F20T12 Bulb LED Replacement

Unlike fluorescent lamps, LEDs use 30% less power, last 10 times longer, and contain no toxic materials. They are a better lighting product. You should replace your fluorescent lights with LEDs if you haven’t already.
By Kelvin Wamalwa Written by Kelvin Wamalwa
Updated on July 25, 2023

Due to a variety of factors, most paramount of which are energy efficiency, cost concerns, and environmental considerations, LEDs are pushing fluorescent lamps out of the market.  

Unlike fluorescent lamps, LEDs use 30% less power, last 10 times longer, and contain no toxic materials. They are a better lighting product. You should replace your fluorescent lights with LEDs if you haven’t already.

What size is an F20T12 bulb?

F20T12 bulbs are two feet long (24 inches) and have a diameter of 1.5 inches. The diameter of any bulb can be gleaned from the name. The T12 part of the name indicates that the bulb in question is tubular and has a diameter of twelve-eighths of an inch. 


F= Fluorescent (type of lighting)

20 = 20 Watts (wattage)

T = Tubular (shape)

12 = 12/8 inches = 1.5 in (bulb diameter)

LED replacements for the F20T12 bulb

If you want to swap out your fluorescent F20T12 for LED equivalents. The following are some of the best options out there.

FEIT Electric T24/840/LEDG2

Type F20T12 (Fluorescent) ‎FEIT Electric T24/840/LEDG2 (LED)
Wattage 20 10
Light intensity (lumens) 1200 800
Color temperature 4200K 4000K

The ten-watt Feit Electric T24 saves you 50% on your lighting bill because it requires only 10 watts to produce the same amount of light while the fluorescent F20T12 needs 20 watts. 

This LED lamp is also plug-and-play. It works with the existing ballasts so you don’t have to worry about rewiring your lighting fixtures. You just take out your fluorescent lamp and put in the Feit Electric T24. Easy peasy

And that’s without even mentioning a lifespan of 50,000 hours. If you use it for ten hours a day, you’re looking at the lamp lasting for nearly 14 years.


Type F20T12 (Fluorescent) ‎ NYLL RL-F17T8 (LED)
Wattage 20 10
Light intensity (lumens) 1200 1900
Color temperature 4200K 4000K

The RL-F17T8 is a 24-in plug-and-play LED lamp from New York LED Luminaries. It works great with both electronic and magnetic ballasts.

The RL-F17T8 only requires ten watts of power and puts out 1100 lumens of light, about the same level of brightness as a 17-watt fluorescent bulb.

Philips CorePro 8.5T8/COR/24-850/MF11/G/BAA 25/1

Type F20T12 (Fluorescent) ‎ Philips 8.5T8/COR/24-850/MF11/G/BAA 25/1(LED)
Wattage 20 8.5
Light intensity (lumens) 1200 1150
Color temperature 4200K 5000K

This two-foot LED from Philips lasts 50,000 hours and requires only 8.5 watts of power. Its only downside is that it’s not plug-and-play so you will have to bypass the ballast.

Probelie‎ P-G13-2FT-5000K

Type F20T12 (Fluorescent) ‎ Probelie‎ P-G13-2FT-5000KNYLL RL-F17T8 (LED)
Wattage 20 8
Light intensity (lumens) 1200 1120
Color temperature 4200K 5000K

Requiring only eight watts of power, the Probelie‎ P-G13-2FT-5000K is a definite improvement on the F20T12 which needs 20 watts of power. That’s 60% less on your power bill.

This LED lamp comes with a hassle-free warranty, shatter-proof plastic casing, and 50,000 hours of operating time. 

The Probelie‎ P-G13-2FT-5000K is not a plug-and-play LED, however. You will need to either remove or bypass your ballast before you can install it. Instructions on how to bypass your ballast are listed in the final section of this article.

Can you fit T8 bulbs in a T12 fixture?

Yes. As long as they are the same length, say two feet or four feet, T8 and T12 lamps are interchangeable. The difference comes from their diameter. T8 lamps are one inch wide while T12 lamps are larger, at 1.5 inches. But they can still fit in the same fixtures because they use the same base pins, the G13.

Why are T12 lamps being discontinued?

Since they’re using technology that is 80 years old, T12 lamps are very energy inefficient. It is for this reason that the Department of Energy banned the manufacture and importation of any new T12 lamps starting in July 2012. 

The lamps that were already in use or sitting in warehouses would still be used but with no new ones being manufactured to replace them, T12 lamps are on their way out.

How do you convert a T12 fluorescent bulb to an LED?

This is pretty simple. You just buy an LED lamp of the same length that uses the G13 bi-pin base. Many LEDs are ballast compatible so there isn’t even any kind of rewiring required. It’s a simple plug-and-play operation

How to bypass T12 ballast for LED bulbs?

Most commercial LEDs are ballast compatible. If the one you have isn’t, your best bet is to hire an electrician. If you have a bit of electrical knowledge and insist on doing it yourself, here you go:

  1. Disconnect power at the mains, not just your light switch
  2. Locate the ballast
  3. Cut the live (red) and neutral wires (white) going into the ballast
  4. Remove the ballast
  5. Reconnect the cut wires to the output circuit
  6. Reattach any coverings you removed
  7. Turn the power back on