It’s that time of year when houses shine a bit brighter. Ever wonder how much the decorative holiday lights add to a monthly electric bill? Here’s an easy way to help calculate energy costs this holiday season.

• Count the bulbs on all of your decorative indoor and outdoor lights.

• Check the wattage per bulb.

• Multiply watts per bulb by number of bulbs. (1 watt per bulb x 1,000 bulbs = 1,000 watts).

• Convert watts to kilowatts — 1,000 watts = 1 kilowatt (kw).

• Estimate the hours per month the lights are on. (5 hours per day x 30 days = 150 hours)

• Multiply the total kilowatts by the total number of hours the

lights will be on to get the total kilowatt-hours (kwh). For example, 1 kw x 150 hours = 150 kwh.

• Multiply the total kilowatt-hours by the total cost ofelectricity per kwh. (150 kwh x $0.14 per kwh = $21) In this example, the cost of holiday lighting would be an additional $21 per month.

Reprinted with permission of RISMedia, publisher of Real Estate Magazine