To size a power supply for LED light sheets: add up the watts of every sheet, add 20% spare capacity, and choose a constant-voltage driver at the same voltage as the sheets (usually 24V). On larger surfaces, split the load into zones so no driver runs above about 80% and every zone can be fed from more than one point.
The formula
Driver watts ≥ (watts per sheet × number of sheets) × 1.2
Use the wattage from the sheet’s datasheet, not an estimate per square metre. Not sure of the sheet count yet? See how many LED sheets you need. Cut pieces draw power in proportion to the LEDs left on them, so a half sheet draws roughly half the watts.
Worked example: a 2.4 × 1.2 m onyx wall
- Area: 2.4 m × 1.2 m = 2.88 m².
- Sheets: using 490 × 245 mm sheets (0.12 m² each), you need 24 sheets.
- Load: at 28 W per sheet (our 242-LED model), 24 × 28 W = 672 W.
- With 20% spare: 672 W × 1.2 ≈ 806 W.
- Zones: two zones of 12 sheets (336 W each), each on a 480 W, 24V driver. That runs each driver at 70%.
- Current per zone: 336 W ÷ 24 V = 14 A, so use cable sized for that current and feed each zone from more than one point.
The LED light sheet calculator does the sheet count and wattage for you.
12V or 24V?
Use 24V for most projects. For the same power, 24V draws half the current of 12V, so cables can be thinner and voltage drop is lower. Use 12V only for small panels or when matching existing 12V equipment. The sheets and the driver must have the same voltage.
Choosing the driver type
| Situation | Driver to use |
|---|---|
| Dry indoor, inside a cabinet or ceiling void | IP20 enclosed constant-voltage supply, such as Mean Well LRS |
| Damp or outdoor locations | IP67 constant-voltage driver, such as Mean Well HLG or LPV |
| Dimming from a wall dimmer or building system | A dimmable driver matching the system: DALI, 0–10V or triac; or a standard driver plus an LED controller |
| RGB, RGBW or tunable white | A standard constant-voltage driver plus a controller rated for the channel current |
When to split into zones
- The total load is more than one driver can carry at about 80%
- A single run of sheets is long enough to show a dimmer far end
- Different areas need separate dimming or colors
- You want one failed driver to darken only part of the wall
Controllers have limits too
Each controller channel has a maximum current, for example 4 A or 5 A per channel. Divide the zone current by the number of channels in use and check it is below that limit; if not, add an amplifier or another controller. See how to choose an LED controller.
Keep the driver reachable
Drivers fail more often than LED sheets. Mount them outside the stone cavity, in a ventilated spot that can be opened later, and keep the low-voltage run to the sheets as short as practical. How far the sheets can be from the power supply covers cable length and voltage drop.
FAQ
What size power supply do I need for one LED light sheet?
The sheet’s watts plus 20%. A 28 W sheet needs at least a 34 W driver, so in practice a 40 W or larger unit.
Can I use one large driver for the whole wall?
You can, but splitting into zones is usually better for voltage drop, heat and service.
Do I need a bigger driver for dimming?
No. Dimming lowers the load. Size the driver for full brightness.
Related: LED light sheet power supply guide · 24V LED power supplies for light sheets