What Size Generator Do You Need to Run Electric Yard Tools?
By the Generator Size Calculator Team · Updated · 5 min read
Quick answer: Corded yard tools are light loads. Honda lists an 18-inch hedge trimmer at 400 running and 550 starting watts, an electric grass trimmer at 500 and 650, a 12-inch electric chain saw at 900 and 1,100, a 14-inch chain saw at 1,100 and 1,400 and a 1/3 HP cultivator at 700 and 1,400. A 2,000-watt inverter generator runs any one of them, and about 2,500 watts two together.
Yard tool watts
| Tool | Running watts | Starting watts |
|---|---|---|
| Electric hedge trimmer, 18 inch | 400 | 550 |
| Electric grass trimmer | 500 | 650 |
| Electric chain saw, 12 inch, 1 1/2 HP | 900 | 1,100 |
| Electric chain saw, 14 inch, 2 HP | 1,100 | 1,400 |
| Electric cultivator, 1/3 HP | 700 | 1,400 |
These are Honda's typical figures. A tool cutting thick growth draws more than one running free, so check the label. Because the surges are small, these tools are some of the easiest loads for a generator.
Which generator size to choose
| Tool | Generator for one tool |
|---|---|
| Hedge trimmer (400 / 550 W) | 2,000 W inverter |
| Grass trimmer (500 / 650 W) | 2,000 W inverter |
| 12 inch chain saw (900 / 1,100 W) | 2,000 W inverter |
| 14 inch chain saw (1,100 / 1,400 W) | 2,000 W inverter |
| Cultivator (700 / 1,400 W) | 2,000 W inverter |
A typical 2,000-watt inverter delivers about 1,600 running watts, so its 80% mark is about 1,280 watts, which covers the biggest tool here (1,100 watts). Larger tools are in what size generator a workshop needs.
Running two tools together
| Pair | Running total | Generator at 80% |
|---|---|---|
| Hedge trimmer and grass trimmer | 900 W | About 1,125 W, so 2,000 W |
| 14 inch chain saw and hedge trimmer | 1,500 W | About 1,875 W, so 2,500 W |
| 14 inch chain saw and cultivator | 1,800 W | About 2,250 W, so 2,500 W |
Add only the largest surge on top. For the 14 inch chain saw and cultivator, that is about 700 watts (1,400 minus 700), so the peak is about 2,500 watts. A 2,500-watt generator with a starting capacity near 3,100 watts covers it. Most people simply run one at a time.
Add the tools you use together and see the size.
Tips for yard work
- Use outdoor-rated, heavy cords. A long, thin cord drops voltage. See the extension cord calculator.
- Keep the generator on level, dry ground and out of the rain. See can you run a generator in the rain.
- Use a GFCI outlet for cords that run across wet grass.
- Mind the fuel. A small unit at light load runs a long time. See how long a generator runs on a tank of gas.
Run the generator outdoors, at least 20 feet from doors, windows and vents. Never in a garage or shed, even with the door open. See how far a generator should be from your house.
Frequently asked questions
How many watts does an electric hedge trimmer use?
Honda lists an 18-inch electric hedge trimmer at 400 running and 550 starting watts.
What size generator do I need for an electric chain saw?
Honda lists a 14-inch electric chain saw at 1,100 running and 1,400 starting watts, so a 2,000-watt inverter runs it on its own.
Can I run a hedge trimmer and a grass trimmer on one generator?
Yes. Together they use about 900 running watts, which a 2,000-watt inverter handles.
Do corded yard tools have a big starting surge?
Small ones do not. The cultivator has the biggest, about 700 watts above its running load.
Is a cordless tool easier?
Often, since a battery tool needs no generator at all. A generator helps if you already own corded tools or have no power at the site.
Related calculators
Sources: Running and starting watts from the Honda generator wattage guide (electric hedge trimmer, grass trimmer, electric chain saws, cultivator). Generator sizes apply the 80% running rule and an assumed starting capacity about 25% above the running rating.