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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
ff47::/16
First address
ff47::
Last address
ff47: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
ff47:0000:0000:0000:0000:0000:0000:0000
Type
Multicast ff00::/8
One-to-many traffic; replaces broadcast
Reverse DNS zone
7.4.f.f.ip6.arpa
Split into smaller subnets/32
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

ff47::/16 makes 65,536 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
1ff47::/32ff47:0:ffff:ffff:ffff:ffff:ffff:ffff
2ff47:1::/32ff47:1:ffff:ffff:ffff:ffff:ffff:ffff
3ff47:2::/32ff47:2:ffff:ffff:ffff:ffff:ffff:ffff
4ff47:3::/32ff47:3:ffff:ffff:ffff:ffff:ffff:ffff
5ff47:4::/32ff47:4:ffff:ffff:ffff:ffff:ffff:ffff
6ff47:5::/32ff47:5:ffff:ffff:ffff:ffff:ffff:ffff
7ff47:6::/32ff47:6:ffff:ffff:ffff:ffff:ffff:ffff
8ff47:7::/32ff47:7:ffff:ffff:ffff:ffff:ffff:ffff
9ff47:8::/32ff47:8:ffff:ffff:ffff:ffff:ffff:ffff
10ff47:9::/32ff47:9:ffff:ffff:ffff:ffff:ffff:ffff
11ff47:a::/32ff47:a:ffff:ffff:ffff:ffff:ffff:ffff
12ff47:b::/32ff47:b:ffff:ffff:ffff:ffff:ffff:ffff
13ff47:c::/32ff47:c:ffff:ffff:ffff:ffff:ffff:ffff
14ff47:d::/32ff47:d:ffff:ffff:ffff:ffff:ffff:ffff
15ff47:e::/32ff47:e:ffff:ffff:ffff:ffff:ffff:ffff
16ff47:f::/32ff47:f:ffff:ffff:ffff:ffff:ffff:ffff
17ff47:10::/32ff47:10:ffff:ffff:ffff:ffff:ffff:ffff
18ff47:11::/32ff47:11:ffff:ffff:ffff:ffff:ffff:ffff
19ff47:12::/32ff47:12:ffff:ffff:ffff:ffff:ffff:ffff
20ff47:13::/32ff47:13:ffff:ffff:ffff:ffff:ffff:ffff
21ff47:14::/32ff47:14:ffff:ffff:ffff:ffff:ffff:ffff
22ff47:15::/32ff47:15:ffff:ffff:ffff:ffff:ffff:ffff
23ff47:16::/32ff47:16:ffff:ffff:ffff:ffff:ffff:ffff
24ff47:17::/32ff47:17:ffff:ffff:ffff:ffff:ffff:ffff
25ff47:18::/32ff47:18:ffff:ffff:ffff:ffff:ffff:ffff
26ff47:19::/32ff47:19:ffff:ffff:ffff:ffff:ffff:ffff
27ff47:1a::/32ff47:1a:ffff:ffff:ffff:ffff:ffff:ffff
28ff47:1b::/32ff47:1b:ffff:ffff:ffff:ffff:ffff:ffff
29ff47:1c::/32ff47:1c:ffff:ffff:ffff:ffff:ffff:ffff
30ff47:1d::/32ff47:1d:ffff:ffff:ffff:ffff:ffff:ffff
31ff47:1e::/32ff47:1e:ffff:ffff:ffff:ffff:ffff:ffff
32ff47:1f::/32ff47:1f:ffff:ffff:ffff:ffff:ffff:ffff
33ff47:20::/32ff47:20:ffff:ffff:ffff:ffff:ffff:ffff
