# Getting Mathematical with Ohm’s Law in Electronics

Sometimes in electronics you have no alternative but to whip out your calculator and do a little maths. The most likely reason is to calculate how much resistance you need for a given situation, how much current a circuit is going to pull or how much voltage will be dropped between two points in a circuit.

You can make all these calculations by using one of the following formulas derived from Ohm’s law:

In the above formulas, *V *represents voltage (in volts, naturally), *I *represents current (in amperes) and *R* represents resistance in ohms.