Science Sunday: RGB LED Power Consumption Calculator

June 7th, 2020
192 words · 1 minutes read

Before delving much-too-far down the rabbit hole of flashy, over-engineered lamp repairs and Arduino funtimes, I thought it advantageous to take an educated guess at the maximum power consumption of replacing some existing LEDs in a friends now-exploded lamp with WS2812 “NeoPixel Stick“ clones.

Num. LEDs {{ bgcolor }}
Red mA Green mA Blue mA Max mA
{{ out.rgbMa }}
Red % Green % Blue % Total Bright.
{{ out.totalBrightness | toFixed(2) }}%
Red Val Green Val Blue Val
{{ out.redVal }} {{ out.greenVal }} {{ out.blueVal }}
Power Usage
mA A Volts Watts
{{ out.ma | toFixed(1) }} {{ out.amp | toFixed(3) }} {{ out.watts | toFixed(2) }}

This calculator is not super-scientific.

  • There may be some inconsistencies due to rounding of values.
  • Even if you have all LEDs at 0% brightness, some power will still be used (though minimal).
  • I doubt (though have no proof) that the relationship between percentage brightness and power consumption scales linearly.

On the off-chance you hate JavaScript, or would just prefer an offline version of this calculator, you can download an Open/LibreOffice or Excel spreadsheet version.
There’s also a copy available on JSFiddle if you want to have a tinker.


Posted in: Science Sunday, Tech