Current Divider
Calculator
Results
- Current in branch 1 (A)
- 1.5
- Current in branch 2 (A)
- 0.5
- Parallel resistance (Ω)
- 75
Electrical results
| Current in branch 1 (A) | 1.5 |
| Current in branch 2 (A) | 0.5 |
| Parallel resistance (Ω) | 75 |
formula-map diagram
- Current in branch 1 (A)
- 1.5
- Current in branch 2 (A)
- 0.5
- Parallel resistance (Ω)
- 75
Electrical relationship
Formula
I1 = I × R2 / (R1 + R2)= 1.5
Note
This is a simplified model: it applies the textbook relationship to the numbers you entered and assumes ideal components, steady-state sinusoidal conditions, balanced loads and copper resistivity of 0.0172 Ω·mm²/m at 20 °C. It ignores component tolerances, temperature drift, skin effect, harmonics, inrush, transformer and battery losses, and it is not a substitute for the wiring code that applies where you are. Have any installation sized and verified by a licensed electrician or engineer.
More in Electrical engineering
See all →Frequently asked questions
How does the current divider formula work?+
For two resistors in parallel, the current through R1 is I1 = I_total x (R2 / (R1 + R2)) — notice the opposite resistor appears on top. More current flows through the branch with less resistance.
Why does the smaller resistor get more current in a current divider?+
Current takes the path of least resistance, so a lower-resistance branch lets more current through for the same voltage across it. That's why R1's current depends on R2 in the numerator, not R1.
Is the current divider rule the mirror image of the voltage divider rule?+
Yes. The voltage divider gives the larger share of voltage to the larger resistor, while the current divider gives the larger share of current to the smaller resistor. Both come from the same underlying Ohm's law relationships.
Does a current divider require the branches to be in parallel?+
Yes, the rule only applies to resistors connected in parallel, since that's the configuration where the total current splits between the branches. In series, all elements carry the exact same current, so there's nothing to divide.
Can I use the current divider formula with more than two resistors?+
The direct two-resistor formula doesn't extend cleanly to three or more branches; instead, find the total parallel resistance first, then use Ohm's law on each branch with the same shared voltage to get its individual current.