Best 21-Inch Push Mowers for Small Yards Today
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A 21 inch push mower is a walk-behind mower with a 21-inch cutting deck, usually powered by a small four-stroke engine, that covers a yard in fewer passes than a narrower machine. The seven options below all share that deck width. They differ in engine size, height settings, wheel size, bagging and mulching options, and whether the drive is self-propelled. Each entry uses only what its product listing states. Where a listing does not give a detail, such as engine oil type or weight for every model, this roundup says so.
Quick answer
- Pick a 21-inch deck when your lawn is small to medium and you want fewer passes. The listings in this group all state a 21-inch cutting width.
- Check the engine size first. The listings state 125cc to 170cc four-stroke engines, with the 170cc AMERISUN model at the top of the range.
- Choose self-propel only if you want the drive to move the mower. The AMERISUN listing is the self-propelled model in this group, and the others are push-only.
- Compare height settings. Most listings give six positions, from about 1.5 inches to 3.9 inches, and the BILT HARD 21-inch listing gives a range from 1.0 to 3.0 inches.
What a 21-inch push mower is good for
A 21-inch deck covers more ground per pass than the 17-inch and 20-inch decks common in smaller mowers. A wider deck means fewer turns on a rectangular lawn, which saves time on medium yards. It also means more weight and a larger footprint, so a 21-inch mower needs more room to turn and more space to store. Before you buy, measure the gates, sheds and garage door opening that the mower will pass through, because the folded height and the handle position vary by model.
Walk-behind push mowers differ from riding mowers in the work you do. You guide the mower with your hands and walk every foot of the lawn. That workload suits small to medium yards and sloped areas where a riding machine is awkward. For a large property, a wider or powered machine may fit better.
How to choose a 21-inch push mower
Start with the engine. The listings in this roundup state the following engines: a 144cc four-stroke in one BILT HARD listing and in one PowerSmart listing, a 201cc four-stroke OHV in a second BILT HARD listing, a 125cc Briggs and Stratton E450 in the SENIX listing, a 140cc OHV in two PowerSmart listings, and a 170cc four-stroke in the AMERISUN self-propelled listing. Larger engines usually give more power for thick grass, but they also add weight and cost. A 140cc or 144cc engine is a common middle choice for a 21-inch deck.
Next, look at height adjustment. Single-lever systems let you change the height on all wheels at once. The BILT HARD 144cc listing describes a single lever with six positions from 1.0 inch to 3.0 inches. The second BILT HARD listing describes a single lever with ten positions from 1.2 inches to 3.75 inches. The SENIX listing describes a dual-lever system with six positions from 1.25 inches to 3.75 inches. The PowerSmart and AMERISUN listings describe six positions from 1.5 inches to 3.9 inches. A lower minimum height suits a finer cut. A higher maximum suits tall or uneven grass.
Then check the cutting options. Most listings describe a three-in-one deck that can bag, mulch or discharge grass to the side or rear. The SENIX listing describes a two-in-one steel deck that mulches or discharges to the side. Bagging matters if you want to remove clippings from the lawn, while mulching returns them to the grass.
Consider wheels and handling. The BILT HARD 144cc listing describes 10-inch front and rear wheels. The second BILT HARD listing describes 9.5-inch rear and 8-inch front wheels. The SENIX listing gives 11-inch rear and 8-inch front wheels. The PowerSmart and AMERISUN listings give 10-inch rear and 7-inch front wheels. Larger rear wheels help on uneven ground, and two PowerSmart listings name rear-wheel drive in their titles.
Finally, check storage. The PowerSmart 144cc listing describes a foldable design that it says saves up to 70 percent of storage space. The SENIX listing describes a fold-down handle for storage. Folded size is a real factor for a garage or shed.
