How to Use the Lighting Lumen Calculator
Enter room dimensions in feet, ceiling height, and room type. The calculator returns the total lumens needed and how many standard LED bulbs (800 lm or 1,600 lm equivalent) to install. Great for home renovation planning and lighting upgrades.
Recommended Illuminance by Room Type
Based on IES (Illuminating Engineering Society) US standards: living rooms 10–20 fc, bedrooms 5–10 fc, kitchens and offices 20–50 fc, bathrooms 15–20 fc, workshops 30–50 fc. Brighter spaces reduce eye strain for task work; dimmer settings suit relaxation areas.
LED Bulb Lumen Reference
A 60W-equivalent LED produces about 800 lm; a 100W-equivalent produces about 1,600 lm. Recessed can lights typically output 400–600 lm each. Always check the lumen rating on the bulb package rather than relying on watts alone.
High Ceiling Adjustment
Ceilings above 8 feet (2.4m) require proportionally more lumens because light spreads more before reaching eye level. This calculator applies a ceiling height multiplier automatically. For vaulted or cathedral ceilings, consider directional fixtures or track lighting to compensate.
Frequently Asked Questions
A foot-candle is a US unit of illuminance equal to one lumen per square foot. 1 fc ≈ 10.76 lux. This calculator works in lux internally and converts room dimensions from feet to meters for consistency.
Space recessed fixtures at roughly 1–1.5× the ceiling height apart. For an 8 ft ceiling, that means 8–12 ft between fixtures. Add accent or task lighting in corners and work areas for even brightness.