Looking How to?

There are two parts, The first parts is the most critical as the second part is very simple as How much by the unit price minus the operating cost for profit, the detail is ignored in this post.

The basic point is Using

The reward per block, Divides The share(Difficulty)

Then You will need to put hashrate (Need Real, for example 600M means 600,000,000) by 86400 / 4294967296

If applied the thing above, for 600mh/s, You will get 0.005 BTC (can be anything) a day based on 50M difficulty and 25 per block.

If you like to predict, Then you will need to sum up.

The second part is all about cost issues, which let yourself to do, it is simple. Out minus In, If In smaller than Out, then Black. Otherwise, Red.

Why 2^32? For 32-bit System as 32-bit system is still on main line. (The actual is 4,294,967,296)

1 day contains 86400 seconds, each hour is 3600 seconds.

Source:

http://bitcoin.stackexchange.com/questions/493/exactly-how-does-one-calculate-how-many-btc-they-will-get-a-certain-hashrate, Accessed on 24 August 2013

I think, If you understand the rule, then you should read the php programming guide to build it. The idea is currently still free, but source code is not free.