Buying light bulbs used to be simple: pick a wattage. Now you're staring at a wall of identical-looking LED packages with numbers that mean nothing to most people. Here's your translation guide.
Lumens: the actual brightness number
Watts measure power consumption, not brightness. Lumens measure the actual light output. For LEDs, 800 lumens is roughly equivalent to the old 60-watt incandescent. 1,600 lumens ≈ 100 watts. This is the number to pay attention to when you're selecting bulbs.
- 400–500 lumens: Accent lighting, small bedside lamp
- 800 lumens: Standard room lamp, bedroom ceiling fixture
- 1,100–1,600 lumens: Kitchen, living room, high-ceiling fixtures
- 2,000+ lumens: Workshop, garage, large open spaces
Color temperature (Kelvin): warm to cool
The Kelvin number (K) describes the color of the light. This is probably the most important spec for how a room feels, and it's the one most people get wrong.
- 2700K: Warm white — the classic incandescent color. Cozy, amber-tinted. Best for bedrooms, living rooms, dining rooms.
- 3000K: Soft white — slightly brighter, still warm. Great for kitchens and bathrooms where you want warmth but good visibility.
- 4000K: Neutral/cool white — neutral, clean look. Common in offices and commercial spaces. Good for kitchens if you prefer a modern feel.
- 5000–6500K: Daylight — very blue-white, like noon sunlight. Best for garages, workshops, and spaces where you need maximum visibility for detail work. NOT recommended for living areas.
A common mistake: buying 5000K 'daylight' bulbs for a bedroom because they seem brighter. The cool blue light disrupts sleep and makes spaces feel clinical. Bedrooms almost always want 2700K.
CRI: how accurately colors render
CRI (Color Rendering Index) is a 0–100 scale measuring how accurately a light source renders colors compared to natural sunlight (100). Cheap LEDs have CRI 70–80 — colors look washed out and flat. Better LEDs have CRI 90+, which makes food look more appetizing, clothing colors appear accurate, and skin tones look natural.
For kitchens and bathrooms where color matters (is that food fresh? do these clothes match?), spend a bit more for CRI 90+. For a garage or utility room, CRI 80 is fine.
Dimmability
Not all LED bulbs work with dimmers — and using a non-dimmable LED on a dimmer switch causes buzzing, flickering, and shortened bulb life. Always check the package for 'dimmable' before buying. Also: older incandescent dimmer switches often don't work well with LEDs. If you're installing pot lights or doing a lighting renovation, upgrade to LED-compatible dimmers at the same time.
A quick room-by-room cheat sheet: Bedroom = 2700K dimmable. Kitchen = 3000K or 4000K. Bathroom = 3000K. Office = 4000K. Garage/workshop = 5000K. Living room = 2700K dimmable.
Safer Electric Team
Licensed Electricians · Toronto, ON
Our team of licensed GTA electricians writes these guides to help homeowners make informed decisions. Every article is reviewed for technical accuracy.