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IP subnet calculator

Type an address with its prefix or mask to see the network, its usable range and masks. Split it into smaller subnets, or look up any prefix in the reference tables.

Prefix/16
Addresses2^112
/64 networks2^48
Network
20ac::/16
First address
20ac::
Last address
20ac:ffff:ffff:ffff:ffff:ffff:ffff:ffff
Addresses
5,192,296,858,534,827,628,530,496,329,220,096 (2^112)
/64 networks (LANs)
281,474,976,710,656 (2^48)
Full form
20ac:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
c.a.0.2.ip6.arpa
Split into smaller subnets/32
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

20ac::/16 makes 65,536 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
120ac::/3220ac:0:ffff:ffff:ffff:ffff:ffff:ffff
220ac:1::/3220ac:1:ffff:ffff:ffff:ffff:ffff:ffff
320ac:2::/3220ac:2:ffff:ffff:ffff:ffff:ffff:ffff
420ac:3::/3220ac:3:ffff:ffff:ffff:ffff:ffff:ffff
520ac:4::/3220ac:4:ffff:ffff:ffff:ffff:ffff:ffff
620ac:5::/3220ac:5:ffff:ffff:ffff:ffff:ffff:ffff
720ac:6::/3220ac:6:ffff:ffff:ffff:ffff:ffff:ffff
820ac:7::/3220ac:7:ffff:ffff:ffff:ffff:ffff:ffff
920ac:8::/3220ac:8:ffff:ffff:ffff:ffff:ffff:ffff
1020ac:9::/3220ac:9:ffff:ffff:ffff:ffff:ffff:ffff
1120ac:a::/3220ac:a:ffff:ffff:ffff:ffff:ffff:ffff
1220ac:b::/3220ac:b:ffff:ffff:ffff:ffff:ffff:ffff
1320ac:c::/3220ac:c:ffff:ffff:ffff:ffff:ffff:ffff
1420ac:d::/3220ac:d:ffff:ffff:ffff:ffff:ffff:ffff
1520ac:e::/3220ac:e:ffff:ffff:ffff:ffff:ffff:ffff
1620ac:f::/3220ac:f:ffff:ffff:ffff:ffff:ffff:ffff
1720ac:10::/3220ac:10:ffff:ffff:ffff:ffff:ffff:ffff
1820ac:11::/3220ac:11:ffff:ffff:ffff:ffff:ffff:ffff
1920ac:12::/3220ac:12:ffff:ffff:ffff:ffff:ffff:ffff
2020ac:13::/3220ac:13:ffff:ffff:ffff:ffff:ffff:ffff
2120ac:14::/3220ac:14:ffff:ffff:ffff:ffff:ffff:ffff
2220ac:15::/3220ac:15:ffff:ffff:ffff:ffff:ffff:ffff
2320ac:16::/3220ac:16:ffff:ffff:ffff:ffff:ffff:ffff
2420ac:17::/3220ac:17:ffff:ffff:ffff:ffff:ffff:ffff
2520ac:18::/3220ac:18:ffff:ffff:ffff:ffff:ffff:ffff
2620ac:19::/3220ac:19:ffff:ffff:ffff:ffff:ffff:ffff
2720ac:1a::/3220ac:1a:ffff:ffff:ffff:ffff:ffff:ffff
2820ac:1b::/3220ac:1b:ffff:ffff:ffff:ffff:ffff:ffff
2920ac:1c::/3220ac:1c:ffff:ffff:ffff:ffff:ffff:ffff
3020ac:1d::/3220ac:1d:ffff:ffff:ffff:ffff:ffff:ffff
3120ac:1e::/3220ac:1e:ffff:ffff:ffff:ffff:ffff:ffff
3220ac:1f::/3220ac:1f:ffff:ffff:ffff:ffff:ffff:ffff
3320ac:20::/3220ac:20:ffff:ffff:ffff:ffff:ffff:ffff
3420ac:21::/3220ac:21:ffff:ffff:ffff:ffff:ffff:ffff
3520ac:22::/3220ac:22:ffff:ffff:ffff:ffff:ffff:ffff
3620ac:23::/3220ac:23:ffff:ffff:ffff:ffff:ffff:ffff
3720ac:24::/3220ac:24:ffff:ffff:ffff:ffff:ffff:ffff
3820ac:25::/3220ac:25:ffff:ffff:ffff:ffff:ffff:ffff
3920ac:26::/3220ac:26:ffff:ffff:ffff:ffff:ffff:ffff
4020ac:27::/3220ac:27:ffff:ffff:ffff:ffff:ffff:ffff
4120ac:28::/3220ac:28:ffff:ffff:ffff:ffff:ffff:ffff