Comparison table
The table uses only the figures the listings state. Where a listing does not give a value, the cell reads “not stated”.
| Model (listing) | Engine | Deck and mulch or bag | Height positions | Wheels (rear / front) | Self-propelled |
|---|---|---|---|---|---|
| BILT HARD 144cc 3-in-1 | 144cc 4-cycle | 21-inch steel, bag, mulch, side discharge | 6, 1.0 to 3.0 in | 10 in / 10 in | No |
| BILT HARD 201cc 3-in-1 | 201cc 4-stroke OHV | 21-inch steel, bag, mulch, side discharge | 10, 1.2 to 3.75 in | 9.5 in / 8 in | No |
| SENIX LSPG-M4 | 125cc Briggs and Stratton E450 | 21-inch steel, mulch, side discharge | 6, 1.25 to 3.75 in | 11 in / 8 in | No |
| PowerSmart 144cc | 144cc 4-stroke OHV | 21-inch steel, mulch, side discharge | 6, 1.5 to 3.9 in | 10 in / 7 in | No |
| PowerSmart 140cc (OHV, 3-in-1) | 140cc OHV | 21-inch steel, bag, mulch, rear discharge | 6, 1.5 to 3.9 in | not stated / not stated | No |
| PowerSmart 140cc (rear-wheel drive) | 140cc OHV | 21-inch steel, bag, mulch, rear discharge | 6, 1.5 to 3.9 in | 10 in / not stated | Rear-wheel drive |
| AMERISUN 170cc | 170cc 4-stroke OHV | 21-inch steel, bag, mulch, side discharge | 6, 1.5 to 3.9 in | 10 in / 7 in | Yes |
Roundup: seven 21-inch push mowers
Each block below uses only the facts in the listing. The listings for this group use the same deck width, so the differences lie in the engine, the controls and the wheels.
1. BILT HARD 21-inch 144cc gas push mower (3-in-1 with bagging, mulching and side discharge)
This BILT HARD listing describes a 21-inch heavy-duty steel deck and a 144cc four-cycle engine rated at 3.4 HP and 5.75 ft-lb torque. It lists a 27.1 fluid ounce fuel tank. The single-lever height adjustment offers six cutting positions from 1.0 inch to 3.0 inches. The listing says the mower bags, mulches and discharges to the side, and it includes a grass bag, a side discharge chute, a mulching plug, engine oil and tools for setup. The wheels are 10 inches at the front and rear, according to the listing. The model number is TMA-0561. This option suits buyers who want a larger fuel tank and a single-lever height setting with a low minimum height.
2. BILT HARD 21-inch 201cc push lawn mower (3-in-1 with 4-cycle engine)
The second BILT HARD listing describes a 21-inch 3-in-1 steel deck with mulching, side discharge and rear bagging. The engine is a 201cc four-stroke OHV unit that the listing says delivers 9.0 ft-lb of torque. The listing says the mower has no choke and no primer, which makes starting simpler. The height adjustment is a single lever with four-wheel synchronized control and ten positions from 1.2 inches to 3.75 inches. The rear wheels are 9.5 inches and the front wheels are 8 inches, both with double ball-bearing hubs. The grip is foam-wrapped and angled. The listing states a cutting width of 21 inches and a weight of 73.8 pounds. This option suits a buyer who wants the most height positions in the group and a larger engine.
3. SENIX LSPG-M4 21-inch gas push lawn mower (125cc Briggs and Stratton engine)
The SENIX listing describes a 21-inch steel deck with a 125cc four-cycle Briggs and Stratton E450 engine. The engine starts with a Prime n Pull start. The listing says the engine is four-stroke, so it needs no oil mixed with fuel, and it describes the engine as low in noise and emissions. The deck is a two-in-one steel design that mulches or discharges to the side. The six-position dual-lever height adjustment ranges from 1.25 inches to 3.75 inches. The rear wheels are 11 inches and the front wheels are 8 inches. The handle folds down for storage. The listing says engine oil is included and that the mower carries a 2-year limited warranty. Buyers who prefer a dual-lever height system and a known engine brand may find this listing a fit.
