Calculating how many watts an air compressor uses is very important. Just consider that electricity accounts for 70% of the air compressor life cycle cost.
To figure out how many watts your air compressor uses, look at the metal nameplate located on the motor. This is usually where manufacturers mention the wattage rating of the air compressor.
If the motor doesn’t have this information, it’s time for some math! Don’t worry, though. It’s easier than you think.
This article will answer the common question of how many watts does an air compressor uses. After that, we will detail a few examples.
How many watts does an air compressor use
In case your air compressors show the energy consumption value in amperes (amps), multiply that figure by the total voltage.
If you live in the following countries, your household voltage is 110-120 volts:
- United States
- Canada
- Mexico
Countries that use the 220-240 voltage include:
- United Kingdom
- Australia
- New Zealand
- South Africa
The majority of small air compressors draw 15 amps during operation. To calculate the wattage rating of your motor, use the following equation:
Watts = Voltage X Amperes
For example, the wattage rating of an air compressor in the United States equals:
Watts = 120 X 15 = 1,800 Watts
Here’s another example for people living in countries that use 220V:
Watts = 220 X 15 = 3,300 Watts
How to use watts to calculate the cost of electricity
The figure below demonstrates how you can convert different units to kilowatts (kW). That’s because you need the energy consumption in the kW/hour unit.
The vast majority of utility companies charge clients based on the kW/hour unit.
The table below demonstrates the largest utility companies in the United States and their cost per kW:
| Utility company | Number of clients | Cost per kW |
| Florida Power& Light | 5,214,220 | 16 ¢/kWh |
| Southern California Edison | 3,881,200 | 30 ¢/kWh |
| Commonwealth Edison | 3,001,870 | 6.8 ¢/kWh |
| Consolidated Edison Co-NY | 2,930,010 | 9 ¢/kWh |
| Georgia Power | 2,657,950 | 5.6 ¢/kWh |
| Virginia Electric & Power | 2,573,750 | 12.4 ¢/kWh |
| Pacific Electric & Power | 2,269,280 | 8 ¢/kWh |
Keep in mind that these rates change drastically, depending on the following factors:
- Time of the year
- Physical location (state)
- Tier (prices change when you reach a threshold of consumption)
To learn how much electricity air compressors use, check out this post.
The life cycle cost of an air compressor
Air compressors account for up to 30% of total industrial electricity consumption in the United States. In Europe and Australia, air compressors contribute to 10% of total industrial energy use.
What’s more, old research shows that only 10-30% of the energy consumed by air compressors reaches the point of end-use. The majority of the energy is lost in the form of heat. For example, an air compressor that generates 1 horsepower (hp) needs about 8 hp of electricity.
Today, modern air compressors use up to 50% of the consumed energy, drastically improving the efficiency of these systems.
All of these numbers serve to emphasize the amount of energy needed to run an air compressor. Take a look at the chart below, which depicts the life cycle cost of owning an air compressor:
As you can see, the initial investment only accounts for 16% of the cost. This refers to the price of buying the air compressor. The biggest portion of the cost is the energy cost, which could be electricity bills or fuel.
How many watts does a small air compressor use
A small air compressor requires a 12-volt outlet. The most common use for small air compressors is to fill car tires. In order to operate these compressors, you need the automobile auxiliary power outlet (i.e., car lighter).
These outlets provide 12 volts. To calculate how many watts a small air compressor uses, let us apply the numbers to our equation:
Watts = 12 X 15 = 180 Watts
Therefore, the answer to this question is 180 W, which equates to 0.018 kW.
How many watts does a 1.5 hp air compressor use
The latest studies estimate that 1 horsepower equals roughly 746 Watts.
Using this rate, a 1.5 hp air compressor uses 1,119 Watts. You can easily calculate how much electricity is needed to run this air compressor. To do this, multiply this figure by the number of hours and the cost of electricity.
Keep in mind that these figures are not 100% accurate. Air compressor manufacturers state that these robust machines require more energy to start compared to running (more on that later).
How many watts does a 2 hp air compressor use
A 2 hp air compressor is robust and efficient, which reflects on your electricity bill (if you use an electric air compressor).
Applying the same principle, a 2 hp air compressor uses approximately 1,492 Watts (± 500). You need to figure out the exact wattage rating of your air compressor for more accurate calculations.
How many watts does a 2.5 hp air compressor use
The running time for a 2.5 hp air compressor requires about 1,865 Watts. However, it may consume up to 3,000 Watts to start. Luckily, this is only necessary for a few seconds, followed by a substantial drop in electricity consumption.
How many watts does a 5 hp air compressor use
A 5 hp air compressor is a very powerful machine that has industrial applications, including:
- Farming
- Airbrushing
- Car painting
- Supplying pneumatic tools in medical and dental clinics
Multiplying 5 hp by 746 gives us 3,730 Watts.
Once again, all of these numbers account for the running time. The starting current is significantly higher. To calculate this number, we need to consider how many watts a generator needs to run an air compressor.
How many watts a generator needs to run an air compressor
Starting electric air compressors with a generator can be a nightmare for users. This is because the starting current is typically 6 times the running current.
Additionally, you need to calculate the apparent power of the needed generator, which has a unit of kilovolts/amperes (kVA).
Here’s the equation:
Apparent Power (kVA) = True Power (kW) (÷) 0.8
If we consider a 1hp air compressor, it requires 0.746 kW. This is referred to as the true power. To calculate how many watts a generator needs to run this motor, divide 0.746 kW by a power factor of 0.8.
Therefore, a 1 hp air compressor needs a generator that produces 0.93 kVA. Now that we have the power necessary to run the air compressor, multiplying the number by 6 gives us the starting current.
That’s equal to 5.6 kVA. Thus, to start and run a 1 hp air compressor, you need a generator that produces approximately 4.5 kW.
This number skyrockets if you want to operate a 5-hp air compressor. The generator needs to produce at least 22 kW.
On a side note, other appliances connected to your generator may be affected due to voltage and frequency fluctuations.
Consider getting the Westinghouse portable generator, which can efficiently start and run most air compressors.
Amazon LinkIf you don’t want to worry about all of these equations, consider buying an engine-driven air compressor.
Learn about gas and diesel air compressors by clicking here.
Takeaway message
The number of Watts necessary for an air compressor varies significantly based on the size and power of the pump.
We hope that this article successfully highlighted how many Watts does an air compressor uses to start and run.
If you have any questions about the figures or equations we detailed above, feel free to share them in the comment section below.
