Watts to Amps Calculator
Disclaimer: Whilst every effort has been made in building this calculator, we are not to be held liable for any damages or monetary losses arising out of or in connection with the use of it. This tool is here purely as a service to you, please use it at your own risk. Full disclaimer. Do not use calculations for anything where loss of life, money, property, etc could result from inaccurate calculations.
How to convert watts to amps
To convert watts (electrical power) to amps (electrical current) at a fixed voltage, you can use a variation of Watt's Law formula: Power = Current × Voltage (P = IV). By working backwards, we get the equation: amps = watts ÷ volts, which can be used to convert watts to amps.
How many watts make an amp?
Your conversion depends upon your voltage. At 120 volts, 1 amp is equal to 120 watts. At 240 volts, 1 amp is equal to 240 watts.
How many amps is 1500 watts?
If you have an electrical appliance using 1500 watts of power on a 120v circuit, you can use the equation Current (Amps) = Power (Watts) ÷ Voltage to calculate that the draw of the electrical appliance is 1500 / 120 = 12.5 amps.
Watts to amps at 120V (AC) chart
| Watts: | Amps (at 120V): |
|---|---|
| 100 watts | 0.83 amps |
| 200 watts | 1.67 amps |
| 300 watts | 2.5 amps |
| 400 watts | 3.33 amps |
| 500 watts | 4.17 amps |
| 600 watts | 5 amps |
| 700 watts | 5.83 amps |
| 800 watts | 6.67 amps |
| 900 watts | 7.5 amps |
| 1000 watts | 8.33 amps |
| 1100 watts | 9.17 amps |
| 1200 watts | 10 amps |
| 1300 watts | 10.83 amps |
| 1400 watts | 11.67 amps |
| 1500 watts | 12.5 amps |
| 1600 watts | 13.33 amps |
| 1700 watts | 14.17 amps |
| 1800 watts | 15 amps |
| 1900 watts | 15.83 amps |
| 2000 watts | 16.67 amps |
| 2500 watts | 20.83 amps |
| 3000 watts | 25 amps |
| Conversions are a guide and are rounded to 2 decimals. | |
Watts to amps at 240V (AC) chart
| Watts: | Amps (at 240V): |
|---|---|
| 100 watts | 0.42 amps |
| 200 watts | 0.83 amps |
| 300 watts | 1.25 amps |
| 400 watts | 1.67 amps |
| 500 watts | 2.08 amps |
| 600 watts | 2.5 amps |
| 700 watts | 2.92 amps |
| 800 watts | 3.33 amps |
| 900 watts | 3.75 amps |
| 1000 watts | 4.17 amps |
| 1100 watts | 4.58 amps |
| 1200 watts | 5 amps |
| 1300 watts | 5.42 amps |
| 1400 watts | 5.83 amps |
| 1500 watts | 6.25 amps |
| 1600 watts | 6.67 amps |
| 1700 watts | 7.08 amps |
| 1800 watts | 7.5 amps |
| 1900 watts | 7.92 amps |
| 2000 watts | 8.33 amps |
| 2500 watts | 10.42 amps |
| 3000 watts | 12.5 amps |
| Conversions are a guide and are rounded to 2 decimals. | |
Understanding watts, amps and volts
Amps are amperes, a unit which measures electrical current. It can be helpful to imagine electrical current as water in a hose. In this analogy, the quantity (volume) of water would be the amps.
Watts represent the amount of energy produced by the amps and volts working together. Multiplying amps (water volume) by volts (water pressure) gives you the wattage (the resulting power or energy). A water wheel would turn faster and longer, generating more energy if it uses increased water volume and higher water pressure; the same applies to the wattage if amps and volts are increased.
Volts are a unit to measure force. They measure the force required to make the electrical current (amps) flow. In the hose analogy, the volts would be the water pressure. North American homes typically use 120V for their electrical supply, whilst 230V is common across many other countries.
What is AC/DC?
DC stands for direct current, when the current flows in one single direction. A flashlight with a battery uses a direct current.
AC stands for alternating current, when the current periodically changes direction. In Northern America and Western Japan, this usually happens 60 times per second, or 60Hz / hertz. In Europe, the UK, East Japan and most of Australia, South America, Africa and Asia, the current changes direction 50 times per second, which is 50Hz. Power supplied to homes and businesses uses AC supply.
Converting watts to amps - examples
To convert a watts power figure into current in amps, you use Watt’s Law formula and work backwards, dividing the wattage (power produced) by the voltage (V):
Current (I) = Power (P) ÷ Voltage (V)
So…
amps = watts ÷ volts
Example: 600 watts are being sent at 120 volts. What's the current?
Current = Power ÷ Voltage
Current = 600W ÷ 120V
Current = 5A
And…
If you’re working with larger units, you need to remember that 1 kilowatt is equal to 1000 watts. The formula for Watt’s law stays the same, just as long as you express the wattage in watts (your sum will go wrong if you use ‘5W’ to mean ‘5KW’; you need to use 5000W instead).
Example: 2.4KW watts are being sent at 120 volts
Current = Power ÷ Voltage
Current = 2400W ÷ 120V
Current = 20A
Converting watts to amps is simple, really, but if you’re feeling short-circuited after all those numbers, just use our watts to amps calculator at the top of this page.
As part of our collection of energy calculators, we also have a lumens to watts calculator available.
Calculator created by Alastair HazellContent reviewed by Derek Bulled, Director of CDS Electrical and an approved electrician with over 30 years of experience.
If you have any problems using this watts and amps calculator, please contact me.
