Nernst Equilibrium Potential Calculator
Enter extracellular and intracellular ion concentrations. An equilibrium potential is calculated when both concentrations are defined and greater than zero.
Example Concentrations
Extracellular:
Source: —
Intracellular:
Source: —
| Ion | Valence (z) | Extracellular (mM) | Intracellular (mM) | Equilibrium Potential (mV) |
|---|
Nernst equation
Eion = (RT / zF) ln([ion]outside / [ion]inside)
R = 8.3145 J·mol⁻¹·K⁻¹; F = 96485 C·mol⁻¹. Concentrations should use the same units; this calculator labels them as mM. Default temperature is 22 °C. Results are rounded to one decimal place.