 # Ohm's Law Calculations With Power

In the four tables below, you may enter two of the four factors in Ohm's Law. They are Power (P) or (W), measured in Watts, Voltage (V) or (E), measured in Volts, Current or Amperage (I), measured in Amps (Amperes), and Resistance (R) measured in Ohms. The needed factor will be calculated for you when you click on the Calculate button for that table.

Though not part of the original theory, in later years, we have also attributed the Power factor to Ohm as well. Power is usually abbreviated by (W) and measured in Watts. The formula generally given for Power is:
W = V x I or W = I2 x R or W = V2 / R. Other basic formulae involving Power are:
I = W / V or I = (W / R)2
V = (W x R)2 or V = W / I
R = V2 / W or R = W / I2

For the original Ohm's Law Calculations, click here. To check the color codes of resistors, use our Resistor Color Code Table And Calculator. This converter requires the use of Javascript enabled and capable browsers.

Ohm's Law Factors With Power

## Calculate Watts

To calculate the circuit power...
The formula is W = V x I or,
W = I2 x R or,
W = V2 / R

Enter any two factors of V, I, and R

Voltage      Current      Resistance

Calculated Power

## Calculate Amperes

To calculate the circuit amperage...
The formula is I = V / R or,
I = W / V or,
I = (W / R)2

Enter any two factors of V, W, and R

Voltage      Power        Resistance

Is it 3-Phase? (Do not enter R if circuit is 3-Phase.)

Calculated Amperage

## Calculate Volts

To calculate the circuit voltage...
The formula is V = I x R or,
V = (W x R)2 or,
V = W / I

Enter any two factors of W, I, and R

Power         Current      Resistance

Calculated Voltage

## Calculate Ohms

To calculate the circuit resistance...
The formula is R = V / A
R = V2 / W or,
R = W / I2

Enter any two factors of V, I, and W

Voltage      Current       Power

Calculated Resistance

 Aluminum 2.828 x 10-6 Copper 1.676 x 10-6 Silver 1.586 x 10-6 Gold 2.214 x 10-6 Tungsten 5.510 x 10-6

For example, a 10 Gauge wire is 2.588mm in diameter.
The resistance per cm of copper wire that thick is
3.186 x 10-5W/cm. A mile of this wire has a resistance of 5.13 W.

 Leave us a question or comment on Facebook Search or Browse Our Site  