On this page we are going to look at the Ohms law equation and an easy way to remember it. They are some of the most important and often used equation’s in electronics.

We will start by looking at three equation’s :-

These equation’s help us to find missing values in a circuit. To do so, we need to know at least two of the three. To make it easier to remember, we can use a special triangle.

The above, is the triangle for Ohm’s law. Similar triangle’s exist for other law’s. If we need to find a value, all we have to do is cover it. This leaves two in different configurations.

If we cover the R, we are left with the V at the top and I to the bottom left.

So Voltage, is over Current. In the equation we write this as V / I. So Resistance is Voltage divided by Current.

If instead we cover the I. We are left with Voltage over Resistance or V / R. So the equation for Current is Voltage divided by Resistance.

Finally if we cover the V. We are left with the I and R next to each other or I X R. So the equation for Voltage is Current multiplied by Resistance.

Here is a simple calculator to help you with Ohms law. Enter two values and leave the third one as 0. So to work out amps. Fill in the volts and Ohms then click calculate.