Generator Sizing for Power Tools: Watts for the Job Site

Running Watts and Starting Watts on a Generator Listing

Generator wattage for power tools is a two-number question. Electricity is measured in units of power called Watts, as the U.S. Energy Information Administration explains on its measuring electricity page. A generator listing states starting watts and running watts, and a tool carries its own figures on its label.

Running watts, which this site also calls continuous output, is the steady load a generator supplies while a tool keeps working. Starting watts, sometimes listed as surge or peak, is the extra power a motorized tool draws for a moment when it begins to turn. A motor that needs a high starting figure can still run on a lower running figure once it is moving.

A title that shows two figures usually puts the higher one first. Reading a generator title means telling which figure is the starting figure and which is the running figure, then comparing them to the tool's label. The article on running versus starting watts explains the terms in more depth.

Where to Read the Numbers for Your Tools

The tool carries the first set of numbers. A nameplate label on the tool lists volts and amps or watts. The maker's website for that model usually lists both running watts and starting watts, and that page is the source for the starting figure.

The generator listing carries the second set of numbers. The stated starting watts and stated running watts are the figures to compare with the tool's label. When a listing states one figure only, the seller has not given the other, and the maker's page is where to confirm it.

Comparing Tool Watts and Generator Watts

Comparing the two sets of numbers is a reading exercise. Place the tool's highest starting figure next to the generator's stated starting watts, and its running figure next to the stated running watts. If the generator's figures are at or above the tool's figures, the listing is worth a closer look alongside the maker's page for the tool.

No figure in this comparison is a promise that a specific tool will run. A generator listing states what the machine can supply; the tool's label states what the tool demands. The decision belongs to the buyer, with the maker's manual for both items.

For tools that draw power only to charge batteries, a battery power station works differently. The watts versus watt-hours article on this site explains how those two figures differ.

Why This Site Does Not Print a Tool Wattage Table

This site does not publish a wattage table for tools. Watts vary by model, motor size, age, and condition. Two tools of the same type from different makers can carry different labels, and a motor can draw more as it wears.

Every number in the guides and articles comes from the listings being compared and from the pages listed under sources. A printed table of typical tool watts would be a general claim, not a stated detail from a listing, so the site leaves the figure to the tool's label and the maker's page.

Job Site Features to Compare in a Listing

Job site shopping means reading more than watts. Outlet count and type appear in a generator title: 120-volt outlets for common tools, a 240-volt outlet for larger equipment, and sometimes an RV-style outlet. The listing states what is included. Wheels, a handle, and a wheel kit are listed items for moving a unit around a site.

Fuel is a shopping choice, not a performance claim. A gasoline, dual-fuel, or tri-fuel listing names the fuels the generator accepts. An inverter generator and an open-frame generator are different listing words; the inverter versus standard generator article on this site explains how those words read.

Follow the maker's operating instructions for setup and placement. The U.S. Consumer Product Safety Commission publishes a page on generators and engine-driven tools that owners should read.

• Stated starting watts and running watts in the title
• Outlet count and types: 120V, 240V, or an RV-style outlet
• Wheels, handle, or wheel kit as listed items
• Fuel type named in the title

A Power Station as a Job Site Alternative

A battery power station is another way to power hand tools on a site. It charges cordless-tool batteries and runs small benchtop equipment through its AC outlets. A power station listing states watt-hours as capacity and a continuous AC output figure.

Those are different numbers from a generator's starting and running watts. The buyer compares the stated continuous output with the tool's label. For a site without fuel delivery, a battery unit removes the fuel question from the purchase, but the output figure still has to be read carefully. The portable power station guide for hurricanes lists models compared on stated details.

What to pick for your situation

Questions

What is the difference between starting watts and running watts on a generator?

Starting watts is the extra power a motor draws at the moment it starts. Running watts is the steady power it needs while it runs. Generator listings state both figures.

Where do I find the watts for a specific power tool?

The tool's nameplate label lists volts and amps or watts, and the maker's page for that model lists running watts and starting watts.

Does this site list typical watts for common tools?

No. Watts vary by model, and the tool's label and the maker's page are the source. This site compares stated details in listings, not general tool figures.

Can a battery power station run power tools?

A power station listing states watt-hours as capacity and a continuous AC output figure. The buyer compares those figures with the tool's label.

What should I look for in a job site generator listing?

Stated starting watts and running watts, outlet count and types, wheels or a handle, and the fuel type named in the title.

Is an inverter generator the right choice for tools?

Inverter and open-frame are listing words for different generator designs. The inverter article explains how the words read, and the choice is a shopping decision.