Mowers
Do I need a self-propelled lawn mower?
Almost everyone answers this with lawn size. Lawn size is the wrong variable.
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We have not tested these units. Every spec on this page comes from the manufacturer's own documentation and is linked to it. Every computed figure is arithmetic you can redo. Prices are checked daily — last verified January 1, 1970. Here is exactly how we pick.
Why lawn size is the wrong variable
The usual advice is "get self-propel if your lawn is over a quarter acre". It has the physics backwards. Pushing a mower on flat ground takes very little force once it is moving — you are overcoming rolling resistance, not lifting anything. Doing that for 40 minutes instead of 20 is tiring in the way any walk is tiring, not in the way pushing something heavy uphill is.
Slope changes the problem completely. On a gradient you are lifting the mower's full weight against gravity on every uphill pass. That is where 75 lb stops being a number on a spec sheet.
The weight numbers that exist
| Mower | Weight | Drive | What that means |
|---|---|---|---|
| Greenworks LM2054 (40V, 20 in) | 57.5 lb | Push | Comfortably pushable on flat ground. The lightest published weight we have. |
| Toro 21356 (60V, 21 in) | 66 lb | Personal Pace RWD | Around the threshold. The variable drive earns its keep on anything but flat. |
| Greenworks LM2108S (80V, 21 in) | 75 lb | Variable-speed RWD | Above the threshold. You would not want to push this uphill. |
| EGO LM2135SP (56V, 21 in) | Not published | 0.9-3.1 MPH RWD | EGO does not publish a weight for a mower you have to steer. |
| Ryobi 40V HP (21 in) | Not published | Variable-speed RWD | Also unpublished. |
| Kobalt 80V SP (21 in) | Not published | RWD, 7 speeds | Two 4Ah packs aboard, so not light, but no figure is published. |
Three of six manufacturers do not publish the weight of their flagship mower. We are not going to estimate it for them.
What the drive motor costs in watt-hours
Be careful how you read that. The comparison is not clean — the push mower also has a smaller deck and a simpler cutting system, so the drive motor is not responsible for the whole gap. What is fair to say is that self-propelled 21-inch mowers consistently consume more per minute than push 20-inch ones, and you pay for that in pack size.
Variable speed is the specification worth having
If you do buy self-propelled, the drive control matters more than the drive itself. EGO publishes a 0.9 to 3.1 MPH range; Kobalt publishes seven speed settings; Toro's Personal Pace system varies with how hard you press the handle.
A single-speed drive that runs faster than your natural walking pace makes you fight the mower on every turn, which is worse than pushing. On mixed or uneven ground, being able to slow it down is the difference between a drive system that helps and one that argues with you.
The decision, in order
- Is there slope? Any meaningful gradient means self-propelled. This overrides everything below. See the hills page.
- Does the mower weigh over 70 lb? Then it wants a drive system even on the flat. Note that most of the heavy mowers only come self-propelled anyway.
- Is the ground uneven? Ruts, tree roots and dips are harder work than gradient, and a variable-speed drive helps here specifically.
- Everything else? Buy the push mower. It is lighter, cheaper, more efficient per watt-hour and simpler — and on a flat quarter acre you will never wish you had the drive.
The products discussed
Specs are the manufacturer's own and linked to the page they came from. Prices come from a live daily check; where we have no verified price we say so rather than print a stale one.
Greenworks 40V 20" Push LM2054
Greenworks · Greenworks 40V · Our score 8.0/10
#ad No verified live price right now, so we show none rather than a stale one. How we're funded.
40 minutes on a 160Wh pack and 57.5 lb to push -- the honest answer for a third of an acre and nothing more.
Published specs
| Model / SKU | LM2054 / 2549902 |
|---|---|
| Deck | 20 in |
| Max blade speed | 3200 RPM |
| Battery included | 40V 4.0Ah |
| Cut height | 1.2-3.6 in, 7 positions |
| Runtime claim | Up to 40 min |
| Weight | 57.5 lb |
| Rated for | Up to 1/3 acre |
| Warranty | 3-yr tool / 3-yr battery |
Source: 40V 20" 4-in-1 Push Lawn Mower (LM2054), greenworkstools.com
40V x 4.0Ah = 160Wh. Note it claims 40 minutes on 160Wh where the 80V flagship claims 33 minutes on 320Wh -- a 20 in deck and no self-propel drive motor is why.
