Potentiometer Output Calculator Formula

Understand the math behind the potentiometer output calculator. Each variable explained with a worked example.

Formulas Used

Output Voltage

v_out = v_in * wiper_frac

Resistance Below Wiper

r_bottom = total_r * wiper_frac

Resistance Above Wiper

r_top = total_r * (1 - wiper_frac)

Variables

VariableDescriptionDefault
v_inInput Voltage(V)5
total_rTotal Pot Resistance(Ω)10000
wiper_pctWiper Position(%)50
wiper_fracDerived value= wiper_pct / 100calculated

How It Works

Potentiometer as Voltage Divider

V_out = V_in x (position / 100)

The wiper divides the pot into two resistors forming a divider. Assumes no load.

Worked Example

10k pot at 50% on 5 V.

v_in = 5total_r = 10000wiper_pct = 50
  1. 01V_out = 5 x 0.50 = 2.5 V
  2. 02R_bottom = 5000 ohms, R_top = 5000 ohms

Ready to run the numbers?

Open Potentiometer Output Calculator