to your lawn
Every robot mower has a published maximum area. It's the largest lawn the maker says it can keep cut, usually assuming it mows most days through the growing season. We compare your lawn size to that number.
Fit = lawn area ≤ rated area, and steepest slope ≤ rated slope.
Why we flag tight fits
Ratings assume good conditions. Complex shapes, narrow passages, many obstacles and fast spring growth all mean more time per square foot. When your lawn uses more than 85% of a rating, we mark it a tight fit so you can consider the next size up.
Slope ratings
Makers give slope as a percentage, degrees or both. 100% equals 45°. We convert where only one is published. A mower rated for 45% will struggle on a 60% bank even if your average slope is gentle, so enter the steepest part it must climb.
Trees and satellite signal
Many wire-free mowers locate themselves with RTK satellite positioning. Dense trees and tall buildings can block that signal. LiDAR mowers measure their surroundings directly, so we tag them as not needing satellites when you choose "lots of cover".
Where the numbers come from
Every model's area, slope and price comes from the manufacturer's or retailer's page, linked on its review and checked 2 November 2026. Some manufacturers list different areas in different regions; we use the US listing.