What's inside
- Quick Comparison
- Best Overall: Ryobi 40V HP Brushless RY402110
- Best for Multi-Tool Users: Ryobi 40V Attachment-Capable Trimmer
- Best for Pro-Grade Build and Runtime: Makita XGT GRU07
- Best Value: Ryobi RY40250 Class
- Best Budget for Small Yards: Greenworks 40V String Trimmer
- How to Choose a 40V String Trimmer
- Ownership Realities
- Worked Example: Time to Trim a Yard
- Common Mistakes
- Tips for Cleaner Results
- Frequently Asked Questions
- Quick Comparison
- Best Overall: Ryobi 40V HP Brushless RY402110
- Best for Multi-Tool Users: Ryobi 40V Attachment-Capable Trimmer
- Best for Pro-Grade Build and Runtime: Makita XGT GRU07
- Best Value: Ryobi RY40250 Class
- Best Budget for Small Yards: Greenworks 40V String Trimmer
- How to Choose a 40V String Trimmer
- Ownership Realities
- Worked Example: Time to Trim a Yard
- Common Mistakes
- Tips for Cleaner Results
- Frequently Asked Questions
As an Amazon Associate I earn from qualifying purchases. This post may contain affiliate links at no extra cost to you.
The best 40 volt string trimmer for most yards is a Ryobi 40V HP brushless model such as the RY402110, with Makita’s XGT 40V max GRU07 as the pick for professional-grade runtime and build, and Greenworks 40V as the budget route. “40V” is not one platform: each brand’s batteries are different, so the trimmer you choose also decides which blowers, chainsaws and mowers you can add later.
Before you shop, note that EGO is a 56V system, not 40V, and Milwaukee and DeWalt use 18V/20V and 60V FLEXVOLT lines for outdoor tools. If you search “40 volt”, the real choices are Ryobi, Makita XGT, Greenworks, Kobalt and a few other store brands.
As an Amazon Associate we earn from qualifying purchases at no extra cost to you.
What we cover
- Quick Comparison
- Best Overall: Ryobi 40V HP Brushless RY402110
- Best for Multi-Tool Users: Ryobi 40V Attachment-Capable Trimmer
- Best for Pro-Grade Build and Runtime: Makita XGT GRU07
- Best Value: Ryobi RY40250 Class
- Best Budget for Small Yards: Greenworks 40V String Trimmer
- How to Choose a 40V String Trimmer
- Ownership Realities
- Worked Example: Time to Trim a Yard
- Common Mistakes
- Tips for Cleaner Results
- Frequently Asked Questions
Our Top Picks
Quick Comparison
| Pick | Best for | Key specs (per maker listings) | Price range |
|---|---|---|---|
| Ryobi 40V HP Brushless String Trimmer (RY402110) | Best overall for homeowners | Brushless, 40V HP battery, line head, shares batteries with Ryobi 40V tools | Mid |
| Ryobi 40V Expand-It trimmer with attachment capability (RY40HPST02 class) | Best for multi-tool users | Brushless, accepts Ryobi attachments such as edger, cultivator | Mid to upper mid |
| Makita 40V max XGT GRU07 | Best for pro-grade runtime and build | Brushless, 40V max XGT battery, cutting swath about 18 inches, speeds up to about 5,700 RPM | Upper mid to premium |
| Ryobi 40V RY40250 class | Best value | Brushless, battery and charger often included, wide attachment support | Budget to mid |
| Greenworks 40V string trimmer | Best budget for small yards | Typically a 12-inch swath, lighter body, 40V battery | Budget |
Best Overall: Ryobi 40V HP Brushless RY402110
The RY402110 is a brushless string trimmer in Ryobi’s higher-power 40V HP range. A brushless motor gives it more cutting power through thick grass and weeds than older brushed 40V models, and the 40V HP battery is also used by Ryobi’s blowers, mowers and chainsaws. It suits average suburban yards of up to about half an acre.
Its main trade-offs are runtime and noise at full power, as with most trimmers in this class. If your yard is large, plan on a second battery. It is also a straight-shaft or standard layout that is easier to balance than a curved-shaft model.
Best for Multi-Tool Users: Ryobi 40V Attachment-Capable Trimmer
Ryobi’s attachment-capable trimmer lets you swap the head for an edger, cultivator, pole saw and more using the same power head. This saves money and storage space if you intend to use several of these tools. The trade-off is that the combined shaft and coupling adds some weight, and attachments are an additional cost.
Best for Pro-Grade Build and Runtime: Makita XGT GRU07
Makita’s GRU07 uses the XGT 40V max platform. Independent shootouts, including one from Pro Tool Reviews, have ranked it among the strongest battery trimmers for professional work, with a wide cutting swath of about 18 inches and a top speed around 5,700 RPM. It is an appropriate choice if you maintain large lawns or want a tool that handles daily use.
