# Ohms Law Calculator

Enter any two known values and press "Calculate" to solve for the others. For example, a 100 watt light bulb operating on 120 volts AC will have 144 ohms of resistance and will draw 0.833 Amps. Enter 100 in the Watts field and 120 in the Voltage field and press Calculate to find the resistance and current. Fields should be reset to 0 before each new calculation.

Voltage (E) = Current (I) * Resistance (R)
Power (watts) = Current Squared (I^2) * Resistance (R)
Power = I*E = E^2 / R

 Volts (E) Amps (I) Ohms (R) Power (Watts)

Ohm's Law

Ohm's Law defines the relationships between (P) power, (E) voltage, (I) current, and (R) resistance. One ohm is the resistance value through which one volt will maintain a current of one ampere.

( I ) Current is what flows on a wire or conductor like water flowing down a river. Current flows from points of high voltage to points of low voltage on the surface of a conductor. Current is measured in (A) amperes or amps.

( E ) Voltage is the difference in electrical potential between two points in a circuit. It's the push or pressure behind current flow through a circuit, and is measured in (V) volts.

( R ) Resistance determines how much current will flow through a component. Resistors are used to control voltage and current levels. A very high resistance allows a small amount of current to flow. A very low resistance allows a large amount of current to flow. Resistance is measured in ohms.

( P ) Power is the amount of current times the voltage level at a given point measured in wattage or watts.  Ohm's Law: Calculators

Before clicking for the answer, enter numbers into the equation you wish to use to calculate for Current, Power, Resistance, or Voltage.

Calculators
 Current (I)
 Power (P)
 Resistance (R)
 Voltage (E)
 Ohm's Law Pie Chart Calculate for Current (I) Power Voltage Current Watts Volts Amps Power Resistance Current Watts Ohms Amps Voltage Resistance Current Volts Ohms Amps

 Calculate for Power (P) Current Resistance Power Amps Ohms Watts Voltage Current Power Volts Amps Watts Voltage Resistance Power Volts Ohms Watts Calculate for Resistance (R) Power Current Resistance Watts Amps Ohms Voltage Current Resistance Volts Amps Ohms Voltage Power Resistance Volts Watts Ohms Calculate for Voltage (E) Current Resistance Voltage Amps Ohms Volts Power Current Voltage Watts Amps Volts Power Resistance Voltage Watts Ohms Volts

  Ohm's Law Pie Chart

GW1NGL NA7KR Kevin Roberts Ham Radio

Page last updated on 09/10/2012 by Kevin Roberts NA7KR a colection of Ham Radio and Electronic Information