4220ac:29::/3220ac:29:ffff:ffff:ffff:ffff:ffff:ffff
4320ac:2a::/3220ac:2a:ffff:ffff:ffff:ffff:ffff:ffff
4420ac:2b::/3220ac:2b:ffff:ffff:ffff:ffff:ffff:ffff
4520ac:2c::/3220ac:2c:ffff:ffff:ffff:ffff:ffff:ffff
4620ac:2d::/3220ac:2d:ffff:ffff:ffff:ffff:ffff:ffff
4720ac:2e::/3220ac:2e:ffff:ffff:ffff:ffff:ffff:ffff
4820ac:2f::/3220ac:2f:ffff:ffff:ffff:ffff:ffff:ffff
4920ac:30::/3220ac:30:ffff:ffff:ffff:ffff:ffff:ffff
5020ac:31::/3220ac:31:ffff:ffff:ffff:ffff:ffff:ffff
5120ac:32::/3220ac:32:ffff:ffff:ffff:ffff:ffff:ffff
5220ac:33::/3220ac:33:ffff:ffff:ffff:ffff:ffff:ffff
5320ac:34::/3220ac:34:ffff:ffff:ffff:ffff:ffff:ffff
5420ac:35::/3220ac:35:ffff:ffff:ffff:ffff:ffff:ffff
5520ac:36::/3220ac:36:ffff:ffff:ffff:ffff:ffff:ffff
5620ac:37::/3220ac:37:ffff:ffff:ffff:ffff:ffff:ffff
5720ac:38::/3220ac:38:ffff:ffff:ffff:ffff:ffff:ffff
5820ac:39::/3220ac:39:ffff:ffff:ffff:ffff:ffff:ffff
5920ac:3a::/3220ac:3a:ffff:ffff:ffff:ffff:ffff:ffff
6020ac:3b::/3220ac:3b:ffff:ffff:ffff:ffff:ffff:ffff
6120ac:3c::/3220ac:3c:ffff:ffff:ffff:ffff:ffff:ffff
6220ac:3d::/3220ac:3d:ffff:ffff:ffff:ffff:ffff:ffff
6320ac:3e::/3220ac:3e:ffff:ffff:ffff:ffff:ffff:ffff
6420ac:3f::/3220ac:3f:ffff:ffff:ffff:ffff:ffff:ffff
6520ac:40::/3220ac:40:ffff:ffff:ffff:ffff:ffff:ffff
6620ac:41::/3220ac:41:ffff:ffff:ffff:ffff:ffff:ffff
6720ac:42::/3220ac:42:ffff:ffff:ffff:ffff:ffff:ffff
6820ac:43::/3220ac:43:ffff:ffff:ffff:ffff:ffff:ffff
6920ac:44::/3220ac:44:ffff:ffff:ffff:ffff:ffff:ffff
7020ac:45::/3220ac:45:ffff:ffff:ffff:ffff:ffff:ffff
7120ac:46::/3220ac:46:ffff:ffff:ffff:ffff:ffff:ffff
7220ac:47::/3220ac:47:ffff:ffff:ffff:ffff:ffff:ffff
7320ac:48::/3220ac:48:ffff:ffff:ffff:ffff:ffff:ffff
7420ac:49::/3220ac:49:ffff:ffff:ffff:ffff:ffff:ffff
7520ac:4a::/3220ac:4a:ffff:ffff:ffff:ffff:ffff:ffff
7620ac:4b::/3220ac:4b:ffff:ffff:ffff:ffff:ffff:ffff
7720ac:4c::/3220ac:4c:ffff:ffff:ffff:ffff:ffff:ffff
7820ac:4d::/3220ac:4d:ffff:ffff:ffff:ffff:ffff:ffff
7920ac:4e::/3220ac:4e:ffff:ffff:ffff:ffff:ffff:ffff
8020ac:4f::/3220ac:4f:ffff:ffff:ffff:ffff:ffff:ffff
8120ac:50::/3220ac:50:ffff:ffff:ffff:ffff:ffff:ffff
8220ac:51::/3220ac:51:ffff:ffff:ffff:ffff:ffff:ffff
8320ac:52::/3220ac:52:ffff:ffff:ffff:ffff:ffff:ffff
8420ac:53::/3220ac:53:ffff:ffff:ffff:ffff:ffff:ffff
8520ac:54::/3220ac:54:ffff:ffff:ffff:ffff:ffff:ffff
8620ac:55::/3220ac:55:ffff:ffff:ffff:ffff:ffff:ffff
8720ac:56::/3220ac:56:ffff:ffff:ffff:ffff:ffff:ffff
8820ac:57::/3220ac:57:ffff:ffff:ffff:ffff:ffff:ffff
8920ac:58::/3220ac:58:ffff:ffff:ffff:ffff:ffff:ffff
9020ac:59::/3220ac:59:ffff:ffff:ffff:ffff:ffff:ffff
9120ac:5a::/3220ac:5a:ffff:ffff:ffff:ffff:ffff:ffff
9220ac:5b::/3220ac:5b:ffff:ffff:ffff:ffff:ffff:ffff
9320ac:5c::/3220ac:5c:ffff:ffff:ffff:ffff:ffff:ffff
9420ac:5d::/3220ac:5d:ffff:ffff:ffff:ffff:ffff:ffff
9520ac:5e::/3220ac:5e:ffff:ffff:ffff:ffff:ffff:ffff
9620ac:5f::/3220ac:5f:ffff:ffff:ffff:ffff:ffff:ffff