34ff47:21::/32ff47:21:ffff:ffff:ffff:ffff:ffff:ffff
35ff47:22::/32ff47:22:ffff:ffff:ffff:ffff:ffff:ffff
36ff47:23::/32ff47:23:ffff:ffff:ffff:ffff:ffff:ffff
37ff47:24::/32ff47:24:ffff:ffff:ffff:ffff:ffff:ffff
38ff47:25::/32ff47:25:ffff:ffff:ffff:ffff:ffff:ffff
39ff47:26::/32ff47:26:ffff:ffff:ffff:ffff:ffff:ffff
40ff47:27::/32ff47:27:ffff:ffff:ffff:ffff:ffff:ffff
41ff47:28::/32ff47:28:ffff:ffff:ffff:ffff:ffff:ffff
42ff47:29::/32ff47:29:ffff:ffff:ffff:ffff:ffff:ffff
43ff47:2a::/32ff47:2a:ffff:ffff:ffff:ffff:ffff:ffff
44ff47:2b::/32ff47:2b:ffff:ffff:ffff:ffff:ffff:ffff
45ff47:2c::/32ff47:2c:ffff:ffff:ffff:ffff:ffff:ffff
46ff47:2d::/32ff47:2d:ffff:ffff:ffff:ffff:ffff:ffff
47ff47:2e::/32ff47:2e:ffff:ffff:ffff:ffff:ffff:ffff
48ff47:2f::/32ff47:2f:ffff:ffff:ffff:ffff:ffff:ffff
49ff47:30::/32ff47:30:ffff:ffff:ffff:ffff:ffff:ffff
50ff47:31::/32ff47:31:ffff:ffff:ffff:ffff:ffff:ffff
51ff47:32::/32ff47:32:ffff:ffff:ffff:ffff:ffff:ffff
52ff47:33::/32ff47:33:ffff:ffff:ffff:ffff:ffff:ffff
53ff47:34::/32ff47:34:ffff:ffff:ffff:ffff:ffff:ffff
54ff47:35::/32ff47:35:ffff:ffff:ffff:ffff:ffff:ffff
55ff47:36::/32ff47:36:ffff:ffff:ffff:ffff:ffff:ffff
56ff47:37::/32ff47:37:ffff:ffff:ffff:ffff:ffff:ffff
57ff47:38::/32ff47:38:ffff:ffff:ffff:ffff:ffff:ffff
58ff47:39::/32ff47:39:ffff:ffff:ffff:ffff:ffff:ffff
59ff47:3a::/32ff47:3a:ffff:ffff:ffff:ffff:ffff:ffff
60ff47:3b::/32ff47:3b:ffff:ffff:ffff:ffff:ffff:ffff
61ff47:3c::/32ff47:3c:ffff:ffff:ffff:ffff:ffff:ffff
62ff47:3d::/32ff47:3d:ffff:ffff:ffff:ffff:ffff:ffff
63ff47:3e::/32ff47:3e:ffff:ffff:ffff:ffff:ffff:ffff
64ff47:3f::/32ff47:3f:ffff:ffff:ffff:ffff:ffff:ffff
65ff47:40::/32ff47:40:ffff:ffff:ffff:ffff:ffff:ffff
66ff47:41::/32ff47:41:ffff:ffff:ffff:ffff:ffff:ffff
67ff47:42::/32ff47:42:ffff:ffff:ffff:ffff:ffff:ffff
68ff47:43::/32ff47:43:ffff:ffff:ffff:ffff:ffff:ffff
69ff47:44::/32ff47:44:ffff:ffff:ffff:ffff:ffff:ffff
70ff47:45::/32ff47:45:ffff:ffff:ffff:ffff:ffff:ffff
71ff47:46::/32ff47:46:ffff:ffff:ffff:ffff:ffff:ffff
72ff47:47::/32ff47:47:ffff:ffff:ffff:ffff:ffff:ffff
73ff47:48::/32ff47:48:ffff:ffff:ffff:ffff:ffff:ffff
74ff47:49::/32ff47:49:ffff:ffff:ffff:ffff:ffff:ffff
