There is no single, definitive answer to this question because:

* The central tallgrass prairie has been significantly fragmented and reduced. Historically, it stretched across millions of acres in the central United States, but now much of it is converted to farmland, urban areas, and other land uses.

* Defining the exact boundaries of the "central" tallgrass prairie is subjective. It's part of a larger biome (the Great Plains) that stretches from Canada to Mexico.

However, we can provide some estimates:

* Historically: The central tallgrass prairie likely spanned over 140 million acres, reaching from central Texas to western Ohio.

* Currently: There are only about 4% of the original central tallgrass prairie remaining in a relatively natural state. This translates to about 5.6 million acres.

Key points to remember:

* The central tallgrass prairie is a highly fragmented ecosystem, with most remaining areas in small patches.

* Ongoing conservation efforts aim to restore and protect this important habitat.

If you have further questions about a specific region or aspect of the central tallgrass prairie, please provide more context, and I'll do my best to help.