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Mowing day should be quick and clean, not a fight with a pull-cord or a cloud of gas fumes. This guide helps you choose between a cordless electric mower that starts instantly and a gas model that runs all season. We compared specs and thousands of owner reviews for 21-inch deck mowers to give you a short, honest shortlist for your yard and your back.
I’m Min — the founder and writer behind Gadgets Feed. This guide is built by comparing the manufacturers’ published specifications and the patterns across verified customer reviews, so you get each pick’s real strengths and trade-offs instead of marketing spin.
The right 21-inch deck balances power, weight, and run time for your specific lawn, and this guide names the best 21 inch lawn mower for every type of yard and budget.
Our Picks at a Glance
How To Choose The Best 21 Inch Lawn Mower
Most 21-inch mowers look similar from across the lawn, but they split into two very different worlds: electric and gas. Your choice starts with how big your yard is, how much noise you tolerate, and if you want to store fuel in the garage.
Electric vs. Gas Power
Electric mowers start instantly, weigh less, and need almost no maintenance — no oil changes, no spark plugs. Gas mowers, on the other hand, keep going as long as you put fuel in them, which makes them the safe pick for larger lots. For a 21-inch deck, electric models now handle up to about half an acre on one charge, so measure your yard before you decide.
Self-Propelled vs. Push
If your yard has any slope, a self-propelled mower is worth the extra cost — it drives itself forward so you just steer. On flat, small lawns, a push mower is lighter and simpler, with fewer parts that can break. Look for a variable speed control so you can match the pace to your walking speed.
Quick Comparison
| Model | Best For | Power Source | Cutting Width | Weight | Amazon |
|---|---|---|---|---|---|
| Greenworks 80V 21in Self-Propelled★ Best Overall | Hills & large yards | Electric 80V | 21 inches | 75 pounds | Amazon |
| SENIX 21-Inch Gas PushBest Value | Budget gas power | Gas 144cc | 21 inches | 50 pounds | Amazon |
| AMERISUN 21″ Gas PushBest for Tall Grass | Tall grass cutting | Gas 144cc | 21 inches | 68 pounds | Amazon |
| BILT HARD 21 Inch Gas | One-pull starts | Gas 144cc | 21 inches | — | Amazon |
| PowerSmart EasyGlide 21-inch | Compact storage | Gas 144cc | 21 inches | 62 pounds | Amazon |
| SENIX 21” Self-Propelled Gas | Guided effort, flat yards | Gas 170cc | 21 inches | 61.7 pounds | Amazon |
| Worx 40V 21″ 3-in-1 | Eco-friendly users | Electric 40V | 20 inches | 55.6 pounds | Amazon |
| Greenworks 60V 21in Push | Gas-like torque | Electric 60V | 21 inches | 59.5 pounds | Amazon |
| EGO Power+ 21″ Self-Propelled | Top-end performance | Electric 56V | 21 inches | 96 pounds | Amazon |
In-Depth Reviews
1. Greenworks 80V 21in Self-Propelled Lawn Mower
Our pick — over 4★ from 650+ verified ratings; the strongest balance of quality and price.
This self-propelled mower handles hills while you just steer.
This 80V self-propelled mower earns the top spot because it tackles the two biggest electric-mower doubts — power and runtime — head-on. The variable-speed rear-wheel drive controls traction on slopes, and the brushless motor (an efficient, long-lasting electric motor without carbon brushes) delivers quiet torque that owners say cuts through thick St. Augustine grass without bogging down.
The 4.0Ah battery (a measure of energy storage) runs about 2 hours per charge, and real-world reports are telling: a city-sized lot uses roughly half a charge. One owner summed up the experience: “Light weight, quiet, easy to assemble, and effective at mowing, this 80 volt mower, self propelled, cuts my city sized lot using about half of full charge.” An integrated LED headlight means you can finish that evening lap when the sun gets low.
The catch is the battery-life debate — some buyers report a full yard per charge, others only half that. It is also heavy at 75 pounds, a 50% weight jump over the SENIX gas push mower below, though the self-propulsion offsets that heft in practice.
Why It Wins
- Variable-speed self-propulsion handles hills with ease
- 4-year warranty on tool and battery
- Works with 75+ Greenworks 80V tools
The Trade-Off
- Battery life reports vary — some get full yard, others half
- At 75 pounds, it’s a heavy unit when not self-propelling
Reach for it if: you have a sloped or medium-to-large yard and hate the pull-start ritual — this one starts on a button.
