How many bitcoins will I mine per day ?

[Bert]

Should I buy more equipment *ponder* I decided to do some simple back of the envelope calculations.

The current Network Hashrate at the time of writing this is 9486.00 Gigahashs/s

The number of bitcoins generated every day assuming that the mining rate is fixed for 2 weeks (2016 blocks) is 50 bitcoins, or a rate of one new block every 10 minutes. Over a single day this would be 50*6*24 or 7200 BTC in total.

Let's say that my mining rig can hash at 1.6 Gigahash per second.

(1.6 x 7200)/9486.00 is 1.214 BTC mined per day.

But this is assuming that the overall network hash rate is constant. But it is currently increasing at at rate of 5% every day.

So the 1.214 BTC mined today is going to decrease by about 5% every day. Tomorrow I will only have 95% of the income of today.

Tomorrow it would be 0.95 x 1.214 = 1.153 BTC
In a week it would be 0.95^7 x 1.214 = 0.85 BTC
In two weeks it would be 0.95^14 x 1.214 = 0.59 BTC
In a month it would be 0.95^(365.25/12) x 1.214 = 0.25 BTC

But again this is ignoring the increases in difficulty once every 2016 block or once every 2 weeks, if the difficulty is right. But because the sole purpose of the increases (or decreases) of the difficulty is to force the hashrate to be one new block on average every 10 minutes for two weeks this can be safely ignored. It can be ignored because the hashrate increase of the network of 5% is what the difficulty increase is trying to compensating for. To pull it up (or down) to 2016 new blocks every 14 days.

The next difficulty increase in 280 blocks (at time of writing) is estimated to increase from 877227 to 1325179 or a 51% increase.

Code:

Date and time       block#  256 Bits Difficulty     Days (since last increase)
------------------- ------- -------- -------------- -----
2009-01-03 18:15:05      0  1d00ffff       1.000000  0.00
2009-01-27 13:38:51   2016  1d00ffff       1.000000 23.81
2009-02-12 19:16:30   4032  1d00ffff       1.000000 16.23
2009-03-02 04:01:53   6048  1d00ffff       1.000000 17.36
2009-03-20 00:26:26   8064  1d00ffff       1.000000 17.85
2009-04-06 22:04:23  10080  1d00ffff       1.000000 17.90
2009-04-24 18:51:38  12096  1d00ffff       1.000000 17.87
2009-05-12 03:20:25  14112  1d00ffff       1.000000 17.35
2009-05-31 02:31:25  16128  1d00ffff       1.000000 18.97
2009-06-26 21:32:53  18144  1d00ffff       1.000000 26.79
2009-07-25 00:30:16  20160  1d00ffff       1.000000 28.12
2009-09-04 13:01:38  22176  1d00ffff       1.000000 41.52
2009-10-02 03:27:08  24192  1d00ffff       1.000000 27.60
2009-10-31 15:28:20  26208  1d00ffff       1.000000 29.50
2009-11-27 21:51:07  28224  1d00ffff       1.000000 27.27
2009-12-18 09:56:01  30240  1d00ffff       1.000000 20.50
2009-12-30 06:11:04  32256  1d00d86a       1.182899 11.84
2010-01-11 22:48:37  34272  1d00c428       1.305062 12.69
2010-01-25 13:07:59  36288  1d00be71       1.344224 13.60
2010-02-04 21:43:14  38304  1d008cc3       1.818648 10.36
2010-02-14 23:52:59  40320  1c654657       2.527738 10.09
2010-02-24 08:41:04  42336  1c43b3e5       3.781179  9.37
2010-03-08 01:14:33  44352  1c387f6f       4.531081 11.69
2010-03-21 22:54:24  46368  1c381375       4.565162 13.90
2010-04-01 11:07:22  48384  1c2a1115       6.085476 10.51
2010-04-12 08:39:46  50400  1c20bca7       7.819796 10.90
2010-04-21 21:52:52  52416  1c16546f      11.464315  9.55
2010-05-04 09:46:16  54432  1c13ec53      12.849183 12.50
2010-05-19 14:13:55  56448  1c159c24      11.846228 15.19
2010-05-29 13:57:28  58464  1c0f675c      16.619078  9.99
2010-06-11 23:26:26  60480  1c0eba64      17.381488 13.40
2010-06-24 12:27:26  62496  1c0d3142      19.404796 12.54
2010-07-06 01:57:44  64512  1c0ae493      23.501257 11.56
2010-07-13 08:03:57  66528  1c05a3f4      45.385822  7.25
2010-07-16 16:29:39  68544  1c0168fd     181.543289  3.35
2010-07-27 02:42:38  70560  1c010c5a     244.213223 10.43
2010-08-05 19:46:35  72576  1c00ba18     352.161209  9.71
2010-08-15 11:11:11  74592  1c00800e     511.773534  9.64
2010-08-26 23:13:23  76608  1b692098     623.386959 11.50
2010-09-08 05:04:49  78624  1b5bede6     712.884864 12.24
2010-09-19 02:04:07  80640  1b4766ed     917.830741 10.87
2010-09-28 19:58:28  82656  1b31b2a3    1318.670050  9.75
2010-10-12 05:35:05  84672  1b2f8e9d    1378.028165 13.40
2010-10-21 05:13:15  86688  1b1e7eca    2149.021814  8.98
2010-10-30 22:58:47  88704  1b153263    3091.736890  9.74
2010-11-09 12:29:28  90720  1b0e7256    4536.353723  9.56
2010-11-18 18:44:34  92736  1b098b2a    6866.898648  9.26
2010-11-30 16:37:55  94752  1b081cd2    8078.195257 11.91
2010-12-09 22:20:02  96768  1b055953   12251.999760  9.24
2010-12-21 18:34:03  98784  1b04864c   14484.162361 11.84
2011-01-03 05:10:11 100800  1b0404cb   16307.420938 12.44
2011-01-15 14:26:07 102816  1b038dee   18437.644392 12.39
2011-01-27 08:16:11 104832  1b02fa29   22012.381337 11.74
2011-02-08 04:53:20 106848  1b028552   25997.879928 11.86
2011-02-18 05:15:52 108864  1b01cc26   36459.886925 10.02
2011-02-27 09:59:20 110880  1b012dcd   55589.518126  9.20
2011-03-09 15:25:55 112896  1b00dc31   76192.619347 10.23
2011-03-25 02:39:45 114912  1b00f339   68977.784630 15.47
2011-04-05 20:09:57 116928  1b00cbbd   82345.644112 11.73
2011-04-18 07:49:36 118944  1b00b5ac   92347.590952 12.49
2011-04-30 02:53:00 120960  1b0098fa  109670.133292 11.79
2011-05-09 21:17:24 122976  1a6a93b3  157416.401843  9.77
2011-05-18 22:04:47 124992  1a44b9f2  244112.487774  9.03
2011-05-26 18:41:56 127008  1a269421  434877.045527  7.86
2011-06-06 12:25:05 129024  1a1d932f  567269.530162 10.74
2011-06-15 13:49:34 131040  1a132185  876954.493513  9.06

