Faraday's Law Calculator
Calculate the mass deposited or consumed in electrolysis from charge passed.
About Faraday's Law Calculator
Mass deposited is proportional to charge passed and inversely proportional to the electron count per ion. Current efficiency accounts for side reactions such as hydrogen evolution that consume charge without depositing metal. Electroplating thickness is controlled entirely by charge, which is why plating is specified in amp-minutes rather than by current or time alone.
Formula
Faraday's Law
m = (Q M) ÷ (z F) × current efficiency, with Q = I t
- z
- Electrons required per ion deposited
- F
- Faraday constant, 96,485 C/mol
Worked example
With the default values below, Faraday's Law Calculator returns Mass Deposited of 5.63147. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Currentminimum 0 A
- 5 A
- Timeminimum 0 s
- 3,600 s
- Molar mass of the deposited speciesminimum 0 g/mol
- 63.55 g/mol
- Electrons per ionaccepts 1–10
- 2
- Current efficiencyaccepts 0–100 %
- 95 %
Results
- Mass Deposited
- 5.63147 g
- Charge Passed
- 18,000.00 C
- Moles Deposited
- 0.088615 mol
- Deposition Rate
- 5.631471 g/h
- Time to Deposit One Gram
- 2,581,735.47 s
Step by step
- 1Values used
- 2Faraday's Law
- 3Mass Deposited= 5.63147 g
- 4Charge Passed= 18,000.00 C
- 5Moles Deposited= 0.088615 mol
- 6Deposition Rate= 5.631471 g/h
- 7Time to Deposit One Gram= 2,581,735.47 s
Assumptions and limits
- The result is derived only from the 5 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 6 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Faraday's Law calculated?
m = (Q M) ÷ (z F) × current efficiency, with Q = I t Mass deposited is proportional to charge passed and inversely proportional to the electron count per ion. Current efficiency accounts for side reactions such as hydrogen evolution that consume charge without depositing metal.
Why does Faraday's Law matter?
Electroplating thickness is controlled entirely by charge, which is why plating is specified in amp-minutes rather than by current or time alone.
What values do I need to enter?
This calculator takes 5 inputs: Current, Time, Molar mass of the deposited species, Electrons per ion, Current efficiency. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.