šŸ’” 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

$$R = \dfrac{V_s - n\,V_f}{I_f} \qquad P = I_f^2\,R$$
+ Vs R — If LED Vf
LEDs
⚠ Check values — supply must exceed total LED voltage drop.

Results

Typical LED Specifications

ColourVf (typical)If (typical)Wavelength
šŸ”“ Red1.8 – 2.2 V10 – 20 mA620 – 750 nm
🟠 Orange2.0 – 2.2 V10 – 20 mA590 – 620 nm
🟔 Yellow2.0 – 2.4 V10 – 20 mA570 – 590 nm
🟢 Green2.0 – 3.5 V10 – 20 mA495 – 570 nm
šŸ”µ Blue2.7 – 3.5 V10 – 20 mA450 – 495 nm
🟣 Violet3.0 – 4.0 V10 – 20 mA380 – 450 nm
⚪ White2.9 – 3.5 V20 – 30 mABroadband
Infrared1.2 – 1.8 V20 – 100 mA850 – 950 nm