Current divider calculator
How current splits between parallel resistors — the mirror image of the voltage divider.
The circuit this computes
Voltage Divider — fully explained →How it works
Parallel branches share one voltage. Ohm's law then fixes each branch's current: I_branch = V/R_branch. Express V as I_total × (R1∥R2) and the divider falls out: I1 = I × R2/(R1+R2). The inverse proportionality is the whole lesson — and the reason a fat copper trace in parallel with your shunt resistor quietly ruins a current measurement.
Common questions
Both branches see the same voltage, so the branch with LESS resistance takes MORE current — division is inverse. I1 = I × R2/(R1+R2): R2 in the numerator because R1's share grows as R2 grows. It's the exact mirror of the voltage divider, where your own resistor sits on top.
No — that phrase is folklore. Current takes EVERY path, in inverse proportion to resistance. A 1 Ω path in parallel with a 1 kΩ path still sends ~0.1% through the 1 kΩ. The only time all current takes one path is when the other is truly open.
Same principle through conductances: each branch takes G_branch/G_total of the current, where G = 1/R. For two branches that algebra simplifies to the R2/(R1+R2) form; for more, work in conductances — it stays one line.