Calculating the power supply for LED pixels

How big does my power supply need to be?

Add up the power of all strings or strips at full white (stated in every item) and choose a power supply with the same voltage that is loaded to no more than 80 %. With pixel strings, also inject power again at every connection between two strings using a T-connector.

Note: Connection to 230 V must be carried out by a qualified electrician.

Power and current at full white

Product	Voltage	Pixels	Power	Current
Pixel string	5 V	50	approx. 15 W	approx. 3 A
Pixel string	12 V	50	approx. 36 W	approx. 3 A
Pixel string	12 V	100	approx. 72 W	approx. 6 A
Pixel strip	5 V	150	max. 45 W	approx. 9 A
Pixel strip	5 V	240	max. 72 W	approx. 14.4 A
Pixel strip	5 V	300	max. 90 W	approx. 18 A
Pixel strip	12 V	100	max. 72 W	approx. 6 A

Values from the item details. The value stated in the respective item always applies.

How to calculate

Read the power per string or strip from the table or the item.
Multiply by the number of strings or strips.
Divide by 0.8: this is the minimum power of the power supply.
Choose the voltage to match the pixels: 5 V pixels on a 5 V power supply, 12 V pixels on a 12 V power supply.

If one power supply is not enough, split the installation across several power supplies.

Example: 500 pixels at 12 V

10 pixel strings at 12 V with 50 pixels each, laid in 2 runs of 5 strings:

Power: 10 × 36 W = 360 W
With reserve: 360 W ÷ 0.8 = 450 W
Split across 2 power supplies, 180 W ÷ 0.8 = 225 W per run, for example 2 × 12 V / 324 W
T-connectors: 10 strings − 2 runs = 8 pieces

Where to inject power

The wires in pixel strings are thin (see the guide Cable cross-section: mm² and AWG). Over the length the voltage drops, and at the end the pixels get darker or the colours are no longer right. At the start of a run, power comes through the connection cable. At every further connection between two strings, inject power again with a T-connector (power injection).

Number of T-connectors = strings − runs. Not just every second connection: two 100-pixel strings together draw up to 12 A, while one connector contact can carry 10 A at most.

Power supplies for indoors and outdoors

Power supplies rated IP67 have a fully potted housing and are suitable for outdoor use. Power supplies in a metal housing without an IP rating are intended for installation, for example in a control cabinet, and must be protected from moisture. The rating is stated in each item.

Frequently asked questions

Why 80 % and not 100 %?

The table values apply to full white, i.e. the highest consumption. With 80 % there is reserve left, and the power supply does not run permanently at its limit.

Do effects need less power?

On average yes, because all pixels rarely light up white. But the power supply must handle the brightest moment of the show. So plan with full white.

What happens without additional power injection?

At the end of the string the voltage drops, the pixels get darker or the colours shift. How this differs for 12 V pixels is explained in the guide Resistor or regulated?.

Is the T-connector also available for JST-SM?

The T-connector in our shop is for the xConnect® plug system. You will find all connectors and cables under Connectors & cables.

Planning a larger installation? Tell us about your project and we will work out the power supplies and injection points with you.

Discuss your project