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_fracResistance Below Wiper
r_bottom = total_r * wiper_fracResistance Above Wiper
r_top = total_r * (1 - wiper_frac)Variables
| Variable | Description | Default |
|---|---|---|
v_in | Input Voltage(V) | 5 |
total_r | Total Pot Resistance(Ω) | 10000 |
wiper_pct | Wiper Position(%) | 50 |
wiper_frac | Derived value= wiper_pct / 100 | calculated |
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
- 01V_out = 5 x 0.50 = 2.5 V
- 02R_bottom = 5000 ohms, R_top = 5000 ohms
Frequently Asked Questions
Does load affect output?
Yes. A low-impedance load reduces V_out. Use a buffer for sensitive circuits.
Linear vs logarithmic?
Linear changes uniformly. Log taper matches human hearing perception.
How to choose pot value?
Pick 10x higher than load impedance. Common: 1k, 10k, 100k.
Ready to run the numbers?
Open Potentiometer Output Calculator