How Many Watts Does a Circular Saw Use

Circular saws are electrically powered tools, and they can come in corded or cordless versions. Cordless circular saws rely on Li-Ion batteries for power, while corded saws connect directly to a power source using an appropriate power cord. 

The power of a circular saw is determined by its voltage and current. So, let’s explore how many watts does a circular saw use.

The power consumption of a circular saw depends on the motor’s current and voltage requirements. When starting, corded circular saws may demand around 2300 watts; while running, they typically require about 1400 watts. 

On the other hand, cordless circular saws generally consume between 30 to 180 watts of power.

To make the most of a circular saw and ensure its long-lasting performance, it’s important to understand how to optimize its power usage. When choosing a circular saw, it’s essential to be aware of its watt consumption. 

For corded circular saws, having knowledge about voltage, current, and power factors is crucial.


Wattage is the most direct way to measure the power needs of a circular saw. According to Diesel Service and Supply, a company that manufactures generators in Colorado, a typical circular saw requires 2,400 watts when it starts up, which is called its “starting wattage,” and 1,200 watts during operation, known as its “running wattage.”

 If you’re using a smaller circular saw with a 7.5-inch diameter, it will typically run at around 900 watts, as estimated by the Mechanical Engineering Department at the University of Texas. Usually, in product specifications, circular saw manufacturers provide the running wattage, the latter figure. 

For instance, the Festool TS 55 EQ Plunge Cut Saw needs 1,200 watts, which is relatively high considering its small 6.25-inch blade diameter. The 7.5-inch Hitachi C7YAH 7 1/4-inch Dust Reducing Circular Saw is even more power-hungry, using 1,680 watts for running operations.

For cordless circular saws, understanding the battery capacity and voltage is essential. This guide provides a detailed explanation of circular saw power consumption. So, let’s dive into the details!


Amps, or amperes, are frequently featured on circular saw product information. They represent the electric current that the motor uses. Most circular saws operate on 15 amps, which aligns with the typical capacity of household electrical circuits. 

This amperage corresponds to a maximum safe wattage of 1,440 watts. There are models that use slightly less, for instance, Ryobi’s CSB141LZK model operates at 14 amps, while Skil’s 5755 uses just 13 amps.

Rotations Per Minute (RPM):

A circular saw doesn’t cut in a straight line but operates with a circular motion, utilizing its power for this rotational force. While amperage only tells you about the electricity it consumes, paying attention to a saw’s rotations per minute, or rpm, provides insight into how that power influences its performance. 

For instance, worm-drive saws and sidewinders have different orientations, and for the same power requirements, the worm-drive model often generates much more torque. According to “Popular Mechanics,” an average circular saw with a 7.25-inch blade typically runs at approximately 5,800 rpm.

 To put it in perspective, that’s roughly equivalent to 125 miles per hour. While most rpms fall in the high 5,000s range, Bosch’s CS20 model stands out with 9,600 rpm, earning praise from “Popular Mechanics” for its “quiet, powerful operation.” On the other hand, the Skil 5755, powered by 13 amps, operates at 4,600 rpm.

What’s the Power Consumption of a Saw with a 15 Amp Rating?

What's the Power Consumption of a Saw with a 15 Amp Rating?

When a 15 amp circular saw is used with a 120-volt power source, it will use up 1800 watts of power. If there’s a power factor of 0.95, then it comes down to 1710 watts.

When you increase the current, the motor’s torque also increases automatically. In the market, you can find both 10-amp and 15-amp tools. If you’re purchasing a 7-1/4 inch saw blade, it’s highly recommended to go for a 15 amp circular saw.

 This is because a higher amp rating provides more torque, which helps prevent the saw blade from binding with the workpiece due to friction. So, opting for higher torque can effectively resolve such issues.

What’s the Power Requirement for a Battery-Powered Circular Saw?

The power needs of cordless circular saws are determined by the capacity and voltage of their batteries. If you’re using a 20V battery with 1.5 amh, it will generate 30 watts of power. With higher-capacity batteries like 3 Amh or 6 Amh, you can easily have 60W or 120W.

Cordless circular saws come with limitations due to their battery capacity. Once the battery is depleted, you need to either stop working or replace it with a new one. Therefore, it’s advisable to have 2-3 spare saw batteries on hand when using a cordless circular saw in your workspace.

Ways to Lower the Power Consumption of a Circular Saw:

You can lower the power consumption of a circular saw by implementing these measures:

  • Ensure the saw blade is sharp.
  • Keep the saw blade clean.
  • Use a blade with an appropriate number of teeth.
  • Maintain the correct cutting speed.

When the circular saw encounters resistance and begins binding with the workpiece, it will require more power to prevent clogs in the material.

If the circular saw shows signs of sparking or the brushes are worn out due to a lack of regular maintenance, it will demand increased power to overcome internal friction.

Bottom Line: How Many Watts Does a Circular Saw Use

Circular saws are among the most effective (and potentially risky) tools for cutting, slicing, ripping, or shaping solid materials such as wood, ceramics, and metals. 

The power of a circular saw depends on various operational factors like its RPM, size, the type of blade it uses, and its overall condition.

The most reliable way to determine how much power a circular saw needs is by considering its wattage. Additionally, comparing different circular saws based on specific criteria can help you make a more efficient choice when buying one.

FAQs: How Many Watts Does a Circular Saw Use

What Generator Size is Required to Operate a Circular Saw?

If your circular saw has a starting wattage of 2400 watts, you’ll require a generator with a capacity exceeding 5000 watts to power the circular saw. Typically, the starting power is higher than the running power of the saw. Therefore, it’s crucial to select a generator with ample power output, capable of exceeding the circular saw’s starting wattage.

Do Circular Saws Require Continuous Power?

Certainly, corded circular saws rely on a continuous power supply to function. However, you have the option to purchase a cordless model that includes a rechargeable battery. This proves highly beneficial in cases of power interruptions or when a power source is unavailable.

Is 1400W Sufficient for a Circular Saw?

This 185mm circular saw is well-suited for professionals due to its impressive power and versatile capabilities. With a robust 1400W motor, it offers ample torque to effortlessly cut through various materials like wood, plastic, and PVC, whether at a 90° angle or a 45° angle. The addition of a parallel guide attachment ensures the creation of precise and straight cuts.

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