Think twice if: you have a tiny flat lawn where the self-propulsion and weight are more than you need.
2. SENIX 21-Inch Gas Push Lawn Mower
This gas mower is budget-friendly and light at 50 pounds.
At just 50 pounds, this is the lightest mower in the lineup — a full 25 pounds lighter than the Greenworks 80V and a much easier push on flat ground. The 144cc four-stroke gas engine keeps steady power in dense turf, and the 11-inch high-rear wheels roll over roots and bumps that stall smaller-wheeled mowers.
Assembly is a genuine highlight. As owners mention, “It took less than 10 minutes to put together and set up,” and several owners call it the best push mower they’ve owned for pulling out thatch and dead grass. The 2-in-1 system lets you switch between mulching (returning nutrients to the soil) and side discharge for tall wet grass in seconds.
The honest trade-off: durability gets mixed feedback in the reviews, with some owners reporting welds breaking over time. It also has a manual 6-position height adjustment, so you’ll bend down to change cut height more often than on lever-equipped models.
Value verdict: you get dependable gas power, easy assembly, and a light push for a budget-friendly price. The durability questions are the only reason it’s not the top pick.
Best for: budget-conscious buyers with flat, small-to-medium lawns who want gas reliability without a heavy machine.
Who it isn’t for: anyone needing self-propulsion on a slope, or long-term durability guarantees.
3. AMERISUN 21″ Gas Lawn Mower
This 68-pound gas mower cuts through foot-high grass without stalling.
It makes noise, but it handles the worst neglect. The 144cc OHV engine (an overhead-valve design that runs cooler and lasts longer) powers a heavy-duty rust-resistant steel deck that cuts clean even when the grass has gotten away from you — some customers note slicing through two-foot-tall growth without stalling.
The 3-in-1 system covers mulching, rear bagging, and side discharge, and the included 1.4-bushel grass catcher reduces emptying trips. Height adjusts across 6 positions from 1.5 to 3.9 inches, letting you baby a drought-stressed lawn or give it a sharp summer trim.
The recurring complaint from owners is the bagger fills fast, and the biggest durability concern is wheel breakage over time — so treat the wheels gently on rough terrain. Assembly is easy even if the instructions are light on detail.
Raw power: it pulls through tall, thick grass that would stall weaker machines.
Fair warning: the bag fills quickly and wheels have been the weak point in long-term reviews.
Reach for this if: you regularly let the lawn go long and need a mower that won’t quit.
Look elsewhere if: you want a big bag capacity or a machine built for years of rough handling.
4. BILT HARD 21 Inch Lawn Mower
This gas mower starts with one pull, no priming needed.
The defining trait of this 21-inch deck gas mower is reliability at startup. The 144cc four-stroke engine delivers 3.4 HP and 5.75 ft-lb of torque, which keeps it cutting through tall grass without stalling.
A synchronized single lever changes cut height across 6 positions from 1.0 to 3.0 inches, though the spec sheet lists up to 10 adjustment positions in total. The 3-in-1 system (rear bag, mulch, side discharge) covers every mowing style, and the 27.1 fl.oz fuel tank means fewer trips back to the gas can.
The honest catch: durability feedback is mixed, with a few owners reporting wheels breaking after about a year of use. There was also a verified report of a bent drive shaft causing vibration, though that appears to be a rare defective unit rather than a pattern.
Standout Strength
- Reliable one-pull, no-prime starting
- Large 27.1 fl.oz fuel tank for longer runs
- Easy, tool-free height adjustment
Durability Caveat
- Wheels reported breaking after ~1 year by some owners
- Occasional defective units with vibration issues
Get it for: fuss-free starting and a wide 21-inch cut on medium to large yards.
skip it if: you expect a decade of service — the wheel durability is the weak link.
5. PowerSmart EasyGlide 21-inch Push Gas Mower
This foldable 144cc gas mower saves 70% of garage storage space.
If your garage is tight, the headline feature here is the foldable handle, which owners say saves about 70% of storage space and lets the mower sit upright against a wall. The auto-choke engine (a system that adjusts the fuel-air mix automatically) means you pull once and it starts — no fiddling with a choke lever, which is a common annoyance on budget gas mowers.
