Why you should trust this review
I cover power tools and yard equipment for The Tested Hub and have run roughly 30 cordless mowers across the past four seasons including the EGO LM2135SP, the Ryobi 40V Brushless 21-inch, and the older Ryobi 40V. The DeWalt arrived as a battery system play for owners who already live in the 20V MAX ecosystem. We purchased the unit at retail.
This review draws on a quarter acre suburban test lot used across multiple cordless mower reviews. See our methodology for the standardized testing protocol.
How we tested the DeWalt 20V MAX 21-inch mower
- Three full mowing sessions on dry 3 inch fescue at a 3 inch cut height.
- One wet mow after overnight rain at roughly 5 inch grass height.
- Self-propel top speed measured against a 100 ft chalked path with a stopwatch.
- Operator ear noise reading at 3 ft using a calibrated sound meter.
- Two 10 Ah pack runtime per session including transitions.
- Charge time per pack on the included dual port charger.
Who should buy the DeWalt 20V MAX 21-inch?
Buy the DeWalt if:
- You already own DeWalt 20V MAX tools and you want one battery system.
- Your lot is a quarter acre or smaller.
- You value the DeWalt build quality on the chassis and folding hardware.
Skip the DeWalt if:
- You do not own DeWalt batteries. Other 21-inch cordless mowers cost less and run longer per charge.
- Your lot is over a quarter acre. Forty-five minute runtime is tight at that scale.
- You mow heavy wet grass weekly. The 40V combined system bogs more than 56V or 80V mowers.
Cut quality: clean on dry grass
On dry 3 inch fescue at a 3 inch cut height, the DeWalt produced clean cut tips across the entire test area. The 21 inch steel deck mulches and bags well in dry conditions. Side discharge throws clippings cleanly enough that you do not double cut on the next pass.
On wet first mow conditions the motor bogged three times on dense patches and recovered within roughly a second each time. That is slower recovery than the EGO 56V (about half a second) and matches the Ryobi 40V Brushless. Mulching mode required two passes in wet grass which is normal.
Self-propel and ergonomics
The variable speed dial is mounted on the upper handle and controls the rear-wheel drive. Top speed measured 3.0 mph against the 100 ft path. The dial response is acceptable. Handle vibration is moderate which is expected from any 21-inch self-propelled mower.
The handle uses sturdy metal latches at the fold points which feels more premium than the plastic clamps on some Ryobi units. After a season of folding the latches still close cleanly without play.
Battery and runtime
Two 10 Ah packs delivered 45 minutes average cut time on dry grass across three runs. Wet first mow at 5 inch grass dropped runtime to about 32 minutes. Charge time per pack on the included dual port charger ran roughly 75 minutes from empty to full so a full kit charge cycle takes about 75 minutes total since both packs charge in parallel.
That runtime is the weak point of the system. Forty-five minutes is enough for a quarter acre but tight for anything larger. The combined 40V architecture cannot match a single battery 56V or 80V mower on cut time per Ah of total capacity.
Build, noise, storage
The DeWalt deck is steel. The folding hardware is metal. Operator ear noise measured 75 dB at the handle at full motor load, similar to other 21-inch cordless mowers and well below a gas mower at 92 to 96 dB.
Folded for storage, the DeWalt stands vertically. The footprint is similar to the EGO and Ryobi at about 4 sq ft of garage floor. The unit weighs 84 lb with both batteries installed which is on the heavier side of this class.
Value vs the EGO and Ryobi
At $599 the DeWalt costs more than the Ryobi 40V Brushless by $150 and slightly less than the EGO LM2135SP by $50. Without an existing DeWalt 20V MAX tool collection, neither comparison goes the DeWalt’s way. The Ryobi runs longer for less. The EGO runs longer with a more refined drive feel. The DeWalt’s pitch is the battery ecosystem and the build quality, not the value.
If you do own DeWalt drills, drivers, and saws, the math flips. A second mower battery system in the garage is a real cost over time, and the DeWalt removes that cost. That is the buyer this mower is built for.
DeWalt 20V MAX 2X 21-Inch Cordless Lawn Mower vs. the competition
| Product | Our rating | Deck | Battery | Runtime | Price | Verdict |
|---|---|---|---|---|---|---|
| DeWalt 20V MAX 2X 21-Inch | ★★★★☆ 4.2 | 21 in | Dual 20V 10 Ah | 45 min | $599 | Recommended |
| EGO LM2135SP 21-Inch | ★★★★★ 4.6 | 21 in | 56V 7.5 Ah | 60 min | $649 | Top Pick |
| Ryobi 40V Brushless 21-Inch | ★★★★☆ 4.4 | 21 in | 40V 7.5 Ah | 50 min | $449 | Best Value |
| Sun Joe MJ401E Corded | ★★★★☆ 4.0 | 14 in | Wired | Unlimited | $129 | Best Budget |
Full specifications
| Deck width | 21 inches steel |
| Voltage | Dual 20V MAX (40V combined) |
| Batteries (included) | Two 10 Ah |
| Runtime | About 45 minutes |
| Cut heights | 1.5 to 4 inches, 6 positions |
| Mode | 3 in 1 (mulch, bag, side discharge) |
| Self-propel | Variable speed up to 3 mph |
| Weight | About 84 lb with batteries |
| Folding | Vertical storage |
| Charger | Dual port fast charger |
| Warranty | 3 year tool, 3 year battery |
Should you buy the DeWalt 20V MAX 2X 21-Inch Cordless Lawn Mower?
The DeWalt 20V MAX 21-inch dual battery mower is the right pick for the homeowner who already owns DeWalt power tools and wants a single battery system across the garage. It cuts cleanly on dry grass, runs about 45 minutes on a pair of 10 Ah packs, and uses standard DeWalt 20V batteries the rest of the year. It does not match a 56V or 80V mower on tall wet grass and the runtime is shorter than the EGO.
Frequently asked questions
Is the DeWalt 20V MAX mower worth $599?+
Only if you already own DeWalt 20V tools. The battery sharing argument is the entire pitch. If you do not own DeWalt tools, the [EGO LM2135SP](/reviews/ego-power-plus-lm2135sp-mower) and [Ryobi 40V Brushless](/reviews/ryobi-40v-21-brushless-mower) are stronger picks at this price.
How long does it run on two 10 Ah packs?+
We measured 45 minutes on dry 3 inch fescue at a 3 inch cut. Tall wet grass dropped runtime to about 32 minutes. That is shorter than the EGO 56V or the Ryobi 40V Brushless on equivalent battery capacity.
Does it bog on tall grass?+
Yes more than higher voltage mowers. The dual 20V MAX system delivers about 40V combined which is below the 56V EGO. On tall first mows of spring, slow the dial and raise the cut height a notch.
Will my existing DeWalt 20V batteries work?+
Yes any DeWalt 20V MAX battery works. Lower capacity packs (5 Ah, 6 Ah) cut runtime proportionally. Two 10 Ah packs are the minimum if you mow more than a small lawn.
Related reviews
EGO Power Plus LM2135SP 21-Inch Self-Propelled Mower Review (2026): A Quieter, Smarter EGO
EGO Power Plus 21-Inch Self-Propelled Cordless Lawn Mower 56V Review (2026): The Battery Mower That Replaces a Gas Mower
