What is the headlight bulb size for the 2015 Toyota Corolla?

The 2015 Toyota Corolla uses a 9005 for the high beam headlight bulb size, and LED for the low beam one. Likewise, it's a LED for the daytime running light bulb. The fog light bulb's going to be an H16, though You can also do a H16 HID here. If You're finding that the front headlight bulbs are blowing out more frequently than they should, for example, in months not years, then there are a couple things that could cause that, with the most likely being that there's moisture leaking into the headlight: See about sealing the housing in this case. The other common thing is going to be a loose electrical connection, which can short the bulb, or just cause it to go on and off as You're driving --- either way, You'll want to get these issues addressed as soon as possible.