The 21-inch steel deck and heavy blade cut more ground per pass, and the 6-position single-lever height adjustment spans 1.5 to 3.9 inches. At 62 pounds, it’s a middle-ground weight — not the lightest, but easy to maneuver around flower beds. Owners praise the clean cut and easy assembly, and note it handles crabgrass well.
The one recurring design flaw: the rubber rear flap attachment can come loose — in one case it got sliced during mowing. It’s a minor fix but worth knowing before you buy. This mower is a strong, balanced gas option that we rank in the mid-range of the lineup for its blend of power and storage convenience.
Storage hero: the folding design is a genuine space-saver in cramped garages.
Minor flaw: the rear flap attachment is the weakest link in an otherwise solid build.
Choose it if: garage space is scarce and you want an auto-choke gas engine that starts first pull.
Pass if: you need self-propulsion or a mower with a flawless rear flap.
6. SENIX 21” Self-Propelled Gas Lawn Mower
The self-propelled SENIX that’s best on flat, open lawns.
With a bigger 170cc OHV engine pushing 3.8 HP and 6.5 ft-lb of torque, this gas mower is built for effort-free mowing on flat terrain — the front-wheel drive pulls itself forward so you just guide it around trees and flower beds. The self-propulsion is the standout feature, with owners noting it’s easy to handle even on uphill roads.
The 21-inch high-strength steel deck supports the full 3-in-1 system (mulch, side discharge, rear bag), and the 1.7-bushel bagger holds more than most. A unique vortex tunnel design reduces grass buildup on the deck, and the 6-position height adjustment spans 1.25 to 3.75 inches. The pre-filled oil means seconds-fast startup from the start.
Durability is the recurring concern here — several reviewers point out plastic parts cracking and the mower being prone to falling apart. There’s also one dramatic report of a complete engine failure after hard use. The front-wheel drive is best for relatively flat yards; on slopes you’ll feel the front wheels lose grip.
easy Mowing
- Self-propelled front-wheel drive reduces fatigue
- Pre-filled oil for fast startup
- Large 1.7-bushel bagger
Watch Out For
- Plastic parts reported cracking over time
- Front-wheel drive struggles on slopes
Best for: flat, 1/3-acre yards where you want gas power without the pushing effort.
Not ideal if: your lawn has a significant slope or you want a machine that survives rough treatment.
7. Worx Cordless Lawn Mower, 40V 21″
The brainy cordless that adjusts its power to the grass ahead.
This Worx stands out for two smart technologies. IntelliCut uses patented sensors to automatically raise cutting speed in thick grass and dial it back in thin areas — saving battery when it can. And the Aerodeck vented design boosts air volume in the deck to prevent clogs and clumping, which owners say improves cut quality and bag collection.
It runs on two 20V 5.0Ah PowerShare Pro batteries in a 40V system, with a 4.0A dual charger included. The brushless motor delivers 40% more power and 10% longer runtime than first-gen brushless motors, and the 50-minute average battery life handles a 1/4-acre lawn on one charge, per owner reports. A single 7-position lever changes height from 1.5 to 4 inches.
The battery life rating is the most-discussed trade-off — while most owners get a full yard, some find it drains faster in dense or wet grass. And critically, this is a push mower, not self-propelled, so there’s no drive assist. It’s also note the cutting width is 20 inches, not 21, despite the marketing naming it a “21”” mower.
Smart power: the auto-adjusting speed makes it efficient on mixed lawns.
Reality check: it’s a push model with a 20-inch deck, and battery life varies with grass conditions.
Reach for it if: you want a quiet, eco-friendly cordless with smart power management and no gas fumes.
pass on it if: you need self-propulsion or a true 21-inch cutting width.
8. Greenworks 60V 21in Push Lawn Mower
Gas-matching torque with zero fumes and self-sharpening blades.
This 60V push mower makes a bold claim: 50% more torque than 40V mowers and a 3200 RPM blade speed that matches 150cc gas mowers. Owners agree it handles foot-tall thick grass without bogging down — some even say it cuts better than their old gas machine. The dual SmartCut blades self-sharpen as they spin, so the cutting edge stays fresh without maintenance.
The 5.0Ah battery delivers a full yard on one charge in most owner reports, and the 4-in-1 system adds a turbo leaf mode to the usual mulch, bag, and side-discharge options. An IPX4 waterproof rating (meaning it resists splashes from any direction) means you can mow damp grass without worry, and the LED headlight extends your mowing window into the evening.
