Ryobi 40V Brushless 21-Inch Self-Propelled Mower Review

Why you should trust this review

I bought this mower and ran it through a full spring on my roughly third-acre suburban lawn. Ryobi did not supply it and had no part in this. A cordless mower is a tool where the only honest test is a real mowing season, because the questions that matter, whether the battery actually lasts a full cut, whether the motor bogs in the spring’s first tall growth, whether the self-propel holds on a slope, only show up when you are actually mowing week after week.

I did not run lab measurements of motor output, so the runtime figures combine my real mowing experience with the published spec, flagged as such. What I can tell you firsthand is how this mower handled a full spring of varied conditions, where it bogged and where it cruised, and whether the value-versus-EGO trade-off actually plays out the way the price tag suggests.

How we evaluated

I mowed my third-acre lawn with it across an entire spring, in every condition the season throws at you: dry maintenance cuts, damp morning grass, and the tall, thick first growth that tests any cordless mower. I timed real cuts against the included 7.5 Ah battery to check the 50-minute claim, and I deliberately pushed it into tall wet patches to find where the motor bogs.

I used the self-propel across flat ground and inclines to judge whether it holds a line, ran all three modes, mulch, bag and side discharge, and lived with the folding storage and the charger’s recharge time. I also paid attention to build quality details like the handle clamp, since that is where value mowers often feel cheaper than premium ones.

Cut quality and the 21-inch deck

On dry and normally damp grass, the 21-inch steel deck cut cleanly and evenly, leaving the kind of finish you want from a maintenance mow with no stragglers or scalping. The wider deck also means fewer passes than a 20-inch mower, which adds up over a third-acre lawn. For the bread-and-butter weekly cut that makes up most mowing, this mower does the job well and looks good doing it.

The honest ceiling is tall, wet grass. In the spring’s first thick growth, the 40V motor bogs more readily than the EGO 56V, and you have to slow down, raise the deck and clear the chute more often to keep it from stalling. That is normal cordless behavior at this voltage, and the brushless motor recovered from every bog, but if your lawn is frequently tall and wet, the higher-voltage mowers handle it with more authority.

Battery, runtime and the self-propel

Runtime on the included 7.5 Ah battery landed around 50 minutes of typical mowing in my use, consistent with the spec, dropping to roughly 35 minutes in tall wet grass where the motor works harder. For a third-acre lawn that is comfortable margin, I finished with charge to spare on a normal cut. The pack also works across the entire Ryobi 40V tool family, so if you own other 40V tools the battery does double duty.

The self-propel is rear-wheel drive with variable speed up to 3 mph, and it held its line well on the inclines in my yard rather than slipping or fighting me. It is genuinely useful on a sloped lawn. The two drags on the package are the slow charger, about 90 minutes for a full charge, which makes a second pack worthwhile for big lawns, and a plastic handle clamp that feels less premium than the EGO’s hardware under heavy use. Neither hurts the cut, but they are where the value pricing shows.

The value case against the EGO

This is the mower’s whole argument. It costs meaningfully less than the EGO 56V 21-inch equivalent while delivering a comparable cut on normal grass, the same 5-year tool warranty, and self-propel that holds slopes. The gap shows up in two places: the EGO has more authority in tall wet grass and a more refined build feel, and its rapid charger is faster. For most suburban lawns, neither difference changes the result on the ground.

So the decision comes down to how demanding your lawn is and which battery platform you want to be in. If your grass is frequently tall and wet, or you want the most refined experience, the EGO earns its premium. If you have a normal suburban lawn up to about a third of an acre, or you already own Ryobi 40V tools, this mower delivers the great majority of the EGO’s real-world performance for less money, which is exactly what makes it the value pick.

Who should buy the Ryobi 40V Brushless 21-inch?

Buy it if you have a normal suburban lawn up to about a third of an acre and want a clean-cutting, self-propelled cordless mower at a real discount to premium 56V machines, especially if you already own Ryobi 40V batteries. The 50-minute runtime, the slope-holding self-propel, and the 5-year warranty make it a strong value, and the cut quality on normal grass is genuinely good.

Skip it if your lawn is frequently tall and wet, where the EGO 56V handles the load with more authority, or you mow a larger lot and cannot work around the slow 90-minute charger without buying a second battery. If you want the most refined build feel and hardware, the premium mowers deliver it, and that is where the extra money goes.

The verdict

A full spring of mowing confirmed the Ryobi 40V Brushless 21-inch is the best value cordless mower in its class. It cut cleanly on dry and damp grass, ran a comfortable 50 minutes on the 7.5 Ah pack, and the self-propel held its line on the inclines in my yard. For the weekly maintenance cut that makes up most mowing, it does everything a suburban owner needs and undercuts the premium competition on price.

Its limits are honest: it bogs more than the EGO 56V in tall wet grass, the handle clamp feels less premium, and the slow charger nudges you toward a second battery for bigger lots. None of that changes the result on a normal lawn. If your grass is typical and you want cordless convenience without the premium price, this mower is the smart buy, and the shared 40V platform makes it smarter still. Best value, earned over a full season.