75ff47:4a::/32ff47:4a:ffff:ffff:ffff:ffff:ffff:ffff
76ff47:4b::/32ff47:4b:ffff:ffff:ffff:ffff:ffff:ffff
77ff47:4c::/32ff47:4c:ffff:ffff:ffff:ffff:ffff:ffff
78ff47:4d::/32ff47:4d:ffff:ffff:ffff:ffff:ffff:ffff
79ff47:4e::/32ff47:4e:ffff:ffff:ffff:ffff:ffff:ffff
80ff47:4f::/32ff47:4f:ffff:ffff:ffff:ffff:ffff:ffff
81ff47:50::/32ff47:50:ffff:ffff:ffff:ffff:ffff:ffff
82ff47:51::/32ff47:51:ffff:ffff:ffff:ffff:ffff:ffff
83ff47:52::/32ff47:52:ffff:ffff:ffff:ffff:ffff:ffff
84ff47:53::/32ff47:53:ffff:ffff:ffff:ffff:ffff:ffff
85ff47:54::/32ff47:54:ffff:ffff:ffff:ffff:ffff:ffff
86ff47:55::/32ff47:55:ffff:ffff:ffff:ffff:ffff:ffff
87ff47:56::/32ff47:56:ffff:ffff:ffff:ffff:ffff:ffff
88ff47:57::/32ff47:57:ffff:ffff:ffff:ffff:ffff:ffff
89ff47:58::/32ff47:58:ffff:ffff:ffff:ffff:ffff:ffff
90ff47:59::/32ff47:59:ffff:ffff:ffff:ffff:ffff:ffff
91ff47:5a::/32ff47:5a:ffff:ffff:ffff:ffff:ffff:ffff
92ff47:5b::/32ff47:5b:ffff:ffff:ffff:ffff:ffff:ffff
93ff47:5c::/32ff47:5c:ffff:ffff:ffff:ffff:ffff:ffff
94ff47:5d::/32ff47:5d:ffff:ffff:ffff:ffff:ffff:ffff
95ff47:5e::/32ff47:5e:ffff:ffff:ffff:ffff:ffff:ffff
96ff47:5f::/32ff47:5f:ffff:ffff:ffff:ffff:ffff:ffff
97ff47:60::/32ff47:60:ffff:ffff:ffff:ffff:ffff:ffff
98ff47:61::/32ff47:61:ffff:ffff:ffff:ffff:ffff:ffff
99ff47:62::/32ff47:62:ffff:ffff:ffff:ffff:ffff:ffff
100ff47:63::/32ff47:63:ffff:ffff:ffff:ffff:ffff:ffff
101ff47:64::/32ff47:64:ffff:ffff:ffff:ffff:ffff:ffff
102ff47:65::/32ff47:65:ffff:ffff:ffff:ffff:ffff:ffff
103ff47:66::/32ff47:66:ffff:ffff:ffff:ffff:ffff:ffff
104ff47:67::/32ff47:67:ffff:ffff:ffff:ffff:ffff:ffff
105ff47:68::/32ff47:68:ffff:ffff:ffff:ffff:ffff:ffff
106ff47:69::/32ff47:69:ffff:ffff:ffff:ffff:ffff:ffff
107ff47:6a::/32ff47:6a:ffff:ffff:ffff:ffff:ffff:ffff
108ff47:6b::/32ff47:6b:ffff:ffff:ffff:ffff:ffff:ffff
109ff47:6c::/32ff47:6c:ffff:ffff:ffff:ffff:ffff:ffff
110ff47:6d::/32ff47:6d:ffff:ffff:ffff:ffff:ffff:ffff
111ff47:6e::/32ff47:6e:ffff:ffff:ffff:ffff:ffff:ffff
112ff47:6f::/32ff47:6f:ffff:ffff:ffff:ffff:ffff:ffff
113ff47:70::/32ff47:70:ffff:ffff:ffff:ffff:ffff:ffff
114ff47:71::/32ff47:71:ffff:ffff:ffff:ffff:ffff:ffff
115ff47:72::/32ff47:72:ffff:ffff:ffff:ffff:ffff:ffff
116ff47:73::/32ff47:73:ffff:ffff:ffff:ffff:ffff:ffff
