Volts, Amps and Watts explained

Volts, Amps and Watts are the three most important measurements when working with electricity. Here is a quick refresher on what they each represent.


Volts = Strength

Amps = Flow of electric current

Watts = Electrical power; the combination of volts and amps




Wattage is a measure for the power of an electrical system, it is simply the combination of Volts and Amps. To calculate wattage multiply the voltage by the amps.

Watts = Volts x Amps

The flowing water analogy is commonly used to explain Volts and Amps but I find it confusing since water pressure will have an effect on the water flow volume so how can pressure and flow be individual metrics?

Instead I prefer the warriors analogy:

Warrior analogy

I'm going to use soldiers for this analogy. A high voltage will mean a strong soldier where as a low voltage will mean a weaker soldier.

A soldier with high voltage with be a better fighting force

The effect of one soldier here is high.

Whereas a soldier with a low voltage will not be as effective.

Everyday examples

Lets put some real life examples to these numbers.

Device Voltage Amps
USB 5v 0.6A-3A
North American power socket 120v 12A max
European & Commonwealth power socket 230-240v 13A