The average time for each of the previous 66 difficulty rounds of 2016 blocks since Bitcoin started is 13.74 days. Or in other words instead of taking 910 days to hash 133056 blocks (66 x 2016) it took 892.81 days. So the network will continue to increase the difficulty until these missing 17.19 days have been regained.

If the hash rate of the network suddenly dropped by 50% the difficulty would drop after a while. This would also mean that my hash rate of 1.6Ghash/sec would start to generated double the Bitcoin income once the missing days were regained by the system. But such a thing is extremely unlikely to happen at least in the short term.

So what does this mean for me, in the short term if I change nothing my income will drop by 5% per day. Every 15 days (compound) my Bitcoin income will half unless I am adding more graphics cards at a rate of about 25% of my hashrate every 5 days (or 50% every 9 days).

The conclusion for me is that it is becoming less and less cost effective to mine using new hardware. Assuming that the increase in overall network hashing is constant at 5% every day, if I am mining at 1.6Ghash/sec over 31 days I will have made in total 19.88 BTC (excluding power costs). If I bought a new graphics card every 5 days to add 25% mining capacity I would make 32.54 Bitcoins.

In my opinion new dedicated mining rigs will rapidly become a thing of the past, if the 5% increase in hashrate a day continues. The only people who will make anything mining is people looking to buy a new computer or a new graphics card and want to reduce the cost by a bit of mining.

After working out for myself if I should add more motherboards/graphics cards to my existing setup, I have decided against it. Not unless the exchange rate of Bitcoins increases. I could swallow the cost in the hope of it rising, but I have now decided that I will make more buying Bitcoins than buying additional hardware.

Thought that I would share my thinking and see if anyone can point out obvious flaws.

