One of the most common questions before a track light installation is: “How many fixtures do I actually need?” Here is a simple formula that works for most spaces, plus adjustments for different room types.
Number of fixtures = Room area (m²) ÷ 4Example: A 4×5 m room = 20 m² → approximately 5 fixtures.
This formula assumes standard ceiling height (2.6–3.0 m) and fixtures rated at approximately 7–12W each.
Different spaces need different light levels. Modify the divisor based on what the room is used for:
| Room Type | Divisor | Example: 20 m² |
|---|---|---|
| Bedroom (soft ambient) | ÷ 5 | 4 fixtures |
| Living room (general) | ÷ 4 | 5 fixtures |
| Retail / showroom (bright) | ÷ 3 | 7 fixtures |
| Office / workspaces | ÷ 3.5 | 6 fixtures |
As a general rule, space fixtures 1–1.5 meters apart along the track.
Example: A 5-meter room needing 4 fixtures:
The exact layout depends on where you want the light to fall, not just the room length. Sketch your furniture positions first and mark where each fixture should point — then work backwards to the track layout.
Total wattage = Number of fixtures × Watts per fixture × 1.2The 1.2 multiplier is a 20% safety margin. Power supplies running at 100% capacity run hot and fail early.
Example: 5 fixtures × 12W × 1.2 = 72W → use a 100W power supply.
When in doubt, round up to the next available PSU size. A 100W supply driving 72W of fixtures runs at 72% capacity — well within its rated range.
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