The trade-off is price and battery cost. XGT batteries and chargers are more expensive than Ryobi’s, and unless you plan to use other XGT tools such as the drills, saws and outdoor tools in Makita’s 40V range, the platform cost is hard to justify for a small yard.
Best Value: Ryobi RY40250 Class
Ryobi’s RY40250 trimmer is frequently sold with a battery and charger at a low price. It offers a brushless motor, an assisted line feed and support for the broad Ryobi 40V attachment range. It is the sensible pick if you want a complete, ready-to-use kit.
Best Budget for Small Yards: Greenworks 40V String Trimmer
Greenworks’ 40V trimmers are light, quiet and sold at friendly prices, often in combo kits with a leaf blower that shares the battery. A typical swath is 12 inches. They suit small yards and light trimming along edges, but they struggle with thick weeds and the narrower swath makes large lawns slower.
How to Choose a 40V String Trimmer
Cutting swath
The swath is the width of the cut circle. A 12-inch swath is fine for tidy small lawns; 15 inches suits average yards; 16 to 18 inches speeds up work on big lawns and heavy growth.
Battery size and runtime math
A 40V pack stores about 36 volts nominal times its amp-hours: a 4.0 Ah pack is roughly 144 watt-hours and a 6.0 Ah pack roughly 216. A trimmer pulling about 250 watts under typical load runs for about 35 minutes on a 4.0 Ah pack and about 50 minutes on a 6.0 Ah pack, less in heavy growth. Many reviewers have measured wide variation between models, so check each manufacturer’s runtime claim and treat it as best case.
Head type
Bump-feed heads advance line when you tap the head on the ground. Auto-feed heads advance it automatically. A fixed-line or blade head handles heavier brush. A line head with 0.080 to 0.095 inch line suits most home use.
Straight shaft or curved shaft
Straight shafts are longer, reach under shrubs and suit tall users, and they accept attachments. Curved shafts are lighter and shorter, which suits small yards and shorter users.
Platform decision
| Your situation | Better platform |
|---|---|
| Want many tools on one battery at low cost | Ryobi 40V |
| Professional use, long days | Makita XGT 40V max |
| Small yard, minimal tools | Greenworks 40V |
| Want maximum power per tool | Consider 56V EGO or 60V systems instead |
Ownership Realities
- String is the main consumable. Keep spare spools or cut lengths.
- Clean grass from the head and shaft guard after use to prevent motor strain.
- Store batteries indoors at partial charge, away from freezing and heat.
- Wear safety glasses and long pants; trimmers throw debris.
Worked Example: Time to Trim a Yard
Suppose you trim 600 linear feet of fence and bed edging. A trimmer moving at about one foot per second covers that in roughly 10 minutes of cutting, but real work with turns, obstacles and thick growth usually triples it. Thirty minutes of work fits on a 4.0 Ah battery at moderate load, so one pack handles this yard with a little left over. A property with 2,000 linear feet needs a second pack or a larger 6.0 Ah battery.
Common Mistakes
- Holding the head flat against the ground, which scalps the lawn and wears line fast.
- Using the turbo setting for light work, which drains the battery quickly.
- Buying a trimmer before choosing a platform, then finding the matching blower or mower is not offered.
- Letting the line wear short. Replace it when the cutting circle visibly shrinks.
Tips for Cleaner Results
Cut in the direction that throws debris away from you, keep the line tilted slightly, and let the tip of the line do the cutting. Trim before mowing so clippings are picked up. For hard edges along concrete, use an edger attachment rather than the standard head.
Frequently Asked Questions
Is 40V enough for a string trimmer?
Yes. A brushless 40V trimmer handles typical residential grass and weeds. Very thick brush and large properties favor 56V or professional systems.
Is EGO a 40V brand?
No. EGO Power+ batteries are 56V. They are not compatible with 40V tools from Ryobi, Greenworks or Makita XGT.
How long does a 40V trimmer run?
Typically 30 to 60 minutes depending on battery size and cutting load. Heavy weeds and full throttle shorten this considerably.
Are Ryobi 40V batteries interchangeable with Makita?
No. Each brand uses its own battery shape and connector, so you need the same brand for every tool.
Which line is best for edging?
A trimmer with an edger attachment, such as Ryobi’s attachment-capable power head, handles edging well. Rotate the head to the vertical position if your model has one.
What size line should I use?
Use the diameter specified in the manual, typically 0.080 to 0.095 inch for homeowner models. Thicker line cuts tougher growth but drains battery faster.