What is cutting width on a robot mower? It is the width of the strip the blade covers in a single pass. A glossary definition treats it as roughly the blade diameter, so a figure of 9.45 in (about 24 cm) means each straight pass cuts a band about that wide. It sits on the spec sheet next to cutting height, slope rating and recommended lawn size, and it is one of the first numbers to read.
The short answer
- Definition: what is cutting width on a robot mower? The width cut in one pass, usually close to the blade or deck diameter.
- Units: listed in inches or millimeters. 203 mm is 8 in, and 9.45 in is about 24 cm.
- Not the same as cutting height: height is measured from the bottom of the wheels to the bottom of the blade.
- Effect on mowing: a wider deck covers more ground per pass, but slope, obstacles and weather can cut real output by up to 30%, according to Robomow.
What is cutting width on a robot mower?
Cutting width describes how much grass one pass removes. The Robot Lawn Mower Glossary puts it plainly: the cutting width is the width the mower will cut in one pass, i.e. the blade diameter. The same glossary adds that a bigger blade needs more power to spin at the speed required for a clean cut, so a bigger blade asks more of the motor.
The figure is a maximum for one path, not a promise about the whole lawn. A robot mower changes direction at the boundary wire, around obstacles and when its sensors trigger, so the strip it cuts is not always the full deck width at every point. Read cutting width as the size of each cut, then check how the mower covers the yard in the app or manual.
Cutting width is not cutting height
Cutting width and cutting height are separate specs, and they are often confused. Width is the sideways reach of the deck. Height sets how long the grass is left after a pass.
The glossary measures cutting height from the bottom of the wheels to the bottom of the blade, and it notes that the wheels have grass under them while the mower runs, not bare soil. Most mowers offer either fixed settings, such as 30, 40 or 50 mm, or a continuous adjustment between a lower and upper limit. Our guide to what height a robot mower should cut grass explains how to pick a setting.
| Spec | Cutting width | Cutting height |
|---|---|---|
| What it measures | Width of the strip cut in one pass | Distance from the bottom of the wheels to the bottom of the blade |
| Typical spec form | One figure in inches or cm | A range, such as 25 to 75 mm on the eufy E15 |
| What it changes | How wide each pass is | How long the grass is left |
| Where it is defined | Glossary: the blade diameter | Glossary: wheel bottom to blade bottom |
Typical cutting width figures on current spec sheets
Spec sheets for current robot mowers list cutting width in different units, so convert before comparing. Figures below are as shown on the manufacturer pages we read on 11 November 2026, and our guide to how big a robot mower you need shows how to match a rating to your yard. Check the current sheet before you buy, because specs change between model years.
| Model (manufacturer page) | Cutting width as listed | Lawn size as listed |
|---|---|---|
| Husqvarna Automower 430X | 9.45 in (about 24 cm) | 0.8 acre, with a ±20% tolerance |
| eufy E15 | 203 mm (8 in, about 20 cm) | 800 m² (0.2 acre) |
| eufy E18 | 203 mm (8 in, about 20 cm) | 1,200 m² (0.3 acre) |
The two eufy models share the same listed width, so the difference we could see on the page is the area rating rather than the deck. The eufy page does not define cutting width or explain how it relates to passes, so the definition above comes from the glossary, not from eufy. Our reading is that the width figure is most useful when you compare it across models that use the same unit and the same kind of lawn rating.
How cutting width relates to lawn size
Cutting width is one input to the area rating, which our explainer on robot mower coverage ratings covers in detail. Robomow’s lawn-size guidance gives a rough ladder. It lists a cutting width from 18 cm (about 7.1 in) as a key feature for a lawn of about 300 m², and it recommends cutting widths up to 56 cm (about 22 in) for lawns of 2,000 m² and above. The same page warns that a wide deck should not come at the expense of cutting results.
The ladder is a guide from one manufacturer, not an industry standard. Our reading is that a wider deck helps most on large, open lawns, where fewer passes cover more ground, and a list of robot mowers with a wide cutting width is a reasonable place to start for that kind of yard. In a small or winding yard with beds and narrow paths, maneuverability and obstacle handling usually matter more, and Robomow makes the same point, saying accurate cutting in winding gardens is vital.
Why a wider deck does not always cut faster
Knowing what is cutting width on a robot mower does not tell you the mowing time, because a larger cutting width does not guarantee a shorter job. Robomow says its maximum area figure is a best-case value, and that the following factors can reduce it by up to 30%: slopes, obstacles, rain, mowing schedule, lawn type and garden layout.
Slope is worth checking alongside width. The Husqvarna Automower 430X page lists two slope figures, 15% for maximum slope performance at the boundary and 45% inside the installation. The page labels them as two different conditions, so confirm which one applies to your lawn before assuming the higher number.
Heads up
A cutting width that looks good on paper may still take the same time on a sloped, cluttered yard. Our reading is that width, slope and obstacle count should be compared together, not one at a time.
What to check on a spec sheet
Once you know what is cutting width on a robot mower, read that figure first, then confirm it against the other figures on the same page.
- Confirm the unit. Convert inches to centimeters or the reverse, so 9.45 in and 24 cm are not treated as different sizes.
- Read the cutting height next. Look for a fixed set or a range, and remember it is measured to the wheel bottoms.
- Compare the lawn-size rating. Note any tolerance, such as the ±20% on the 430X page.
- Check the slope figures. Confirm whether the number applies at the boundary or inside the installation.
- Check the noise rating if it matters. The 430X page lists 58 dB(A) and the eufy E15 lists 56 dB.
Frequently asked questions
What is cutting width on a robot mower compared with blade size?
The glossary treats cutting width as the blade diameter, which is the width cut in one pass. Check the spec sheet figure for the exact value rather than assuming it from the blade alone.
Does a wider cutting width mean the mower finishes faster?
Not on its own. Robomow says slopes, obstacles, rain, mowing schedule, lawn type and layout can reduce the maximum area by up to 30%, so a wider deck may not save as much time as the width suggests.
Is cutting width the same as cutting height?
No. Cutting width is the width of one pass. Cutting height is the distance from the bottom of the wheels to the bottom of the blade, and it sets how long the grass is left.
How do I compare cutting widths from different brands?
Convert both figures to the same unit first. For example, 203 mm is 8 in and 9.45 in is about 24 cm. Then compare widths alongside the lawn-size rating, slope and obstacle handling, since a single number does not capture coverage.
Sources
- Robot Lawn Mower Glossary: Know the Terms, Buy Smarter (therobotmower.co.uk): cutting width as the width cut in one pass, blade diameter, cutting height measured from wheel bottom to blade bottom, fixed and adjustable height settings.
- Automower 430X (Husqvarna): cutting width 9.45 in, slope figures at the boundary and inside the installation, 0.8 acre lawn size with ±20%, 58 dB(A) sound level.
- eufy Robot Lawn Mower E-Series (eufy): E15 and E18 cutting width 203 mm (8 in), cutting height 25 to 75 mm, 18° slope, 800 m² and 1,200 m² recommended areas, 56 dB.
- Which robotic lawn mower is suitable for which lawn size (Robomow): cutting width from 18 cm for about 300 m², up to 56 cm for 2,000 m² and above, and the up-to-30% output reduction factors.
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