Potentiometer Output Voltage Calculator

How it is calculated

The tool treats the potentiometer as a two-resistor voltage divider with nothing connected to the wiper:

Vout = Vin × p / 100

where Vin is the voltage across the two end terminals in volts, and p is the wiper position in percent of full travel, 0 at the ground end and 100 at the supply end. The track's total resistance cancels out, so a 10 kΩ and a 100 kΩ pot give the same unloaded voltage. A position below 0 or above 100 returns no result. The answer is rounded to two decimals and shown in volts; a negative input voltage simply gives a negative output, because the formula is linear.

Common mistakes

• Entering the position as a fraction, such as 0.375, instead of a percentage. The field expects 0 to 100, so 0.375 is read as 0.375% and gives a tiny voltage.
• Using the result for a loaded circuit. The formula assumes nothing draws current from the wiper; a load in parallel with the lower part of the track pulls the voltage down, and the lower the load resistance, the larger the error.
• Confusing the rotation angle with the track position. On a logarithmic (audio) taper pot, 50% of the knob rotation is not 50% of the resistance, so convert the knob angle to the real track percentage first.
• Typing the potentiometer's resistance and expecting it to matter. It is not an input, because it cancels out for an unloaded output.
• Entering a position above 100, for example a raw ADC reading. The tool returns nothing outside 0 to 100.