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Tool

LED Calculator

Estimate LED module count, total wattage and power supply for channel letters, light boxes and LED strip or neon.

Dimensions

Dimension source

Height of the tallest capital letter.

Do not count spaces or punctuation.

Font weight

Stroke width of the letters; bold lettering needs more modules.

LED and installation

Inside depth of the letter or box. Module spacing grows with depth.

Voltage
Installation

Wide-angle (lens) modules can be spaced further apart.

Advanced settings

Added for failures and installation losses; 10% recommended.

Cable from the power supply to each feed line; cross-section and voltage drop are chosen from it.

Enter the dimensions to see the result.

How it works

From dimensions to a material list in three steps.

  1. Choose the calculation

    Channel letters, light box, or LED strip and neon. For letters, enter the size or upload your SVG drawing.

  2. Set the model and location

    Choose the return depth, module or strip model and indoor/outdoor; the result updates instantly.

  3. Add the list to the basket

    Add the module, power supply and cable list to the project basket and request one quote.

Frequently asked questions

How many LED modules does a channel letter need?

It depends on letter height, stroke width and return depth. With wide-angle (160°) lens modules the module spacing is about 1.5 times the return depth; at 10 cm depth modules are about 15 cm apart. A 50 cm letter in a regular weight needs about 7 modules; 8 letters come to about 56 modules plus 10% spares. The result is an estimate; test the layout on a sample letter.

How do I choose the power supply?

First find the total power: modules × module wattage (or metres × W/m). No more than 80% of a power supply’s capacity should be used, so the required PSU power is 1.25 times the total. For an 84 W load at least 105 W is needed; a 100 W unit is not enough, so 120 W is chosen. Use an IP67 power supply outdoors.

Should I choose 12 V or 24 V?

At the same power, a 24 V system draws half the current. A line can carry a longer strip or more modules, the cable can be thinner and voltage drop is lower. 12 V is more common, with a wider choice of modules and power supplies. 24 V pays off on long strip runs and large signs. 12 V and 24 V products cannot share a power supply.

Which IP rating is needed outdoors?

Where rain and dust reach, LEDs should be at least IP65 and the power supply IP67. Cable joints are sealed with heat shrink or silicone, and the power supply is placed out of direct sun and water, with ventilation. Moisture can get into even a closed channel letter.

How often should an LED strip be fed?

Typical values are 5 m from one end for a 12 V strip and 10 m for a 24 V strip. On longer runs the voltage drops and the end of the strip turns yellow or dim. The tool divides the length by this limit and gives the number of feed points; each point has its own cable to the power supply. The exact value is in the data sheet.

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