Knowledge Base

How Many Watts Does a Welder Use? (Welder Power Consumption)

By:Michael Johns

arc welder in basement

On this page, you will find out how many watts a welder draws.

There’s something very satisfying about welding. The heat and the glow feel powerful as you melt two objects into one. It almost feels like a lightsaber as you slice through metal. Unlike Luke Skywalker, you’ll need to be plugged into an electricity supply for your electric tools. If you’re arc welding then it’s important to know the power consumption to ensure reliable performance. 

Below we will discuss and test welder wattage, explain how to work it out for yourself, and calculate the total electricity required.

How Many Watts is a Welder?

An electric welder uses between 3000 to 5000 watts.

The exact number depends on the size and model of your welder. For example, a smaller portable device uses upwards of 3000W, while a more substantial machine can reach 5000W!

That’s a lot of power. The reason for this huge electricity draw is because of the heat required to melt metal. Large welders can reach 10,000℉ (5500℃), that’s 4 or 5 times hotter than lava. Knowing this, it is no surprise it gobbles up so much energy to complete a job.

How to Find Out Your Welder Wattage

There’s 3 ways you can work out the wattage of a welder.

  1. Check Product Specification

The quickest way is to look at the welder’s specification. The watts (W) is usually written on a sticker on the base of the appliance. If not, you can check the user manual or the manufacturer’s website for technical details.

welder power spec
  1. Use a Wattmeter

A wattmeter is brilliant for getting a live wattage reading and tracking total energy usage of any appliance. You can plug it into your welder to get instant information. 

  1. Wattage Formula or Calculator

If you know the amperage and voltage of your welder you can use this to find the maximum watt rating. Simply use the formula Amps x Volts = Watts. Or you can head over to the ‘Watt Calculator’ to work this out.

Welder Wattage Examples

Let’s take a look at specific examples of how many watts a welder draws. Below is a collection of modern welders with their listed power ratings.

Welder ModelPower Rating (Watts)
HandheldWelder ARC Welding Machine4000
MasterTig AC Weld3500

As you can see, the power ratings vary between different welders. So you should take the time to check your own appliance.

How Much Electricity Does a Welder Use?

You can use welder wattage to work out how much electricity it uses. Plus this can be useful in understanding how much it costs to run your welder.

A watt (W) is a measurement of power at a single point in time. A watt-hour (Wh) is the total amount of electricity used in an hour. For example, a welder drawing 4000W would use 4000Wh when running for an hour.

Happily, electricity bills are recorded in kilowatt-hours (kWh). A kilowatt is simply 1000 watts. So a 4000W welder running for 1 hour uses 4000kWh.

Let’s say you actively run your welder for 1 hour a month. This means a welder uses about 4000Wh or 4kWh electricity a month. That’s 48kWh a year. 

That’s a rough electricity cost of $7.2 a year to weld for 1 hour each month.

Of course, the exact number varies a lot depending on the amount of work you do. A professional can use the equipment much more, while casual users will require a lot less electricity.

Using a Welder Off-Grid

If you’re planning to use your welder in an off-grid situation like a power outage or remote location the information above is important. It helps you to select the correct electrical equipment with enough power.

You can either use a power inverter or generator to produce AC electricity. 

To make sure everything runs smoothly you should check two things on this equipment – wattage capacity and total energy capacity. 

Your power source, like an inverter, should have a wattage capacity of at least 20% more than your welder. This ensures it will be able to deliver enough power as they are never 100% efficient.

Secondly, you need to ensure your energy source, like a battery, has enough energy to run the welder for the required amount of time. As we already know, it will use about 4000Wh electricity for 1 hour of work. This is the equivalent to 333Ah on a 12V battery.

You can see that it is going to need some serious equipment. While you can get 5000W inverters, the battery capacity will need to be huge to keep up. It’s easiest to use a large generator in this scenario.

How Many Watts Does a Welder Use Summary

I hope you now have a better handle on how many watts a welder uses.

There’s no getting away from the fact that these are very high powered tools. You’ll be drawing thousands of watts to generate the required heat. Plus if you run for an extended period it’s going to guzzle plenty of electricity.  If you want to reduce this as much as possible then look for a smaller portable machine. Although, you will lose cutting and welding depth.