How Many Recessed Lights Do I Need? Room Size Calculator Guide
How Many Recessed Lights do You Actually Need?
Everybody wants a simple number. I get it. When I was holding that hole saw, I wanted one too.
There’s a rule of thumb that an electrician finally gave us after laughing at my first attempt. Start with one light for every 25 square feet. Then adjust based on what the room is actually for.
Example from my own kitchen: it’s 12×12, so 144 square feet. 144 divided by 25 gives me a little under six. I ended up putting in five, plus some under‑cabinet strips, and it turned out fine. The starting number just kept me from going totally off the rails.
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The Spacing Trick That Finally Worked
- 8‑foot ceiling → about 4 feet apart
- 9‑foot ceiling → about 4.5 feet apart
- 10‑foot ceiling → about 5 feet apart
- 12‑foot ceiling → about 6 feet apart
A Guide Based on Room Size
I’ve put this together from my own screw‑ups and a few friends’ houses. This assumes a normal ceiling, like 8 or 9 feet, and standard LED brightness. Use it as a starting point, not a commandment.
| Room Size | Square Feet | Ballpark Lights |
|-----------|-------------|-----------------|
| 10×10 | 100 | 4–6 |
| 12×12 | 144 | 4–6 |
| 12×18 | 216 | 6–8 |
| 14×20 | 280 | 8–10 |
| 20×20 | 400 | 12–14 |
You’ll see the ranges are pretty wide. That’s because a dining room and a workshop can be the same size but need totally different amounts of light. I usually start on the low end and add more if it feels dim.
How Far Apart Should They Be? (The Real Answer)
If you don’t want to do math, just remember 4 to 6 feet apart for most rooms. But here’s the stuff nobody told me.
Between lights
That ceiling‑height trick covers it. On an 8‑foot ceiling, stay around 4 feet apart.
Where to Put Them (Not Just a Grid)
For a long time, the thought is just to make a nice grid and call it done. That’s how people cook in my the shadows of their kitchen.
Don’t let recessed be your only light
This one takes a bit to accept. Recessed cans are a base layer. You still need pendants, lamps, under‑cabinet strips, something. In my current living room, I only have four cans, but I’ve got a floor lamp in one corner and a table lamp in another. Feels way warmer than my old “12 cans and nothing else” setup.
Room by Room (From Someone Who’s Done Them All Wrong)
Living Room
I’d rather have too few than too many. Four to six cans in a medium room is plenty if you add lamps. And for the love of everything, use a dimmer. I can’t tell you how many times I’ve wished I’d put one in.
Bedroom
Never, ever put a light directly over the bed. I made that mistake and spent a year rolling over to avoid the glare. Put them around the perimeter, or over dressers and closets. And again, dimmer.
Bathroom
Overhead cans are fine for general light, but you need something at the mirror. I did sconces on both sides in my last bathroom and it changed my life.
Mistakes I’ve Made So You Don’t Have To
Too many lights
This is my signature move. More lights do not equal better light. It equals a room that feels like a warehouse.
Forgetting the walls
Lights too close to walls = glare. Too far away = dark corners. 2 to 3 feet is the sweet spot. I’ve got a mark on my tape measure that says “recessed wall distance” so I don’t forget.
Frequently Asked Questions
What’s the 4‑foot rule?
It’s that ceiling‑height‑divided‑by‑two trick. On an 8‑foot ceiling, space them about 4 feet apart. Keeps the light even without dark spots.
How far apart should 6‑inch recessed lights be?
I usually go 4 to 6 feet. With an 8‑foot ceiling, stay closer to 4 feet. With a 10‑foot ceiling, you can push it to 5 or 6 feet.
How many recessed lights for a 12x12 room?
Four to six is safe. I’ve done five in most of mine. Enough to feel bright but not overwhelming.
Do I need more lights in a kitchen?
Yeah, kitchens usually need more because you’re working in them. Task lighting over counters makes a huge difference. I’ve done kitchens with the same square footage as living rooms but twice the number of cans.
Should lights align with cabinets?
In a kitchen, yes. Align them with the front edge of the upper cabinets so you’re lighting the counter, not the back of your own head.
How close to the wall should recessed lights be?
2 to 3 feet is the number I use. If you’re lighting a specific wall, like art or a fireplace, you can cheat closer, but for general room lighting, stick to that range.
Can I use a recessed lighting calculator?
Sure, there are plenty online. Punch in your dimensions and they’ll give you a layout. I’ve used a few. Just remember they’re giving you a mathematical layout, not one that accounts for your furniture or how you actually use the room.
How many lumens per room?
Living room: 10–20 per square foot
Kitchen: 30–40 per square foot
Bathroom: 70–80 per square foot (task areas)
Multiply by square footage to get total lumens, then divide by your fixture’s lumens to get a rough count.