9720ac:60::/3220ac:60:ffff:ffff:ffff:ffff:ffff:ffff
9820ac:61::/3220ac:61:ffff:ffff:ffff:ffff:ffff:ffff
9920ac:62::/3220ac:62:ffff:ffff:ffff:ffff:ffff:ffff
10020ac:63::/3220ac:63:ffff:ffff:ffff:ffff:ffff:ffff
10120ac:64::/3220ac:64:ffff:ffff:ffff:ffff:ffff:ffff
10220ac:65::/3220ac:65:ffff:ffff:ffff:ffff:ffff:ffff
10320ac:66::/3220ac:66:ffff:ffff:ffff:ffff:ffff:ffff
10420ac:67::/3220ac:67:ffff:ffff:ffff:ffff:ffff:ffff
10520ac:68::/3220ac:68:ffff:ffff:ffff:ffff:ffff:ffff
10620ac:69::/3220ac:69:ffff:ffff:ffff:ffff:ffff:ffff
10720ac:6a::/3220ac:6a:ffff:ffff:ffff:ffff:ffff:ffff
10820ac:6b::/3220ac:6b:ffff:ffff:ffff:ffff:ffff:ffff
10920ac:6c::/3220ac:6c:ffff:ffff:ffff:ffff:ffff:ffff
11020ac:6d::/3220ac:6d:ffff:ffff:ffff:ffff:ffff:ffff
11120ac:6e::/3220ac:6e:ffff:ffff:ffff:ffff:ffff:ffff
11220ac:6f::/3220ac:6f:ffff:ffff:ffff:ffff:ffff:ffff
11320ac:70::/3220ac:70:ffff:ffff:ffff:ffff:ffff:ffff
11420ac:71::/3220ac:71:ffff:ffff:ffff:ffff:ffff:ffff
11520ac:72::/3220ac:72:ffff:ffff:ffff:ffff:ffff:ffff
11620ac:73::/3220ac:73:ffff:ffff:ffff:ffff:ffff:ffff
11720ac:74::/3220ac:74:ffff:ffff:ffff:ffff:ffff:ffff
11820ac:75::/3220ac:75:ffff:ffff:ffff:ffff:ffff:ffff
11920ac:76::/3220ac:76:ffff:ffff:ffff:ffff:ffff:ffff
12020ac:77::/3220ac:77:ffff:ffff:ffff:ffff:ffff:ffff
12120ac:78::/3220ac:78:ffff:ffff:ffff:ffff:ffff:ffff
12220ac:79::/3220ac:79:ffff:ffff:ffff:ffff:ffff:ffff
12320ac:7a::/3220ac:7a:ffff:ffff:ffff:ffff:ffff:ffff
12420ac:7b::/3220ac:7b:ffff:ffff:ffff:ffff:ffff:ffff
12520ac:7c::/3220ac:7c:ffff:ffff:ffff:ffff:ffff:ffff
12620ac:7d::/3220ac:7d:ffff:ffff:ffff:ffff:ffff:ffff
12720ac:7e::/3220ac:7e:ffff:ffff:ffff:ffff:ffff:ffff
12820ac:7f::/3220ac:7f:ffff:ffff:ffff:ffff:ffff:ffff
12920ac:80::/3220ac:80:ffff:ffff:ffff:ffff:ffff:ffff
13020ac:81::/3220ac:81:ffff:ffff:ffff:ffff:ffff:ffff
13120ac:82::/3220ac:82:ffff:ffff:ffff:ffff:ffff:ffff
13220ac:83::/3220ac:83:ffff:ffff:ffff:ffff:ffff:ffff
13320ac:84::/3220ac:84:ffff:ffff:ffff:ffff:ffff:ffff
13420ac:85::/3220ac:85:ffff:ffff:ffff:ffff:ffff:ffff
13520ac:86::/3220ac:86:ffff:ffff:ffff:ffff:ffff:ffff
13620ac:87::/3220ac:87:ffff:ffff:ffff:ffff:ffff:ffff
13720ac:88::/3220ac:88:ffff:ffff:ffff:ffff:ffff:ffff
13820ac:89::/3220ac:89:ffff:ffff:ffff:ffff:ffff:ffff
13920ac:8a::/3220ac:8a:ffff:ffff:ffff:ffff:ffff:ffff
14020ac:8b::/3220ac:8b:ffff:ffff:ffff:ffff:ffff:ffff
14120ac:8c::/3220ac:8c:ffff:ffff:ffff:ffff:ffff:ffff
14220ac:8d::/3220ac:8d:ffff:ffff:ffff:ffff:ffff:ffff
14320ac:8e::/3220ac:8e:ffff:ffff:ffff:ffff:ffff:ffff
14420ac:8f::/3220ac:8f:ffff:ffff:ffff:ffff:ffff:ffff
14520ac:90::/3220ac:90:ffff:ffff:ffff:ffff:ffff:ffff
14620ac:91::/3220ac:91:ffff:ffff:ffff:ffff:ffff:ffff
14720ac:92::/3220ac:92:ffff:ffff:ffff:ffff:ffff:ffff
14820ac:93::/3220ac:93:ffff:ffff:ffff:ffff:ffff:ffff
14920ac:94::/3220ac:94:ffff:ffff:ffff:ffff:ffff:ffff
