1. What is a Downlights Calculator?

Definition: This calculator estimates the number of downlights needed based on desired illumination level (foot-candles), room area, and light output (lumens).

Purpose: It helps homeowners, interior designers, and electricians determine how many downlights are required for proper room lighting.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( FC \) — Desired illumination level (foot-candles)
• \( \text{Area} \) — Room area (square feet)
• \( \text{Lumens per Light} \) — Light output of each downlight (lumens)

Explanation: The total required lumens (FC × Area) is divided by the lumens provided by each light to determine how many lights are needed.

3. Importance of Proper Lighting Calculation

Details: Correct lighting ensures adequate visibility, creates desired ambiance, and prevents energy waste from over-lighting.

4. Using the Calculator

Tips: Enter the desired foot-candles (10-20 for living rooms, 30-50 for kitchens), room area in square feet, and lumens per downlight (typically 800-1200 lm). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What are typical foot-candle requirements?
A: Living rooms: 10-20 fc, Kitchens: 30-50 fc, Bathrooms: 70-80 fc, Offices: 30-50 fc.

Q2: How do I find lumens per downlight?
A: Check the product specifications. Standard LED downlights typically range from 800-1200 lumens.

Q3: Should I round up the result?
A: Yes, the calculator automatically rounds up since you can't install a fraction of a light.

Q4: Does this account for light loss factors?
A: No, consider multiplying the result by 1.2-1.5 to account for light loss due to fixture type, room colors, and aging.

Q5: How does ceiling height affect this calculation?
A: Higher ceilings may require more lights or higher-lumen fixtures to achieve the same illumination at floor level.