How Many Recessed Lights Do I Need? Free Spacing & Layout Calculator
Tip: drag any light in the layout to fine-tune placement.
How Many Recessed Lights Do I Need?
The honest answer is: enough to hit the brightness your room actually needs, spread evenly so there are no dark corners. Start from lumens, not fixture count. Multiply your room area (length times width) by a target lumens-per-square-foot for the room type, then divide by the lumens each fixture puts out. A 12×12 kitchen at roughly 40 lumens per square foot needs about 5,800 lumens, which is around eight to nine 800-lumen 6-inch fixtures. The calculator above does this math live and lays the fixtures out for you.
How Far Apart Should Recessed Lights Be?
A reliable rule of thumb is to divide your ceiling height by two and use that as the spacing in feet. An 8-foot ceiling gives roughly 4-foot spacing; a 10-foot ceiling gives about 5 feet. Wider spacing leaves dark gaps between pools of light, tighter spacing wastes fixtures and money. The layout tool keeps spacing even automatically and shows the exact center-to-center distance for your room.
How Far From The Wall Should Recessed Lights Be?
Keep the first row of fixtures about 1.5 to 3 feet off the wall, usually around half of your fixture-to-fixture spacing. Too close and you wash the wall with hot spots; too far and the perimeter falls into shadow. If you are lighting artwork or cabinets, pull that first row a little tighter to the wall so the beam grazes the surface. Use the wall-distance setting in the calculator to compare tight, standard, and wide layouts.
How Many Lights For A 12×12 Room?
A 12×12 room is 144 square feet. For general living-room light (about 30 lumens per square foot) that is roughly 4,300 lumens, or about six 6-inch fixtures in a 2×3 or 3×2 grid. For a 12×12 kitchen at 40 to 50 lumens per square foot, plan on eight to nine fixtures in a 3×3 grid spaced about 4 feet apart. Load 12 and 12 into the calculator to see the exact layout.
How Many Lights For A 20×20 Room?
A 20×20 room is 400 square feet. A living room at 30 lumens per square foot needs about 12,000 lumens, roughly fifteen 800-lumen fixtures. A 20×20 kitchen pushes that to twenty or more in a 4×5 or 5×5 grid. Because the room is large, even spacing matters a lot here, which is exactly where the coverage heat-map view helps you spot gaps before you cut a single hole.
4-inch vs 6-inch Recessed Lights
4-inch fixtures throw a tighter, more focused beam and look cleaner in modern rooms, bathrooms, hallways, and for accent lighting. 6-inch fixtures spread more light per can, so you need fewer of them to fill big rooms like kitchens, garages, and living rooms. Many builds mix both: 6-inch for general coverage, 4-inch for accents. The calculator lets you switch fixture type and instantly see how the count and layout change.
Best Recessed Lights For Garages
Garages want bright, cool, color-accurate light: target 50 to 75 lumens per square foot, 5000K color temperature, and CRI 90+ so you can match paint and read labels. High-lumen canless wafer lights or 6-inch fixtures both work well. See the real build in the detached garage project for how the lighting was laid out.
Best Recessed Lights For Workshops
Workshops need task-grade light: 75 to 100 lumens per square foot, 5000K, CRI 90+, and tight enough spacing that tools and benches never sit in shadow. Use the Workshop template in the calculator as a starting point, then drag fixtures to line them up over your benches and machines.
Best Recessed Lights For Kitchens
Kitchens do best around 35 to 50 lumens per square foot at 4000K, which reads clean and natural without feeling clinical. Plan general recessed lighting on an even grid, then add under-cabinet and over-sink task lights separately. CRI 90+ keeps food and finishes looking true.
How Many Lumens Per Room?
Rough targets in lumens per square foot: kitchen 35 to 50, garage 50 to 75, workshop 75 to 100, bathroom 40 to 60, basement 40 to 60, living room 20 to 40, bedroom 15 to 30, patio 20 to 40. Multiply by your room area for total lumens, then divide by the lumens per fixture. The calculator applies these targets automatically and lets you nudge them with the brightness selector.
How Many Recessed Lights Do I Need for a Living Room?
A standard living room targets 20–30 lumens per square foot. For a 15×18 ft living room (270 sq ft), you need roughly 5,400–8,100 total lumens. Using 800-lumen LED wafers, that’s 7–10 fixtures spaced about 4–5 feet apart on an 8-foot ceiling. Use the calculator above to dial in your exact count based on ceiling height and desired brightness.
What Size Recessed Lights Should I Use — 4-Inch or 6-Inch?
Use 4-inch fixtures for accent lighting, under-cabinet areas, hallways, and rooms under 10 ft wide. Use 6-inch fixtures for kitchens, living rooms, garages, and any space requiring high general light output. Six-inch cans emit more lumens per fixture, so you need fewer of them — which lowers installation cost in larger rooms.
