Shapes sizes and bases.
Fluorescent light bulb sizes chart.
Sizes range from t2 to t17.
T4 t5 t8 and t12.
The most common form of fluorescent lamp is a straight tube.
Find the light bulb base type you re looking for with this visual chart detailed illustrations of general bases fluorescent bases and specialty halogen base types.
The t stands for tubular and the numbers are an index for the diameter in inches of the tube.
There are 4 different fluorescent light options.
Here you have a simple light bulb replacement guide showing you how easy transitioning from your incandescent bulbs to leds can be.
The diameter of the tube is described in eighths of an inch as it is for incandescent lamps so a fluorescent lamp 1 inch in diameter eight eighths is a t8.
Fluorescent tube sizes guide.
Lamps are typically identified by a code such as fxxty where f is for fluorescent the first number xx indicates either the power in watts or length in inches the t indicates that the shape of the bulb is tubular and the last number y is the diameter in eighths of an inch sometimes in millimeters rounded up to the nearest millimeter.
If you are using a 60 watt incandescent or a 13 watt compact fluorescent cfl you can switch to a 10 watt led bulb.