# SI unit of voltage

Voltage is the difference of energy of two points in any electrical circuit. This is a simple way to know about voltage on electrical point of view if we consider any electrical circuit. Now do we know how to express voltage? Suppose someone ask you: what is your weight? Our quick reply generally could be: 60 kg or 50 kg or etc. So, kg or kilogram is the general expression of weight. This is the unit of weight. Now what is the unit of voltage? Generally, worldwide SI unit system is popular. SI unit system means the **International System of Unit**. So, what is the unit of voltage in SI system? Let’s find the answer:

For electrical point of view, generally voltage equation is,

** Voltage = q/t** ; where q is quantity of charge and t is time.

*Unit of charge in SI unit is coulombs and unit of time in SI*

*unit is seconds.*

Then we get,

*Voltage = coulombs / seconds*

*= coulombs per seconds*

*= volt*

This is the unit of voltage in SI unit.