It is 0.01 BTC minimum payouts.  All of my payouts on middlecoin have happened once I reached > 0.01 Balance.

I believe the minimum payout has been changed to .01.  All you can really do is guess at your 24 hour earnings because it depends on too many factors.  You can look at past performance to guess at how much you might make in a 24 hour period, but past performance can never guarantee future performance.  It may be higher or lower.  Sorry for the vague answer, but the question is difficult to really nail down.

Chad