15020ac:95::/3220ac:95:ffff:ffff:ffff:ffff:ffff:ffff
15120ac:96::/3220ac:96:ffff:ffff:ffff:ffff:ffff:ffff
15220ac:97::/3220ac:97:ffff:ffff:ffff:ffff:ffff:ffff
15320ac:98::/3220ac:98:ffff:ffff:ffff:ffff:ffff:ffff
15420ac:99::/3220ac:99:ffff:ffff:ffff:ffff:ffff:ffff
15520ac:9a::/3220ac:9a:ffff:ffff:ffff:ffff:ffff:ffff
15620ac:9b::/3220ac:9b:ffff:ffff:ffff:ffff:ffff:ffff
15720ac:9c::/3220ac:9c:ffff:ffff:ffff:ffff:ffff:ffff
15820ac:9d::/3220ac:9d:ffff:ffff:ffff:ffff:ffff:ffff
15920ac:9e::/3220ac:9e:ffff:ffff:ffff:ffff:ffff:ffff
16020ac:9f::/3220ac:9f:ffff:ffff:ffff:ffff:ffff:ffff
16120ac:a0::/3220ac:a0:ffff:ffff:ffff:ffff:ffff:ffff
16220ac:a1::/3220ac:a1:ffff:ffff:ffff:ffff:ffff:ffff
16320ac:a2::/3220ac:a2:ffff:ffff:ffff:ffff:ffff:ffff
16420ac:a3::/3220ac:a3:ffff:ffff:ffff:ffff:ffff:ffff
16520ac:a4::/3220ac:a4:ffff:ffff:ffff:ffff:ffff:ffff
16620ac:a5::/3220ac:a5:ffff:ffff:ffff:ffff:ffff:ffff
16720ac:a6::/3220ac:a6:ffff:ffff:ffff:ffff:ffff:ffff
16820ac:a7::/3220ac:a7:ffff:ffff:ffff:ffff:ffff:ffff
16920ac:a8::/3220ac:a8:ffff:ffff:ffff:ffff:ffff:ffff
17020ac:a9::/3220ac:a9:ffff:ffff:ffff:ffff:ffff:ffff
17120ac:aa::/3220ac:aa:ffff:ffff:ffff:ffff:ffff:ffff
17220ac:ab::/3220ac:ab:ffff:ffff:ffff:ffff:ffff:ffff
17320ac:ac::/3220ac:ac:ffff:ffff:ffff:ffff:ffff:ffff
17420ac:ad::/3220ac:ad:ffff:ffff:ffff:ffff:ffff:ffff
17520ac:ae::/3220ac:ae:ffff:ffff:ffff:ffff:ffff:ffff
17620ac:af::/3220ac:af:ffff:ffff:ffff:ffff:ffff:ffff
17720ac:b0::/3220ac:b0:ffff:ffff:ffff:ffff:ffff:ffff
17820ac:b1::/3220ac:b1:ffff:ffff:ffff:ffff:ffff:ffff
17920ac:b2::/3220ac:b2:ffff:ffff:ffff:ffff:ffff:ffff
18020ac:b3::/3220ac:b3:ffff:ffff:ffff:ffff:ffff:ffff
18120ac:b4::/3220ac:b4:ffff:ffff:ffff:ffff:ffff:ffff
18220ac:b5::/3220ac:b5:ffff:ffff:ffff:ffff:ffff:ffff
18320ac:b6::/3220ac:b6:ffff:ffff:ffff:ffff:ffff:ffff
18420ac:b7::/3220ac:b7:ffff:ffff:ffff:ffff:ffff:ffff
18520ac:b8::/3220ac:b8:ffff:ffff:ffff:ffff:ffff:ffff
18620ac:b9::/3220ac:b9:ffff:ffff:ffff:ffff:ffff:ffff
18720ac:ba::/3220ac:ba:ffff:ffff:ffff:ffff:ffff:ffff
18820ac:bb::/3220ac:bb:ffff:ffff:ffff:ffff:ffff:ffff
18920ac:bc::/3220ac:bc:ffff:ffff:ffff:ffff:ffff:ffff
19020ac:bd::/3220ac:bd:ffff:ffff:ffff:ffff:ffff:ffff
19120ac:be::/3220ac:be:ffff:ffff:ffff:ffff:ffff:ffff
19220ac:bf::/3220ac:bf:ffff:ffff:ffff:ffff:ffff:ffff
19320ac:c0::/3220ac:c0:ffff:ffff:ffff:ffff:ffff:ffff
19420ac:c1::/3220ac:c1:ffff:ffff:ffff:ffff:ffff:ffff
19520ac:c2::/3220ac:c2:ffff:ffff:ffff:ffff:ffff:ffff
19620ac:c3::/3220ac:c3:ffff:ffff:ffff:ffff:ffff:ffff
19720ac:c4::/3220ac:c4:ffff:ffff:ffff:ffff:ffff:ffff
19820ac:c5::/3220ac:c5:ffff:ffff:ffff:ffff:ffff:ffff
19920ac:c6::/3220ac:c6:ffff:ffff:ffff:ffff:ffff:ffff
20020ac:c7::/3220ac:c7:ffff:ffff:ffff:ffff:ffff:ffff
20120ac:c8::/3220ac:c8:ffff:ffff:ffff:ffff:ffff:ffff
20220ac:c9::/3220ac:c9:ffff:ffff:ffff:ffff:ffff:ffff
20320ac:ca::/3220ac:ca:ffff:ffff:ffff:ffff:ffff:ffff