How Many Recessed Lights for a 12×12 Kitchen?
A 144 sq ft kitchen at 35–50 lumens per square foot needs 5,040–7,200 total lumens. With 6-inch 800-lumen LED fixtures, that’s 7–9 lights in a 3×3 grid spaced about 4 feet apart. Add dedicated task lighting over countertops and islands on a separate circuit to avoid over-crowding the ceiling grid.
Recessed Lighting Calculator FAQs
How many recessed lights for a 10×10 room?
About four 6-inch fixtures in a 2×2 grid for general lighting (100 sq ft at roughly 30 lumens per square foot). Bump to five or six for a bright kitchen. Spacing lands near 5 feet on an 8-foot ceiling.
How many recessed lights for a 12×12 room?
Six for a living room, eight to nine for a kitchen in a 3×3 grid spaced about 4 feet apart. Enter 12 x 12 in the calculator to see the layout.
How many recessed lights for a garage?
Garages target 50 to 75 lumens per square foot. A 24×24 two-car garage needs roughly forty to fifty 800-lumen fixtures, or fewer if you use high-output canless wafers. Use the Garage template to start.
Can recessed lights be too close together?
Yes. Spacing tighter than about 3 feet on a standard ceiling creates overlapping hot spots, wastes fixtures, and can look busy. The calculator keeps spacing in a sensible range automatically.
What spacing should I use with 8-foot ceilings?
About 4 feet center-to-center, with the first row roughly 2 feet off the wall. That follows the ceiling-height-divided-by-two rule.
What spacing should I use with 10-foot ceilings?
Around 5 feet center-to-center. Higher ceilings spread each beam wider, so you can space fixtures a bit further apart while keeping even coverage.
Can I use this calculator for canless lights?
Yes. Choose Canless wafer as the fixture type. Wafers are thin and need no housing, so they fit tight ceilings, but the spacing and lumen math are the same.
Can I use this for wafer lights?
Yes, wafer lights are the canless option in the fixture menu. Set your wafer’s rated lumens in the lumens-per-fixture field for an exact count.
What color temperature should each room be?
Garage and workshop 5000K, kitchen and bathroom 4000K, living room and patio 3000K, bedroom 2700K. Aim for CRI 90+ everywhere for true-to-life color.
How many lumens do I need per square foot?
It depends on the room: 15 to 30 for bedrooms, 20 to 40 for living rooms, 35 to 50 for kitchens, up to 100 for workshops. The calculator applies the right target for the room you pick.
Do I need an electrician to install recessed lights?
For new circuits, wiring changes, or anything you are unsure about, yes. Many homeowners replace existing fixtures themselves, but always follow local electrical code and have work inspected when required.
How many recessed lights on one circuit?
LED recessed lights draw very little power, so a standard 15-amp circuit can run many of them. Add up the wattage and stay under 80 percent of the circuit rating, and confirm with your local code.
Can I save or share my layout?
Yes. Use Download PNG for an image of the plan, Print / Save PDF to print or save a PDF, and Share layout to copy a link that reopens the calculator with your exact numbers.
Can I move individual lights in the layout?
Yes. Drag any light in the Top view or Coverage view to reposition it. Use Reset drag to snap back to the even grid.
Is this recessed lighting calculator free?
Completely free. No signup, no email wall, no lead capture. Bookmark it and use it on every project.
How far from the wall should recessed lights be placed?
Place the first row of recessed lights roughly 2 feet from the wall on an 8-foot ceiling — or about one-quarter of your fixture spacing distance. This prevents harsh shadows at the wall while delivering even coverage across the floor. Increase the offset to 2.5–3 feet on 9- and 10-foot ceilings.
What wattage recessed lights should I use?
Most modern LED recessed lights use 8–15 watts and produce 600–1,200 lumens. Choose by lumens, not watts: target 800 lumens per 6-inch fixture for general lighting. Avoid bulb wattage comparisons — a 10W LED equals roughly a 65W incandescent in light output.
Can I use recessed lighting in a bathroom?
Yes, but choose fixtures rated for wet or damp locations depending on placement. Fixtures directly in a shower or above a tub must be wet-rated. Fixtures elsewhere in the bathroom can be damp-rated. Always verify the fixture’s IP rating and check local electrical code for required clearances from water sources.
Related HOMEJECT projects
- Detached garage build and design
- Garage workshop and detail center
- Patio ceiling and outdoor kitchen lighting
- Deck and LED lighting project
- All free DIY home calculators
Disclaimer: This calculator is intended for planning purposes only. Lumen targets, spacing, and counts are estimates and will vary with fixture optics, beam angle, ceiling color, and room contents. Always verify local electrical code requirements. Electrical work should be performed or inspected by a qualified electrician.