What Can a 12000-Watt Generator Run?-[Will it Fill My Needs]

This article aims to mitigate your queries about “What can a 12000-watt generator run? How many appliances I can run simultaneously and should I be able to power My ACs, Heat pumps, etc.?

Read on to unleash the potential of a 12kw machine!

A 12,000-watt generator can run almost every essential of household, RV, or Job sites including the Air Conditioner, Washing machines, Refrigerator/freezer, Electric Stove, Water heater, LED TVs, Electric Drills, Saws, Welders, etc.

What Can a 12000-Watt Generator Run?

Starting and Running Watts of a Generator

Starting/Surge Watts: The amount of wattage a machine could produce for a short time to fire up power-hungry motorized appliances. Starting watts/amps could be found on the specification section of the generator and will always be higher compared to the running or rated watts.

NOTE: Sufficient surge watts are necessary to operate a heavy-duty motorized appliances such as air conditioners, sump pumps, and others. Without them, running these appliances couldn’t be possible.

Running Watts: The number of wattages a machine could draw for a longer time to run an appliance in a stable condition.  Rated watts will always be lower compared to the surge or peak watts.

What Appliance Can Be Run With a 12000 Watt Machine?

ApplianceRunning WattsStarting Watts
Electric Kettle12003000
Central AC (24,000 BTU)380011400
Ceiling Fan60-700
Electric Water Heater40000
Clothes Dryer (Electric)54006750
Heat Pump47004500
Circular Saw 7 1/4 inch14002300
Furnace Fan Blower (1/2 HP)8002350
Garage Door Opener (1/2 HP)8752350
Deep Freezer5001500
Table Saw 10 inch20002800
Clothes Dryer (Gas)7001800
Electric Mower15000
Air Compressor 1 HP16004500
Rice Cooker200500
Electric Strimmer300500
Window AC (10,000 BTU)12003600
Outdoor Light String2500
Security System5000
Furnace Fan Blower (1/3 HP)7001400
Sump Pump (1/3 HP)8001300
Electric Drill 3/8 inch 4 Amps450700
Electric Drill 1/2 inch 5.4 Amps600900
Belt Sander12002400
Airless Sprayer6001200
Humidifier (13 Gal.)1750
Planer/Jointer 6 inch18002500
Common Light Bulb750
Halogen Work Light 1 kW10000
Halogen Work Light 500 W5000
Halogen Work Light 300 W3000
Copy Machine16000
Refrigerator / Freezer7002200
Curling Iron15000
Coffee Maker10000
Cell Phone Battery Charger250
Central AC (10,000 BTU)15004500
Home Internet Router515

Recommended Guide: What appliances a 10,000 generator can run?

How Many Appliances Can I Run Simultaneously?

Typically a 12,000-watt machine could run about 10 – 20 appliances of normal wattage, however, if you are going to plug 5 or 6 appliances of 2kw-2.2kw you may not have access to plug another one.

The bottom is you don’t have to overload your machine, however, within the limit of 0 – 12kw, you can plug any appliance you want. We encourage our readers to do the wattage calculation of the household or RV appliances before making a buying decision.

The wattage calculation is a one-time process; however, you can use that data for installing solar panels, battery banks, etc.

Power Requirement Calculation:

  • Write down the appliance with the starting and running amps/wattages you are going to use, you can find the power rating from the energy labeling of the appliance. If you have found the power rating in amps and your generator has a power rating in wattages, make sure to convert the amps into wattages with the help of Ohm’s law.

Ohm’s Law = W (watts or kilo watts) = V (volts) X Amps (Amperes)

e.g.: An appliance is consuming 25 running and 30 starting amps at the voltage of 240.

With the help of Ohm’s law

W (watts or kilowatts) = V (volts) X Amps (Amperes)

Running Watts = 240 X 25 = 6,000 watts

Starting Watts = 240 X 30 = 7200watts

  • Sum up their starting and running wattages and keep them in a separate column.
  • Compare the wattage needs of your household or RV with the generator you are going to purchase.

Practical Example:

AppliancesStarting WattsRunning Watts
Refrigerator1200 Watts200 Watts
Dishwasher1500 Watts1500 Watts
Deep Freezer1300 Watts700 Watts
Washing Machine0 Watts1200 Watts
Vacuum Cleaner 12 Amps25001440
Microwave0 Watts800 Watts
Belt Sander24001200
Table Saw 10 inch2800 Watts2000 Watts
Toaster0 Watts900
TOTAL11700 Watts9940 Watts

From the above calculations, we got 11700 starting watts and 9940 running watts, hence a solid 12kw machine would be enough for that quotation.

Recommended Read: What Will a 15000-Watt Generator Run?

Is a 12000 Watt Generator Good?

Yes, A 12,000-watt machine is considered an ideal machine to run almost every essential of not only the household but also the job site.

Doesn’t matter whether you have power-hungry welders, drills, saws, grinders, etc. a brandable 12,000-watt machine is known to be a one-stop solution for extended blackouts/hurricane seasons.

Can I Run My Whole House on a 12000 Watt Generator?

Yes, a 12,000-watt machine is sufficient for a medium–large household with a bunch of power-hungry appliances like central AC, water heater, vacuum cleaner, washing machine, refrigerator/freezer, sump/heat pump, etc. Even a 12kw machine could run most of the appliances simultaneously.

Will a 12,000 Watt Generator Run a Heat Pump?

Yes, a standard heat pump needs about 500 – 8,000 watts which isn’t a big deal for a 12kw generator.

How Long Will a 12,000-Watt Generator Run?

It depends on the fuel tank size, efficiency, and how much load you are pulling from the machine.

Typically a solid 12kw unit of DuroMax, Champion, or WEN should provide 8 – 10 hours of runtime at the load of 25 – 40% with a single tank of fuel, however, if you increase the load from 60% you may have to see a significant drop down in the runtime.

Will a 12,000 Watt Generator Run a 4-ton AC Unit?

It depends on the model, type, and power efficiency of the air conditioner you own, below is the list of 4 tons of air conditioners that can be easily run with a 12kw machine.

AC UnitRunning Watts Starting Watts
Split air conditioner3,0004,500
Central Air conditioner4,0006,000
Window air conditioner3,5005,000

NOTE: The above calculation is made with respect to the SEER rating of each AC unit, maybe your unit has a different SEER make sure to check it for accurate calculation.


Though A 12,000-watt generator is ideal to cope with extended blackouts/hurricanes, still you have to cross-check the wattage needs before making any buying decision.

Wattage calculation will not only save your initial cost but also make sure that you don’t have to spend more on fuel and maintenance.

FAQs – Frequently Asked Questions

Will a 12,000 Watt Generator Run Central Air?

Yes, a 12,000-watt watt is capable of running a central air conditioner unit of (12,000 – 42,000 BTUs), however, if you have an old-school inefficient AC unit you may have to consider a bigger machine of at least 15,000 – 18,000 watts.

How Loud Is a 12000-Watt Generator?

On average, a 12,000-watt machine emits 74 – 80dB from a distance of 25 – 30fts.



Kashif has been a valuable asset to the electric generator industry for over 5 years. Now, As a skilled energy engineer, he’s been on the front lines of diagnosing problems, fixing broken parts, and performing routine maintenance tasks to keep generators running smoothly.

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