Need replacement XT lens cap. Which one is it?

If someone could direct me to the right lens cap, I would be very grateful. I need to order one for my friend but am not sure which one to get. He's got the kit lens, 18-55. Is that a 52mm? 58mm?

the kit lens uses a 58mm lens cap.

Thanks, overclock!

It tells the lens size on the front of the lens if you forget.

Eagle wrote in post #2179984
It tells the lens size on the front of the lens if you forget.

The filter thread size (not the "lens size") is shown on the front ring (around the lens element) of most lenses. You will usually see it as: Φ77mm for a 77mm filter thread diameter, for example. Lens caps are generally sized for the filter thread diameter.

SkipD wrote in post #2180946
The filter thread size (not the "lens size") is shown on the front ring (around the lens element) of most lenses. You will usually see it as: Φ77mm for a 77mm filter thread diameter, for example. Lens caps are generally sized for the filter thread diameter.

You are correct and I meant what you said.

Thanks for the clarification.