With a generator, we usually just get the wattage.* Example:* 5kW generator, 22kW generator, and so on. We don’t really know how many amps does a generator put out. To help everybody out, we’ll look into how to calculate how many amps does a generator produce.

Below, you will also find a ‘**Generator Amps Calculator**‘ and a **calculated table** of how many amps do generators draw at 220V and 240V voltage *(500W to 30kW generators)*.

Here’s are two pieces of information that you will need if you want to find out the amps any generator produces:

**Wattage.**This is easy to find out; pretty much everybody knows how many watt generator they have.*Example:*10,000W generator.**Voltage.**This is the electric potential; usually 220V, or in the case of big generators, 240V.

This is all you need to determine how many amps does your generator draw. We are going to look into how to calculate the amps by hand (using the basic electric power equation) for a 5,000W Honda generator.

Further on, you will also find the ‘Generator Amps Calculator’ and the calculated table to help you out determine the amperage of your generator.

## How To Calculate How Many Amps Does A Generator Draw?

If you know the wattage and voltage of your generator, you can quite easily use the electric power equation to calculate the amps. Here’s the equation:

**P (power) = I (current) × V (voltage)**

To better illustrate how to use this equation, let’s use electric units instead of power, current, and voltage:

**Watts = Amps × Volts**

To calculate the amps, we need to express the amps like this:

**Amps = Watts ÷ Volts**

If you want to calculate amps generator draws, you need to divide watts by volts. Simple, right? Let’s do 1 example before we check out the automatic ‘Generator Amps Calculator’.

*Example:* How many amps does a Honda 5,000W generator produce at 220V?

We know both the wattage (5,000W) and the voltage (220V). Here’s how we can calculate the amps based on these two figures:

Amps = 5,000W ÷ 220V = **22.73 Amps**

In short, Honda 5,000W generator produces 22.73 amps.

To make things even easier, you can use the before-mentioned watts to amps calculator for generators:

## Generator Amps Calculator

You just insert (or use the slider) wattage and voltage, and the calculator will dynamically calculate the amps such a generator produces. You can also play around with numbers a bit to see how this calculation works:

You can check the above 5,000W Honda generator amperage. If you slide ‘Wattage’ to 5,000W and ‘Voltage’ to 220V, you will get the result ‘22.73 Amps’, the same as in our example above.

Here is the promised calculated table for ampacity of 500W to 30kW generators:

### Ampacity For 500W To 30kW Generators (Calculated Table)

Generator Wattage: |
Amps at 220V: |
Amps at 240V |

500W generator: | 2.27 Amps | 2.08 Amps |

1,000W generator: | 4.55 Amps | 4.17 Amps |

1,500W generator: | 6.82 Amps | 6.25 Amps |

2,000W generator: | 9.09 Amps | 8.33 Amps |

2,500W generator: | 11.36 Amps | 10.42 Amps |

3,000W generator: | 13.64 Amps | 12.50 Amps |

3,500W generator: | 15.91 Amps | 14.58 Amps |

4,000W generator: | 18.18 Amps | 16.67 Amps |

4,500W generator: | 20.45 Amps | 18.75 Amps |

5,000W generator: | 22.73 Amps | 20.83 Amps |

6,000W generator: | 27.27 Amps | 25.00 Amps |

7,000W generator: | 31.82 Amps | 29.17 Amps |

8,000W generator: | 36.36 Amps | 33.33 Amps |

9,000W generator: | 40.91 Amps | 37.50 Amps |

10,000W generator: | 45.45 Amps | 41.67 Amps |

11kW generator: | 50.00 Amps | 45.83 Amps |

12kW generator: | 54.55 Amps | 50.00 Amps |

13kW generator: | 59.09 Amps | 54.17 Amps |

14kW generator: | 63.64 Amps | 58.33 Amps |

15kW generator: | 68.18 Amps | 62.50 Amps |

16kW generator: | 72.73 Amps | 66.67 Amps |

17kW generator: | 77.27 Amps | 70.83 Amps |

18kW generator: | 81.82 Amps | 75.00 Amps |

19kW generator: | 86.36 Amps | 79.17 Amps |

20kW generator: | 90.91 Amps | 83.33 Amps |

21kW generator: | 95.45 Amps | 87.50 Amps |

22kW generator: | 100.00 Amps | 91.67 Amps |

23kW generator: | 104.55 Amps | 95.83 Amps |

24kW generator: | 109.09 Amps | 100.00 Amps |

25W generator: | 113.64 Amps | 104.17 Amps |

26kW generator: | 118.18 Amps | 108.33 Amps |

27kW generator: | 122.73 Amps | 112.50 Amps |

28kW generator: | 127.27 Amps | 116.67 Amps |

29kW generator: | 131.82 Amps | 120.83 Amps |

30kW generator: | 136.36 Amps | 125.00 Amps |

If you still didn’t find the answer, you can pose a question in the comments below and we’ll try to help you out.

Table of Contents

My distribution center from the power co says 400 amps on the main breaker. (1 phase) To determine generator size, do I multiply 400 by 120 or 240?

Thnank you.

Hi Alan, well, it all depends on the voltage in the circuit. If you have a standard 120V voltage, multiply by 120. If you have an upgraded 240V voltage, multiply by 240.

Be sure to remember that a 400 amp breaker can be loaded up to 80% of its capacity at most, in accordance with the NEC 80% rule. So, it can handle 320 amps of current. The breaker doesn’t really care if this is a 12V battery voltage of a big 240V voltage. Hope this helps a bit.