IPv6 Subnetting Reference - tcp0.com https://tcp0.com/netmasks-ipv6.html Prefix, /48 count, /56 count, /64 subnet count, total address count, and approximate short-scale magnitude for every IPv6 prefix from /0 to /64. Prefix /48 count /56 count /64 subnets Number of addresses ~ scale ------ ------------------- ---------------------- -------------------------- --------------------------------------------------- ----------------- /64 - - 1 18,446,744,073,709,551,616 18.4 quintillion /63 - - 2 36,893,488,147,419,103,232 36.9 quintillion /62 - - 4 73,786,976,294,838,206,464 73.8 quintillion /61 - - 8 147,573,952,589,676,412,928 147.6 quintillion /60 - - 16 295,147,905,179,352,825,856 295.1 quintillion /59 - - 32 590,295,810,358,705,651,712 590.3 quintillion /58 - - 64 1,180,591,620,717,411,303,424 1.2 sextillion /57 - - 128 2,361,183,241,434,822,606,848 2.4 sextillion /56 - 1 256 4,722,366,482,869,645,213,696 4.7 sextillion /55 - 2 512 9,444,732,965,739,290,427,392 9.4 sextillion /54 - 4 1,024 18,889,465,931,478,580,854,784 18.9 sextillion /53 - 8 2,048 37,778,931,862,957,161,709,568 37.8 sextillion /52 - 16 4,096 75,557,863,725,914,323,419,136 75.6 sextillion /51 - 32 8,192 151,115,727,451,828,646,838,272 151.1 sextillion /50 - 64 16,384 302,231,454,903,657,293,676,544 302.2 sextillion /49 - 128 32,768 604,462,909,807,314,587,353,088 604.5 sextillion /48 1 256 65,536 1,208,925,819,614,629,174,706,176 1.2 septillion /47 2 512 131,072 2,417,851,639,229,258,349,412,352 2.4 septillion /46 4 1,024 262,144 4,835,703,278,458,516,698,824,704 4.8 septillion /45 8 2,048 524,288 9,671,406,556,917,033,397,649,408 9.7 septillion /44 16 4,096 1,048,576 19,342,813,113,834,066,795,298,816 19.3 septillion /43 32 8,192 2,097,152 38,685,626,227,668,133,590,597,632 38.7 septillion /42 64 16,384 4,194,304 77,371,252,455,336,267,181,195,264 77.4 septillion /41 128 32,768 8,388,608 154,742,504,910,672,534,362,390,528 154.7 septillion /40 256 65,536 16,777,216 309,485,009,821,345,068,724,781,056 309.5 septillion /39 512 131,072 33,554,432 618,970,019,642,690,137,449,562,112 619.0 septillion /38 1,024 262,144 67,108,864 1,237,940,039,285,380,274,899,124,224 1.2 octillion /37 2,048 524,288 134,217,728 2,475,880,078,570,760,549,798,248,448 2.5 octillion /36 4,096 1,048,576 268,435,456 4,951,760,157,141,521,099,596,496,896 5.0 octillion /35 8,192 2,097,152 536,870,912 9,903,520,314,283,042,199,192,993,792 9.9 octillion /34 16,384 4,194,304 1,073,741,824 19,807,040,628,566,084,398,385,987,584 19.8 octillion /33 32,768 8,388,608 2,147,483,648 39,614,081,257,132,168,796,771,975,168 39.6 octillion /32 65,536 16,777,216 4,294,967,296 79,228,162,514,264,337,593,543,950,336 79.2 octillion /31 131,072 33,554,432 8,589,934,592 158,456,325,028,528,675,187,087,900,672 158.5 octillion /30 262,144 67,108,864 17,179,869,184 316,912,650,057,057,350,374,175,801,344 316.9 octillion /29 524,288 134,217,728 34,359,738,368 633,825,300,114,114,700,748,351,602,688 633.8 octillion /28 1,048,576 268,435,456 68,719,476,736 1,267,650,600,228,229,401,496,703,205,376 1.3 nonillion /27 2,097,152 536,870,912 137,438,953,472 2,535,301,200,456,458,802,993,406,410,752 2.5 nonillion /26 4,194,304 1,073,741,824 274,877,906,944 5,070,602,400,912,917,605,986,812,821,504 5.1 