Amps To kWh Calculator: Calculate kWh From Amps

Calculating kWh from amps is quite a challenge. First, we need to convert amps to watts (using voltage), and then we can convert watts to kWh. To make this process easier, we have developed the Amps To kWh Calculator that does all of this automatically.

On top of that, we have also checked how many kWh do different devices (from 1 amp to 1000 amps) use at 12V, 24V, 120V, and 120V voltages if we run them for 1 hour. All the calculations are summarized in the chart below.

how to calculate kwh from amps
A standard 1500W 120V heater draws 12.5 amps. If we run this 12.5A 120V heater for 10 hours, it will consume 15 kWh of electricity.

First of all, let’s look at what amps and kilowatt-hours (kWh) actually are:

  • Amps or amperes are units of electric current. If we multiply amps by voltage, we get watts (units of electric power).
  • Kilowatt-hours (kWh) are units of electric energy. If we multiply watts by hours of use, we get watt-hours (Wh). To further convert Wh to kWh, we have to divide Wh by a factor of 1000.

The whole amps to kWh conversion can be written in this formula:

kWh = Amps × Volts × Hours Of Use / 1000

Here is a quick example: Let’s say that we have a 10 amp electric device running on a standard 120V circuit for 5 hours. How to calculate kWh from amps? We use the formula above like this:

kWh Used  = 10 Amps × 120 Volts × 5 Hours / 1000 = 6 kWh

This 10 amp electric device will use 6 kWh of electricity.

As we can see, the amps to kilowatt-hour conversion depend on only 3 factors (we will use these 3 factors in the Amp To kWh Calculator further on):

  1. How many amps we are using (1st slider in the calculator).
  2. What kind of voltage we are using (2nd slider in the calculator).
  3. For how long we run the electric device (3rd slider in the calculator).

If we know all these 3 factors, we can easily use this calculator to convert amps to kWh:

Amps To kWh Calculator

 

To illustrate how this calculator works, you can use the example from above: 10 amp device running on 120V for 5 hours. Just slide the 1st slider to ’10’, 2nd slider to ‘120’, and the 3rd slider to ‘5’. You get the result: Running a 10 amp 120V device for 5 hours consumes 6 kWh of electricity.

This is just one example. Let’s see how many kWh do different amp devices (from 1 amp to 1000 amps) running at 12V, 24V, 120V, and 220V voltages for 1 hour use:

Amps To kWh Chart For 1 Hour Of Use

Current (Amps): 12V Voltage: 24V Voltage: 120V Voltage: 220V Voltage:
1 Amp 0.012 kWh 0.024 kWh 0.12 kWh 0.22 kWh
2 Amps 0.024 kWh 0.048 kWh 0.24 kWh 0.44 kWh
3 Amps 0.036 kWh 0.072 kWh 0.36 kWh 0.66 kWh
4 Amps 0.048 kWh 0.096 kWh 0.48 kWh 0.88 kWh
5 Amps 0.060 kWh 0.120 kWh 0.60 kWh 1.10 kWh
6 Amps 0.072 kWh 0.144 kWh 0.72 kWh 1.32 kWh
7 Amps 0.084 kWh 0.168 kWh 0.84 kWh 1.54 kWh
8 Amps 0.096 kWh 0.192 kWh 0.96 kWh 1.76 kWh
9 Amps 0.108 kWh 0.216 kWh 1.08 kWh 1.98 kWh
10 Amps 0.12 kWh 0.24 kWh 1.20 kWh 2.20 kWh
15 Amps 0.18 kWh 0.36 kWh 1.80 kWh 3.30 kWh
20 Amps 0.24 kWh 0.48 kWh 2.40 kWh 4.40 kWh
30 Amps 0.36 kWh 0.72 kWh 3.60 kWh 6.60 kWh
40 Amps 0.48 kWh 0.96 kWh 4.80 kWh 8.80 kWh
50 Amps 0.60 kWh 1.20 kWh 6.00 kWh 11.0 kWh
60 Amps 0.72 kWh 1.44 kWh 7.20 kWh 13.2 kWh
70 Amps 0.84 kWh 1.68 kWh 8.40 kWh 15.4 kWh
80 Amps 0.96 kWh 1.92 kWh 9.60 kWh 17.6 kWh
90 Amps 1.08 kWh 2.16 kWh 10.8 kWh 19.8 kWh
100 Amps 1.20 kWh 2.40 kWh 12.0 kWh 22.0 kWh
150 Amps 1.80 kWh 3.60 kWh 18.0 kWh 33.0 kWh
200 Amps 2.40 kWh 4.80 kWh 24.0 kWh 44.0 kWh
250 Amps 3.00 kWh 6.00 kWh 30.0 kWh 55.0 kWh
300 Amps 3.60 kWh 7.20 kWh 36.0 kWh 66.0 kWh
350 Amps 4.20 kWh 8.40 kWh 42.0 kWh 77.0 kWh
400 Amps 4.80 kWh 9.60 kWh 48.0 kWh 88.0 kWh
450 Amps 5.40 kWh 10.8 kWh 54.0 kWh 99.0 kWh
500 Amps 6.00 kWh 12.0 kWh 60.0 kWh 110 kWh
600 Amps 7.20 kWh 14.4 kWh 72.0 kWh 132 kWh
700 Amps 8.40 kWh 16.8 kWh 84.0 kWh 154 kWh
800 Amps 9.60 kWh 19.2 kWh 96.0 kWh 176 kWh
900 Amps 10.8 kWh 21.6 kWh 108 kWh 198 kWh
1000 Amps 12.0 kWh 24.0 kWh 120 kWh 220 kWh

As you can see, this chart will tell you exactly how many kWh will different amp devices use per hour.

It all depends on voltage:

  • 1 amp at 12V will spend 0.012 kWh per hour.
  • 1 amp at 24V will spend 0.024 kWh per hour.
  • 1 amp at 120V will spend 0.12 kWh per hour.
  • 1 amp at 220V will spend 0.22 kWh per hour.

If you still find converting amps to kWh a bit difficult, you can use the comments below, give us some numbers, and we’ll try to help you out as best we can.

4 thoughts on “Amps To kWh Calculator: Calculate kWh From Amps”

  1. Hello, I’m trying to figure out circuit breaker panel capacity if I need to upgrade my panel.
    Current panel is 800amps.
    Daily usage is 542kwh.
    240v incoming power

    Reply
    • Hi Simon, 800 amps is a huge current. 800 amps at 240V voltage results in 192,000 watts or 192 kW power. If you have a stable daily usage (542 kWh per day), you would need 542 kWh/ 24h = 22.6 kW power. Given these considerations, the 800 amp panel current is more than enough.

      Reply
    • Hi Amitesh, first you calculate the wattage like this: 17A × 440V = 7,480W. That’s 7.48kW. If you run it for 1 hour (60 minutes), that’s 7.48 kWh. Hope this helps.

      Reply

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