🏆 Our #1 robot mower for 2026: Navimow X4 · See today's price →

What size robot lawn mower do I need?

Buying an undersized mower is the most common — and most expensive — mistake. Drag the sliders to describe your yard and we'll match you with wire-free models that actually fit.

How big is your lawn, really?Squares drawn to scale. Most US suburban lots have ⅛–½ acre of actual grass.
Tennis court~2,800 sq ft
⅛ acre5,445 sq ft
¼ acre10,890 sq ft
½ acre21,780 sq ft
1 acre43,560 sq ft

Measure your mowable area (not the whole lot) with a free satellite tool, then add 15–20% headroom. The size matcher does the math.

How the matching works

We filter for mowers rated at least 15% above your lawn size (headroom for charging time and narrow zones) and rated for your steepest slope. Yards with many obstacles get vision-guided models that handle complex layouts without a boundary wire.

Still unsure about hills? Try the slope compatibility checker, or compare running costs with the robot vs. lawn service calculator. For the full picture, read our best robot mowers of 2026 guide.