Electric field is the electric force per electric charge unit. It's originated from the positive charge (proton) and end up at the negative charge (electron).
Electric field calculation formula: E (Electric field) = F (Electric force) / Q (Electric charge)
SI unit of electrical field is newtons per coulomb which equals to volt per meter. Other common units are kilovolt per meter, millivolt per meter, volt per inch, newton per coulomb.
For other electrical unit conversions, please go to Electrical Unit Conversion