Bitcoin Forum

Can someone breakdown this calculation for me?
$per24 = ($totalHashingPower * 25 / $difficulty) * (60 * 60 * 24 * 65535 * pow(10,6) / pow(2,48));

The above fromula is wrong, the concept is very easy.  You need three things:

y = your hash rate
n = the network hash rate
b = bitcoin subsidy for the period of interest

Then the amount of coins you will make, c, is just your slice of the total hash rate:

c = b(y/n)

Looks like you want the number of coins you will make per day (ignoring fees).  In that case:

b = (25 BTC per block)(6 blocks per hour)(24 hours per day) = 3,600 BTC/day

The network hash rate is estimated here:  https://bitcoinwisdom.com/bitcoin/difficulty (https://bitcoinwisdom.com/bitcoin/difficulty)

And right now is about 126,228,905 GH/s = 126,229 TH/s = 126 PH/s

Let's assume you had 126.229 TH/s then on average you would make 126.229 / 126,229 =  0.1% of the coins every day:  3,600 * 0.001 = 3.6 BTC per day.

In terms of the formula you gave, so far, we have accounted for only the bolded part:

$per24 = ($totalHashingPower * 25 / $difficulty) * (60 * 60 * 24 * 65535 * pow(10,6) / pow(2,48));

Now if you want to use difficulty, D, instead of the estimated total hash rate you use the formula given here:

https://en.bitcoin.it/wiki/Difficulty

n = D(2⁴⁸ / 0xffff)

0xffff = 65535 so we have:

n = D(2⁴⁸ / 65535)

Substituting into the formula in the previous post:

c = (25)(6)(24)(y/(D(2⁴⁸ / 65535)))

c = y(25)(6)(24)(65535)/(D(2⁴⁸))

So in your formula we have accounted for:

$per24 = ($totalHashingPower * 25 / $difficulty) * (60 * 60 * 24 * 65535 * pow(10,6) / pow(2,48));

Finally, the 10⁶ factor is just so you can enter your hashing rate ($totalHashingPower) in MH/s instead of H/s.  This leaves the following parts of the formula as wrong:

$per24 = ($totalHashingPower * 25 / $difficulty) * (60 * 60 * 24 * 65535 * pow(10,6) / pow(2,48));

The corrected formula ($totalHashingPower in MH/s) is:

$per24 = ($totalHashingPower * 25 / $difficulty) * (6 * 24 * 65535 * pow(10,6) / pow(2,48));

Where did you get this equation? =-O

I Googled the incorrect formula and found it in three places.  The authors should be notified that the formula is incorrect (just point them back to this thread):

https://bitcointa.lk/threads/pb-mining-5-year-mining-contracts.238321/page-7#post-4610463

https://bitcointa.lk/threads/pb-mining-5-year-mining-contracts.238321/page-168#post-7368443

http://www.cryptomania.info/pbmining-bitcoin-review

So the culprit is pbmining.

It appears to be a mistake in the post, rather than a mistake in our actual system. 

Please correct your post so as not to confuse your current or potential customers.

I would really hope so... As that's a significant "mistake"

Sure, just let me know how to correct the post on bitcointa.lk?  I believe that website shows past posts there were already changed/deleted from here, am I right?