Current Divider Calculator Formula
Understand the math behind the current divider calculator. Each variable explained with a worked example.
Formulas Used
Current through R1
i1 = total_current * r2 / (r1 + r2)Current through R2
i2 = total_current * r1 / (r1 + r2)Variables
| Variable | Description | Default |
|---|---|---|
total_current | Total Current(A) | 1 |
r1 | Resistance R1(Ω) | 100 |
r2 | Resistance R2(Ω) | 200 |
How It Works
Current Divider Rule
When two resistors are in parallel, current splits inversely proportional to resistance.
Formula
I1 = I_total x R2 / (R1 + R2)
I2 = I_total x R1 / (R1 + R2)
More current flows through the smaller resistance.
Worked Example
1 A splits between R1 = 100 ohms and R2 = 200 ohms in parallel.
total_current = 1r1 = 100r2 = 200
- 01I1 = 1 x 200 / (100 + 200) = 0.6667 A
- 02I2 = 1 x 100 / (100 + 200) = 0.3333 A
- 03Check: 0.6667 + 0.3333 = 1.0 A
Frequently Asked Questions
Why does the smaller resistor carry more current?
Lower resistance offers an easier path so more current flows through it.
Does this work for more than two resistors?
Yes, but the formula extends. For two resistors the simplified form here is most convenient.
What if R1 equals R2?
Current divides equally: each branch carries half the total.
Ready to run the numbers?
Open Current Divider Calculator