20420ac:cb::/3220ac:cb:ffff:ffff:ffff:ffff:ffff:ffff
20520ac:cc::/3220ac:cc:ffff:ffff:ffff:ffff:ffff:ffff
20620ac:cd::/3220ac:cd:ffff:ffff:ffff:ffff:ffff:ffff
20720ac:ce::/3220ac:ce:ffff:ffff:ffff:ffff:ffff:ffff
20820ac:cf::/3220ac:cf:ffff:ffff:ffff:ffff:ffff:ffff
20920ac:d0::/3220ac:d0:ffff:ffff:ffff:ffff:ffff:ffff
21020ac:d1::/3220ac:d1:ffff:ffff:ffff:ffff:ffff:ffff
21120ac:d2::/3220ac:d2:ffff:ffff:ffff:ffff:ffff:ffff
21220ac:d3::/3220ac:d3:ffff:ffff:ffff:ffff:ffff:ffff
21320ac:d4::/3220ac:d4:ffff:ffff:ffff:ffff:ffff:ffff
21420ac:d5::/3220ac:d5:ffff:ffff:ffff:ffff:ffff:ffff
21520ac:d6::/3220ac:d6:ffff:ffff:ffff:ffff:ffff:ffff
21620ac:d7::/3220ac:d7:ffff:ffff:ffff:ffff:ffff:ffff
21720ac:d8::/3220ac:d8:ffff:ffff:ffff:ffff:ffff:ffff
21820ac:d9::/3220ac:d9:ffff:ffff:ffff:ffff:ffff:ffff
21920ac:da::/3220ac:da:ffff:ffff:ffff:ffff:ffff:ffff
22020ac:db::/3220ac:db:ffff:ffff:ffff:ffff:ffff:ffff
22120ac:dc::/3220ac:dc:ffff:ffff:ffff:ffff:ffff:ffff
22220ac:dd::/3220ac:dd:ffff:ffff:ffff:ffff:ffff:ffff
22320ac:de::/3220ac:de:ffff:ffff:ffff:ffff:ffff:ffff
22420ac:df::/3220ac:df:ffff:ffff:ffff:ffff:ffff:ffff
22520ac:e0::/3220ac:e0:ffff:ffff:ffff:ffff:ffff:ffff
22620ac:e1::/3220ac:e1:ffff:ffff:ffff:ffff:ffff:ffff
22720ac:e2::/3220ac:e2:ffff:ffff:ffff:ffff:ffff:ffff
22820ac:e3::/3220ac:e3:ffff:ffff:ffff:ffff:ffff:ffff
22920ac:e4::/3220ac:e4:ffff:ffff:ffff:ffff:ffff:ffff
23020ac:e5::/3220ac:e5:ffff:ffff:ffff:ffff:ffff:ffff
23120ac:e6::/3220ac:e6:ffff:ffff:ffff:ffff:ffff:ffff
23220ac:e7::/3220ac:e7:ffff:ffff:ffff:ffff:ffff:ffff
23320ac:e8::/3220ac:e8:ffff:ffff:ffff:ffff:ffff:ffff
23420ac:e9::/3220ac:e9:ffff:ffff:ffff:ffff:ffff:ffff
23520ac:ea::/3220ac:ea:ffff:ffff:ffff:ffff:ffff:ffff
23620ac:eb::/3220ac:eb:ffff:ffff:ffff:ffff:ffff:ffff
23720ac:ec::/3220ac:ec:ffff:ffff:ffff:ffff:ffff:ffff
23820ac:ed::/3220ac:ed:ffff:ffff:ffff:ffff:ffff:ffff
23920ac:ee::/3220ac:ee:ffff:ffff:ffff:ffff:ffff:ffff
24020ac:ef::/3220ac:ef:ffff:ffff:ffff:ffff:ffff:ffff
24120ac:f0::/3220ac:f0:ffff:ffff:ffff:ffff:ffff:ffff
24220ac:f1::/3220ac:f1:ffff:ffff:ffff:ffff:ffff:ffff
24320ac:f2::/3220ac:f2:ffff:ffff:ffff:ffff:ffff:ffff
24420ac:f3::/3220ac:f3:ffff:ffff:ffff:ffff:ffff:ffff
24520ac:f4::/3220ac:f4:ffff:ffff:ffff:ffff:ffff:ffff
24620ac:f5::/3220ac:f5:ffff:ffff:ffff:ffff:ffff:ffff
24720ac:f6::/3220ac:f6:ffff:ffff:ffff:ffff:ffff:ffff
24820ac:f7::/3220ac:f7:ffff:ffff:ffff:ffff:ffff:ffff
24920ac:f8::/3220ac:f8:ffff:ffff:ffff:ffff:ffff:ffff
25020ac:f9::/3220ac:f9:ffff:ffff:ffff:ffff:ffff:ffff
25120ac:fa::/3220ac:fa:ffff:ffff:ffff:ffff:ffff:ffff
25220ac:fb::/3220ac:fb:ffff:ffff:ffff:ffff:ffff:ffff
25320ac:fc::/3220ac:fc:ffff:ffff:ffff:ffff:ffff:ffff
25420ac:fd::/3220ac:fd:ffff:ffff:ffff:ffff:ffff:ffff
25520ac:fe::/3220ac:fe:ffff:ffff:ffff:ffff:ffff:ffff
25620ac:ff::/3220ac:ff:ffff:ffff:ffff:ffff:ffff:ffff