[ribuck]

Your rate of bitcoin generation depends only on the difficulty level.

If a lot of other people join the network, it just means that more blocks will be solved each hour. It doesn't mean that you will solve fewer blocks.

Then, when the difficulty adjusts, the target is set back to 6 per hour.

So, when doing profitability calculations, all you need to consider is your hashing rate and the difficulty level.

So the network will continue to increase the difficulty until these missing 17.19 days have been regained.

There's no catch-up. Each difficulty adjustment considers only the previous 2016 blocks.

[Bert]

Your rate of bitcoin generation depends only on the difficulty level.

If a lot of other people join the network, it just means that more blocks will be solved each hour. It doesn't mean that you will solve fewer blocks.

Thanks, that makes perfect sense.

There's no catch-up. Each difficulty adjustment considers only the previous 2016 blocks.

Are you sure ?

2010-05-04 09:46:16  54432  1c13ec53      12.849183 12.50
2010-05-19 14:13:55  56448  1c159c24      11.846228 15.19
2010-05-29 13:57:28  58464  1c0f675c      16.619078  9.99
...
2011-03-09 15:25:55 112896  1b00dc31   76192.619347 10.23
2011-03-25 02:39:45 114912  1b00f339   68977.784630 15.47
2011-04-05 20:09:57 116928  1b00cbbd   82345.644112 11.73

I thought that there was something strange about the last six digits of the hex Bits value decreasing, so I double checked the difficulty by hand but the numbers are fine. By decreasing the last 6 hexadecimal numbers the difficulty increases.

[SlipperySlope]

Take a look at this cool new bitcoin mining calculator that incorporates projected difficulty increases....

http://striketeam.ath.cx/btccalc/btccalc.php

[Bert]

Very very nice, but is there a typo on the results page ? "This change is fixed in this model to every 10 days."

[zipxavier]

Take a look at this cool new bitcoin mining calculator that incorporates projected difficulty increases....

http://striketeam.ath.cx/btccalc/btccalc.php

Very useful thank you.

[deepceleron]

Here's the current bitcoin difficulty: http://blockexplorer.com/q/getdifficulty.

I reduced the formula down to: average BTC per Day = (megahashes per second / difficulty) * 1005.82838

so: 100 megahashes/s at 1379223.4296725 difficulty = ( 100 / 1379223.4296725 ) * 1005.82838 = .07292715 BTC per day

Add ~1% in transaction fee wins (if paid by pool), subtract downtime, connectivity issues, and rejected block overhead, and subtract pool fees.

If you join a large pool that solves several blocks a day your results will be very close to this. If you are solo mining with a GPU, it is more like a lottery - although stats say it would average eight months to win 50 BTC at current difficulty with a good ATI GPU, you might win it tomorrow or you might never win in your lifetime.

Difficulty increases are calculated every 2016 blocks based on the past performance, which are every two weeks if the bitcoin network hashrate is constant. Since the network keeps on increasing it's computing power, the recalculation happens more often than that.

[unbanned]

its going to be very difficult to get any machine bought today to pay itself off.

the next difficulty will be in the range of 1.4 million that should happen in about 20 hours.

[Seaco]

I talked the other day to a member that has been mining for over a year, and he stated that mining is pretty much as profitable as it was 1 year ago (difficulty and price have shown a correlation, although i wouldnt trust that it will stay that way), so id say that it is still ok to mine. Plus its not that easy to buy coins everywhere, especially in smaller countries. Consider your mining rig as low-risk coin buy, given that you can always resell the hardware, so techinally id say that the "break even" point would be for 40-50% of your hardware cost, not 100% as most people suggest.

[deepceleron]

In my opinion new dedicated mining rigs will rapidly become a thing of the past, if the 5% increase in hashrate a day continues. The only people who will make anything mining is people looking to buy a new computer or a new graphics card and want to reduce the cost by a bit of mining.

Thought that I would share my thinking and see if anyone can point out obvious flaws.

I suppose you also have to consider if the BTC -> USD exchange rate could also increase 5% a day..

There is more and more money invested in hardware these days fighting over the same 50 BTC prizes. The value of those new 100,800 BTC mined every 10 days or so may settle in close to the cost of all the electricity and hardware wasted to generate them, as long as the early adopters who got 10,000x more BTC per watt don't decide to cash out, at which time it will be mining game over.

[ribuck]

There's no catch-up. Each difficulty adjustment considers only the previous 2016 blocks.

