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How Many Amps is 7500 Watts? (Answered)

Written by Edwin Jones / Fact checked by Andrew Wright

how many amps is 7500 watts

Some devices, especially portable generators, use 7,500 watts to run. But now you’re wondering how many amps is 7500 watts.

A 7,500-watt device typically draws 62.5 amps when connected to a 120-volt circuit. This value changes when the electrical system is 220 or 240 volts.

You can use a formula to calculate the amps of a 7,500-watt device. But you must know the volt and watt ratings of that product. For now, continue reading to learn how to use this formula to find amps, volts, and watts.

Convert 7500 Watts to Amps at Different Volts


The formula for calculating amps, volts, or watts is Watts = Amps x Volts.

So, if you’re looking for the amps, you must know a product’s voltage and wattage ratings.

Next, modify the formula so that you’re looking for amps instead of watts. The formula will then become Amps = Watts / Volts. You can also manipulate this formula to convert amps or watts to volts.

Calculating Amps From Watts

You can calculate the amp draw of a 7,500-watt device using the formula mentioned earlier. Here’s the calculation if the circuit is at 120 volts:

\text{Amps} = \frac{7,500 \, \text{Watts}}{120 \, \text{Volts}} = 62.5 \, \text{Amps}

On the other hand, the ampacity changes if the unit is at 240 volts. If so, the formula and the calculation are as follows:

\text{Amps} = \frac{7,500 \, \text{Watts}}{240 \, \text{Volts}} = 31.25 \, \text{Amps}

Note that the formula used above is generally only for DC systems. If you’re calculating for a three-phase AC circuit, the equation to use becomes the following:

\[ \text{Watts} = \text{Voltage} \times \text{Amps} \times \text{Power Factor (PF)} \times 1.732 \]

Assuming that you’re using unity PF (which is equal to 1) and converting three-phase 750 watts to amps at 120 volts (line-to-line), the calculation and answer are the following:

\text{Amps} = \frac{750 \, \text{Watts}}{120 \, \text{Volts} \times 1 \times 1.732} = 3.61 \, \text{Amps}

As for single-phase and three-phase line-to-neutral amperage, the formulas are:

\text{Amps (AC, single-phase)} = \frac{\text{Watts}}{\text{volts} \times \text{PF}}

\text{Amps (AC, line-to-neutral)} = \frac{\text{Watts}}{\text{volts} \times 3 \times \text{PF}}

Alternatively, you can use an online watts-to-amps converter to skip the manual calculations. Some online tools can also help users convert watts to kWh.

Another way to check the amps, watts, and volts/ohms is to use a conversion chart like the one below:

7500 W to amps AC (single-phase) AC (three-phase, line to line) AC (three-phase, line to neutral) Power Factor (for AC circuits) DC
At 120V 78.1 45.1 26.04 0.8 62.5 A at 120V

31.2 A at 240V

At 240V 39.1 22.5 13.02
At 120V 125 72.2 41.7 0.5
At 240V 62.5 36.1 20.8

Importance of Understanding Amps And Watts


Amps and watts are both units of measurement when reading electrical currents. However, the values provided by amps and watts serve dissimilar purposes.

For starters, amp is short for ampere, and it represents the amount of electric charge passing through a wire at any given time.

On the other hand, watt measures power or the amount of energy used or generated.

For example, perhaps you’re using a 7500 watts generator; if you look at the formulas mentioned earlier, the amp limit of the generator running at 240 volts is 31.25 amps for each 120-volt hot leg.

Now, with that ampacity, what will it run? You can use different devices, such as a furnace blower, computer, smartphone charger, and multiple lights.

Frequently Asked Questions


What Size Breaker Do I Need For A 10,000-Watt Heater?

Use a 48.1-amp circuit breaker for a 10,000-watt heater at 220 volts. You can also determine the heater breaker size with the 80% rule. Find the heater’s amperage and make sure it equals 80% of the breaker’s rating.

How Many Amps Is 5000 Watts At 120 Volts?

Using the formula mentioned in this post, 5,000 watts at 120V draws 41.67 amps. Again, you can use an online calculator or a conversion table if you don’t want to use manual calculations for this concern.


How many amps is 7500 watts? This post should have the answer to this question. But remember, use the correct formula if you’re looking for the amperage of a device on an AC or DC connection.

Also, the formula to use differs if you’re searching for the amps in a single- or three-phase circuit. Ensure that you have the required information, such as the voltage and wattage, to find the amperage correctly.

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