Parking Lot Light Calculator

Light Fixtures Formula:

\[ \text{Fixtures} = \frac{\text{Area} \times \text{Footcandles}}{\text{Lumens Per Fixture} \times \text{UF} \times \text{LLF}} \]

Area:

sq ft

Footcandles:

Lumens Per Fixture:

Utilization Factor (UF):

Light Loss Factor (LLF):

Fixtures (number):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is a Parking Lot Light Calculator?

Definition: This calculator determines the number of light fixtures needed for a parking lot based on area, desired illumination level, fixture output, and efficiency factors.

Purpose: It helps lighting designers, engineers, and facility managers properly illuminate parking areas while optimizing energy use and costs.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ \text{Fixtures} = \frac{\text{Area} \times \text{Footcandles}}{\text{Lumens Per Fixture} \times \text{UF} \times \text{LLF}} \]

Where:

\( \text{Fixtures} \) — Number of light fixtures needed
\( \text{Area} \) — Parking lot area in square feet
\( \text{Footcandles} \) — Desired illumination level (typically 2-5 fc for parking lots)
\( \text{Lumens Per Fixture} \) — Light output of each fixture
\( \text{UF} \) — Utilization Factor (0-1, accounts for light reaching the target area)
\( \text{LLF} \) — Light Loss Factor (0-1, accounts for depreciation over time)

Explanation: The formula calculates how many fixtures are needed to achieve the desired footcandle level, considering the light output and efficiency factors.

3. Importance of Proper Lighting Calculation

Details: Accurate calculations ensure adequate visibility for safety, meet regulatory requirements, and optimize energy efficiency and maintenance costs.

4. Using the Calculator

Tips: Enter the parking lot area, desired footcandles (default 2 fc), lumens per fixture (default 20,000 lm), UF (default 0.7), and LLF (default 0.8). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical footcandle level for parking lots?
A: Most parking lots require 2-5 footcandles, with higher levels for security-sensitive areas.

Q2: How do I determine the Utilization Factor?
A: UF depends on fixture type and mounting. Consult manufacturer specifications or lighting design guides.

Q3: What affects the Light Loss Factor?
A: LLF considers lamp lumen depreciation, fixture dirt accumulation, and other maintenance factors.

Q4: Can I use this for other outdoor areas?
A: Yes, the same calculation applies to walkways, loading docks, and other outdoor spaces.

Q5: Should I round up the fixture count?
A: Yes, always round up to the nearest whole number since you can't install a fraction of a fixture.