This question doesn't have a simple answer. It depends on what you mean by "bigger".

Here's why:

* Butte is a smaller, isolated hill with a flat top and steep sides.

* Mesa is a larger, flat-topped plateau with steep sides, often much wider than it is tall.

So, a mesa will always be larger in terms of area. However, a butte could be taller than a mesa.

Think of it like this:

* A butte is like a tall, thin building.

* A mesa is like a large, flat platform.

Therefore, you need to define "bigger" in terms of area or height to determine which is bigger.