How Many Amps Does A Central Air Conditioner Use?

By - Hs Saini

Updated -

It is only right to have an air conditioner unit to combat the heating season. However, knowing how much current the AC unit pulls is essential in installing one.

Below you’ll learn how much electrical power these appliances pull and how to calculate the amps.

Central air conditioners need between 15 to 60 Amps. But the ton rating of the air conditioner determines the amperage. It also depends on the SEER rating and the number of volts they have, usually around 208 to 240 volts.

How Many Amps Does a Central Air Conditioner Pull?

Central Air Conditioner Use

A central air conditioner pulls about 15 to 60 Amps, depending on its voltage, efficiency, and number of tons.

Knowing these three ratings on an air conditioner unit will enable you to calculate the amps. 

#1. Voltage Rating

The voltage of the air conditioner unit is found on its label stuck on the exterior of the condensing component casing. Central air conditioners typically have circuits of 230 volts or below.

#2. SEER Rating

Central air conditioners’ efficiency is valued by SEER, which is an abbreviation for Seasonal Energy Efficiency Ratio.

This ratio measures the cooling effect of the air conditioner over a normal cold season, which is then divided by energy consumed in Watt-hours.

It is measured over a full cold season. The metrics used are a regular internal temperature and a range of outdoor temperatures from 60 to 100 degrees.

This ratio is located on the air conditioner unit or in the text handed to you when installed.

#3. Ton Rating

In addition, central air conditioners have ton ratings. A ton rating is the proportion of heat eliminated by a ton of ice daily. One ton is measured as 12,000 BTU/hour.

You can find the ton rating on the exterior of the AC unit or the owner’s manual. The rating might be written by hand or typed together with the model and serial numbers.

Tons are rated from 1.5, 2.0 2.5, 3.0, 3.5, 4.0 and 5.0. They can also be written in BTUs. If that’s the case, you can divide the figure written by 12,000. Whatever you get is the ton rating of the air conditioner unit.

With these ratings known, you can use the following formula to find out the amps of an air conditioner.

#4. Amp = BTU / ((SEER * 0.875) * Volt)

If all the ratings of an air conditioner unit are available, you can input the values in the above formula. Whatever result you get is the number of amps that the air conditioner uses.

Good knowledge of how electricity functions in air conditioners are very important. This knowledge is vital if you’re going out to purchase one.

Typically, air conditioners deal with amperage (electrical current), voltage (electrical potential), and wattage (electrical power). 

Voltage is the variance of electrical potential across two ends. Appliances with higher voltage will have lower amp pull. This feature gives the appliance higher capacitance and makes it last.

Amperes is the amount of electricity drifting between two ends in a given period. Appliances need circuits capable of handling the quantity of amp being pulled from them. Otherwise, they stop the current flow.

Watts is the amount of electrical energy needed to run an appliance. Knowledge of these will help you deliberate the varying power necessities of the air conditioner unit.

The differences between these electrical units will determine what outlet to buy. It can also let you know if you’ll need a dedicated circuit.

A particular air conditioner unit might not want to share an outlet with another appliance.

This knowledge will also help locate the right space for the air conditioner. You can also consult an expert electrician to guide you.

There are two types of central air conditioners which are;

#5. Split-system Central Air Conditioner

This type of air conditioner is an outdoor steel cabinet. It features a compressor and condenser with an indoor cubicle having the evaporator.

Most of these air conditioners have a furnace in the indoor cubicle. The evaporator coil is found in the cubicle or the furnace’s major supply tube. 

#6. Packaged Central Air Conditioner

This kind of central air conditioner has the condenser, compressor, and evaporator installed in a single cabinet.

It is usually put on the roof or a block of concrete close to the home. The return tubes and air supply arrive indoors via the roof or through the outside wall.

This tube is attached to the packaged air conditioner that’s located outside. These conditioners sometimes feature an electric heating system or a typical gas furnace.

The central heater works with the air conditioner, making indoor furnaces obsolete. 

Air Conditioner Amperage Chart

16 SEER is the most regular air conditioner efficiency. This chart will therefore be based on the 16 SEER rating.


Besides electric current, another thing to take note of is wire sizes. The size of the wire for AC depends on the fall in voltage and ambient temperature.

This cable size chart below will be important when working with air conditioners.

#1. Cable Size Chart Regarding Air Conditioner Ton Rating

The chart below shows wire sizes for regular 230V/1P/60HZ air conditioners. For this chart, the ambient temperature is 30°C, and the voltage drop is 2.5%.


The chart below shows wire sizes for regular 480V/3P/60HZ air conditioners. For this chart, the ambient temperature is 30°C, and the voltage drop is 2.5%.



Central air conditioner units pull about 15 to 60 amps of electricity. Amperage is dependent on voltage, efficiency, and the number of tons.

If you have these ratings, you can calculate the amperage using this formula, Amp = BTU / ((SEER * 0.875) * Volt).

Central air conditioners are great to use as some units are credited for enhancing air quality in the house.

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