What Size Generator Do You Need to Run Work Lights and Floodlights?
By the Generator Size Calculator Team · Updated · 5 min read
Quick answer: Honda lists a mercury halogen floodlight at 1,000 watts, with no start-up surge. One needs a 2,000-watt inverter, two about 2,500 watts, three about 4,000 watts and four about 5,000 watts. A 50-watt LED work light (an example value, so check yours) uses a twentieth of that, so four LED lights fit a 1,000-watt inverter. For lights, LED is the biggest saving on generator size.
Light watts
| Light | Running watts | Starting watts |
|---|---|---|
| Flood light, mercury halogen | 1,000 | 1,000 |
| Other lights | As printed on the bulb | As printed on the bulb |
Honda lists mercury halogen floodlights at 1,000 watts each and lights in general at whatever wattage is printed on the bulb. Lights have no big start-up surge, so the running watts set the size. LED work lights use far less, and the 50-watt figure below is an example value, so use the wattage on your own fixtures.
Which generator size to choose
| Setup | Load | Generator at 80% |
|---|---|---|
| One halogen floodlight | 1,000 W | About 1,250 W, so 2,000 W inverter |
| Two halogen floodlights | 2,000 W | About 2,500 W |
| Three halogen floodlights | 3,000 W | About 3,750 W, so 4,000 W |
| Four halogen floodlights | 4,000 W | About 5,000 W |
| Four 50-watt LED work lights | 200 W | 1,000 W inverter |
If you add a saw or a compressor, include its start-up surge. See what size generator runs a circular saw and what size generator a workshop needs.
Why LED is the smart upgrade
On a generator, every watt of lighting is a watt you cannot use for tools or a fridge. Replacing four 1,000-watt halogen floods (4,000 watts) with four 50-watt LED lights (200 watts) frees 3,800 watts, which is the difference between a 5,000-watt generator and a small inverter. LED lights also run cooler and use less fuel. Estimate the fuel with the fuel consumption calculator.
Add every light and tool you run together.
Tips for job-site lighting
- Use outdoor-rated cords and fixtures, and keep connections off wet ground. See the extension cord calculator.
- Mount lights up high so they cover more area with fewer fixtures.
- Check the lamp type. Halogen lamps run hot, so keep them clear of anything flammable.
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 a floodlight use?
Honda lists a mercury halogen floodlight at 1,000 watts. LED floodlights use much less, so check the label on yours.
What size generator runs two floodlights?
Two 1,000-watt halogen floods total 2,000 watts, so about a 2,500-watt generator at the 80% rule.
Can a 2000-watt generator run a floodlight?
One 1,000-watt halogen floodlight, yes. Two are at the limit, so a 2,500-watt generator is safer.
Do lights have a starting surge?
Honda lists the same starting and running watts for a halogen floodlight, so no extra surge. Allow for any tools you add.
Is LED worth it on a generator?
Yes. LED lights use a fraction of the watts, so you can use a much smaller generator.
Related calculators
Sources: Running and starting watts from the Honda generator wattage guide (mercury halogen floodlight; lights as indicated on the bulb). Generator sizes apply the 80% running rule. The 50-watt LED work light is an assumed example value.