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Appliance Surge and Running Watts: A Reference Table

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Most household appliances draw more power to start than to run, and anything with a compressor or motor can spike to several times its running figure for a second or less. This table gives typical running and surge ranges for common loads. Every figure here is a range rather than a number, because the actual draw depends on the specific unit, and the nameplate on your appliance always beats a chart.

How to use this table

Two columns matter for two different decisions.

Running watts determines whether your generator or inverter can sustain the load, and combined across everything you plan to run at once it gives you continuous demand. Surge watts determines whether the load can start at all. Inverters and generators publish both figures, usually as continuous and peak, and the peak rating must exceed the largest single surge on your list plus whatever else is already running.

Watts are not watt-hours. Nothing in this table tells you how long a battery will last, only what it takes to run the appliance at a given moment. For runtime you need daily consumption, which comes off the EnergyGuide label, and the distinction is explained in watts versus watt-hours.

Refrigeration

ApplianceRunning wattsSurge watts
Full-size refrigerator (modern, Energy Star)100 to 250600 to 1,200
Full-size refrigerator (pre-2000)300 to 8001,200 to 2,400
Chest freezer100 to 400600 to 1,500
Upright freezer150 to 400800 to 1,600
Mini fridge50 to 100300 to 600
RV or 12V compressor fridge40 to 60100 to 200

Refrigerators duty cycle, meaning the compressor runs perhaps a third of each hour and idles the rest. A unit listed at 200 running watts averages closer to 60 to 70 watts across a full hour. That averaging is why runtime estimates based on the running figure are pessimistic by a factor of two or three, and it is worked through in how long a power station runs a refrigerator or freezer.

Water and sanitation

ApplianceRunning wattsSurge watts
Submersible well pump, 1/2 HP800 to 1,0502,000 to 3,000
Submersible well pump, 1 HP1,500 to 2,0004,000 to 6,000
Shallow well jet pump, 1/2 HP750 to 1,0001,500 to 2,500
Sump pump, 1/3 HP600 to 8001,300 to 2,200
Sump pump, 1/2 HP800 to 1,0501,800 to 3,000
Septic or effluent pump700 to 1,2001,800 to 3,500

Well pumps are the load that most often exceeds a portable power station's inverter, and they are also the load people most want during an outage. Sizing around one is its own problem, covered in running a well pump during an outage. Sump pump backup has an entirely different set of answers, including options that do not use electricity at all, in the sump pump backup comparison.

Heating and cooling

ApplianceRunning wattsSurge watts
Gas furnace blower, 1/3 HP300 to 700700 to 1,800
Gas furnace blower, 1/2 HP600 to 9001,400 to 2,300
Boiler circulator pump75 to 250200 to 600
Pellet stove300 to 500800 to 1,200
Window air conditioner, 8,000 BTU600 to 9001,700 to 2,700
Window air conditioner, 12,000 BTU1,000 to 1,4002,500 to 4,000
Central air, 3 ton3,000 to 4,0008,000 to 15,000
Electric space heater750 to 1,500750 to 1,500
Box fan50 to 100100 to 200

Resistive loads such as space heaters, toasters, and electric kettles have no meaningful surge because there is no motor to start. They draw their rated wattage the instant they switch on and hold it. That makes them easy on an inverter's peak rating and brutal on a battery, since a 1,500 watt heater empties a 1,000 watt-hour station in well under an hour. Alternatives that do not depend on the grid are in heating a house when the power is out.

Central air conditioning is on this table to establish that it is out of reach, not to suggest it can be planned around.

