Current Divider Calculator

Created: 18/03/2026Updated: 03/06/2026By: Mert
Current Divider Calculator
In = IT × RT/Rn
Two branches: I₁ = IT × R₂/(R₁+R₂)
Current Divider — Enter Total Current & Branch Resistances
I Total Current (IT)
Enter total current and branch resistances
Current Divider Results
RT (parallel)
—
Ω
IT (total)
—
A
V (across all)
—
V
Current Divider: I Splits Inversely to R IT R₁ I₁ (large) R₂ I₂ (small) (small R) (large R) More current flows through the smaller resistance

Figure 1: In a current divider, current splits inversely proportional to resistance. The branch with the smallest resistance carries the largest share of the total current.

Table of Contents
Fundamentals
  1. What Is a Current Divider?
  2. The Current Divider Formula
Worked Examples
  1. Two-Branch Divider
  2. Three-Branch Sensor Circuit
  3. Equal Branches
Deep Dive
  1. Current Divider vs Voltage Divider
  2. Practical Applications
Reference
  1. Frequently Asked Questions
  2. Related Circuit Analysis Calculators

What Is a Current Divider?

A current divider is a parallel circuit that splits a total current into smaller branch currents. Each branch carries a share of the total current that is inversely proportional to its resistance — smaller resistors carry more current, larger resistors carry less. This is the dual of a voltage divider, where voltage divides proportionally to resistance in a series circuit.

The Parallel Circuit Calculator provides the full parallel analysis including voltage and power. This calculator focuses specifically on the current-splitting behaviour.

The Current Divider Formula

General (any number of branches): In = IT × (RT / Rn)
Two branches only: I₁ = IT × R₂ / (R₁ + R₂)
Where RT is the total parallel resistance of all branches.

Note that in the two-branch formula, the “other” resistor (R₂) appears in the numerator, not the branch’s own resistor. This reflects the inverse relationship: a larger R₂ pushes more current through R₁.

Worked Example — Two-Branch Divider

Given: IT = 100 mA, R₁ = 1 kΩ, R₂ = 2.2 kΩ

I₁ = 100 × 2200 / (1000 + 2200) = 100 × 0.6875 = 68.75 mA

I₂ = 100 × 1000 / (1000 + 2200) = 100 × 0.3125 = 31.25 mA

The 1 kΩ branch carries more than twice the current of the 2.2 kΩ branch, as expected from the inverse relationship. The Circuit Current Calculator can verify each branch independently.

Worked Example — Three-Branch Sensor Circuit

Given: IT = 500 mA, R₁ = 47 Ω, R₂ = 100 Ω, R₃ = 220 Ω

RT = 1/(1/47 + 1/100 + 1/220) = 28.08 Ω

I₁ = 500 × 28.08/47 = 298.7 mA (59.7%)

I₂ = 500 × 28.08/100 = 140.4 mA (28.1%)

I₃ = 500 × 28.08/220 = 63.8 mA (12.8%)

Worked Example — Equal Branches

Given: IT = 1 A, four equal 10 Ω branches

Each branch carries I/n = 1/4 = 250 mA

With equal branch resistances, the current divides equally. This is used in high-current applications where you parallel multiple resistors to share the load and spread heat dissipation. The Power Dissipation Calculator helps verify each branch stays within its rating.

Current Divider vs Voltage Divider

A voltage divider uses series resistors to split voltage. A current divider uses parallel resistors to split current. The key difference is that voltage divides proportionally to resistance (larger R gets more voltage), while current divides inversely (smaller R gets more current). Both are fundamental circuit analysis tools that appear throughout the Series and Parallel calculators.

Practical Applications

Current dividers appear in ammeter shunt resistors (diverting most current around the meter), transistor biasing networks, current mirrors in analogue IC design, current sensing, and LED arrays where current must split between multiple strings. The Wheatstone Bridge Calculator uses the current divider principle in its balanced-bridge analysis.

Frequently Asked Questions

Can the current in one branch exceed the total?
No. Each branch current is always less than or equal to the total. The sum of all branch currents must equal the total current (Kirchhoff’s Current Law). If one branch goes to zero (open), the remaining branches carry the full total.
What if one branch resistance is much smaller?
It carries nearly all the current, effectively short-circuiting the other branches. In the limit of Rn → 0, all current flows through that branch. This is why parallel short circuits are dangerous.
Does the current divider work for AC circuits?
Yes, but you must use impedances (Z) instead of resistances, and the calculations involve complex numbers. The principle is the same: current divides inversely proportional to impedance magnitude.
How is this different from the Parallel Circuit Calculator?
The Parallel Circuit Calculator takes source voltage as input and finds everything. The Current Divider Calculator takes total current as input — useful when you know the current from a previous analysis stage or a current source.
Voltage Drop Calculator Induced Current Calculator Thevenin Equivalent Calculator Norton Equivalent Calculator KVL Circuit Calculator KCL Circuit Calculator Magnetic Force Between Wires Calculator Magnetic Force on Wire Calculator

Browse all Electronics Calculators →

Last updated: March 2026