Mining Difficulty in Different Coins
This is a list of the main characteristics of the most popular cryptocurrencies
Basic definitions
Difficulty is a measure of how difficult it is to find a hash below a given target. The Bitcoin network has a global block difficulty. Valid blocks must have a hash below this target. Mining pools also have a pool-specific share difficulty setting a lower limit for shares.
- The formula for difficulty:
difficulty = difficulty_1_target / current_target
(target is a 256 bit number)
difficulty_1_target can be different for various ways to measure difficulty. Traditionally, it represents a hash where the leading 32 bits are zero and the rest are one (this is known as "pool difficulty" or "pdiff"). The Bitcoin protocol represents targets as a custom floating point type with limited precision; as a result, Bitcoin clients often approximate difficulty based on this (this is known as "bdiff").
- The maximum of difficulty is no minimum target. The maximum difficulty is roughly: maximum_target / 1 (since 0 would result in infinity), which is a ridiculously huge number (about 2^224).
The actual maximum difficulty is when current_target=0, but we would not be able to calculate the difficulty if that happened. (fortunately it never will, so we're ok.)
- The minimum difficulty is when the target is at the maximum allowed value, is 1.
This is a list of the main characteristics of the most popular cryptocurrencies
| Coin | Symbol | Last price | Exchanges | Difficulty | Nethashrate | Daily income | Volume 24h | Your hashrate | Website |
|---|---|---|---|---|---|---|---|---|---|
| 42 | 3.85234199฿ 64.99999899(24/H) 2.25000001(24/L) |
Cryptsy | 6.25072094 54.17777275(24/H) 0.19231841(24/L) |
668.7Mh/s 18,929.2Mh/s(24/H) 6.8Mh/s(24/L) |
0.00052071฿ 0.00013517COINS 0.23US-Dollar |
0.66 ฿ | 1,000 Mh/s | [1] | |
| Aiden | n/a n/a (24/H) n/a (24/L) |
Poloniex Allcoin |
0.49926483 205.3885706(24/H) 0.49926483(24/L) |
71.9Mh/s 18,987.8Mh/s(24/H) 71.9Mh/s(24/L) |
n/a 2,015Coins n/a |
n/a | 1,000 Mh/s | - | |
| Alphacoin | 0.00000037฿ 0.00000379(24/H) 0.00000027(24/L) |
Cryptsy | 1.90331668 4.39215949(24/H) 0.00024414(24/L) |
193.5Mh/s 3,751.7Mh/s(24/H) 0.0Mh/s(24/L) |
0.00019553฿ 528.5Coins 0.09US-Dollar |
0.01 ฿ | 1,000 Mh/s | - | |
| AmericanCoin | 0.00000090฿ 0.00000579(24/H) 0.00000085(24/L) |
Cryptsy | 3.79345657 3.79345657(24/H) 0.75632725(24/L) |
4.5Mh/s 4,300.3Mh/s(24/H) 1.8Mh/s(24/L) |
0.00047727฿ 530.3Coins 0.21US-Dollar |
0.01 ฿ | 1,000 Mh/s | [2] | |
| AnonCoin | ANC | 0.00096159฿ 0.00300000(24/H) 0.00088817(24/L) |
Cryptsy | 160.81129525 167.6522434(24/H) 26.45352843(24/L) |
