kW To Amps Calculator: Insert kW, Get Amps

One of the most frequently needed electricity conversions is kW (kilowatts) to Amps.

  • kW is a unit of measure of electrical power (wattage).
  • Ampere (A) is a unit of measure of electrical current (amperage).

To convert kW to Amps, we can use the equation for electrical power:

Power (kW) = I (A) * V (V)

You can use this kilowatt to amperes converter. Below you will find 3 examples of a kW to Amps conversion for:

  1. 4 kW central air conditioner (220 V).
  2. 1 kW washing machine (220 V).
  3. 36 kW tankless electric water heater (240 V).

kW To Amps Calculator

0.00 Amps

Calculated Amps


Using the calculator, we have calculated a kW to Amps table:

Power (kW) Voltage (220 V) Amperage (A)
1 kW to Amps: 220 V 4.55 Amps
2 kW to Amps: 220 V 9.09 Amps
4 kW to Amps: 220 V 18.18 Amps
6 kW to Amps: 220 V 27.27 Amps
9 kW to Amps: 220 V 40.91 Amps
18 kW to Amps: 220 V 81.82 Amps
27 kW to Amps: 220 V 122.73 Amps
36 kW to Amps: 220 V 163.64 Amps
45 kW to Amps: 220 V 227.27 Amps

Example 1: How Many Amps Does 4 kW Central AC Unit Draw?

For example, let’s take a 36,000 BTU central air conditioner with a power output of 4 kW. The electrical circuit can provide 220 V voltage. How many amps does the 4 kW AC unit draw? Let’s use the kW to Amps calculator:

We can see that the 4 kW air conditioner needs 18.18 amps to function properly. 

Example 2: 1 kW Washing Machine To Amps

Most washing machines draw about 1,000 W or 1 kW of electrical power. You don’t need upgrades to your electrical circuit for an average washing machine. Here is how many amps it draws:

1 kW washing machine needs about 4.55 Amps to run.

Example 3: 36 kW Electrical Tankless Water Heater

Tankless water heaters are notorious for needing a huge amount of electrical current (amps). For example, you have 9 kW, 18 kW, 27 kW, and even 36 kW tankless water heaters that run on electricity. Usually, they run on 240 V and can reach up to 200 amps. 

For this example, let’s take a bigger 36 kW tankless water heater on 240 V potential:

As you can see, 36 kW converts to 150 amps. This is some serious amperage; for such a device, you would need 4 x 40 A breakers.

If you have any questions about kW to amps calculation, you can pose them in the comments below.

7 thoughts on “kW To Amps Calculator: Insert kW, Get Amps”

    • Hello there, it’s a 3,000 W unit. If you use 115V, it draws 3,000W / 115V = 26 amps. Most probably, it uses 230V, thus the total amps draw is 13 amps.

  1. I understand Volts x Amps = Watts.
    i Solar panel giving 300watta @ 6 Volts =50Amps (A big cable) Obviously 300W Devided by 230= 1.3 Amps, What percentage of power will I loose passing through the Inverter?

    • Hello David, your calculations are on point. Inverter efficiency is another matter; I’m afraid we don’t have adequate knowledge to answer what % of power you’ll lose passing it the inverter.

  2. I’ve measured a total KW load of 8.94 on our combined 120/220 volts (220 water heater) on our 100 amp service. Using the Calculator for 120v it says 75 Amp. We are looking at a 19KW – 51 Amp auxiliary generator. Will this work or will there be issues due to the 51 Amp rating of the generator?

    • Hello Richard, the new 19kW – 51 Amp generator has high voltage. 19,000W / 51A = 373V. If it can put out 19 kW and has proper voltage reduction to 220V or 120V, it shouldn’t be a problem to power an 8.94 kW water heater.


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