Faraday's law of electrolysis tells you how much substance will be deposited as a function of the charge going through the solution, form that - and knowing the surface - you can calculate the thickness of the plating.

Charge itself is a function of the current used, to some extent that can be calculated from the voltage/concentration, but it is not trivial. Practical approach is to not bother with calculations, but to use the voltage to control the current.