1. What is a Lux to Watts Calculator?

Definition: This calculator converts illuminance (lux) to required electrical power (watts) based on area and luminous efficacy.

Purpose: It helps lighting designers and engineers determine the power needed to achieve desired illumination levels in a space.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( W \) — Required wattage (watts)
• \( L \) — Illuminance (lux)
• \( A \) — Area (square meters)
• \( E \) — Luminous efficacy (lumens per watt)

Explanation: The lux value (lumens per m²) multiplied by area gives total lumens needed, which is then divided by efficacy to get required watts.

3. Importance of Lighting Calculation

Details: Proper lighting calculations ensure adequate illumination while optimizing energy efficiency and cost.

4. Using the Calculator

Tips: Enter the desired lux level, area to be illuminated, and luminous efficacy of your light source (default 80 lm/W for LED). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical lux level for offices?
A: Office spaces typically require 300-500 lux for general work areas.

Q2: What's the efficacy of different light sources?
A: Incandescent (~15 lm/W), CFL (~60 lm/W), LED (~80-120 lm/W).

Q3: How does area affect the calculation?
A: Larger areas require more total lumens to maintain the same lux level.

Q4: Can I use this for outdoor lighting?
A: Yes, but consider higher lux requirements for outdoor spaces.

Q5: Does this account for light loss factors?
A: No, you may need to add 20-30% to account for fixture efficiency and light loss over time.