IPv4 CIDR reference (/0 to /32)

IPv4 prefix lengths
PrefixSubnet maskWildcardAddressesUsable hostsSizeTypical use
/00.0.0.0255.255.255.2554,294,967,2964,294,967,29416,777,216 × /24
/1128.0.0.0127.255.255.2552,147,483,6482,147,483,6468,388,608 × /24
/2192.0.0.063.255.255.2551,073,741,8241,073,741,8224,194,304 × /24
/3224.0.0.031.255.255.255536,870,912536,870,9102,097,152 × /24
/4240.0.0.015.255.255.255268,435,456268,435,4541,048,576 × /24
/5248.0.0.07.255.255.255134,217,728134,217,726524,288 × /24
/6252.0.0.03.255.255.25567,108,86467,108,862262,144 × /24
/7254.0.0.01.255.255.25533,554,43233,554,430131,072 × /24
/8255.0.0.00.255.255.25516,777,21616,777,21465,536 × /24Old class A; 10.0.0.0/8
/9255.128.0.00.127.255.2558,388,6088,388,60632,768 × /24
/10255.192.0.00.63.255.2554,194,3044,194,30216,384 × /24
/11255.224.0.00.31.255.2552,097,1522,097,1508,192 × /24
/12255.240.0.00.15.255.2551,048,5761,048,5744,096 × /24172.16.0.0/12
/13255.248.0.00.7.255.255524,288524,2862,048 × /24
/14255.252.0.00.3.255.255262,144262,1421,024 × /24
/15255.254.0.00.1.255.255131,072131,070512 × /24
/16255.255.0.00.0.255.25565,53665,534256 × /24Old class B; 192.168.0.0/16
/17255.255.128.00.0.127.25532,76832,766128 × /24
/18255.255.192.00.0.63.25516,38416,38264 × /24
/19255.255.224.00.0.31.2558,1928,19032 × /24
/20255.255.240.00.0.15.2554,0964,09416 × /24
/21255.255.248.00.0.7.2552,0482,0468 × /24
/22255.255.252.00.0.3.2551,0241,0224 × /24Large office or guest Wi-Fi (1,022 hosts)
/23255.255.254.00.0.1.2555125102 × /24Larger office LAN (510 hosts)
/24255.255.255.00.0.0.2552562541 × /24Typical office LAN (old class C)
/25255.255.255.1280.0.0.1271281261/2 of a /24Smaller LAN or VLAN
/26255.255.255.1920.0.0.6364621/4 of a /24Smaller LAN or VLAN
/27255.255.255.2240.0.0.3132301/8 of a /24Small VLAN, phones, cameras
/28255.255.255.2400.0.0.1516141/16 of a /24Small VLAN, phones, cameras
/29255.255.255.2480.0.0.7861/32 of a /24Small fixed public block (5 usable)
/30255.255.255.2520.0.0.3421/64 of a /24Point-to-point (old style)
/31255.255.255.2540.0.0.1221/128 of a /24Point-to-point link (RFC 3021)
/32255.255.255.2550.0.0.0111/256 of a /24One host

