How Many Watts Does A Circular Saw Use? [Easy Calculation]

Last Updated On February 10, 2023

A cordless circular saw will consume way less power than a corded one. In general, you can expect the startup wattage requirement of a corded circular saw to be 2300 Watts, while running it should require about 1400 Watts. Depending on the strength of the cordless circular saw, its wattage can be anywhere between 30 to 180 Watts.

However you can find out exactly how many watts does a circular saw use by using a simple calculation as long as you know the unit’s power factor, voltage, and current requirements.

How Many Watts Does A Circular Saw Use?

Depending on the type of circular saw, its voltage requirements and the current supplied to it, the wattage of a circular saw varies widely. But you can easily calculate how many watts a circular saw is if you follow the method we explore below.

Wattage of a device is the power it consumes. You need to calculate the power of the unit. The formula differs slightly for corded and battery operated devices. Let’s take a look below.

Calculation For Corded Circular Saw

You need to know the power factor, voltage, & current requirements. The power factor is actually a ratio of real power to apparent power and can vary from device to device. For our purpose, in the case of a circular saw, the power factor is 0.95.

You need to find the phase current of the power outlet you are connecting your device to as well as the rated voltage of the unit.

Then, put the obtained values in the formula below,

Power = Power factor × voltage × phase current

For example, let’s say,

Voltage             = 120 V

Phase current= 10 A

Power Factor = 0.95

So, Power = 0.95 × 10 A × 120 V

                      = 1140 W

Therefore, the power consumption of a circular saw rated 120 V, running on 10 amps of current is 1140 Watts.

Calculation For Battery-Powered Circular Saw

You need to know the battery capacity and the rated voltage of the device. Because in this case,

Power = Voltage × Battery Capacity

For example, let’s say,

Voltage   = 20 V

Capacity = 4 A

So, Power = 20 V × 4 A

                      = 80 Watts

Therefore, the power or wattage  of the cordless circular saw is 80 watts. Hopefully, you can now calculate the power usage of your own device easily now.

How Many Watts Does A Dewalt Circular Saw Use?

Dewalt is a very popular and reputed circular saw brand that is a pioneer in bringing about new technological advancements in the field. So it is hardly a surprise that Dewalt has a wide range of circular saws all with different specs and power requirements. We can’t give you one specific number as their products vary a lot in battery capacity and maximum voltage.

Even some of their cordless circular saws are powerful enough to run on 60 V which can lasts up to 4 to 9 hours. However, the other options are mostly 12 V and 20 V. The power that each of these saw runs on is different.

You will need to use the formula we already discussed to find the watts consumed by each Dewalt circular saw.

Power = Voltage × Battery Capacity

Let’s find out the power consumption of  the DCS574W1 model of Dewalt circular saw. It is rated to have the maximum voltage capacity of 20 V and 8 Ah battery capacity.

So, power of DCS574W1 = 20 V × 8 Ah

                                                  = 160 Watts

Therefore, you can safely say that the DCS574W1 uses 160 Watts.

What Size Generator Do I Need For A Circular Saw?

Commonly, people purchase generators for RVing, other outdoor cookouts or camping activities that can require a temporary power source. However, generators are highly useful to run power tools where you can’t get access to electrical outlets, such as a construction site.

If you are thinking of purchasing a generator to run your power tools with, you need to know the wattage of each tool you plan on using to calculate how big a generator to get.

From the formula in the  above section, you can easily calculate the running power of your circular saw. However, you also need to calculate the starting power. Typically, you will be safe to assume that the starting power is 3 times the running power of a circular saw.

For example, we calculated the running power to be 1140 W. Therefore the starting power is 3420 Watts (1140 W × 3).  In case you plan on using other smaller tools with the circular saw, keep adding the running wattage of the other smaller tools with the starting wattage of the circular saw.

So, to summarize, you will need a generator that can supply 3420 Watts of power at the very least to run a circular saw that runs on 1140 Watts. Keep on adding more wattage to the generator for additional tool usage.

Note: This video might help you understand more about this article.

Will A 2000 Watt Generator Run A Table Saw?

Even if you operate a 2 HP table saw typical for most hobbyist woodworkers, it is not going to safely run on a 2000 Watts generator.

To run a 2 HP table saw smoothly a minimum of 1725 Watts is needed. But again we also have to take into account the starting wattage which will easily exceed 2000 Watts and take about 3500 Watts of power. So, overall we don’t think it’s a good idea to run a table saw on such a small generator.

You need to get at the very least, a 4000 Watt generator and you can’t run any other heavy tool at the same time on it. However, feel free to use a couple of smaller tools simultaneously if they won’t exceed 500 Watts of power consumption while running.

Final Words

The more powerful a tool is, the more energy it will require to run it. We recommend you get the right circular saw for you by checking its power requirements and assessing whether that much is enough to do the things you want to put the circular saw in use of.

If you are a woodworking hobbyist who can make do with a 20V cordless circular saw, there is no need for you to invest in heavy duty circular saws whose capabilities you are unlikely to put to full use. This will save a lot of your money both in terms of monthly electric bills and also the initial cost of buying the tool. Moreover, knowing the wattage of your tools also is necessary to purchase the right size of generator if you need one.