Unless you are designing the lighting for a room that not been lit before, you can determine the wattage you need based upon the bulb that you are replacing or by the maximum wattage that the socket or fixture which you are looking to fill can handle. As a rule, never exceed the wattage recommended for your lamp. If you are trying to determine the wattage for a room that has not been lit before, multiply the square footage by 1.5 to determine the total wattage you need. Light bulbs run on line voltage (120V) or are low voltage, which use a transformer to reduce the line to 12V. The requirements of the bulb will stipulate which you need. If you are designing a room that has not been lit before, you will need to consider installing transformers and should consult a designer and/or electrician for expert advice.
Calculating the right wattage needed to light up a room can be tricky. There are number of factors that must be taken into account and personal lighting preference is one of them.
One popular way to determine the amount of incandescent wattage needed to light up a room is to multiply the room square footage by 1.5
For example: a room that is 10 feet by 10 feet has a total square footage of 100. When multiplying the 100 square feet by 1.5 we get 150. Using this example would require that the 100 square foot room requires 150 watts on incandescent light.
To get the calculated 150 watts worth of incandescent light you can use a variety of lighting options.
- 2 incandescent 75W watt bulbs
- 3 50W incandescent bulbs.
- 2 Compact Fluorescent 18W bulbs
- 3 10W LED bulbs
Incandescent Light bulbs will burn out from time to time and should always be replaced with the right wattage light bulb for the light fixture that you are installing it in. Matching the bulb to the fixture's specification will eliminate some safety hazards.
The manufacturer of the fixture lists a caution sticker around the light socket area to warn the consumer of installing the wrong wattage light bulb. In essence, the manufacturer usually states, "in order to reduce the risk of fire, use a 60-watt type A or smaller lamp." This warning tells you what the maximum wattage of bulb to use as well as the preferred type of light bulb, type A (standard shape).
Using light bulbs of higher wattage than the fixture recommends could cause the fixture to overheat. This in turn often leads to an electrical fire. One warning sign to look for is a brown spot on the light fixture's insulation. Another is the wire insulation will become brittle from continued exposure to high heat from the bulb. And in the case of can lights, the fixture's built-in thermal trip will automatically shut the power to the light bulb off. If you have a can light turning itself on and off, you probably have the wrong light bulb in the fixture, causing overheating.