nonillion /25 8,388,608 2,147,483,648 549,755,813,888 10,141,204,801,825,835,211,973,625,643,008 10.1 nonillion /24 16,777,216 4,294,967,296 1,099,511,627,776 20,282,409,603,651,670,423,947,251,286,016 20.3 nonillion /23 33,554,432 8,589,934,592 2,199,023,255,552 40,564,819,207,303,340,847,894,502,572,032 40.6 nonillion /22 67,108,864 17,179,869,184 4,398,046,511,104 81,129,638,414,606,681,695,789,005,144,064 81.1 nonillion /21 134,217,728 34,359,738,368 8,796,093,022,208 162,259,276,829,213,363,391,578,010,288,128 162.3 nonillion /20 268,435,456 68,719,476,736 17,592,186,044,416 324,518,553,658,426,726,783,156,020,576,256 324.5 nonillion /19 536,870,912 137,438,953,472 35,184,372,088,832 649,037,107,316,853,453,566,312,041,152,512 649.0 nonillion /18 1,073,741,824 274,877,906,944 70,368,744,177,664 1,298,074,214,633,706,907,132,624,082,305,024 1.3 decillion /17 2,147,483,648 549,755,813,888 140,737,488,355,328 2,596,148,429,267,413,814,265,248,164,610,048 2.6 decillion /16 4,294,967,296 1,099,511,627,776 281,474,976,710,656 5,192,296,858,534,827,628,530,496,329,220,096 5.2 decillion /15 8,589,934,592 2,199,023,255,552 562,949,953,421,312 10,384,593,717,069,655,257,060,992,658,440,192 10.4 decillion /14 17,179,869,184 4,398,046,511,104 1,125,899,906,842,624 20,769,187,434,139,310,514,121,985,316,880,384 20.8 decillion /13 34,359,738,368 8,796,093,022,208 2,251,799,813,685,248 41,538,374,868,278,621,028,243,970,633,760,768 41.5 decillion /12 68,719,476,736 17,592,186,044,416 4,503,599,627,370,496 83,076,749,736,557,242,056,487,941,267,521,536 83.1 decillion /11 137,438,953,472 35,184,372,088,832 9,007,199,254,740,992 166,153,499,473,114,484,112,975,882,535,043,072 166.2 decillion /10 274,877,906,944 70,368,744,177,664 18,014,398,509,481,984 332,306,998,946,228,968,225,951,765,070,086,144 332.3 decillion /9 549,755,813,888 140,737,488,355,328 36,028,797,018,963,968 664,613,997,892,457,936,451,903,530,140,172,288 664.6 decillion /8 1,099,511,627,776 281,474,976,710,656 72,057,594,037,927,936 1,329,227,995,784,915,872,903,807,060,280,344,576 1.3 undecillion /7 2,199,023,255,552 562,949,953,421,312 144,115,188,075,855,872 2,658,455,991,569,831,745,807,614,120,560,689,152 2.7 undecillion /6 4,398,046,511,104 1,125,899,906,842,624 288,230,376,151,711,744 5,316,911,983,139,663,491,615,228,241,121,378,304 5.3 undecillion /5 8,796,093,022,208 2,251,799,813,685,248 576,460,752,303,423,488 10,633,823,966,279,326,983,230,456,482,242,756,608 10.6 undecillion /4 17,592,186,044,416 4,503,599,627,370,496 1,152,921,504,606,846,976 21,267,647,932,558,653,966,460,912,964,485,513,216 21.3 undecillion /3 35,184,372,088,832 9,007,199,254,740,992 2,305,843,009,213,693,952 42,535,295,865,117,307,932,921,825,928,971,026,432 42.5 undecillion /2 70,368,744,177,664 18,014,398,509,481,984 4,611,686,018,427,387,904 85,070,591,730,234,615,865,843,651,857,942,052,864 85.1 undecillion /1 140,737,488,355,328 36,028,797,018,963,968 9,223,372,036,854,775,808 170,141,183,460,469,231,731,687,303,715,884,105,728 170.1 undecillion /0 281,474,976,710,656 72,057,594,037,927,936 18,446,744,073,709,551,616 340,282,366,920,938,463,463,374,607,431,768,211,456 340.3 undecillion // /0 is the entire IPv6 address space: 2^128 addresses. Nobody's routing that.