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T8 vs T12

Electric lighting continues to power majority of the commercial buildings found in North America. The most common type of bulbs used are those designated the letter “T” in their names. T stands for tubular, which describes the shape of the lamp.

The number that follows the letter T represents the diameter of the lamp when expressed as an eighth of an inch. A T12 lamp measures 1.5 inches (12/8 = 1.5) or 3.81 cm while a T8 lamp measures 1 inch (8/8 = 1) or 2.54 cm in diameter.

Both lamps use the same bi-pin base, meaning that users can fit T8 lamps into sockets designed for T12 lamps. Due to high power consumption, the world is slowly moving away from T12 lamps. The U.S. alone has not imported or produced T12 lamps since July 14, 2012. It has even gone ahead to create incentive programs in various districts for owners that upgrade to T8s and other better lighting options.

T8 Description


T8 lamps are smaller than T12 lamps. They, therefore, save more energy and use 35% less electricity. This does not affect their light output as it’s the same as that of T12s. Sometimes, they even produce more light than T12s.

A typical second generation T8 bulb produces about 80 lumens per Watt. This is higher than the 70 lumens per Watt produced by a standard T12 bulb. T8 bulbs are ideal for normal lighting in spaces under 12 feet. Their nominal power averages 32 Watts. They can last up to 24,000 hours of use and have a color rendering index (CRI) of 85.

t8Strong Sides

1. More energy efficient thanks to electrical ballasts.

2. Provide superior lighting.

3.  Give better color quality.

Weak Sides

1. Replacement bulbs can be hard to find.

2. Options available in stores may be limited in color, lumen, and size.

T12 Description


A typical T12 bulb consumes about 172 watts when used in a four-lamp fixture. Equivalent LED variants use about 50 watts to produce the same amount of light. This is 71% less energy consumption.

Not only are LED options brighter, they’re also more durable. They have grown to become the go-to fluorescent bulbs for commercial lighting. T12s are considered to be first generation lamps. The largest have a diameter of about 1.5 inches.

Most variants have been taken off the market to make room for more energy efficient bulbs. However, some stores still stock them for those needing replacements. The average T12 tube will consume about 40 Watts and produce about 2520 lumens. Average lifespan stands at 12,000 hours.

t12Strong Sides

1. Cost less than incandescent lamps

Weak Sides

1. Less energy efficient

2. Cost more to operate

3. Can be noisy while running.


The T8 bulb produces more lumens per Watt when compared to the T12 bulb. It’s also energy efficient and lowers power costs in commercial buildings. Sometimes, the difference in lighting may not be noticeable to the naked eye. However, considering that the T8 is more energy efficient and produces more light, it’s definitely a better choice than the T12 bulb.

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