4. PowerSmart 21-inch gas lawn mower with 144cc OHV engine and mulching and side discharge
This PowerSmart listing describes a 144cc four-stroke OHV engine with an auto-choke for easier starting. The deck is a heavy-duty all-steel design that combines mulching and side discharge. The cutting path is 21 inches. The six-position single-lever height adjustment ranges from 1.5 inches to 3.9 inches. The listing says the mower is foldable and saves up to 70 percent of storage space, and it describes 10-inch rear wheels and 7-inch front wheels for smooth handling on uneven terrain. The listing does not state a bagging option, so this model should be treated as mulch and side discharge. The model is DV8621C. This option fits a buyer who wants the largest engine among the PowerSmart listings and a compact folding design.
5. PowerSmart 21-inch gas push lawn mower with 140cc OHV engine (3-in-1 bag, mulch and rear discharge)
This PowerSmart listing describes a 140cc OHV engine known for smooth start-up in its bullet points. The 21-inch steel deck covers a wide path, and the three-in-one function includes a 1.4-bushel bag, mulching and rear discharge. Height runs in six steps, from 1.5 inches to 3.9 inches, set with one lever. The listing describes the mower as suited to medium and large yards. It does not state wheel sizes in its bullets, so check the listing photos or description before you buy if wheel size matters for your lawn. The model number in the listing is B8721S2. Choose this listing when you want bagging in a PowerSmart model and an OHV engine.
6. PowerSmart 21-inch gas push mower with 140cc OHV engine and rear-wheel drive
This PowerSmart listing uses a 140cc OHV engine and a 21-inch steel deck with three cutting options: rear bagging, mulching and rear discharge. The listing describes a single-lever six-position height adjustment from 1.5 inches to 3.9 inches. Its title and bullets name rear-wheel drive with 10-inch rear wheels, which the listing says improves traction on slopes and rough terrain. The listing describes the rear-wheel drive as a way to propel the mower, but it does not describe a self-propel speed. Buyers who want rear-wheel drive without a front-wheel propel system may find this listing a fit. The model number is B8721S2, the same as the listing in item 5, so compare the title and bullets before you order.
7. AMERISUN 21-inch 3-in-1 gas self-propelled lawn mower (170cc 4-stroke engine)
The AMERISUN listing is the only self-propelled model in this roundup. It describes a 170cc four-stroke OHV gas engine and a 21-inch cutting deck with side discharge, mulching and a rear bag. The bag holds 1.4 bushels, according to the listing. The six-position height adjustment ranges from 1.5 inches to 3.9 inches. The wheels are 10 inches at the rear and 7 inches at the front, and the listing describes them as easy to maneuver on uneven terrain, hills and slopes. The foldable handle is listed as a storage feature, and the listing describes an assembly that the buyer completes in minutes. The model number is AV8621S1. This option suits a buyer who wants the drive to move the mower on a larger or sloped lawn.
Closer look: the BILT HARD 201cc model
Of the seven listings, the BILT HARD 201cc model gives the most height positions and the largest engine size in the group. Its ten-position single-lever system runs from 1.2 inches to 3.75 inches, so you can set a close cut or a taller cut without changing wheels. The listing says the engine has no choke and no primer. For many owners, a simpler start routine is worth more than a higher engine size, so the no-choke design is an important detail in the listing.
The wheel and grip details round out the picture. The 9.5-inch rear and 8-inch front wheels use double ball-bearing hubs, according to the listing. The foam-wrapped, angled grip is meant to reduce hand fatigue on long mowing sessions. The listing also states a weight of 73.8 pounds, which is heavy for a push mower. Plan for that weight if you need to lift the mower into a truck or onto a deck or step.
Two close alternatives are the SENIX 125cc model and the PowerSmart 144cc model. The SENIX listing uses a dual-lever height control and a known Briggs and Stratton engine, with 11-inch rear wheels that the other models in this group do not match. The PowerSmart 144cc listing uses a single-lever system with six positions and an auto-choke, plus a folding design. Choose the BILT HARD if you want more height positions, the SENIX if you prefer a Briggs and Stratton engine, and the PowerSmart if folding storage matters most.
