LED Series Resistor & Wattage Calculator
Calculate exact series resistance (Ohms), standard E24 component value, and resistor power dissipation in Watts for LED circuits.
- 100% free
- Private in browser
- No signup
- No watermarks
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About LED Series Resistor & Wattage Calculator
Calculate exact series resistance (Ohms), standard E24 component value, and resistor power dissipation in Watts for LED circuits. Enter Source Voltage, LED Forward Voltage and Target LED Current and the tool works out Required Resistance, Nearest Standard E24 Resistor and Resistor Power Dissipation straight away. Everything runs in your browser, so your data never leaves your device.
How to use LED Series Resistor & Wattage Calculator
- Enter Source Voltage, LED Forward Voltage and Target LED Current.
- Adjust the remaining options (Number of LEDs in Series) to match your case.
- Read Required Resistance, Nearest Standard E24 Resistor and Resistor Power Dissipation in the results panel — copy or download what you need.
Key features
- Shows Required Resistance (Ohms Ω)
- Shows Nearest Standard E24 Resistor (Ω)
- Shows Resistor Power Dissipation (Watts)
- 4 adjustable inputs, results update as you type
- No signup, no limits
Frequently asked questions
- Is this calculation free and private?
- Yes, 100% of calculations execute locally in your web browser. No inputs or personal data are stored or transmitted.
- What does the LED Series Resistor & Wattage Calculator give me?
- It works out Required Resistance, Nearest Standard E24 Resistor, Resistor Power Dissipation and Minimum Resistor Power Rating, updating live as you change the inputs.
- What do I need to enter?
- Just Source Voltage, LED Forward Voltage, Target LED Current and Number of LEDs in Series. Every field has a sensible default you can start from.
- Is my data uploaded anywhere?
- No. The calculation runs in your browser with JavaScript — nothing you type is sent to a server or stored.
- Does it work on a phone?
- Yes. The layout adapts to small screens and needs no app or signup.
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