IPv6 prefix reference

IPv6 prefix lengths
PrefixAddresses/64 LANs/48 sitesNibbleTypical use
/342,535,295,865,117,307,932,921,825,928,971,026,432 (2^125)2,305,843,009,213,693,95235,184,372,088,832NoAll global unicast (2000::/3)
/165,192,296,858,534,827,628,530,496,329,220,096 (2^112)281,474,976,710,6564,294,967,296Yes
/20324,518,553,658,426,726,783,156,020,576,256 (2^108)17,592,186,044,416268,435,456YesLarge provider allocation (RIPE minimum for some)
/29633,825,300,114,114,700,748,351,602,688 (2^99)34,359,738,368524,288NoRIPE allocation to a provider (often)
/3279,228,162,514,264,337,593,543,950,336 (2^96)4,294,967,29665,536YesProvider allocation (RIPE default)
/364,951,760,157,141,521,099,596,496,896 (2^92)268,435,4564,096Yes
/40309,485,009,821,345,068,724,781,056 (2^88)16,777,216256Yes
/4419,342,813,113,834,066,795,298,816 (2^84)1,048,57616Yes
/481,208,925,819,614,629,174,706,176 (2^80)65,5361YesOne site or organisation (RIPE PI / assignment)
/5275,557,863,725,914,323,419,136 (2^76)4,096Yes
/564,722,366,482,869,645,213,696 (2^72)256YesSmall site or home (common provider assignment)
/60295,147,905,179,352,825,856 (2^68)16YesSome home broadband (16 LANs)
/6418,446,744,073,709,551,616 (2^64)1YesOne LAN or VLAN (needed for SLAAC)
/7272,057,594,037,927,936 (2^56)1/256 of a /64Yes
/80281,474,976,710,656 (2^48)1/65,536 of a /64Yes
/964,294,967,2961/4,294,967,296 of a /64YesEmbeds an IPv4 address (NAT64)
/11265,5361/281,474,976,710,656 of a /64Yes
/1202561/72,057,594,037,927,936 of a /64Yes
/124161/1,152,921,504,606,846,976 of a /64Yes
/12641/4,611,686,018,427,387,904 of a /64No
/12721/9,223,372,036,854,775,808 of a /64NoPoint-to-point link (RFC 6164)
/12811/18,446,744,073,709,551,616 of a /64YesOne host or loopback

