Electrochemical Galvanic Cell EMF Calculator (Nernst Equation

Electromotive Force (EMF) is the maximum potential difference in electrical voltage between the two electrodes of a galvanic cell. Standard cell potentials are calculated at 25°C (298.15 K), 1 atm, and 1 M ion concentrations.

To use the Electrochemical Galvanic Cell EMF Calculator (Nernst Equation), enter your Cathode Standard Reduction Potential (E° cathode), Anode Standard Reduction Potential (E° anode), Number of Transferred Electrons (n) and other values. The calculator instantly computes Standard Cell Potential (E° cell), Non-Standard Cell EMF (E cell) and more. Results update in real time as you change any input — no submit button needed.

How to Use This Calculator

Enter your Cathode Standard Reduction Potential (E° cathode) (e.g. 0.34 in V), Anode Standard Reduction Potential (E° anode) (e.g. -0.76 in V), Number of Transferred Electrons (n) (e.g. 2 in e⁻), and Reaction Quotient (Q = [Products]/[Reactants]) (e.g. 1.0). Verify your units match the formula standard (SI vs imperial) before entering values.

The Formula

Standard Cell Potential E° cell = E° cathode - E° anode

Nernst Equation: E cell = E° cell - (0.05916 ÷ n) × log10(Q)

Gibbs Free Energy ΔG° = -n × F × E° cell (F = 96,485 C/mol)

Worked Example

Daniell Cell: Cu²⁺/Cu Cathode and Zn²⁺/Zn Anode with n = 2 e⁻ at Q = 1.0:

E° cell = +0.34 - (-0.76) = +1.100 V.

Non-Standard E cell = +1.100 V.

Understanding Your Result

Force in Newtons (N): 1 N = 1 kg·m/s². Reference values: 1 kg object at Earth's surface weighs 9.81 N, atmospheric pressure 101,325 Pa (N/m²). Pressure benchmarks: car tire 30–35 psi (207–241 kPa), blood pressure systolic 120 mmHg (16 kPa), deep sea at 3,000m depth ~300 atm (30 MPa). Torque = Force × moment arm length — doubling the wrench length doubles the torque for the same applied force. Always verify whether gauge or absolute pressure is required for the application.