How to Replace Fluorescent T8 & T12 Tubes With LED (Step by Step)

Converting fluorescent shop lights, troffers, and strip fixtures to LED slashes energy use, ends the flicker and hum, and removes mercury from your space. It's a very doable upgrade. Here's the step-by-step for T8 and T12 fixtures.

Electrical work carries risk. Turn off power at the breaker before wiring, and hire a licensed electrician if you're not confident. See our safety disclaimer.

Step 1: Identify Your Tubes

Check the printing on the old tube. T12 tubes are fat (1.5" diameter) and old-school, usually on magnetic ballasts. T8 tubes are slimmer (1" diameter) and typically on electronic ballasts. Note the length (2/3/4/8 ft) and the base (G13 bi-pin for most T8/T12; single-pin FA8 on many 8-footers). See our tube size guide.

Step 2: Pick Your Conversion Type

This is the key decision:

  • Type A (plug-and-play): works with your existing electronic ballast — easiest, no wiring. Great for T8 fixtures with a healthy ballast.
  • Type B (ballast-bypass): rewire to line voltage and remove the ballast — most efficient and the usual choice for old T12 magnetic-ballast fixtures (LED Type A tubes generally don't run on magnetic ballasts).
  • Type A+B (universal): do plug-and-play now, convert later.

Full comparison in our Type A/B/C guide. Tip: T12 fixtures almost always call for Type B, since their magnetic ballasts aren't LED-compatible.

Step 3 (Type A): Just Swap

Remove the fluorescent tube, insert the matching Type A LED tube into the same sockets, and switch on. Confirm instant, flicker-free light. That's it.

Step 3 (Type B): Rewire Safely

  1. Cut power at the breaker and confirm it's off.
  2. Remove the tubes and the fixture cover.
  3. Disconnect and remove (or fully bypass) the ballast.
  4. Wire line and neutral to the sockets per the tube's diagram — single-ended or double-ended as specified — using the correct (often non-shunted) tombstones.
  5. Restore the cover, install the LED tubes, and restore power.

Always follow the specific tube's wiring instructions; they vary by model.

Step 4: Match Brightness and Color

Replace by lumens — a 15W–18W LED matches a 32W T8 4-footer (~1,800–2,250 lm). Choose 4000K for neutral spaces or 5000K daylight for shops and garages. Clear lenses maximize brightness; frosted reduce glare.

Step 5: Recycle the Old Tubes

Fluorescent tubes contain mercury — don't trash them where prohibited. Use a hazardous-waste or lamp-recycling drop-off. If a tube breaks, ventilate and follow EPA cleanup (don't vacuum).

Shop Tubes and Save in Bulk

Find your size and type in our LED Tubes collection, available in singles and discounted 6- and 12-packs for whole-fixture or whole-building jobs. Not sure which tube fits? Tell us your length, base, and ballast and we'll help you choose.

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