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Pixel Power Calculator


This page will help you plan by providing the formulas, and functional calculators to help determine:

Plug in your own numbers into the text boxes below for it to auto-calculate. Alternatively, use one of the two links below to autofill the two most common setups, and change the numbers in blue to match your specific layout or design.


Pixels Per Power Supply

This formula will give you a baseline of how many pixels you can load each power supply before having to add another. These calculations are worst case scenario in which you run full white for all pixels at a given brightness.

Formula: (Power Supply Wattage × 80%) / (Pixel Wattage × Brightness Percentage) = Pixels Per Power Supply

Example: 12v pixels running at 50% brightness on a 350w power supply:
(350w × 80%) / (0.6w × 50%) = 933.33 Pixels Per Power Supply

( × 80% ) / ( × ) = 933 Pixels Per PSU

Power Supplies Needed

This formula will tell you how many power supplies you will need to use if you want to power XX amount of pixels. The formula provides a worst case scenario in that it assumes all pixels will be run at full white at a given brightness.

Formula: (Pixel Count × Pixel Wattage × Brightness Percentage) / (Power Supply Wattage × 80%) = Power Supplies Needed (Round Up)

Example: 1,500 pixels running at 30% brightness using 350w power supplies:
(1,500 × 0.6w × 30%) / (350w × 80%) = 0.96 rounded up to 1

( × × ) / ( × 80%) = 2 Power Supplies Needed

Power From The Grid

This last formula will tell you how many amps of AC power your power supplies will draw from the grid. This again is a worst case scenario in which it assumes the power supply will be running at 100% of the rated wattage. The formulas above under-rate the power supply by 20% to allow for headroom.

Formula: Power Supply Count × (Power Supply Rated Wattage / Efficiency / Power Factor / AC Voltage) = Grid Amps Needed

Example: Two Meanwell LRS style 350w power supplies on North American 115vac
2 × (348w / 85% / 52% / 115vac) = 13.69 amps

× ( / / / ) = 13.69 Grid Amps Needed

Originally Published 9/13/2022 12:27 PM EST
Updated 9/14/2022 2:46 PM EST
By Ken MacMaster