# Ohm's Law Calculator

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

### Updated Ohm’s Law calculator: will now calculate based on any two of the four values.

Enter the TWO known values then click on the "Calculate" button. To start over, click on "Reset".

If you have a device that gives you the ability to adjust voltage and adjust wattage: here’s how it works, you can only adjust one at a time. When you put a *tomizer on your battery, it already has ohms set. The ohms are dependent on the "coil" ... how many twists of the coil, thickness of the wire, diameter of the inner coil wrap. If you then adjust voltage, the circuitry in your mod will determine automatically what the wattage will be. If you adjust the wattage, the circuitry in your mod will determine what the volts will be. You cannot define volts and watts and have a fixed *tomizer ohm – it’s impossible and defies the laws of physics.

Which is best? That really is a personal preference based on how you use your device. If you like ultimate control and frequently adjust your device to match your eLiquid, change volts. If you prefer to find the "sweet spot" and use the same eLiquid (particularly same viscosity), adjust your wattage. Overall, I believe that wattage is the most flexible. On most devices adjustage wattage has a greater range of adjustment than volts. That means that your device has finer control over the volts based on the *tomizer and wattage setting you have picked. If you change *tomizer and you have not changed the wattage, the device will compensate for the *tomizer by modifying the volts. Seems to be the most practical way to use these VV/VW devices.

### How the calculation works

We also received an email asking how the calculation works, particularly can rounding out cause errors or false answers. The calculations are performed based on Ohm’s Laws. The rounding out happens only when displaying the answer. At no point is any calculation performed on any rounded out input. What you see in the field is the data used for the calculation. For example, if you enter in watts with a 6 digit precision, and volts with a six digit precision, the answer will be calculated on those exact numbers and answered with two digit precision.

### What are the calculations

R = Resistance (ohms)
V = Volts
I = Current (amps)
P = Power (watts)

Ohm’s Law:
R = V / I
I = V / R
V = I x R

Other ways of achieving same calculations:

R = V2 / P (Voltage squared divided by Power)
R = P / I2 (Power divided by Current squared)
I = P / V
I = square root of (P / R)
V = P / I
V = square root of (P x R)
P = V x I
P = V2 / R (Voltage squared divided by Resistance)
P = I2 x R (Current squared times Resistance)