Private and special ranges

IPv4

Special-purpose ranges
RangeNameWhat it is
255.255.255.255/32Limited broadcastEvery host on the local network
0.0.0.0/8This networkNot routed; 0.0.0.0 means "any address" in settings
10.0.0.0/8Private (RFC 1918)Office and home networks; not routed on the internet
100.64.0.0/10Shared address space (CGNAT)Used by providers behind carrier-grade NAT (RFC 6598)
127.0.0.0/8LoopbackThis computer
169.254.0.0/16Link-local (APIPA)Self-assigned when no DHCP server answers
172.16.0.0/12Private (RFC 1918)Office and home networks; not routed on the internet
192.0.0.0/24IETF protocol assignmentsSpecial uses such as DS-Lite
192.0.2.0/24Documentation (TEST-NET-1)For examples; never used on a network
192.88.99.0/246to4 relay (deprecated)Formerly anycast for 6to4
192.168.0.0/16Private (RFC 1918)Office and home networks; not routed on the internet
198.18.0.0/15BenchmarkingNetwork equipment testing (RFC 2544)
198.51.100.0/24Documentation (TEST-NET-2)For examples; never used on a network
203.0.113.0/24Documentation (TEST-NET-3)For examples; never used on a network
224.0.0.0/4MulticastOne-to-many traffic, such as IPTV and routing protocols
240.0.0.0/4ReservedFuture use; not usable on most systems

IPv6

Special-purpose ranges
RangeNameWhat it is
::/128UnspecifiedNo address; :: means "any address" in settings
::1/128LoopbackThis computer
::ffff:0:0/96IPv4-mappedAn IPv4 address written as IPv6
64:ff9b::/96NAT64IPv4 addresses reached through a NAT64 gateway
100::/64Discard onlyTraffic sent here is dropped (RFC 6666)
2001:db8::/32DocumentationFor examples; never used on a network
2001::/32TeredoIPv6 tunnelled over IPv4 UDP
2002::/166to4IPv6 tunnelled over IPv4 (largely retired)
3fff::/20DocumentationFor examples (RFC 9637)
fc00::/7Unique local (ULA)Private IPv6, like RFC 1918; usually fd00::/8
fe80::/10Link-localEvery IPv6 interface has one; not routed
ff00::/8MulticastOne-to-many traffic; replaces broadcast
2000::/3Global unicastPublic internet addresses

About this tool

A network is written as an address and a prefix length, such as 192.168.1.0/24: the first 24 bits name the network and the rest number the devices on it. The calculator works out where the network starts and ends, how many devices it holds, its subnet and wildcard masks, and the reverse DNS zone to ask your provider for.

It also splits a network into equal smaller ones (one per VLAN or site), turns a range of addresses into the fewest CIDR blocks for a firewall rule, and lists every IPv4 prefix length and the common IPv6 ones in reference tables.

Common questions

Why are two addresses lost in every IPv4 subnet?

The first address names the network and the last is the broadcast address, so a /24 has 256 addresses but 254 for devices. A /31 (a link between two routers) and a /32 (one host) are the exceptions.

What size of IPv6 network should a LAN use?

Always /64. Devices pick their own address within it (SLAAC), which needs the full 64 bits. A site usually gets a /48 or /56 from its provider, which holds 65,536 or 256 LANs.

What is a wildcard mask?

The subnet mask turned inside out: 255.255.255.0 becomes 0.0.0.255. Cisco access lists and OSPF use it to say which bits must match.

Which ranges can I use inside an office?

IPv4: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. IPv6: unique local addresses from fd00::/8, though most networks use the public prefix from their provider.