Electrode Potential (Nernst Equation)

Calculate reduction potential of an electrode under non‑standard conditions.

Standard reduction potential E° (V)

e.g., Cu²⁺/Cu = +0.34 V

Temperature T (K)

Number of electrons transferred (n)

Concentration of oxidized form [Ox] (M)

Concentration of reduced form [Red] (M)

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E = E° - (RT / nF) ln(Q) , where Q = [Red]/[Ox] for reduction: Ox + n e⁻ → Red

At 298 K, (RT/F) = 0.0257 V, so E = E° - (0.0257 / n) ln(Q)

Using log₁₀: E = E° - (0.05916 / n) log₁₀(Q) at 298 K

For a reduction half‑cell, Q = [Red]/[Ox].
If you have activities instead of concentrations, use those for higher accuracy.
This calculator uses the natural log form with R=8.314, F=96485; temperature in Kelvin.