Dimming Range
The brightness span a dimmer can achieve — typically expressed as a percentage (e.g., 5%-100%). A wider range means dimming to a lower level without flickering or shutting off.
Dimming range describes how far down a dimmer can take the brightness before the LED flickers, drops out, or shuts off entirely. An ideal dimming range is 1%-100% — from barely perceptible glow to full brightness. In practice, most residential LED dimming setups achieve somewhere between 10%-100% and 20%-100%.
The range depends on three factors working together: the dimmer, the LED driver, and the bulb itself. A high-quality trailing edge dimmer with adjustable low-end trim can push compatible bulbs down to 1-5%. A cheap TRIAC dimmer might drop out at 30% with the same bulb. Some LED bulbs simply can't dim below 20% regardless of the dimmer — their driver doesn't support it.
If smooth low-end dimming matters to you (bedrooms, dining rooms, home theaters), look for bulbs explicitly rated for "deep dimming" or "1% dimming" and pair them with a quality trailing edge dimmer that has an adjustable low-end trim pot. The trim lets you fine-tune the cutoff point where the bulb turns off instead of flickering.
Related Terms
- Minimum Load
The lowest wattage a dimmer switch needs to function properly. Many older dimmers require 40-60W minimum — a single 9W LED bulb won't meet that threshold, causing flickering or failure to dim.
- Trailing Edge Dimmer
A dimmer type that cuts the trailing end of each AC wave cycle. Smooth, quiet, and compatible with most LED bulbs — the recommended type for LED dimming.
- Flicker
Rapid, repeated changes in light output. Can be visible (strobe effect) or invisible but still cause headaches. Usually caused by incompatible dimmers or poor LED drivers.