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Average dayly income= (((((Hashrate (hashes/sec) * average block reward * 600 * 65535) / 2^48) / Difficulty) * 6 * 24)
Since OP didn't give the hashrate maybe he is asking himself how to get that information, and i would like to share my favorite source for this:
https://en.bitcoin.it/wiki/Non-specialized_hardware_comparisonIn that link we will get the MHash/sec for almost any mining hardware (Miner, CPU or graphic card).