IPv6 Subnet Size Reference Table

More numbers than you can shake a stick at. Just to give you an idea, at the ISP level (/32) that’s 79 septillion IP addresses assigned. That number is so big I had to go look it up on Wikipedia to find out what it’s called. Every home user will have 18 quntillion addresses at his disposal – I don’t have 18 quntillion pieces of lint  in my house, let alone a desire to connect every single one to the internet!

CIDR Subnet Nos. of IPs
/128 1
/127 2
/126 4
/125 8
/124 16
/123 32
/122 64
/121 128
/120 256
/119 512
/118 1,024
/117 2,048
/116 4,096
/115 8,192
/114 16,384
/113 32,768
/112 65,536
/111 131,072
/110 262,144
/109 524,288
/108 1,048,576
/107 2,097,152
/106 4,194,304
/105 8,388,608
/104 16,777,216
/103 33,554,432
/102 67,108,864
/101 134,217,728
/100 268,435,456
/99 536,870,912
/98 1,073,741,824
/97 2,147,483,648
/96 4,294,967,296
/95 8,589,934,592
/94 17,179,869,184
/93 34,359,738,368
/92 68,719,476,736
/91 137,438,953,472
/90 274,877,906,944
/89 549,755,813,888
/88 1,099,511,627,776
/87 2,199,023,255,552
/86 4,398,046,511,104
/85 8,796,093,022,208
/84 17,592,186,044,416
/83 35,184,372,088,832
/82 70,368,744,177,664
/81 140,737,488,355,328
/80 281,474,976,710,656
/79 562,949,953,421,312
/78 1,125,899,906,842,624
/77 2,251,799,813,685,248
/76 4,503,599,627,370,496
/75 9,007,199,254,740,992
/74 18,014,398,509,481,984
/73 36,028,797,018,963,968
/72 72,057,594,037,927,936
/71 144,115,188,075,855,872
/70 288,230,376,151,711,744
/69 576,460,752,303,423,488
/68 1,152,921,504,606,846,976
/67 2,305,843,009,213,693,952
/66 4,611,686,018,427,387,904
/65 9,223,372,036,854,775,808
Residential – /64 18,446,744,073,709,551,616
/63 36,893,488,147,419,103,232
/62 73,786,976,294,838,206,464
/61 147,573,952,589,676,412,928
/60 295,147,905,179,352,825,856
/59 590,295,810,358,705,651,712
/58 1,180,591,620,717,411,303,424
/57 2,361,183,241,434,822,606,848
/56 4,722,366,482,869,645,213,696
/55 9,444,732,965,739,290,427,392
/54 18,889,465,931,478,580,854,784
/53 37,778,931,862,957,161,709,568
/52 75,557,863,725,914,323,419,136
/51 151,115,727,451,828,646,838,272
/50 302,231,454,903,657,293,676,544
/49 604,462,909,807,314,587,353,088
Business – /48 1,208,925,819,614,629,174,706,176
/47 2,417,851,639,229,258,349,412,352
/46 4,835,703,278,458,516,698,824,704
/45 9,671,406,556,917,033,397,649,408
/44 19,342,813,113,834,066,795,298,816
/43 38,685,626,227,668,133,590,597,632
/42 77,371,252,455,336,267,181,195,264
/41 154,742,504,910,672,534,362,390,528
/40 309,485,009,821,345,068,724,781,056
/39 618,970,019,642,690,137,449,562,112
/38 1,237,940,039,285,380,274,899,124,224
/37 2,475,880,078,570,760,549,798,248,448
/36 4,951,760,157,141,521,099,596,496,896
/35 9,903,520,314,283,042,199,192,993,792
/34 19,807,040,628,566,084,398,385,987,584
/33 39,614,081,257,132,168,796,771,975,168
ISP – /32 79,228,162,514,264,337,593,543,950,336
/31 158,456,325,028,528,675,187,087,900,672
/30 316,912,650,057,057,350,374,175,801,344
/29 633,825,300,114,114,700,748,351,602,688
/28 1,267,650,600,228,229,401,496,703,205,376
/27 2,535,301,200,456,458,802,993,406,410,752
/26 5,070,602,400,912,917,605,986,812,821,504
/25 10,141,204,801,825,835,211,973,625,643,008
/24 20,282,409,603,651,670,423,947,251,286,016
/23 40,564,819,207,303,340,847,894,502,572,032
/22 81,129,638,414,606,681,695,789,005,144,064
/21 162,259,276,829,213,363,391,578,010,288,128
/20 324,518,553,658,426,726,783,156,020,576,256
/19 649,037,107,316,853,453,566,312,041,152,512
/18 1,298,074,214,633,706,907,132,624,082,305,024
/17 2,596,148,429,267,413,814,265,248,164,610,048
/16 5,192,296,858,534,827,628,530,496,329,220,096
/15 10,384,593,717,069,655,257,060,992,658,440,192
/14 20,769,187,434,139,310,514,121,985,316,880,384
/13 41,538,374,868,278,621,028,243,970,633,760,768
/12 83,076,749,736,557,242,056,487,941,267,521,536
/11 166,153,499,473,114,484,112,975,882,535,043,072
/10 332,306,998,946,228,968,225,951,765,070,086,144
/9 664,613,997,892,457,936,451,903,530,140,172,288
/8 1,329,227,995,784,915,872,903,807,060,280,344,576
Leave a comment ?

10 Comments.

  1. Wikipedia » IPv6 Subnet Size Reference Table - pingback on February 18, 2009 at 11:18 am
  2. Email Blacklisting | Defending Networks - pingback on March 29, 2011 at 6:51 pm
  3. thanks for the table!

    I just see that he.net is recommending a /48 for residential users.

    Still trying to figure out why a /64 isn’t enough.

  4. useful table!
    But is there any mathematical way to calculate the number of IP addresses? I thought it was 2 ^ (128 CIDR), but that only works for the highest CIDR subnet. Like: for /48 that should give you 1208925819614629174706176 not 1,208,925,819,614,629,500,000,000

  5. I mean 2 ^ (128 – CIDR)

  6. thanks for putting this together for all of us and making it available on the web. its a GREAT reference.

  7. IPv6 in pochi passi con ALIX e SixXS | TommyBlue.it - pingback on August 3, 2011 at 3:42 pm
  8. I just wanted to take a moment to thank you for creating this, it was very helpful to me. I was trying to gain a better understanding of IPv6 in General, and this put it all into perspective for me. Again Thank you.

  9. You’ve got an error in your table at the /74 level. Each successive CIDR prefix should be twice its next-lowest ordinal; but you are off by one. (a /74 contains 18014398509481984, not 18014398509481985 addresses.) Every shorter prefix after that is incorrect.

  10. You’re right! I wonder how I missed that all this time. Well, it’s fixed now.

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