Standard Cell Potential Calculator
Find the standard cell potential of an electrochemical cell from its electrode reduction potentials and determine whether the reaction is spontaneous.
V
V
Spontaneous (galvanic) cell
- 1
Cathode reduction potential
0.34 - 2
Anode reduction potential
-0.76 - 3
Cell potential: E°cathode − E°anode
0.34 − (-0.76) = 1.1000Positive E°cell → spontaneous (galvanic) reaction.
How does this calculator work?
Standard cell potential is E°cell = E°cathode − E°anode, using standard reduction potentials in volts. A positive E°cell means the reaction is spontaneous (a galvanic cell). With the electrons transferred n, the standard Gibbs free energy is ΔG° = −n · F · E°cell, where F = 96485 C/mol, reported in kJ/mol.
Formula
How this is calculated
Enter the standard reduction potentials (in volts) for the cathode and the anode. Both values must be standard reduction potentials taken from a standard electrode potential table, measured relative to the standard hydrogen electrode at 25 °C, 1 M concentrations and 1 atm.
The standard cell potential is calculated as E°cell = E°cathode − E°anode. The cathode is the electrode where reduction occurs and the anode is where oxidation occurs; subtracting the anode reduction potential accounts for reversing that half-reaction. A positive E°cell means the cell is spontaneous (a galvanic/voltaic cell that releases energy), while a negative value means it is non-spontaneous and would require external energy (electrolytic cell).
If you supply the number of electrons transferred (n) in the balanced redox reaction, the calculator also returns the standard Gibbs free energy change using ΔG° = −n · F · E°cell, where F = 96485 C/mol is the Faraday constant. The result is converted to kJ/mol. A negative ΔG° confirms spontaneity. Note that E°cell does not depend on the number of moles or how the equation is scaled, but ΔG° does.
Frequently asked questions
Both inputs are standard reduction potentials. Since oxidation occurs at the anode, its half-reaction is reversed, which flips the sign — equivalent to subtracting the anode reduction potential from the cathode reduction potential.
A positive E°cell indicates a spontaneous reaction, meaning the cell acts as a galvanic (voltaic) cell that can produce electrical work. A negative value indicates a non-spontaneous reaction requiring an external power source.
No. E°cell is an intensive property and is independent of how the balanced equation is scaled. However, ΔG° = −nFE°cell is extensive and doubles when n doubles.
Also known as
TG we-Calculate Editorial Team. (2026). Standard Cell Potential Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/standard-cell-potential-calculator
TG we-Calculate Editorial Team. "Standard Cell Potential Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/standard-cell-potential-calculator.
TG we-Calculate Editorial Team, "Standard Cell Potential Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/standard-cell-potential-calculator
@misc{wecalculate_standard_cell_potential_calculator, title = {Standard Cell Potential Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/standard-cell-potential-calculator}}, year = {2026}, note = {TG we-Calculate} }
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