Calculate how current splits between parallel branches.
Parallel branches share the same voltage, so current divides in proportion to conductance — the lowest resistance takes the most current. Adding conductances is the simplest route to the combined resistance. Current sharing in parallel devices is never perfectly equal because resistances differ, which is why paralleled semiconductors need ballast resistors.
Current Divider
I_n = I_total × (1/R_n) ÷ Σ(1/R); equivalently I_n = V ÷ R_n
I_n = I_total × (1/R_n) ÷ Σ(1/R); equivalently I_n = V ÷ R_n Parallel branches share the same voltage, so current divides in proportion to conductance — the lowest resistance takes the most current. Adding conductances is the simplest route to the combined resistance.
Current sharing in parallel devices is never perfectly equal because resistances differ, which is why paralleled semiconductors need ballast resistors.
This calculator takes 4 inputs: Total current, Branch 1 resistance, Branch 2 resistance, Branch 3 resistance. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.