Physics

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Current Divider Calculator.

Calculate current in each branch of a two-resistor current divider.

On-device calculationNo signup
01

Set your values

Results update as you type.

branchCurrent1: 0.666667 A

branchCurrent1

0.000000A
branchCurrent2: 0.333333 A

branchCurrent2

0.000000A

Results update automatically as you type.

This page applies only the stated idealized equation and explicit inputs; verify specialized engineering, medical, or safety decisions against applicable standards.

Use Cases

Circuit Analysis

Quickly determine how current splits between two parallel resistors in a circuit, useful for designing or troubleshooting electronic circuits.

Example: If total current is 2 A, R1=10 Ω, R2=20 Ω, currents are 1.333 A and 0.667 A.

Educational Tool

Helps students verify calculations and understand the current divider rule in physics or electrical engineering coursework.

Example: Check your homework by entering values and comparing results.

Frequently Asked Questions

How does the current divider calculator work?
It uses the current divider rule: for two parallel resistors, the current through one branch equals the total current multiplied by the opposite resistance divided by the sum of both resistances. Enter total current and the two resistances to get each branch current.
What units should I use for current and resistance?
Enter total current in amperes (A) and resistances in ohms (Ω). The calculator will output branch currents in amperes. Ensure consistent units for accurate results.
Can I use this calculator for more than two branches?
No, this calculator is specifically designed for a two-resistor current divider. For more branches, you would need a different tool or extend the formula manually.

Tips & Common Mistakes

Tips

  • Ensure the total current is the current entering the parallel combination, not the source current if there are other components.
  • Double-check that resistances are in ohms; convert kΩ to Ω by multiplying by 1000 if needed.
  • For a quick sanity check, the sum of the two branch currents should equal the total current.
  • If one resistance is much smaller, most of the current flows through that branch; use this to predict results.

Common Mistakes to Avoid

  • Using the wrong formula: current through a branch is not simply total current divided by that branch's resistance; it depends on the other branch.
  • Forgetting to convert units, such as using milliamps or kilo-ohms without conversion, leading to incorrect results.
  • Assuming the calculator accounts for internal resistance or other circuit elements; it only considers the two given resistors.

Last updated: August 13, 2026