This short post aims at helping miners or aspiring miners estimate ETH earnings.  Finding an easy-to-use ETH profit formula on the web was quite hard for me, so it might help you.

This formula is very useful if your goal is to make estimate of future earnings (and profit) with your own spreadsheet.

Formula:

EarningsPerMonth = (UserHashMh * 1e6 / ((difficultyTH / BlockTimeSec)*1000*1e9))*((60/ BlockTimeSec)*BlockReward)*(60*24*30)*(EthPrice)

 With:

UserHashMh = Mining servers hashpower (in MH/s)
Difficulty in TH/s
BlockTime in seconds
BlockReward = number of ETH per block mined (5 currently)
EthPrice in fiat

Enjoy =)