What size lawn mower do I need?

Measure your lawn first

Most people guess their lawn size, and most guesses are wrong. Measure the length and width of each rectangle of grass in metres, multiply, and add the pieces together, taking off beds or patios. Our lawn area calculator does this for rectangles, circles and triangles and gives the answer in m² and square feet.

Note anything that makes mowing slower: narrow side passages, lots of beds and trees, slopes, or a lawn split between front and back. These all reduce how much a battery will cut and favour a narrower, lighter mower.

Quick size table

These bands are a practical starting point, not a rule. Makers' rated areas assume dry grass cut regularly on a simple lawn, so leave some headroom if your garden is awkward or the grass grows fast.

Cutting width explained

Cutting width is the diameter of the blade's sweep. A wider deck covers more ground per pass, so you walk less on an open lawn. But a wider mower is heavier, needs more power and is harder to steer round tight curves and into corners.

On a small lawn, a 33 cm deck such as the Ryobi OLM1833B or the Greenworks 24 V 33 cm model is easy to lift, turn and hang up. On a medium lawn, a 37 to 41 cm deck like the Yard Force 40 V 37 cm or the Greenworks 40 V 41 cm saves passes. On a large lawn, a 46 to 48 cm deck such as the Makita DLM462PT4 or Hayter Harrier 48 AD covers ground quickly, and self drive helps with the extra weight.

Battery capacity and rated lawn area

On a battery mower, the deck width only tells half the story. The energy in the pack, measured in watt hours (volts x amp hours), decides how far you get. Makers also quote a rated lawn area, which is the easiest number to compare.

Some examples from listings in our guides: the Greenworks 24 V 33 cm mower is listed for lawns up to 260 m² on its 4 Ah battery; the Einhell GE-CM 18/33 for up to 200 m²; the Greenworks 40 V 41 cm for about 250 m² per 2 Ah battery; the Greenworks 48 V 41 cm for up to 440 m² on two 24 V 4 Ah packs; and the Makita DLM462PT4 for up to 1,900 m² with four 5 Ah packs.

• Greenworks 24 V 33 cm: up to 260 m², one 4 Ah pack.
• Greenworks 40 V 41 cm: about 250 m² per 2 Ah pack, 500 m² with two.
• Greenworks 48 V 41 cm: up to 440 m², two 24 V 4 Ah packs.
• Makita DLM462PT4: up to 1,900 m², four 5 Ah packs supplied.

Other things that change the right size

Storage space matters: a shed with a narrow door or a flat with a small balcony store favours a compact mower that folds. Slopes favour lighter mowers or self drive. Long grass, cut less often, uses more energy per square metre, so allow more headroom.

If you would rather not mow at all, a robot mower is sized by area too. Our small garden robot mower guide covers compact lawns. For push mowers, see the small garden cordless mower guide or, for bigger plots, the large garden cordless mower guide.

Cordless mowers for small gardens →

Frequently asked questions

What size mower do I need for a small garden? For lawns up to about 150 to 200 m², a 30 to 34 cm cordless mower is usually enough and easy to store.

Is a bigger cutting width always better? No. A wider deck saves passes on open lawns but is heavier and harder to steer round beds, trees and narrow paths.

How much battery do I need? Pick a mower rated a little above your lawn area. If you are near the limit, a second battery avoids stopping halfway.

What size mower for a 1,000 m² lawn? Look at 46 cm or wider decks with large or multiple batteries, ideally self drive, or consider a robot mower rated for that area.