Free Recessed Lighting Calculator

Free Recessed Lighting Calculator

Plan downlight counts, spacing, and an optimized layout grid—plus wattage & energy cost.

Room & Fixture Inputs

Room Length (ft)

Room Width (ft)

Ceiling Height (ft)

Room Type (Target Foot‑Candles) Living / Bedroom (10–20 fc) Kitchen / Office (30–50 fc) Bathroom (20–50 fc) Hallway (5–20 fc) Task / Workbench (50+ fc)

Lumens per Fixture (lm)

Fixture Wattage (W)

Spacing Ratio (0.6 – 1.2 typical)

Wall Offset Factor (% of spacing to walls)

Energy Cost ($ per kWh)

Daily Use (hours/day)

Color Temperature 2700K (Warm) 3000K (Warm White) 3500K (Neutral) 4000K (Cool White)

Reflectance / Efficiency Factor Bright Finishes (0.85) Typical (0.75) Darker Finishes (0.65)

Tip: Adjust Spacing Ratio to tune the grid. Larger ceilings often support wider spacing. Start at 0.8 × ceiling height.

Results

Lights Needed

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Ideal Spacing

—

Half spacing from walls

Total Wattage

—

@ 10 W each

Energy Cost (mo)

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5 h/day • $0.15/kWh

3000K • Warm White Target: 40 fc Room: Typical (0.75)

Top‑Down Layout Preview

Blue = fixtures • Border = room • Unit: ft

FAQs

What is a good rule for recessed light spacing?

A practical starting point is Spacing ≈ 0.8 × Ceiling Height. Keep approximately half‑spacing from the walls to avoid scalloping and shadows. Adjust based on beam angles and tasks.

How many lumens do I need in a room?

Multiply area (sq ft) by target foot‑candles (fc). For general living spaces use 10–20 fc, kitchens and offices 30–50 fc, and task zones 50+ fc.

Can I mix color temperatures?

For consistent appearance, keep recessed lights the same CCT. Add accent/task lights with higher CCT if needed.

Built‑in features: offline single file, SEO meta + Schema, dark/light theme, CSV export, share/print, auto‑save, animated gauge, and layout canvas.

Pro tip: Press Ctrl/Cmd + S to save your settings locally.