WS2812B power is where most LED projects fail: the strip flickers, turns pink at the far end, or the power supply shuts down the moment you set everything to white. Each WS2812B pixel can draw up to about 60 mA at full white, so 300 LEDs can theoretically pull 18 A at 5 V. Use the calculator below to size the power supply, then read how to wire power injection and set the WLED current limiter.
WS2812B / addressable LED power calculator
How much current does a WS2812B draw?
Each pixel contains red, green and blue LEDs at roughly 20 mA each at full brightness. Full white is the worst case:
| LED type | Voltage | Max per pixel (white, 100%) |
|---|---|---|
| WS2812B, SK6812 RGB | 5 V | about 60 mA |
| SK6812 RGBW | 5 V | about 80 mA |
| WS2815 | 12 V | about 15–20 mA |
| WS2811 (3 LEDs per IC) | 12 V | about 20 mA per group |
Real strips often draw less than the datasheet maximum, and typical animations run at 30–60% brightness with mixed colors. That is why sizing for the absolute worst case often gives an oversized supply — but you must then limit brightness in software.
Choosing the power supply
- Calculate the expected current at your brightness and content.
- Add at least 20% headroom.
- Make sure the supply can handle the absolute maximum if a bug ever sets everything to full white — or set a current limit in the controller.
A good-quality 5 V 10 A supply comfortably powers about 300 LEDs at 50% brightness with mixed effects.
Power injection
A 5 V strip has thin copper traces. Over 1–2 meters the voltage drops enough that blue and green fade first and the far end turns orange or pink. The fix is to feed power at several points:
- 5 V strips: inject roughly every 50–60 LEDs (about 1 m at 60 LED/m).
- 12 V strips (WS2815, WS2811): every 150 pixels or so is usually enough.
- Connect all grounds together, including the controller’s ground.
- Use 18 AWG (0.75 mm²) or thicker wire for injection lines; 22 AWG is fine only for short runs.
WLED current limiter
WLED has an automatic brightness limiter (ABL). Set LED Preferences → Maximum current to about 85% of your supply rating. WLED estimates current from the colors it sends and dims the strip before it exceeds the limit, which protects both the supply and the wiring. The calculator above suggests a value.
Data line tips
- Keep the data wire from the ESP32 to the first LED short, under about 1 m.
- Add a 330–470 Ω resistor in series with the data line close to the strip.
- Put a 1000 µF capacitor across 5 V and GND at the strip input.
- For 3.3 V controllers driving 5 V strips over long wires, use a level shifter such as 74AHCT125.
To flash WLED, use the official installer or our ESP32 web flasher. For a single plain LED, the LED resistor calculator gives the series resistor.
Install WLED from your browser
Our free ESP32 web flasher writes WLED or any other firmware to ESP32, S3, C3 and ESP8266 boards — no software to install.
Flash WLED onto ESP32FAQ
Can I power WS2812B from the ESP32’s 5 V pin?
Only a handful of LEDs at low brightness. The USB port and the board’s traces handle about 500 mA. Power the strip directly from the supply.
Why do my LEDs turn pink at the end of the strip?
Voltage drop. Inject power at more points and use thicker wires.
5 V or 12 V strip for a long run?
12 V strips (WS2815, WS2811) need four times less current for the same power, so voltage drop is far smaller. For runs longer than a few meters they are easier to power.
Sources: WLED documentation and Adafruit NeoPixel Uberguide — powering.