Convert Watts to Amps: Learn How With Our Online Calculator

Determining how much power your home electronics take will help you efficiently calculate your monthly energy bill.

If you have ever bought an electronic appliance, chances are you may have come across terms such as voltage (volts), wattage (watts), and amperage (amps).

But what do watts and amps mean? And why should they matter?

Having a better understanding of volts, watts, and amps is the key to minimizing your monthly utility bills. Want to know more about them and how to convert watts to amps and vice versa? Read on

Understanding Watts & Amps

Both volt-amperes and watts are measurement units for electrical energy. Watts indicate real-power, while volts-amperes indicate apparent-power.

Typically, electronic products such as air conditioners and heat pumps display both these values to inform consumers about their energy requirements.

Understanding Watts & AMPS


The real-power in watts is the power that generates heat or performs work. It’s used to measure the rate of energy transfer or power flow in your appliance.Watt or Watts is a unit of power and is classified by the “W” symbol. The equation to derive watts is:

W = V x A


Amps or Amperes is the SI system’s base unit. It measures the volume of electrons in an electrical circuit. The capitalized “A” is a symbol for amps or amperes.

Amperes measure electricity flow as the electric current. To better understand this, think of electric current as the water flowing through a hosepipe; the more it flows, the bigger the current is.The formula of amps is:

A = W/V

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How To Convert Watts To Amps

You have an air conditioner powered by 800 wattages. Do you know how many amperes that amounts to? It’s 5 amperes (or amps)!

For many people living in different parts of the world, it may be beneficial to learn how to make this conversion.

Therefore, here are three helpful ways you can use to convert watts to amperes:

Convert Manually

To convert power (watts) to current (amps), use the following electrical power formula:

P = I x V

Where P means power (in watts), I represents amperage or electrical current (in amperes or amps), and V signifies voltage or electrical potential (in volts).

Since we have to find amperes, the equation will be:

I = P/V

Most electrical units have a standard voltage of 110 to 120 volts, whereas upgraded electric units use 220 volts. By using this formula, you can convert watts to amps directly if you know the voltage.

For example: let’s suppose you have a 500 watts AC unit plugged into 120 volts voltage. Put these values into the amperes’ equation:

I = P/V

I = 500/120 = 4.17 Amps

Watts To Amps Table

If you don’t want to waste time doing all the computations, use the handy watts to amps table.

One major benefit of this conversion table is that it’s much easier to read and displays conversions from 100 watts to amperes, 600 watts to amps, 3000 watts to amps, or more.

So, if you want to know how many amps is 600 watts, how many amps is 1200 watts, or even how many amps is 1500 watts, you won’t need to calculate anything.

All you have to do is refer to the table:

Watts:Amps (at 120V):
100 Watts to amps0.83 Amps
200 Watts to amps1.67 Amps
300 Watts to amps2.50 Amps
400 Watts to amps3.33 Amps
500 Watts to amps4.17 Amps
600 Watts to amps5.00 Amps
700 Watts to amps5.83 Amps
800 Watts to amps6.67 Amps
900 Watts to amps7.50 Amps
1000 Watts to amps8.33 Amps
1100 Watts to amps9.17 Amps
1200 Watts to amps10.00 Amps
1300 Watts to amps10.83 Amps
1400 Watts to amps11.67 Amps
1500 Watts to amps12.17 Amps
1800 Watts to amps15.00 Amps
2000 Watts to amps16.67 Amps
2500 Watts to amps20.83 Amps
3000 Watts to amps25.00 Amps

Related Article Kilowatts To Amps Conversion

Online Calculator

If you want to convert watts to amps by yourself but do not want to do the maths, you can use an online converter.

An online conversion calculator is more helpful if you are rummaging through the market purchasing a heat pump or an air conditioner for your house. It’s excellent for on-the-spot results!

The watts to amps online converter is simple to use: input the watts (W) and volts (V), and you’ll get amps.

Various Methods For Watts To Amps Calculation

Fixed Voltage Calculation

You can either use the formula I (A) = W / V or use an online converter calculator to convert watts to amps.

However, if you want to calculate through a table, here are steps:

  1. .Find a watts to amps conversion table. The table above works too.
  2. .Search the power (watts) value you would like to convert.
  3. .Once you pick a value, look for the corresponding electrical current (amperes)
DC Calculation

Here’s how you can calculate amps using watts and direct current (DC) voltage:

  1. .Know your circuits’ power (measured in watts)
  2. .Locate the voltage value on the device. You can find this at the same place you found the power value.
  3. .Put these values into the ampere equation, which is I (A) =  P (W) / V (v), and you’ll get amperes.
AC Single Phase Calculation

To calculate watts to amps for a single-phase alternative current (AC) circuit, follow the steps below:

  1. .Know your power factor (ratio of real power to apparent power)
  2. .Use the single-phase equation that is I (A) = P (W) / V (v) x PF where I signifies amps, P indicates watts,  V implies volts, and PF means power factor.
  3. .Input the values in the above equation, and you’ll have the answer.
AC Three-Phase Calculation

To calculate watts to amps using three-phase AC voltage, follow the steps below:

  1. .Know your power factor. Find it on the schematic or circuit label.
  2. .If you’re using line-to-line voltage, you can use the following equation to convert watts to amperes: (I (A) = P (W) / VL-L(V) x PF x √3)
  3. .But if you use line-to-neutral voltage for three-phase alternative current circuits, than the equation is: I (A) = P (W) / V L-N(v) x PF x 3
  4. .Now, solve the equations to get amperes.

The Relationship Between Watts, Amps & Energy Efficiency

Energy Savings List

Each month your power company sends you an electricity bill, detailed in kW (one kilowatt = 1000 watts).

Therefore, the more volts and amps your HVAC system and other electronic appliances use, the higher your energy bills will be — It’s as simple as that!

It’s also important to know that even when your appliances are shut, they may draw some power (watts) if plugged in. This phenomenon is known as phantom load or vampire power.

In short, more watts and amps indicate less energy efficiency and more energy cost.

People Also Ask (FAQ)

Who invented the watt unit?

The watt unit was named after the famous eighteenth-century Scottish inventor, James Watt. It was first proposed by William Siemens in 1882.

How many amps are in a watt?

One watt has one ampere.

How many amps is a 3000-watt generator?

On 120 volts, a 3000-watt generator usually puts out 25 Amps.

Do heaters and air conditioners use the same conversion metrics?

Yes, air conditioners and heaters use the same conversion metrics such as EER, SEER, COP, etc.

Do most home HVAC devices come in 120v or 240v?

Though many everyday electrical appliances come in 120 and 240 volts, 120-volt outlets take a slight edge over the 240-volt ones.

Related Article 110V Vs 220V Central AC

What is an amp breaker and when is it used?

Amp breaker carries the amperage needed by the unit. When there’s more current in the system than it’s meant for, chances are it may start a fire. However, the amp breaker senses this and automatically interrupts the power flow.


It’s essential to know how many watts and amps your electrical home appliance consumes. Being aware of how much you’re consuming will help you strategize your overall electricity usage.

If your devices use excessive power, you’ll have to pay hefty bills. To avoid this situation, you should consider the watts and amps of a unit before investing in it.

Related Article kVA to Amps Calculation

Josh Mitchell

Josh Mitchell

My name is Josh and I am obsessed with DIY and improving my family home. HVAC topics can be tricky for homeowners so I decided to share my knowledge on the subject. When I am not working on DIY projects, you can find me at the beach or my local coffee shop.