Are you sure ?

Yes I'm sure.

Firstly, from the "Difficulty" page that you referenced on the wiki, it explicitly says "The difficulty is adjusted every 2016 blocks based on the time it took to find the previous 2016 blocks".

Secondly, we can see from the history that there have seen several difficulty rises of over 50% (and one of the maximum allowed, 400%). It would be mathematically impossible to get this amount of rise if the calculation was measuring all blocks to allow for catch-up. No matter how fast the most recent 2016 blocks are mined they can't increase the total historical mining rate (since the genesis block) by a factor of 50% to 400%.

[Bert]

... snip ...
Firstly, from the "Difficulty" page that you referenced on the wiki, it explicitly says "The difficulty is adjusted every 2016 blocks based on the time it took to find the previous 2016 blocks".

Secondly, we can see from the history that there have seen several difficulty rises of over 50% (and one of the maximum allowed, 400%). It would be mathematically impossible to get this amount of rise if the calculation was measuring all blocks to allow for catch-up. No matter how fast the most recent 2016 blocks are mined they can't increase the total historical mining rate (since the genesis block) by a factor of 50% to 400%.

It also says "If the previous 2016 blocks took more than two weeks to find, the difficulty is reduced. If they took less than two weeks, the difficulty is increased." Which is not the case for the two examples I gave above. They took over 15 days and the difficulty still increased. Any ideas why ? Or is it time to dig through the source code on a bug hunt.

[frizzl]

The way I see it is anyone that adopted early (pre 2011) has it made if everything continues to go up.  It was easy to obtain hundreds+ of BTC then.  Anyone joining in the last few months has made some $ hopefully but nowhere near the earlies.  They had a much better opportunity to make BTC than we do now.  I haven't invested anything at all beside a new vid card and put out about 300m/h earning a measly 4 BTC in a few weeks.  At this rate of mining next diff.  I will be lucky to make 1 BTC a week, electricity will likely become a much higher factor I haven't worked out the exact numbers as its pretty much common sense at this point.  If the network continues to rise then making BTC out of thin air for people under 500MH isn't going to be as fun.  Investing the produced BTC is likely the next option for this group of miners as it simply wont be worth it to stress high end gear to pretty much break even.  Breaking even is a stretch when you count in the time/risk it takes to convert BTC into your countries currency.  With all the fucking bs hackers around you never know whos watching o.O

[BkkCoins]

I'll be interested to see if the USD-BTC rates change when the difficulty goes up. I would think in theory there should be some adjustment as people re-interpret the value of BTC.

[Cory]

I don't think that the value depends on the difficulty. It's the other way around.

[V4Vendettas]

http://forum.bitcoin.org/index.php?topic=22691.0

[Title12USC§411]

I'll be interested to see if the USD-BTC rates change when the difficulty goes up. I would think in theory there should be some adjustment as people re-interpret the value of BTC.

I am thinking the "value" of BTC ultimately will be in their inherent ease to transfer to others to accomplish transactions. 

Because for example I recently needed to convert FRN (so called "USD") from a credit union account to IDR and then transmit same to a foreign bank account. The credit union - which had a so called "wire transfer" office - acted like complete idiots in terms of how may times I needed to contact them to get the job done in addition to having to pay $35 FRN to these currency hackers to transmit about $400 FRN.  And I had to do a lot of splainin like who/what/where/why in addition to how much, all of which was none of these currency hackers business!

Fook FRNs, the suicide banksters and the jackals they rode in on. 

[V4Vendettas]

@ Title12USC§411

Your in the right place and surrounded by alot of other pissed off people. o/\o

[deepceleron]

Here's the current bitcoin difficulty: http://blockexplorer.com/q/getdifficulty.

I reduced the formula down to: average BTC per Day = (megahashes per second / difficulty) * 1005.82838

Necro-bump. Due to the scheduled halfing of the block reward every four years, the new number is:

Average BTC per Day = (megahashes per second / difficulty) * 502.91419

New realistic examples using today's network stats

Radeon HD 5830:
300 Mhash/s at 3438908.96 difficulty = ( 300 / 3,439,000 ) * 502.91419 = 0.043 BTC per day
 or 1.32 BTC/month ≅ $16/month

BFL Single FPGA Miner:
832 Mhash/s at 3438908.96 difficulty = ( 832 / 3,439,000 ) * 502.91419 = 0.12 BTC per day
 or 3.65 BTC/month ≅ $45/month