Fact Sheet: LightingDifferences between T12, T8, T5

T12, T8 and T5 bulbs are different types of fluorescent tubes often present in

school and office buildings. The older bigger bulbs are the least efficient and

can be upgraded to the newer bulbs. It is often best to change the light fitting

completely to fit the new bulbs for the best results, but if your fittings are quite

new than the adaptor can be used instead.

This is an example of an adaptor:

T12 Bulbs

This is the oldest type of fluorescent tube and is no longer sold.

The average wattage of these bulbs is: 40 W

The bulb is 38 mm in diameter (this can be used to measure your bulb)

A T12 Fitting looks a bit like:

T8 Bulbs

This is the most common type of bulb used in schools and offices

The average wattage of these bulbs is: 32 W

The bulb is 26 mm in diameter (this can be used to measure your bulb)

A T8 Fitting looks a bit like:

T5 Bulbs

This is the smallest and most efficient bulb.

The average wattage of these bulbs is: 28 W

The bulb is 16 mm in diameter (this can be used to measure your bulb)

A T5 Fitting looks a bit like: