Mowers
What Size Mower for 1.5 Acres With Hills? Tractor, Deck and Slope
Quick answer
An acre and a half with hills needs a 42 to 48 inch lawn tractor rated for your slope. A 46 inch tractor such as the Husqvarna TS 120 46 in. takes about 1 hr 18 min on hilly ground, compared with 1 hr 3 min on flat. Drive straight up and down slopes, never across.
On 1.5 acres, slopes tend to be long rather than short: a yard that falls away from the house, or a hillside pasture turned into lawn. Long grades are where a lawn tractor's front-wheel steering and pedal-controlled hydrostatic drive earn their place. A zero-turn would be about 26 minutes faster on this lot, but it steers and brakes with its rear wheels, and a long wet slope is exactly where those can lose grip.
Hills also add about 23 percent to the mowing time, which changes the battery math and the case for a bigger deck.
On this page
- How long does it take to mow 1.5 acres with hills?
- How do I convert my mower manual slope limit to my yard?
- What is the best riding mower for 1.5 acres with hills?
- How much longer do hills make the mow?
- Why not use a zero-turn on a sloped 1.5 acres?
- What should I use on slopes too steep for a tractor?
- Which mowers suit 1.5 hilly acres?
How long does it take to mow 1.5 acres with hills?
| Mower | Time per mow | Fit for this lawn |
|---|---|---|
| 21 in walk-behind | 4 hr 16 min | Slow for this size |
| 30 in rider | 1 hr 59 min | Slow for this size |
| 42 in lawn tractor | 1 hr 25 min | Recommended |
| 46 in lawn tractor | 1 hr 18 min | Recommended |
| 48 in zero-turn | 52 min | Zero-turn: not advised on slopes |
| 54 in zero-turn | 46 min | Zero-turn: not advised on slopes |
| 60 in zero-turn | 41 min | Zero-turn: not advised on slopes |
Recommended deck: 42 to 48 inches, lawn tractor rated for your slope (front-wheel steering holds a line on grades better than a zero-turn). Times assume typical cutting speeds (3 mph walk-behind, 4.5 mph tractor, 6.5 mph zero-turn), a 15 percent overlap and 65 percent efficiency for this terrain.
How do I convert my mower manual slope limit to my yard?
Manuals usually state slope limits in degrees, while measurements and robot ratings are in percent. On a long slope, the rise over 100 feet makes the numbers easier to picture.
| Degrees | Percent | Rise per 10 ft | Rise over 100 ft | What it means on 1.5 acres |
|---|---|---|---|---|
| 5.7 | 10 percent | 12 in | 10 ft | Typical gentle yard fall; tractor up and down within the manual |
| 8.5 | 15 percent | 18 in | 15 ft | Check the manual; mow only dry, with no bagger weight |
| 11.3 | 20 percent | 24 in | 20 ft | Walk-behind across with firm footing; a rider is often past its limit |
| 16.7 | 30 percent | 36 in | 30 ft | Trimmer or a slope-rated robot like the Mammotion LUBA 3 AWD 5000 Robot Mower |
Percent = rise / run x 100. Degrees = arctangent of percent / 100. General guidance only; the operator manual limit governs.
What is the best riding mower for 1.5 acres with hills?
A 42 to 48 inch lawn tractor with a hydrostatic transmission. The Husqvarna TS 120 46 in. Lawn Tractor is the fit: a 22 HP engine, a 46 inch deck and pedal speed control. The Husqvarna TS 120 42 in. Lawn Tractor costs less and adds about 7 minutes per mow. The electric EGO POWER+ T6 TR4204 42 in. Electric Lawn Tractor is rated for 1.5 acres per charge, so on hilly ground, which uses more energy than flat, plan on a possible mid-mow recharge. It fits better if part of the lot is mowed by other means.
How much longer do hills make the mow?
Hilly ground is modeled at 65 percent efficiency versus 80 percent on flat ground, because of turns at each strip end and slower climbs.
| Mower | Flat 1.5 acres | Hilly 1.5 acres | Extra per season (26 mows) |
|---|---|---|---|
| 42 in lawn tractor | 1 hr 9 min | 1 hr 25 min | about 7 hr |
| 46 in lawn tractor | 1 hr 3 min | 1 hr 18 min | about 6.5 hr |
| 48 in zero-turn (not recommended on real slopes) | 42 min | 52 min | about 4.3 hr |
Why not use a zero-turn on a sloped 1.5 acres?
Because a long slope gives a sliding zero-turn plenty of distance to pick up speed. With steering and braking only at the rear wheels, damp grass can take away both at once. A tractor's front wheels still steer when the rear slips, and its hydrostatic pedal slows it smoothly. If most of your land is flat with one gentle rise inside the zero-turn manual limit, a zero-turn can work, but trim or walk-mow anything beyond it. See best mowers for hills.
