Why shouldn't I run a power supply at 100% of its rated wattage?
Continuous full-load operation shortens a PSU's lifespan and increases heat, which is why this calculator adds a safety headroom (default 20%) on top of the strip's actual power draw before recommending a size.
When do I need power injection on a long run?
Voltage drop becomes noticeable on runs longer than about 16 feet at 12V or 32 feet at 24V, showing up as dimming or color shift toward the far end. Feeding power in at both ends of the run (power injection) evens out the voltage along the strip.
Should I choose 12V or 24V strips for longer runs?
24V strips carry the same power at half the current of 12V, which cuts voltage drop roughly in half and lets you run longer single runs before needing power injection. For runs beyond about 16 feet, 24V is usually the better choice.
How is the recommended PSU size chosen?
The calculator takes your total wattage, adds the safety headroom percentage, and picks the smallest common PSU size (12, 20, 30, 60, 100, 150, 200, or 350W) that still covers the padded load.