How to Calculate LED Strip Power Supply Requirements

How to calculate power supply requirements

The recommended power supplies above are based on our assumption that you will use the entire LED strip reel as a continuous strip. If you decide to use a smaller segment or search for your own power supply units, use the following method to calculate the necessary power draw:

Step 1: Determine the length of LED strip you will connect to a single power supply

Step 2: Determine the voltage and amps per foot (or meter) for the LED strip. For example, the Waveform FilmGrade LED strip amps per foot are:

  • 12V: 0.50 Amps per foot (1.5 Amps per meter)
  • 24V: 0.25 Amps per foot (0.75 Amps per meter)

You can typically find this information listed on the product page or specification sheet.

Step 3: Calculate the total power draw in Amps using the formula [LED Strip Amps] = [Amps per foot] x [Length of LED strip]

Step 4: Find a power supply that has an amperage rating for more than 20% of the LED strip power draw calculated in Step 3.

Example: What power supply amperage is necessary to power 10 feet of the 24V LED strips?

Step 1: Length = 10 ft

Step 2: Voltage = 24V, amps per foot

Step 3: Total power draw = 0.25 Amps x 10 feet = 2.5 Amps

Step 4: Minimum power supply amperage = 2.5 Amps x 120% = 3 Amps