3,802.0Mh/s 4,607.3Mh/s(24/H) 504.6Mh/s(24/L) |
0.00060145฿ 0.62547123COINS 0.27US-Dollar |
4.91 ฿ | 1,000 Mh/s | [3] |
| AuroraCoin | 0.00009574฿ 0.00239798(24/H) 0.00010057(24/L) |
Poloniex Bittrex BTER |
63.50651268 216.6362357(24/H) 32.99939811(24/L) |
695.7Mh/s 5,831.5Mh/s(24/H) 296.2Mh/s(24/L) |
0.00037909฿ 3.96Coins 0.17US-Dollar |
5.32 ฿ | 1,000 Mh/s | [4] | |
| CasinoCoin | 0.00000273฿ 0.00001232(24/H) 0.00000177(24/L) |
Cryptsy | 0.00024414 47.28381631(24/H) 0.00024414(24/L) |
0.0Mh/s 474.8Mh/s(24/H) -0.2Mh/s(24/L) |
n/a n/a n/a |
0.58 ฿ | 1,000 Mh/s | [5] | |
| Coinye | n/a n/a (24/H) n/a (24/L) |
- | 5.21043506 7.67822499(24/H) 0.47289009(24/L) |
169.6Mh/s 731.1Mh/s(24/H) 4.3Mh/s(24/L) |
n/a 1,286,940Coins n/a |
n/a | 1,000 Mh/s | [6] | |
| Cryptogenic Bullion | 0.00030000฿ 0.00095400(24/H) 0.00020003(24/L) |
Bittrex Cryptsy |
0.10845264 3.42585429(24/H) 0.02167005(24/L) |
8.0Mh/s 401.2Mh/s(24/H) 0.5Mh/s(24/L) |
0.00055646฿ 1.85Coins 0.25US-Dollar |
0.12 ฿ | 1,000 Mh/s | - | |
| Diamond | 0.00021016฿ 0.00151500(24/H) 0.00020010(24/L) |
Cryptsy | 70.36193895 127.2244424(24/H) 0.00024414(24/L) |
4,785.5Mh/s 9,737.3Mh/s(24/H) 0.0Mh/s(24/L) |
0.00060085฿ 2.86Coins 0.27US-Dollar |
0.21 ฿ | 1,000 Mh/s | [7] | |
| DigiByte | 0.00000034฿ 0.00000089(24/H) 0.00000026(24/L) |
Cryptsy | 483.09606082 599.9055997(24/H) 4.07838035(24/L) |
1,871.8Mh/s 8,980.0Mh/s(24/H) 73.7Mh/s(24/L) |
0.00011326฿ 333.1Coins 0.05US-Dollar |
0.33 ฿ | 1,000 Mh/s | [8] | |
| Doge | DOGE | 0.00000036฿ 0.00000144(24/H) 0.00000004(24/L) |
Poloniex Bittrex BTER |
844.96292407 2,417.519203(24/H) 381.7891359(24/L) |
44,784.2Mh/s 107,570.9Mh/s(24/H) 28,600.3Mh/s(24/L) |
0.00214269฿ 5,952Coins 0.95US-Dollar |
65.65 ฿ | 1,000 Mh/s | - |
| DopeCoin | 0.00000013฿ 0.00000154(24/H) 0.00000005(24/L) |
Allcoin | 6.08886932 56.18859748(24/H) 0.00218114(24/L) |
55.9Mh/s 638.0Mh/s(24/H) 20.4Mh/s(24/L) |
0.00020401฿ 1,569Coins 0.09US-Dollar |
0.01 ฿ | 1,000 Mh/s | [9] | |
| DuckDuckCoin | n/a n/a (24/H) n/a (24/L) |
- | 0.00182463 4.25683678(24/H) 0.00024414(24/L) |
0.0Mh/s 77.7Mh/s(24/H) -73,232.2Mh/s(24/L) |
n/a 1.33Coins n/a |
n/a | 1,000 Mh/s | [10] | |
| ECCoin | 0.00000013฿ 0.00000087(24/H) 0.00000002(24/L) |
Poloniex Bittrex Allcoin |
37.53923539 98.57434957(24/H) 13.76310213(24/L) |
3,619.1Mh/s 30,042.8Mh/s(24/H) 225.4Mh/s(24/L) |
7.0E-8฿ 0.53588112COINS 0US-Dollar |
0.01 ฿ | 1,000 Mh/s | [11] | |
| Earthcoin | 0.00000005฿ 0.00000013(24/H) 0.00000001(24/L) |
Poloniex Bittrex Cryptsy |
16.59911706 70.89625213(24/H) 1.63457461(24/L) |
734.1Mh/s 3,355.6Mh/s(24/H) 62.4Mh/s(24/L) |
0.00063625฿ 12,725Coins 0.28US-Dollar |
2.58 ฿ | 1,000 Mh/s | [12] | |
