Pick the room and its size. You get how many lumens it needs, how many recessed lights give them and where they go on the ceiling, and the bulb color that suits the room.
Your lighting
4 recessed lights2,520 lumens for 168 sq ft · 800 lm each · 2700–3000K warm white
Quick answer: multiply the room’s square feet by the foot-candles it needs: 10–20 for a living room or bedroom, 30–40 for a kitchen or dining room, 70–80 for a bathroom. A 12′ × 14′ living room needs about 2,520 lumens: 4 recessed lights of 800 lumens, 7′ × 6′ apart. Warm white 2700–3000K suits most rooms; 3500–4100K suits kitchens.
How to use the lighting calculator
- Pick the room and type its length, width and ceiling height.
- Pick the brightness of each light: the lumens printed on the box. Already have a chandelier, lamps or vanity lights? Add their lumens and the recessed lights make up the rest.
- Read the answer: the lumens the room needs, how many recessed lights, how far apart and how far from the walls, and the bulb color. The ceiling is drawn to scale.
How much light each room needs
A foot-candle is one lumen for every square foot of floor (10.76 lux). These are the levels lighting makers publish for each room (Maxim Lighting’s room table); the calculator aims at the middle.
| Example room | Foot-candles | Lumens | Recessed lights (800 lm) | Bulb color |
|---|---|---|---|---|
| Living room, 12′ × 14′ | 10–20 | 1,680–3,360 | 4 | 2700–3000K |
| Bedroom, 10′ × 12′ | 10–20 | 1,200–2,400 | 4 | 2700–3000K |
| Kitchen, 10′ × 12′ | 30–40 | 3,600–4,800 | 6 | 3500–4100K |
| Dining room, 12′ × 12′ | 30–40 | 4,320–5,760 | 8 | 2700–3000K |
| Bathroom, 5′ × 8′ | 70–80 | 2,800–3,200 | 4 | 2700–3000K |
| Hallway, 4′ × 12′ | 5–10 | 240–480 | 2 | 2700–3000K |
Kitchen counters want more on top: 70–80 foot-candles from under-cabinet lights or pendants over the island.
Lumens to watts
For brightness, look for lumens, not watts. ENERGY STAR’s equivalents for the old incandescent bulbs:
| Old bulb | LED to match it |
|---|---|
| 40 W | 450 lumens |
| 60 W | 800 lumens |
| 75 W | 1,100 lumens |
| 100 W | 1,600 lumens |
Bulb color by room
- 2700–3000K, soft or warm white: living rooms, bedrooms, dining rooms, bathrooms and hallways. ENERGY STAR calls it ideal for most indoor rooms; it is the color of an old incandescent bulb.
- 3500–4100K, neutral or cool white: kitchens, home offices and workshops, where you want to see clearly. If an open kitchen shares its light with a warm-lit living room, 3000K keeps the two from clashing.
- 5000K and up, daylight: reading and close work. Bluish, like the sky at noon, and cold for a room you relax in.
Three worked examples
A 12′ × 14′ living room, 8′ ceiling. 168 sq ft × 15 foot-candles = 2,520 lumens. With 800-lumen lights that is 4 lights, in 2 rows of 2: 7′ apart along the room, 6′ across, 3′ 6″ and 3′ from the walls.
A 10′ × 12′ kitchen. 120 sq ft × 35 = 4,200 lumens: 6 lights of 800 lumens in 2 rows of 3, at 3500–4100K. Add under-cabinet lights for the counters.
A 5′ × 8′ bathroom with a 1,600-lumen vanity light. The room needs 3,000 lumens; the vanity gives 1,600 of them, so 2 recessed lights of 800 lumens make up the rest.
Common lighting mistakes
- Buying by watts. An LED’s watts say how much power it uses, not how bright it is. Read the lumens.
- Lights too far apart. Past the ceiling’s height apart, their pools of light stop meeting and the floor between them goes dark. More, dimmer lights beat fewer bright ones.
- Every light in one row down the middle. The walls stay dark and the room looks smaller. Keep the outer lights half a spacing from the walls.
- Daylight bulbs in a living room. 5000K and up is for reading and work; in the evening it feels like an office.
Sizing the fixtures too? The ceiling fan and chandelier size calculator picks the chandelier, and the room square footage calculator measures an L-shaped room.
See the whole room before you cut a hole in the ceiling: the free 2D room planner draws the room and its furniture to scale.
Open the free room plannerRead next
- Warm lighting ideas that make a room glow after dark
- Mood lighting for the living room
- Pendant lighting for the kitchen island
- Bathroom vanity lighting over the mirror
- Hallway lighting ideas
Lighting questions
How many recessed lights do I need?
Work out the lumens (square feet × foot-candles) and divide by the lumens of one light. A 12′ × 14′ living room needs about 2,520 lumens: 4 lights of 800 lumens. Then check the spacing: no farther apart than the ceiling is high.
How far apart should recessed lights be?
Evenly, no farther apart than the ceiling is high (8′ on an 8′ ceiling), with the outer lights about half that spacing from the walls. A common rule of thumb puts them at half the ceiling height apart, 4′ on an 8′ ceiling, for bright, even task light.
How many lumens do I need for a living room?
10–20 lumens for every square foot. A 12′ × 14′ living room (168 sq ft) needs 1,680–3,360 lumens, about 2,520 in the middle. Lamps count toward it.
How many lumens do I need for a kitchen?
30–40 lumens a square foot for the room, and 70–80 on the counters. A 10′ × 12′ kitchen needs about 4,200 lumens from the ceiling, plus under-cabinet lights.
What is the difference between soft white and daylight?
Soft white is warm, yellowish light at 2700–3000K, the color of an old incandescent bulb and ENERGY STAR’s pick for most rooms. Daylight is 5000K and up, bluish like the sky at noon: good for reading and close work, cold for a living room.
2700K or 3000K?
Both are warm white. 2700K is a little more yellow and cozy, the better match for a bedroom or a living room; 3000K is a little whiter and crisper, a good middle for a bathroom or an open kitchen.
How many lumens is a 60 watt bulb?
About 800 lumens. ENERGY STAR’s equivalents: 40 W = 450 lumens, 60 W = 800, 75 W = 1,100, 100 W = 1,600.