Faraday Calculator

Relate current, charge, time, substrate amount, and electrons transferred in an electrolysis experiment.

Electrochemistry lab tool

Fill any three values and the calculator will determine the missing fourth parameter: substrate amount, current, charge equivalents, or electrolysis time.

Leave the value you want to calculate empty.

Faraday constant 96485.33212 C/mol
Mode Calculates any one missing parameter
Input rule Enter three values

Inputs

Reaction parameters

Results

Calculated output

Calculated parameter Not set
Substrate amount Not set
Current Not set
Charge equivalents Not set
Charge passed Not set

Time result

Not set

Calculation summary

Enter any three parameters and leave the fourth blank.

Method

Charge, current, and electrolysis time

Q = It and Q = nszF, where Q is charge in coulombs, I is current in amperes, t is time in seconds, ns is substrate amount in moles, z is the entered charge equivalents in F mol⁻¹ of substrate, and F is 96,485.33212 C mol⁻¹.

Worked example

Passing 2.00 F through 0.50 mmol substrate requires 96.49 C. At a constant current of 10.0 mA, the calculated electrolysis time is approximately 2 h 40 min 49 s.

Limitations: this is a charge balance. It does not predict conversion, current efficiency, competing electrochemical processes, mass transport, electrode passivation, changing cell resistance, or changes in current during controlled-potential electrolysis.

Tool version 1.1, released 21 July 2026. Faraday constant from the NIST Reference on Constants. The worked example above is the calculation check used for version 1.1.

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