| Feathercoin | FTC | 0.00005818฿ 0.00026000(24/H) 0.00004901(24/L) |
Bittrex BTER Cryptsy |
247.53541076 311.8567950(24/H) 0.00992053(24/L) |
4,516.0Mh/s 56,823.5Mh/s(24/H) 56.8Mh/s(24/L) |
0.00094563฿ 16.25Coins 0.42US-Dollar |
4 ฿ | 1,000 Mh/s | [13] |
| Grandcoin | 0.00000010฿ 0.00000062(24/H) 0.00000008(24/L) |
Cryptsy | 5.40472210 6.78685103(24/H) 0.35338747(24/L) |
11.8Mh/s 285.8Mh/s(24/H) 2.0Mh/s(24/L) |
0.00037551฿ 3,755Coins 0.17US-Dollar |
0.01 ฿ | 1,000 Mh/s | [14] | |
| KarmaCoin | n/a n/a (24/H) n/a (24/L) |
Bittrex | 27.60167417 48.79846190(24/H) 3.93372420(24/L) |
1,742.2Mh/s 3,929.0Mh/s(24/H) 215.3Mh/s(24/L) |
n/a 25,509Coins n/a |
n/a | 1,000 Mh/s | [15] | |
| Klondikecoin | 0.00000305฿ 0.00006013(24/H) 0.00000305(24/L) |
Poloniex BTER Cryptsy |
0.83098752 45.35882684(24/H) 0.00024414(24/L) |
6.5Mh/s 825.1Mh/s(24/H) 2.0Mh/s(24/L) |
0.00029534฿ 96.83Coins 0.13US-Dollar |
0.01 ฿ | 1,000 Mh/s | [16] | |
| LegendaryCoin | 0.00000291฿ 0.00067900(24/H) 0.00000252(24/L) |
Bittrex | 57.26745813 84.54168892(24/H) 0.01634498(24/L) |
2,104.3Mh/s 3,699.6Mh/s(24/H) 0.1Mh/s(24/L) |
3.73E-6฿ 1.28Coins 0US-Dollar |
n/a | 1,000 Mh/s | [17] | |
| Litebar | 0.00003351฿ 0.00300000(24/H) 0.00003350(24/L) |
Cryptsy | 5.05296028 21.74654591(24/H) 1.76046312(24/L) |
127.4Mh/s 729.8Mh/s(24/H) 22.1Mh/s(24/L) |
0.00026682฿ 7.96Coins 0.12US-Dollar |
0.02 ฿ | 1,000 Mh/s | [18] | |
| Litecoin | LTC | 0.01299682฿ 0.04849960(24/H) 0.01097000(24/L) |
Poloniex Bittrex BTER |
22,724.5884083 22,724.58841(24/H) 5,162.439372(24/L) |
648,595.8Mh/s 811,441.2Mh/s(24/H) 108,317.2Mh/s(24/L) |
0.00057526฿ 0.04426168COINS 0.26US-Dollar |
42.01 ฿ | 1,000 Mh/s | [19] |
| LottoCoin | 0.00000001฿ 0.00000003(24/H) 0.00000001(24/L) |
Cryptsy | 0.50016409 25.54138363(24/H) 0.06119836(24/L) |
74.3Mh/s 5,690.0Mh/s(24/H) 20.7Mh/s(24/L) |
0.00173247฿ 173,247Coins 0.77US-Dollar |
0.02 ฿ | 1,000 Mh/s | [20] | |
| Megacoin | 0.00008855฿ 0.00037920(24/H) 0.00007779(24/L) |
Poloniex BTER Cryptsy |
77.46096239 157.4843003(24/H) 0.00024414(24/L) |
2,067.2Mh/s 7,186.1Mh/s(24/H) 0.4Mh/s(24/L) |
0.00057491฿ 6.49Coins 0.26US-Dollar |
2.07 ฿ | 1,000 Mh/s | [21] | |
| Mintcoin | 0.00000005฿ 0.00000019(24/H) 0.00000003(24/L) |
Poloniex Bittrex BTER |
0.06147789 121.4946990(24/H) 0.00024414(24/L) |
10.6Mh/s 17,221.6Mh/s(24/H) 0.0Mh/s(24/L) |
1.636E-5฿ 327.2Coins 0.01US-Dollar |
1.73 ฿ | 1,000 Mh/s | [22] | |
| MoonCoin | n/a n/a (24/H) n/a (24/L) |
Cryptsy | 0.00024414 0.98510357(24/H) 0.00024414(24/L) |
0.0Mh/s 51.1Mh/s(24/H) 0.0Mh/s(24/L) |
n/a 82,397,671,876Coins n/a |
n/a | 1,000 Mh/s | [23] | |
| Muniti | 0.00000015฿ 0.00001496(24/H) 0.00000003(24/L) |
Poloniex Bittrex |