What should I use on slopes too steep for a tractor?
Mow moderate banks across with a rear-wheel-drive walk-behind such as the SENIX 22 in. Variable Speed RWD Self-Propelled Gas Mower, 201cc. Trim steep banks with a gas trimmer like the Husqvarna 130L 28cc Straight Shaft Gas String Trimmer, working from stable ground. For the whole lot, a robot is an option: the Husqvarna Automower 440iQ Robot Mower is rated for 2 acres on 45 percent slopes, and the Mammotion LUBA 3 AWD 5000 Robot Mower for 80 percent on 1.25 acres. See robot mower size for steep yards.
Which mowers suit 1.5 hilly acres?
Husqvarna TS 120 46 in. Lawn Tractor
$3,185.00A 22 HP Briggs PXi engine with a Tuff Torq hydrostatic transmission and a 46-inch 2-blade deck, rated at 5 mph forward.
Best for: Mid-size lawns with some obstacles
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Husqvarna TS 120 42 in. Lawn Tractor
$2,799.00A 19 HP, 540cc Briggs & Stratton engine, 42-inch twin-blade stamped deck and pedal-operated transmission, the lowest-cost way onto a seat in this list.
Best for: Smaller, fairly flat properties
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EGO POWER+ T6 TR4204 42 in. Electric Lawn Tractor
$4,399.00Six included 6.0Ah batteries power a 42-inch tractor rated for up to 1.5 acres per charge, with cruise control, a rear tow hitch and belt-free dual blade motors.
Best for: Up to 1.5 acres for buyers who want a steering wheel and a hitch
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SENIX 22 in. Variable Speed RWD Self-Propelled Gas Mower, 201cc
$509.99Variable-speed rear-wheel drive and a single-handle, four-wheel synchronized height adjuster sit on a 201cc, 22-inch 3-in-1 platform with a 2-year warranty.
Best for: Larger yards where you want to set your own pace
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Husqvarna Automower 440iQ Robot Mower
$2,649.99The largest iQ model is rated for up to 2 acres on 45% slopes, using EPOS positioning instead of boundary wire, with GPS theft tracking and a 4-year warranty.
Best for: Large lawns up to 2 acres
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Mammotion LUBA 3 AWD 5000 Robot Mower
$3,299.00360-degree LiDAR, network RTK and dual-camera vision combine for navigation, with four-motor drive for 80% slopes and a rated 1.25 acres.
Best for: Steep or complex lawns up to 1.25 acres
Check price on AmazonHow we chose
We did not test these products in person. Picks are researched from manufacturer specifications and owner manuals, engine and safety certifications where they apply, warranty terms, public recall records, and the recurring themes in verified owner reviews. We favor established brands with large review counts and parts support, match each pick to a real yard size or task, and place it in the tier where its price and capability actually belong.
Frequently asked questions
How long does it take to mow 1.5 acres of hills?
About 1 hr 18 min with a 46 inch lawn tractor and 1 hr 25 min with a 42 inch tractor, using 65 percent efficiency for hilly ground. On flat ground the same lot takes about 1 hr 3 min with the 46 inch tractor. Over a 26 mow season, the hills add roughly 6 to 7 hours of seat time.
Is a hydrostatic transmission better for hills?
It makes a tractor easier to control on grades. You set speed with a foot pedal, so you can slow down gradually without shifting gears. Husqvarna lists a Tuff Torq hydrostatic transmission on the TS 120 46 in. A hydrostatic drive does not raise the safe slope limit, which remains whatever the operator manual states for dry grass.
Can an electric lawn tractor handle 1.5 hilly acres?
Possibly, but without margin. The EGO T6 TR4204 is rated for 1.5 acres per charge, a figure that assumes normal conditions. Climbing uses more energy, so a fully hilly 1.5 acres may need a recharge before you finish. It fits better on lots where part of the area is mowed another way, or where the slopes are gentle.
What is a safe slope for a riding lawn mower?
The one in your operator manual, for dry grass, driving straight up and down. Manuals often state it in degrees, so convert your measurement: 10 percent is about 5.7 degrees, 15 percent about 8.5 and 20 percent about 11.3. Wet grass, a full bagger, a towed load and soft soil all lower the real limit.
Researched, not professional advice. This page is compiled from published specifications, manuals, labels and owner-review consensus, not hands-on testing. Follow the manufacturer's instructions and product label, and consult a qualified professional where safety, chemicals, fuel or structures are involved. As an Amazon Associate we earn from qualifying purchases.