What Size Generator Do I Need to Run a Log Splitter?

If you use a fireplace or a wood stove, then you might be cutting and storing firewood. You might be using an ax or a saw to cut the wood into smaller, workable pieces or using a machine called a log splitter.

A log splitter is a machine or a piece of equipment that splits firewood from hardwood or softwood logs. A chainsaw cuts fresh wood into smaller sections and then a log splitter splits the log so these are ready to use or store.

What size portable generator do you need for a log splitter?

What size generator do I need to run a log splitter? The perfect answer depends on the type of gas-powered or electric log splitter you are using. For a log splitter with a 1200-watt well pump, a 5000-watt generator will suffice.

A 4-ton log splitter runs on a 3000-watt generator. These generators are enough to run small power tools, an electric wood splitter, fast-acting tools, etc. To be on the safe side, refer to your generator’s user manual. 

Using an inverter generator

An inverter generator are small generators, these are the best for power tools like a log splitter. This type allows you to throttle your tool up and down instead of running with the motor spinning in full blast. This will help you save on fuel with more woodcut, reduce emissions, and runs quietly than most consumer model generators. This type of generator also guarantees a long service life.

Somewhat larger generator systems like a Honda generator or a much bigger generator, works with larger and more powerful log splitting machines with air-cooled engines.

Using rechargeable battery packs

Some updated log splitters run on batteries. These are mostly portable, small scale splitters that work fine with smaller wood pieces. Although battery-powered splitters work great for home use, these won’t work on very few tree species that have very hard, dense structures like knotty oak and split birch.

With a battery-operated splitter, you don’t need to change oil and you won’t need to maintain the machine’s gas oil mixer system. There is less surge watts/surge amps used as this type of machine produces less power. These splitters run fine when fully charged but after a while, may need a fresh charge to work properly.

How many tons do I need for a log splitter?

Most log splitters come with a hydraulic or an electric rod and piston system which can split large pieces of wood into smaller pieces. These systems are rated according to the tons of force that the machine can create. The higher the force rating, the thicker log the machine can split. Common home log splitters have a 10-ton rating while professional models come with a 30+ tons rating.

Hydraulic log splitters tonnage

When sizing a log splitter tonnage or ton splitter such as a four-ton splitter, log size plays a huge factor. You must first determine the type of wood you will use and how small or how large the logs will be.

Consider the largest log diameter you want to split through its width. You will eventually get the tonnage rating afterward. Take note that the length of the log does not affect tonnage but there are splitters with only standard length logs.

General log splitters tonnage

For the tonnage rating according to the log diameter and hardness of the wood, consider this chart:

Wood Hardness of 300 to 600 pounds

Log Diameter of 6 inches – 4+ tons, 12 inches – 12+ tons, 18 inches – 20+ tons, and 24 inches – 27+ tons

Wood Hardness of 601 to 900 pounds

Log Diameter of 6 inches – 6+ tons, 12 inches – 15+ tons, 18 inches – 20+ tons, and 24 inches- 27+ tons

Wood Hardness of 901 to 1500 pounds

Log Diameter of 6 inches – 7+ tons, 12 inches – 20+ tons, 18 inches- 26+ tons, and 24 inches – 30+ tons

Wood Hardness of 1501 to 2200 pounds

Log Diameter of 6 inches – 10+ tons, 12 inches – 22+ tons, 18 inches – 26+ tons, and 24 inches – 30+ tons

Hardness pertains to the density of the wood. Dense woods take more force to split. Thus, different wood types vary in the amount of force needed to split logs. The Janka Hardness Test measures the wear and denting resistance of wood.

The Janka test uses force to find out the pressure needed to embed a small (11.28mm) steel ball about halfway through the surface of the wood.

Common woods like oak has a hardness of 1620 pounds force which means the best log splitter needs 10+ tons splitting force for a 6-inch diameter log.

Meanwhile, cedar has a hardness rating of 900 pounds force which means you need 12+ tons to split a cedar long with a 12-inch diameter.

How much gas does a log splitter use?

To get the fuel capacity of a gas-powered gas splitter, consider the following factors:

The type of gas-powered splitter you have

New gas-powered splitters are fuel-efficient and won’t require fill-ups compared to old splitters. Meanwhile, home use splitters produce less power than commercial or industrial log splitters and thus, will require less gas.

The kind of wood you want to cut

High-capacity log splitters can split very dense or hardwood and require more fuel than regular splitters.

Emergency power

Be sure to keep an amount of gas left for emergencies. You’ll never know when unexpected emergencies happen like a power outage and you don’t have enough firewood on hand. With this in mind, your splitter should carry more than enough gas to provide emergency cutting power.

The size of the wood the splitter accepts.

Large-diameter logs require powerful splitters that can cut through wide logs with ease. These are heavy-duty machines that need more fuel than regular log splitters.

Consider the following when computing the amount of fuel for the electric motor of a log splitter:

A 29-ton log splitter with a twin-cylinder engine consumes 2 gallons of fuel per cord or about 1.5 cords per tank. How much wood is in a cord? A cord is approximately 700 pieces of wood. A full cord of wood has 600 to 800 pieces of split logs.

Some people compute the amount of gas needed by a log splitter according to its hours of use. A full five gal fuel tank can cut wood for up to 4 hours nonstop.

For a splitter with a quart gas tank, you’ll get an hour of use with anywhere from 1/3 to ½ of a cord. But it still depends on the type of wood you want to cut.


The generator size you need to power a log splitter depends on the type of splitter you’re using and the hardness and the diameter of the wood you want to cut. New gas-powered log cutters are more efficient and more powerful which are best for working on different types of wood and for high volume log cutting.