1.79106313 113.5196801(24/H) 0.17752850(24/L) |
79.3Mh/s 11,204.3Mh/s(24/H) 10.3Mh/s(24/L) |
0.00018571฿ 1,238Coins 0.08US-Dollar |
n/a | 1,000 Mh/s | [24] | |
| NyanCoin | n/a n/a (24/H) n/a (24/L) |
Cryptsy | 0.84757052 7.32730650(24/H) 0.39006375(24/L) |
66.9Mh/s 4,731.8Mh/s(24/H) 12.4Mh/s(24/L) |
n/a 7,998Coins n/a |
n/a | 1,000 Mh/s | - | |
| PXL Coin | n/a n/a (24/H) n/a (24/L) |
- | 0.00024414 16.00000000(24/H) 0.00024414(24/L) |
0.1Mh/s 298.4Mh/s(24/H) -0.2Mh/s(24/L) |
n/a 2,059,942Coins n/a |
n/a | 1,000 Mh/s | [25] | |
| ParallaxCoin | 0.00004502฿ 0.00004503(24/H) 0.00003785(24/L) |
Poloniex Bittrex |
55.27336942 76.81898936(24/H) 12.44698870(24/L) |
2,520.6Mh/s 3,106.5Mh/s(24/H) 622.3Mh/s(24/L) |
0.00122887฿ 27.30Coins 0.55US-Dollar |
n/a | 1,000 Mh/s | - | |
| PawnCoin | 0.00000565฿ 0.00001999(24/H) 0.00000002(24/L) |
Poloniex Bittrex |
0.46799015 66.79311086(24/H) 0.00128139(24/L) |
8.2Mh/s 2,023.1Mh/s(24/H) 0.0Mh/s(24/L) |
0.0007286฿ 129.0Coins 0.32US-Dollar |
n/a | 1,000 Mh/s | [26] | |
| QQCoin | n/a n/a (24/H) n/a (24/L) |
Allcoin | 0.00091614 0.05668377(24/H) 0.00034665(24/L) |
0.3Mh/s 13.4Mh/s(24/H) 0.0Mh/s(24/L) |
n/a 8,783Coins n/a |
n/a | 1,000 Mh/s | [27] | |
| Rapidcoin | n/a n/a (24/H) n/a (24/L) |
- | 0.00024414 0.02909390(24/H) 0.00024414(24/L) |
0.0Mh/s 1.5Mh/s(24/H) 0.0Mh/s(24/L) |
n/a 6,591,814Coins n/a |
n/a | 1,000 Mh/s | [28] | |
| ReddCoin | 0.00000035฿ 0.00000040(24/H) 0.00000002(24/L) |
Poloniex Bittrex Cryptsy |
80.99568395 95.82946347(24/H) 0.44561322(24/L) |
5,771.3Mh/s 11,569.7Mh/s(24/H) 32.9Mh/s(24/L) |
0.00869281฿ 24,837Coins 3.87US-Dollar |
713.57 ฿ | 1,000 Mh/s | [29] | |
| RonPaulCoin | 0.00010115฿ 0.00881000(24/H) 0.00010113(24/L) |
Cryptsy | 3.58151832 147.9749861(24/H) 2.44724666(24/L) |
128.2Mh/s 6,156.9Mh/s(24/H) 18.9Mh/s(24/L) |
0.00056814฿ 5.62Coins 0.25US-Dollar |
0.14 ฿ | 1,000 Mh/s | [30] | |
| UltraCoin | 0.00001613฿ 0.00018200(24/H) 0.00001201(24/L) |
Poloniex Bittrex Cryptsy |
0.00044400 29.03080453(24/H) 0.00024414(24/L) |
0.1Mh/s 4,024.3Mh/s(24/H) -8.7Mh/s(24/L) |
0.32627072฿ 20,228Coins 145.19US-Dollar |
1.28 ฿ | 1,000 Mh/s | [31] | |
| Vertcoin | 0.00022826฿ 0.00295000(24/H) 0.00022826(24/L) |
Poloniex Bittrex BTER |
161.68382098 339.4840041(24/H) 13.44495146(24/L) |
4,637.2Mh/s 11,690.5Mh/s(24/H) 397.6Mh/s(24/L) |
0.00071฿ 3.11Coins 0.32US-Dollar |
8.57 ฿ | 1,000 Mh/s | [32] | |
| VirtualMiningCoin | VMC | 0.00000040฿ 0.00000494(24/H) 0.00000005(24/L) |
Bittrex | 0.17582763 2.50798537(24/H) 0.00148959(24/L) |
12.5Mh/s 206.0Mh/s(24/H) 0.4Mh/s(24/L) |
0.00313394฿ 7,835Coins 1.39US-Dollar |
n/a | 1,000 Mh/s | [33] |
| Whitecoin | 0.00000102฿ 0.00002383(24/H) 0.00000059(24/L) |
