Electric Field Calculator

This calculator finds the electric field strength produced by a point charge at a given distance, the quantity that describes the electrical influence a charge exerts on the space around it. An electric field is what a charge creates in its surroundings, ready to push or pull on any other charge that enters it. Its strength at a point tells you the force per unit charge that a test charge would feel there, and it falls off with the square of the distance from the source, just like gravity. The field points away from a positive charge and toward a negative one. Understanding electric fields is fundamental to all of electrostatics and underpins capacitors, electronics, particle physics and the behaviour of matter at the atomic level. This calculator computes it from Coulomb's law. You enter the source charge in coulombs, using scientific notation for the usually tiny values, and the distance from it in metres, and the calculator returns the electric field strength in newtons per coulomb, the same value in kilonewtons per coulomb, the force this field would exert on a one-microcoulomb test charge, and Coulomb's constant. The results update as you type, so you can see how the field weakens rapidly with distance. Use it for physics study, for electrostatics problems, or to understand fields around charges. The field strength is Coulomb's constant times the charge, divided by the distance squared. Because of the inverse-square relationship, moving twice as far from the charge reduces the field to a quarter, which is why fields are intense close to a charge and fade quickly with distance. The force on any charge placed in the field is simply the field strength times that charge, which links the field directly back to Coulomb's force law. The calculation uses Coulomb's constant of about 8.988 times ten to the nine.

E = k x charge / distance². Field falls with the square of distance. Force on a charge in the field = field x charge. Use scientific notation for small charges.