Kitchen

ApplianceRunning wattsSurge watts
Microwave, 1,000W output1,200 to 1,7001,200 to 1,700
Coffee maker, drip800 to 1,400800 to 1,400
Electric kettle1,200 to 1,5001,200 to 1,500
Toaster800 to 1,500800 to 1,500
Slow cooker150 to 300150 to 300
Induction hob, single burner1,300 to 1,8001,300 to 1,800
Electric range, one element1,500 to 3,0001,500 to 3,000
Dishwasher, no heated dry1,200 to 1,5001,500 to 2,200

Microwave labeling is a persistent trap. The wattage printed on the front is cooking output, not electrical input, and input runs roughly 1.5 to 1.7 times higher. A 1,000 watt microwave is a 1,500 watt load.

Lighting, electronics, medical

ApplianceRunning wattsSurge watts
LED bulb6 to 12negligible
CFL bulb13 to 20negligible
Incandescent bulb40 to 100negligible
Laptop45 to 100negligible
Phone charger5 to 20negligible
Wi-Fi router and modem10 to 30negligible
Television, 55 inch LED60 to 150negligible
Desktop computer200 to 600300 to 800
CPAP without humidifier30 to 60negligible
CPAP with heated humidifier70 to 120negligible
Oxygen concentrator300 to 600600 to 1,200
Nebulizer50 to 200negligible

Medical equipment deserves its own planning rather than a line in a table. Manufacturer figures for a specific model are authoritative, and running a concentrator or CPAP through an outage is a case where measuring rather than estimating is worth the effort.

Tools and outdoor

ApplianceRunning wattsSurge watts
Circular saw, 7-1/4 inch1,200 to 1,5002,300 to 4,000
Table saw, 10 inch1,800 to 2,0003,500 to 6,000
Air compressor, 1 HP1,000 to 1,6002,500 to 4,500
Corded drill600 to 900900 to 1,800
Chainsaw, electric1,200 to 1,8002,400 to 3,600
Battery charger for cordless tools50 to 200negligible
Garage door opener, 1/2 HP550 to 9001,400 to 2,500

Why every figure here is a range

Four things move these numbers, and knowing which one applies to you is worth more than a more precise chart.

Age and efficiency dominate the refrigeration category. A refrigerator built in 2024 and one built in 1996 differ by a factor of three or more on running watts, and the older unit surges harder because its compressor is less sophisticated.

Motor type matters next. Conventional induction motors surge hard. Inverter-driven and variable-speed compressors, now common in higher-end refrigerators, heat pumps, and air conditioners, ramp up gradually and can have almost no surge at all. If your appliance is described as inverter, variable speed, or soft start, the surge column above is pessimistic for you, sometimes dramatically.

Soft start devices change the picture deliberately. A hard start kit or soft starter fitted to an air conditioner or a well pump cuts the inrush substantially, and they are the standard remedy for a load that a generator or inverter cannot otherwise start.

Load state is the last one. A compressor starting against high head pressure, a well pump starting against a full column of water, or a saw starting with the blade already in the cut all draw more than the same tool starting unloaded.

Finding your own numbers

The nameplate is the first place to look, usually inside a refrigerator door, on the back of an appliance, or on the motor housing. Full load amps multiplied by voltage gives running volt-amps, which is close enough to watts for planning. Locked rotor amps multiplied by voltage gives the worst-case surge, and it is the figure worth writing down when it appears.

A plug-in energy meter with a peak-hold function will capture the actual surge on a plug-in appliance. Cheap meters sample too slowly to catch a spike lasting a fraction of a second, so peak capture is the feature to check for before buying.

For hardwired equipment, a clamp meter with inrush capture on the branch circuit does the same job.

Manufacturer specification sheets are more reliable than any aggregated chart, this one included. Search the model number and the word specifications rather than trusting a general figure for the category.

Adding it up

Sum the running watts of everything you intend to run simultaneously. Then take the single largest surge figure on that list and add it to the running total, because in practice only one motor starts at a time, and sizing for every motor starting at once produces an absurd number.

A generator or inverter needs a continuous rating above the running sum and a peak rating above the running sum plus that largest surge. How that arithmetic translates into a purchase is worked through in generator sizing, and the comparison between generator, power station, and home battery is in which backup actually fits your house.