Poloniex Bittrex Cryptsy |
3.62502655 2,716.067828(24/H) 0.00024414(24/L) |
161.5Mh/s 124,177.3Mh/s(24/H) 0.0Mh/s(24/L) |
0฿ n/a 0US-Dollar |
n/a | 1,000 Mh/s | [34] | |
| microCoin | n/a n/a (24/H) n/a (24/L) |
Poloniex | 0.00053062 0.29205587(24/H) 0.00053047(24/L) |
0.1Mh/s 54.2Mh/s(24/H) 0.0Mh/s(24/L) |
n/a 53,248,010Coins n/a |
n/a | 1,000 Mh/s | - | |
| Chaincoin | n/a n/a (24/H) n/a (24/L) |
- | 0.17094541 1.83617719(24/H) 0.00242404(24/L) |
8.2Mh/s 86.2Mh/s(24/H) -17,472.5Mh/s(24/L) |
n/a 188.3Coins n/a |
n/a | 100 Kh/s | [35] | |
| CopperLark | CLR | 0.00001906฿ 0.00020992(24/H) 0.00001478(24/L) |
Cryptsy | 3,620.61323379 13,401.84216(24/H) 2,782.978899(24/L) |
52,106.6Mh/s 50,318,190.5Mh/s(24/H) -10,809,075.5Mh/s(24/L) |
5.3E-7฿ 0.02778061COINS 0US-Dollar |
0.18 ฿ | 100 Kh/s | [36] |
| MaruCoin | 0.00000001฿ 0.00107900(24/H) 0.00000001(24/L) |
Bittrex | 9.29529660 222.4146571(24/H) 1.44944044(24/L) |
105.9Mh/s 3,622.3Mh/s(24/H) 47.6Mh/s(24/L) |
1.144E-5฿ 1,144Coins 0.01US-Dollar |
n/a | 100 Kh/s | [37] | |
| MaxCoin | 0.00004050฿ 0.00025347(24/H) 0.00003769(24/L) |
Poloniex BTER Cryptsy |
15,475.7292496 167,786.0366(24/H) 0.00390625(24/L) |
2,177,810.6Mh/s 19,885,770.2Mh/s(24/H) 3.3Mh/s(24/L) |
2.5E-7฿ 0.00623942COINS 0US-Dollar |
2.3 ฿ | 100 Kh/s | [38] | |
| Metiscoin | n/a n/a (24/H) n/a (24/L) |
Poloniex | 2,607.84981356 18,723.87757(24/H) 2,607.849814(24/L) |
342.5Mh/s 14,650,081.7Mh/s(24/H) 31.5Mh/s(24/L) |
n/a 0.03856926COINS n/a |
n/a | 100 Kh/s | [39] | |
| Quark | QRK | 0.00002027฿ 0.00006768(24/H) 0.00001893(24/L) |
Bittrex BTER Cryptsy |
685.17567540 1,706.766365(24/H) 140.7829217(24/L) |
101,648.4Mh/s 252,246.6Mh/s(24/H) 5,145.8Mh/s(24/L) |
6.0E-8฿ 0.00293597COINS 0US-Dollar |
9.79 ฿ | 100 Kh/s | [40] |
| Bitcoin | BTC | 1.00000000฿ 1.00000000(24/H) 1.00000000(24/L) |
BTC-e | 18,736,441,558.3100 100,000,000.00(24/H) 100,000,000.00(24/L) |
150,885,757,005.7Mh/s 6,631,234,429,521.8Mh/s(24/H) 16,918,105.3Mh/s(24/L) |
0.00014763฿ 0.00014763COINS 0.07US-Dollar |
n/a | 5.5 Gh/s | [41] |
| Bonus | 0.00000010฿ 0.00000031(24/H) 0.00000001(24/L) |
Poloniex Bittrex |
50,655.7893992 581,179.3480(24/H) 7,879.021255(24/L) |
-13,531,779.8Mh/s 133,592,870.7Mh/s(24/H) -103,543,072.7Mh/s(24/L) |
0.00103355฿ 10,336Coins 0.46US-Dollar |
n/a | 5.5 Gh/s | [42] | |
| MazaCoin | 0.00000020฿ 0.00000192(24/H) 0.00000018(24/L) |
Poloniex Bittrex Cryptsy |
4,080.16279224 11,797,028.47(24/H) 1,388.661332(24/L) |
902.1Mh/s 6,080,339,573.9Mh/s(24/H) 0.0Mh/s(24/L) |
0.02711684฿ 135,584Coins 12.07US-Dollar |
0.18 ฿ | 5.5 Gh/s | [43] | |
| Takcoin | 0.00000002฿ 0.00000044(24/H) 0.00000002(24/L) |
