A one ladle can is a eighteen-liter container, which is also a five-gallon container. That must be one big ladle!

If you live in Japan you've probably seen these. They're rectangular shaped containers made of metal that are used mostly for industrial purposes, for storing liquids like paint, fuel and chemicals. The 斗 actually refers to an old Japanese measurement, which is roughly equivalent to eighteen liters.

This is a jukugo word that uses the on'yomi readings of the kanji. Just watch out for the 一, which gets shortened to いっ.