LED Resistor Calculator

Input Parameters

Colorblind Mode

Supply Voltage (Vₛ)

DC power source voltage in volts

Must be > 0

LED Forward Voltage (Vᶠ)

Typical range: 0.5V - 4.0V

Must be less than supply voltage

Desired LED Current (I)

Operating current in milliamps (0.1-100mA)

Must be > 0

Number of LEDs (n)

Connected in series

Integer ≥ 1 required

LED Configuration

Electrical connection type

Efficiency Mode

Current derating for safety

Resistor Series

Standard resistor tolerance series

Min Resistor Power (W)

Minimum available power rating

Calculation Results

Enter parameters and click Calculate

Voltage Headroom Diagram

LED: 0V

Supply: 0V

Instantly shows voltage budgeting - exposes insufficient headroom errors

Resistor Power Dissipation Bar Thermal Safety

Power Used: 0W

Rating: 0W

Prevents resistor overheating - shows safety margin visually

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