Maintenance that keeps a push mower running
A gas mower needs routine care. Change the engine oil at the interval named in the owner’s manual, and check the oil level before each mowing session. Keep the deck clean, because packed grass under the deck reduces airflow and cutting quality. Sharpen or replace the blade when it is dull or bent, and keep the blade bolts tight. The listings in this group name engine oil in the box for some models, but the owner’s manual is the source for the correct grade and fill amount.
Store the mower with the fuel system emptied or treated, as the manual directs. Keep the mower on a flat surface when stored, and cover it if it stays outdoors. A folded mower takes less room, but check the cables and the handle locks before you fold it each time.
Safety basics for push mowers
A rotating blade can throw debris and cut hands and feet, so wear closed shoes, long trousers and eye protection. Clear the lawn of stones, sticks and toys before you start. Keep children and pets indoors while you mow. Never reach under a running deck, and stop the engine and wait for the blade to stop before you clear a clog, change the blade or check the deck.
Gas engines produce carbon monoxide, so run them outdoors only and keep the exhaust away from windows and doors. If you have a heart, back or breathing condition, ask your doctor before you use a push mower for long periods, and consider a self-propelled model if walking the mower is hard for you.
Mistakes to avoid
- Choosing the 21-inch deck for a very small yard, where a narrower mower may be easier to store and turn.
- Cutting too low for the grass type. A wider deck with a low setting can scalp a lawn in one pass.
- Assuming every listing includes bagging. The SENIX and PowerSmart 144cc listings describe mulch and side discharge, and their bullets do not describe a bag.
- Skipping the height check. Compare the minimum and maximum settings to the lawn you have.
- Buying on engine size alone. Height settings, wheels and storage size can matter more day to day.
FAQ
What is the best engine size for a 21-inch push mower?
The listings in this roundup run from 125cc to 201cc, with the AMERISUN self-propelled model at 170cc. A 140cc or 144cc engine is a common middle choice. The right size depends on grass thickness, slope and how much walking you want to do. Larger engines add weight and cost.
Does a 21-inch push mower bag grass?
Some listings do. The BILT HARD 144cc and 201cc listings include a grass bag or rear bagging, and the PowerSmart 140cc listing and the AMERISUN listing describe a 1.4-bushel rear bag. The SENIX listing and the PowerSmart 144cc listing describe mulching and side discharge, without a bag in the bullets.
Which mower is self-propelled?
The AMERISUN listing describes a self-propelled 21-inch mower with a 170cc engine. The other listings in this group describe push-only operation, although one PowerSmart listing names rear-wheel drive in its title and bullets. Check the drive description before you buy if self-propel matters to you.
How many height settings do these mowers have?
Most listings give six positions. The BILT HARD 201cc listing gives ten positions from 1.2 to 3.75 inches. Choose the range that matches the grass height you want to keep.
Is a 21-inch push mower good for a small yard?
It can be. A 21-inch deck covers more ground per pass, which helps on small to medium lawns. On a very small lot or a tight corner, a narrower mower may be easier to handle and store.
Do these listings state the weight of every model?
No. The BILT HARD 201cc listing states a weight of 73.8 pounds, and most other listings in this roundup do not give a weight in their bullets. Check the product details on the listing for each model you consider.
Bottom line
For a 21-inch push mower, choose the engine, height range and bagging option that match your lawn, then compare wheels and storage size. The BILT HARD 201cc listing offers the most height positions and the largest engine size in this group. The SENIX listing suits buyers who want a Briggs and Stratton engine and a dual-lever height control. The AMERISUN listing is the self-propelled choice for larger or sloped lawns. Confirm the details on each listing before you order.
Related reading: Best 21 Inch Electric Lawn Mower: What to Check Before You Buy covers the same deck width with a battery focus, and SENIX 20-Inch Gas Push Mower Review looks at a related gas model in more depth.
