💡 LED Resistor Calculator
Find the correct current-limiting resistor for a single or multi-LED circuit.
Common LED Presets
Click to auto-fill typical values for common LED colours.
Circuit Values
R = (Vs − n × Vf) / If | Power = If² × R
LEDs
⚠ Check values — supply must exceed total LED voltage drop.
Results
Typical LED Specifications
| Colour | Vf (typical) | If (typical) | Wavelength |
|---|---|---|---|
| 🔴 Red | 1.8 – 2.2 V | 10 – 20 mA | 620 – 750 nm |
| 🟠 Orange | 2.0 – 2.2 V | 10 – 20 mA | 590 – 620 nm |
| 🟡 Yellow | 2.0 – 2.4 V | 10 – 20 mA | 570 – 590 nm |
| 🟢 Green | 2.0 – 3.5 V | 10 – 20 mA | 495 – 570 nm |
| 🔵 Blue | 2.7 – 3.5 V | 10 – 20 mA | 450 – 495 nm |
| 🟣 Violet | 3.0 – 4.0 V | 10 – 20 mA | 380 – 450 nm |
| ⚪ White | 2.9 – 3.5 V | 20 – 30 mA | Broadband |
| Infrared | 1.2 – 1.8 V | 20 – 100 mA | 850 – 950 nm |