What the numbers favor
- Lightest published weight on this page at 57.5 lb, and the only sub-60 lb mower here
- Claims 40 minutes from 160Wh -- the best published minutes-per-watt-hour of any mower on this page
- Same 3200 RPM blade speed as the 80V flagship
- 4-in-1 deck at the entry price
What they don't
- Push only -- no drive assist on any slope
- 1.2 in minimum cut height is lower than most cool-season lawns should ever be cut
- 120-minute recharge, three times the 80V model's 40 minutes
your lawn is over a third of an acre or has any real slope. Greenworks rates it to 1/3 acre and you will be pushing all 57.5 lb of it up the hill yourself.
How it scores
Scores are our editorial weighting of the published specs above, not a test result. They are deliberately kept out of this page's structured data.
EGO Power+ 21" Select Cut LM2135SP
EGO · EGO 56V ARC Lithium · Our score 9.1/10
#ad No verified live price right now, so we show none rather than a stale one. How we're funded.
The most watt-hours in the box of any flagship walk-behind here, on the platform with the widest tool range to grow into.
Published specs
| Deck | 21 in |
|---|---|
| Cutting torque | Up to 7.0 ft-lbs |
| Battery included | 56V 7.5Ah |
| Cut height | 1-4 in, 8 positions |
| Self-propel speed | 0.9-3.1 MPH |
| Runtime claim | Up to 60 min |
| Warranty | 5-yr tool / 3-yr battery |
Source: EGO POWER+ 21" Select Cut System (LM2135SP), egopowerplus.com
56V x 7.5Ah = 420Wh, using EGO's advertised pack voltage.
What the numbers favor
- 420Wh in the box -- the largest included pack of any flagship walk-behind on this page
- Eight cut-height positions from 1 to 4 in, the widest published range here
- Three interchangeable lower blades (mulching, high-lift bagging, extended runtime)
- 5-year tool warranty, the longest published on this page
What they don't
- EGO publishes torque (7.0 ft-lbs), not motor wattage, so it cannot be compared directly against Greenworks' 1500W figure
- The 7.5Ah pack that earns the runtime claim is also the expensive one to replace
your yard is under a quarter acre. You would be paying for 420Wh of headroom you will never discharge, and a 20 in push mower cuts the same grass.
How it scores
Scores are our editorial weighting of the published specs above, not a test result. They are deliberately kept out of this page's structured data.
Kobalt 80V Max 21" Self-Propelled (dual-port)
Kobalt · Kobalt 80V Max · Our score 8.4/10
#ad No verified live price right now, so we show none rather than a stale one. How we're funded.
Two 4Ah bays, 80 published minutes and an acre rating -- the most runtime per purchase of any 80V walk-behind here.
Published specs
| Deck | 21 in, steel |
|---|---|
| Motor | Brushless |
| Batteries included | 2 x 80V 4.0Ah (dual port) |
| Runtime claim | Up to 80 min |
| Rated for | Up to 1 acre |
| Drive | Self-propelled RWD, 7 speed settings |
| Recharge | Approx. 60-90 min |
Source: Kobalt 80-Volt 21-in Self-propelled Battery Mower (2 batteries), lowes.com
80V x 4.0Ah = 320Wh per pack; two bays = 640Wh installed. Kobalt's listing does not state whether the two ports discharge simultaneously or in sequence, so we do not claim either -- what is verifiable is that 640Wh is on the machine when you start.
What the numbers favor
- 640Wh installed across two bays, the most of any walk-behind on this page
- Rated to 1 acre, twice the Greenworks 80V flagship's half-acre rating
- Seven published speed settings on the self-propel drive
- All Kobalt 80V packs are cross-compatible across the 80V outdoor line
What they don't
- Sold through Lowe's only, so availability and price track one retailer
- The listing does not publish weight, cut-height range or a noise figure
- Kobalt's 80V outdoor range is narrower than EGO's or Ryobi's
you want a platform rather than a mower. Kobalt is a single-retailer house brand -- fine for the tool, thinner as a decade-long ecosystem bet.
How it scores
Scores are our editorial weighting of the published specs above, not a test result. They are deliberately kept out of this page's structured data.
Common questions
Do I need a self-propelled lawn mower?
Does self-propel drain the battery faster?
How heavy is too heavy for a push mower?
What is variable speed self-propel worth?
Is rear-wheel or front-wheel drive better?
Sources
- Greenworks 40V 20" 4-in-1 Push Lawn Mower (LM2054), greenworkstools.com
- EGO POWER+ 21" Select Cut System (LM2135SP), egopowerplus.com
- Kobalt 80-Volt 21-in Self-propelled Battery Mower, lowes.com
- Greenworks 80V 21" 4-in-1 Self-Propelled Mower (LM2108S), greenworkstools.com
- Toro 60V Max 21 in. Recycler Self-Propel Lawn Mower (21356T), toro.com
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