The trade-off: it’s a push model, so on slopes you provide the muscle at 59.5 pounds. Battery life is the most-discussed mixed aspect — while most get a full lawn, heavy use with the turbo mode drains the battery roughly twice as fast. The deck is plastic, though the steel construction is what gives gas mowers their durability.
Gas-like performance: the torque and blade speed genuinely match gas mowers in owner reports.
Honest limit: it’s a push mower, and the turbo leaf mode is a battery hog.
Reach for this if: you want gas-level cutting power without the noise, fumes, or maintenance — a 4-year warranty covers it.
Think twice if: you need self-propulsion or you expect a full day of mowing on one charge.
9. EGO Power+ 21″ Cordless Self-Propelled Lawn Mower
The 7.0 ft-lb torque monster that outperforms gas and steers with a touch.
This is the flagship of the lineup, and it earns that status with serious numbers. The EGO delivers up to 7.0 ft-lbs of cutting torque — enough that owners consistently say it exceeds the power of their old gas mowers. The Touch Drive self-propelled system is the cleverest in this guide: you engage the drive with palm pressure, and a fingertip dial controls variable speed between 0.9 and 3.1 miles per hour.
Runtime is a headline feature. Two included 56V 6.0Ah batteries deliver up to 100 minutes on a single charge, which in real terms mows about 75% of a typical lawn on the first battery. The Select Cut multi-blade system lets you swap lower blades for mulching, high-lift bagging, or extended runtime — a level of customization no other mower here offers. Eight cutting height positions span 1 to 4 inches.
The honest trade-offs: at 96 pounds, it’s the heaviest mower in this guide, and the rear-wheel drive makes turning feel awkward — you must release the drive button and sometimes rock the mower. The “go forward” button has also been noted to cause hand cramping during long mows. Value for money is mixed in the reviews, with some owners feeling the premium is worth it and others questioning the cost.
The Premium Payoff
- 7.0 ft-lbs torque exceeds gas mower power
- Up to 100 minutes runtime with two 6.0Ah batteries
- Interchangeable blades for custom cut styles
The Premium Cost
- Heaviest in the guide at 96 pounds
- Rear-wheel drive turning feels awkward
- Button placement can cause hand cramping
Get it if: you want the absolute best cordless performance and don’t mind a heavy machine that drives itself.
Pass if: you have a tight budget or need a lightweight mower you can lift into a truck.
Understanding the Specs
Battery Voltage & Amp-Hours
Voltage (like 40V, 60V, or 80V) roughly tells you the power ceiling — higher voltage generally means more torque to cut thick grass. Amp-hours (Ah) tells you how long the battery lasts. A 4.0Ah battery lasts longer than a 2.0Ah on the same mower. For a 21-inch deck, look for at least 40V and 4.0Ah to handle a typical third-to-half-acre lot.
Cutting Width & Deck Material
A 21-inch deck (the width of the cut) is the balance for most residential yards — wide enough to cover ground fast, narrow enough to maneuver around flower beds. Steel decks hold up better to impacts and last longer than plastic, which is why heavy-duty and rust-resistant steel decks are the ones to prefer for years of service.
FAQ
How long does a 21-inch electric mower battery last on one charge?
Will a 21-inch gas mower fit in my shed?
What is the difference between mulching, bagging, and side discharge?
Is a self-propelled mower worth the extra cost?
How do I choose the right cutting height?
Can I use one battery brand across multiple tools?
Is a gas mower better than an electric one for a large yard?
Why is the EGO mower so much heavier than other cordless models?
Final Thoughts: The Verdict
For most buyers, the 21 inch lawn mower winner is the Greenworks 80V Self-Propelled because it combines hill-taming drive with quiet, gas-free power — the crowd favorite holding a strong 4.4-star score. If you want raw gas power with self-propulsion and a premium feel, grab the EGO Power+. And for a budget-friendly gas option that won’t strain your back at 50 pounds, the SENIX 21-Inch Gas Push is the one to reach for.
How We Picked
We do not accept paid placement. Every pick is matched to a real buyer and a real use-case; we do not hands-on test units.
Sources & Methodology
Specifications: manufacturer listings and product documentation. Review insights: verified customer reviews, as of August 2026. Pricing: not shown on this page (it changes often); check the current price via the retailer link.
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