What Size Generator Do You Need to Run an Electric Demolition Hammer?
By the Generator Size Calculator Team · Updated · 5 min read
Quick answer: Honda lists a Kango hammer at 900 running and 1,200 starting watts, a small surge of only 300. A 2,000-watt inverter runs it, and a 2,500-watt generator adds work lights and a radio with room to spare. Bigger breakers use far more, so check the label on your own tool.
Hammer watts
| Tool | Running watts | Starting watts | Extra start-up surge |
|---|---|---|---|
| Kango hammer | 900 | 1,200 | 300 |
Kango is a brand name for an electric breaker or demolition hammer, and Honda uses it for this figure. Large breaker hammers use much more, so use the data plate on your tool. Other tools are covered in what size generator a workshop needs.
Which generator size to choose
| Setup | Generator |
|---|---|
| Hammer alone (900 / 1,200 W) | 2,000 W inverter |
| Hammer, lights and a radio | 2,000 W, or 2,500 W for margin |
Sizes keep the running load under 80% of the rating. A 900-watt hammer needs a rating of at least 1,125 watts. A typical 2,000-watt inverter's 80% mark is about 1,280 watts, which covers the hammer but leaves little for lights, so 2,500 watts is more comfortable.
Example: hammer, lights and a radio
| Load | Running watts |
|---|---|
| Kango hammer | 900 |
| Work lights | 200 |
| Radio | 100 |
| Running total | 1,200 |
The hammer's extra start-up load is 300 watts, so the peak is about 1,500 watts. A 2,000-watt generator rated for 2,000 running watts has an 80% mark of 1,600 watts and about 2,500 starting watts, so it fits, though a typical inverter-type 2,000-watt unit delivers less running power. The lights and radio are example values.
List the hammer, lights and anything else.
Tips for a clean start
- Start the hammer first, with nothing else running, then add lights.
- Use a short, heavy cord. See the extension cord calculator.
- Wear hearing protection. A generator and a hammer are both loud. See inverter vs conventional generators for quieter options.
Run the generator outdoors, at least 20 feet from doors, windows and vents. Never in a garage, barn or shed, even with the door open. See how far a generator should be from your house.
Frequently asked questions
How many watts does a demolition hammer use?
Honda lists a Kango hammer at about 900 running and 1,200 starting watts. Larger breakers use much more.
Can a 2000-watt generator run a demolition hammer?
A 900-watt Kango-type hammer, yes, if the generator can supply about 1,200 watts at start-up. Check the label on yours.
What size generator runs a hammer and lights?
About 2,000 to 2,500 watts for a 900-watt hammer, work lights and a radio.
What is a Kango hammer?
Kango is a brand name for an electric breaker or demolition hammer.
Does a hammer have a big starting surge?
Not as big as some tools. Honda lists a 300-watt difference between starting and running watts.
Related calculators
Sources: Running and starting watts from the Honda generator wattage guide (Kango hammer). Generator sizes apply the 80% running rule and an assumed starting capacity about 25% above the running rating. The lights and radio in the example are assumed values.