user4138: Irrespective of the length of time required to calculate one hash, how many hash operations are required to produce one Bitcoin?

user3155: Difficulty changes regularly, but there are calculators that take all current factors into account:
https://www.cryptocompare.com/mining/calculator/btc?HashingPower=15&HashingUnit=TH%2Fs&PowerConsumption=0&CostPerkWh=0
As of today (17 Jan 2017): a theoretical 1,581 TH/s (equivalent of running a hundred Antminer S9's) will return 1 BTC in a day. 
Tomorrow, it will be different. 

user4138: A good and simple website to calculate how much bitcoin can be created with what machine can be found at: http://www.alcula.com/calculators/finance/bitcoin-mining/

user5837: These charts show the approximate network hash rate on the left axis:
  http://bitcoin.sipa.be/
We know the network adjusts for 25 new bitcoins per 10 minutes.
Together this provides enough info to give an approximate answer to your question:
hashes per bitcoin 
= (network hash rate) / (25 BTC per 10 minutes)
= (180 * Th / s) / (25 * BTC / (600 * s) )
= 180 * 600 / 25 * Th / s / BTC * s
= 2,700 Th / BTC
= 2,700,000,000,000,000 h/BTC


4138: <p>Irrespective of the length of time required to calculate one hash, how many hash operations are required to produce one Bitcoin?</p>
 3155: <p>Difficulty changes regularly, but there are calculators that take all current factors into account:</p>

<p><a href="https://www.cryptocompare.com/mining/calculator/btc?HashingPower=15&amp;HashingUnit=TH%2Fs&amp;PowerConsumption=0&amp;CostPerkWh=0" rel="nofollow noreferrer">https://www.cryptocompare.com/mining/calculator/btc?HashingPower=15&amp;HashingUnit=TH%2Fs&amp;PowerConsumption=0&amp;CostPerkWh=0</a></p>

<p>As of today (17 Jan 2017): a theoretical 1,581 TH/s (equivalent of running a hundred Antminer S9's) will return 1 BTC in a day. </p>

<p>Tomorrow, it will be different. </p>
 4138: <p>A good and simple website to calculate how much bitcoin can be created with what machine can be found at: <a href="http://www.alcula.com/calculators/finance/bitcoin-mining/" rel="nofollow">http://www.alcula.com/calculators/finance/bitcoin-mining/</a></p>
 5837: <p>These charts show the approximate network hash rate on the left axis:
  <a href="http://bitcoin.sipa.be/" rel="noreferrer">http://bitcoin.sipa.be/</a></p>

<p>We know the network adjusts for 25 new bitcoins per 10 minutes.</p>

<p>Together this provides enough info to give an approximate answer to your question:</p>

<pre><code>hashes per bitcoin 
= (network hash rate) / (25 BTC per 10 minutes)
= (180 * Th / s) / (25 * BTC / (600 * s) )
= 180 * 600 / 25 * Th / s / BTC * s
= 2,700 Th / BTC
= 2,700,000,000,000,000 h/BTC
</code></pre>
