Lighting Tip

Calculating Light Energy Costs

Here is a simple formula for calculating the energy costs of your light.

Information to gather:

1. Get your energy costs in kW/hr from your utility bill. (KW) $0.12
2. Fixture Qty (FQ) 30
3. Bulb Wattage (BW) Use 1 for 1000W, 0.6 for 600W, and 0.4 for 400W 0.6
4. Hour lights run per day (HR) 16


BW x KW x HR x FQ  = Cost to run fixtures per day
0.6 x $0.12 x 16 x 30 = $34.56 / Day
Multiply by the number of days in a month to get the monthly rate