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.

12 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.

      • Bonsoir à tous.
        Après un relevé de charge dans une institution, on a trouvé 158 Ampères pour tous les appareils.
        Combien faut-il de Kw pour faire fonctionner ces appareils ? A noter que tous les appareils se fonctionnent sur une tension de 120 volts. Mais, ils consomment en général 158 Ampères.
        Merci pour vos réponses

        • Hello Schello, French is not our first language but Google Translate will serve well here. You have 158 amps at 120V. Here’s how you calculate the wattage: Wattage = 158 amps x 120V = 18,960 watts. This is 19 kW. Merci beaucoup.

    • Hello FM, that’s correct. It’s always best to use the basic units (W, A, V) but we used kW to better illustrate the kW to amps conversion. In the calculation, we do use the 1 kW = 1,000 W conversion.


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