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

VariableDescriptionDefault
total_currentTotal Current(A)1
r1Resistance R1(Ω)100
r2Resistance 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
  1. 01I1 = 1 x 200 / (100 + 200) = 0.6667 A
  2. 02I2 = 1 x 100 / (100 + 200) = 0.3333 A
  3. 03Check: 0.6667 + 0.3333 = 1.0 A

Ready to run the numbers?

Open Current Divider Calculator