MIG/Stick Welder Wattage for Generator Sizing
About the MIG/Stick Welder
A MIG or stick welder rated at approximately 180 to 220 amps. Welders are among the most power-hungry portable tools and require a substantial generator to operate. The starting surge occurs when the arc is initiated and the power supply energizes. Actual power draw varies with the amperage setting and duty cycle. A 10,000-watt generator is typically the minimum for running a welder, and many welding applications benefit from a generator-welder combination unit designed specifically for this purpose. TIG welders generally draw less power than MIG or stick welders.
Generator Sizing for a MIG/Stick Welder
Running a mig/stick welder by itself requires a generator with at least 12,500 W of capacity (13 kW), which includes a 25% safety margin. However, you rarely run a single appliance on a generator. When combined with other appliances, the mig/stick welder contributes 7,500 W to the continuous running load and adds a potential 2,500 W starting surge gap when its motor starts.
The mig/stick welder is an inductive (motor-driven) load with a starting surge of 10,000 W, which is 1.3 times its running wattage. This starting surge occurs for a fraction of a second when the motor first engages and must overcome inertia to begin rotating. Your generator must be capable of delivering this peak wattage even though it only lasts briefly. If the mig/stick welder has the largest starting surge gap of any appliance in your generator load, its surge gap of 2,500 W will be the primary driver of your peak demand calculation. Avoid starting the mig/stick welder at the same time as other large motor loads to prevent generator overload.
To determine the total generator size you need, use our interactive calculator to combine the mig/stick welder with your other appliances. The calculator automatically handles the starting surge calculation and applies the 25% safety margin to give you an accurate recommendation. Alternatively, browse the scenarios below to see common generator setups that include the mig/stick welder.
Scenarios That Include MIG/Stick Welder
The following pre-calculated generator scenarios include the mig/stick welder in their appliance list. Each scenario shows the total generator size needed for all appliances in the set, not just the mig/stick welder alone. Click any scenario to see the full appliance breakdown.
| Scenario | Total Appliances | Running Watts | Recommended Size |
|---|---|---|---|
| Mobile Welding / Fabrication Shop | 3 | 9,020 W | 15 kW |
Tips for Running a MIG/Stick Welder on a Generator
When running the mig/stick welder on a generator, the most important consideration is the starting surge. Before starting the mig/stick welder, check that no other large motor-driven appliances are starting simultaneously. Stagger your startups: let the mig/stick welder reach steady-state operation (usually within 1-2 seconds) before starting the next motor load.
If the generator struggles to start the mig/stick welder (indicated by the generator bogging down, lights dimming significantly, or the appliance failing to start), it likely means the generator's peak surge capacity is insufficient. Try reducing other loads before attempting to start the mig/stick welder again. If the problem persists, you may need a larger generator with more surge capacity.
Modern inverter generators handle motor starting surges particularly well due to their electronic power management. If you are purchasing a new generator specifically for loads that include the mig/stick welder, verify that the generator's peak (starting) wattage specification meets or exceeds the 10,000 W starting requirement plus the running wattage of all other connected appliances.
MIG/Stick Welder Wattage Compared to Similar Appliances
The following table compares the mig/stick welder to other appliances in the power tools category. Understanding relative power requirements helps you make informed decisions about which appliances to prioritize on your generator and where you might find opportunities to reduce your total load.
| Appliance | Running Watts | Starting Watts |
|---|---|---|
| MIG/Stick Welder (this appliance) | 7,500 W | 10,000 W |
| Circular Saw | 1,400 W | 2,100 W |
| Table Saw | 1,800 W | 3,600 W |
| Air Compressor (1 HP) | 1,500 W | 4,500 W |
| Drill Press | 750 W | 1,200 W |
| Miter Saw (Compound) | 1,800 W | 2,700 W |
| Angle Grinder | 1,200 W | 1,800 W |
Frequently Asked Questions
How many watts does a mig/stick welder use?
A mig/stick welder uses approximately 7500 watts of continuous (running) power during normal operation. It also requires 10000 watts of starting (surge) power when the motor first turns on, which is 1.3 times the running wattage. This starting surge lasts only a fraction of a second but your generator must be capable of delivering it.
What size generator do I need to run a mig/stick welder?
To run a mig/stick welder by itself, you need a generator rated for at least 12,500 W (13 kW), which includes a 25% safety margin above the starting wattage of 10000W. However, most people run additional appliances alongside the mig/stick welder, so your actual generator needs will be higher. Use our calculator to add your other appliances and get a comprehensive recommendation.
Can I run a mig/stick welder on an inverter generator?
Yes, a mig/stick welder can run on an inverter generator as long as the generator's peak (starting) wattage capacity meets or exceeds 10000 watts. Inverter generators handle motor starting surges well and provide clean power that is safe for the electronic controls found in many modern mig/stick welder models. Verify the inverter generator's surge rating in the specifications.