Network hashes and difficulty correlation

[Jrock]

I'm looking for a calculator type site that will allow me to type in a certain amount of network hashes so I can see the estimated difficulty that would come along with it.

Like I type in 100 Terahashes and it estimates what the network difficulty would be at that level.

Does this exist? Google isn't finding it for me if it does.

[crazyates]

What network hash rate results in a given difficulty?

Code:

D * 2**32 / 600 / 1000000000000

D = Difficulty, and the resulting answer will be in TH/s.

Difficulty of 4,850,000. (current)
Difficulty of 25million.
Difficulty of 50million.
Difficulty of 75million.
Difficulty of 100million.
Difficulty of 150million.
Difficulty of 200million.
Difficulty of 250million.
Difficulty of 500million.