How to identify G13
- Two pins appear at each tube end.
- Measure 13 mm between pin centers.
- Read the tube and ballast labels.
Where it is commonly used
Common use is a clue, not proof. The fixture label and model documentation take priority over a visual match.
Bulb shapes sold with this base
You may see these shapes with a G13 base. The base code does not guarantee the bulb width, length, beam angle, or clearance.
Before you buy a replacement
- LED tubes can be ballast-compatible, ballast-bypass, or externally driven.
- Rewiring should be performed by a qualified person.
- Match tube length and electrical configuration.
Quick answers
Questions about the G13 bulb base
What is a G13 bulb base?
G13 is the two-pin base used at the ends of many T8 and T12 linear lamps. A matching base does not establish ballast or wiring compatibility.
What size is a G13 bulb base?
G13 has a nominal 13 mm pin spacing. Pin spacing is measured from the center of one pin to the center of the other. Use the printed base code when available because a visual estimate is not conclusive.
Where is a G13 bulb base commonly used?
Common examples include t8 tubes, t12 tubes, offices, garages and utility rooms. Fixture type is only a clue; confirm the code on the bulb, socket, fixture label, or manufacturer documentation.
Can I choose a G13 replacement by appearance alone?
No. Match the G13 connection first, then verify voltage, actual input wattage, bulb dimensions, fixture restrictions, controls, and any enclosure or location rating required by the installation.