Cryptsy | 9,455.28343383 169,503.2738(24/H) 6,588.384175(24/L) |
477,851.8Mh/s 92,743,493.4Mh/s(24/H) 439,681.0Mh/s(24/L) |
0.00023403฿ 11,702Coins 0.1US-Dollar |
0.04 ฿ | 5.5 Gh/s | [44] | |
| Terracoin | 0.00005869฿ 0.00028628(24/H) 0.00004001(24/L) |
Cryptsy BTC-e |
1,083,848.41484 2,063,930.234(24/H) 555.4653231(24/L) |
24,764,820.3Mh/s 36,819,324,446.2Mh/s(24/H) -1,349,382,346.7Mh/s(24/L) |
0.00011982฿ 2.04Coins 0.05US-Dollar |
1.12 ฿ | 5.5 Gh/s | [45] | |
| Tigercoin | 0.00000037฿ 0.00000270(24/H) 0.00000034(24/L) |
Cryptsy | 151,558.635279 657,212.9084(24/H) 1.00000000(24/L) |
1,835,332.7Mh/s 1,268,653,745.4Mh/s(24/H) -165,192,150.3Mh/s(24/L) |
1.729E-5฿ 46.72Coins 0.01US-Dollar |
0.02 ฿ | 5.5 Gh/s | [46] | |
| Unobtanium | 0.00370000฿ 0.00693474(24/H) 0.00000100(24/L) |
Cryptsy | 0.00141455 6,096,044.902(24/H) 0.00024414(24/L) |
0.0Mh/s 659,668,499.0Mh/s(24/H) -1,772,553,614.8Mh/s(24/L) |
18฿ 4,888,530Coins 8010US-Dollar |
1.82 ฿ | 5.5 Gh/s | [47] | |
| Zetacoin | 0.00003181฿ 0.00010325(24/H) 0.00002055(24/L) |
BTER Cryptsy |
44,262.2794307 161,195.4780(24/H) 4,965.525814(24/L) |
8,983,063.1Mh/s 350,866,964.3Mh/s(24/H) 2,684.9Mh/s(24/L) |
7.951E-5฿ 2.50Coins 0.04US-Dollar |
3.31 ฿ | 5.5 Gh/s | [48] |
How it work
Example for Bitcoin, the difficulty is adjusted every 2016 blocks based on the time it took to find the previous 2016 blocks. At the desired rate of one block each 10 minutes, 2016 blocks would take exactly two weeks to find. 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. The change in difficulty is in proportion to the amount of time over or under two weeks the previous 2016 blocks took to find.
To find a block, the hash must be less than the target. The hash is effectively a random number between 0 and 2**256-1. The offset for difficulty 1 is
0xffff * 2**208
and for difficulty D is
(0xffff * 2**208)/D
The expected number of hashes we need to calculate to find a block with difficulty D is therefore
D * 2**256 / (0xffff * 2**208)
or just
D * 2**48 / 0xffff
The difficulty is set such that the previous 2016 blocks would have been found at the rate of one every 10 minutes, so we were calculating (D * 2**48 / 0xffff) hashes in 600 seconds. That means the hash rate of the network was
D * 2**48 / 0xffff / 600
over the previous 2016 blocks. Can be further simplified to
D * 2**32 / 600
without much loss of accuracy.
At difficulty 1, that is around 7 Mhashes per second.
At the time of writing, the difficulty is 22012.4941572, which means that over the previous set of 2016 blocks found the average network hash rate was
22012.4941572 * 2**32 / 600 = around 157 Ghashes per second.
See Also on BitcoinWiki
- Mining Pools List