117ff47:74::/32ff47:74:ffff:ffff:ffff:ffff:ffff:ffff
118ff47:75::/32ff47:75:ffff:ffff:ffff:ffff:ffff:ffff
119ff47:76::/32ff47:76:ffff:ffff:ffff:ffff:ffff:ffff
120ff47:77::/32ff47:77:ffff:ffff:ffff:ffff:ffff:ffff
121ff47:78::/32ff47:78:ffff:ffff:ffff:ffff:ffff:ffff
122ff47:79::/32ff47:79:ffff:ffff:ffff:ffff:ffff:ffff
123ff47:7a::/32ff47:7a:ffff:ffff:ffff:ffff:ffff:ffff
124ff47:7b::/32ff47:7b:ffff:ffff:ffff:ffff:ffff:ffff
125ff47:7c::/32ff47:7c:ffff:ffff:ffff:ffff:ffff:ffff
126ff47:7d::/32ff47:7d:ffff:ffff:ffff:ffff:ffff:ffff
127ff47:7e::/32ff47:7e:ffff:ffff:ffff:ffff:ffff:ffff
128ff47:7f::/32ff47:7f:ffff:ffff:ffff:ffff:ffff:ffff
129ff47:80::/32ff47:80:ffff:ffff:ffff:ffff:ffff:ffff
130ff47:81::/32ff47:81:ffff:ffff:ffff:ffff:ffff:ffff
131ff47:82::/32ff47:82:ffff:ffff:ffff:ffff:ffff:ffff
132ff47:83::/32ff47:83:ffff:ffff:ffff:ffff:ffff:ffff
133ff47:84::/32ff47:84:ffff:ffff:ffff:ffff:ffff:ffff
134ff47:85::/32ff47:85:ffff:ffff:ffff:ffff:ffff:ffff
135ff47:86::/32ff47:86:ffff:ffff:ffff:ffff:ffff:ffff
136ff47:87::/32ff47:87:ffff:ffff:ffff:ffff:ffff:ffff
137ff47:88::/32ff47:88:ffff:ffff:ffff:ffff:ffff:ffff
138ff47:89::/32ff47:89:ffff:ffff:ffff:ffff:ffff:ffff
139ff47:8a::/32ff47:8a:ffff:ffff:ffff:ffff:ffff:ffff
140ff47:8b::/32ff47:8b:ffff:ffff:ffff:ffff:ffff:ffff
141ff47:8c::/32ff47:8c:ffff:ffff:ffff:ffff:ffff:ffff
142ff47:8d::/32ff47:8d:ffff:ffff:ffff:ffff:ffff:ffff
143ff47:8e::/32ff47:8e:ffff:ffff:ffff:ffff:ffff:ffff
144ff47:8f::/32ff47:8f:ffff:ffff:ffff:ffff:ffff:ffff
145ff47:90::/32ff47:90:ffff:ffff:ffff:ffff:ffff:ffff
146ff47:91::/32ff47:91:ffff:ffff:ffff:ffff:ffff:ffff
147ff47:92::/32ff47:92:ffff:ffff:ffff:ffff:ffff:ffff
148ff47:93::/32ff47:93:ffff:ffff:ffff:ffff:ffff:ffff
149ff47:94::/32ff47:94:ffff:ffff:ffff:ffff:ffff:ffff
150ff47:95::/32ff47:95:ffff:ffff:ffff:ffff:ffff:ffff
151ff47:96::/32ff47:96:ffff:ffff:ffff:ffff:ffff:ffff
152ff47:97::/32ff47:97:ffff:ffff:ffff:ffff:ffff:ffff
153ff47:98::/32ff47:98:ffff:ffff:ffff:ffff:ffff:ffff
154ff47:99::/32ff47:99:ffff:ffff:ffff:ffff:ffff:ffff
155ff47:9a::/32ff47:9a:ffff:ffff:ffff:ffff:ffff:ffff
156ff47:9b::/32ff47:9b:ffff:ffff:ffff:ffff:ffff:ffff
157ff47:9c::/32ff47:9c:ffff:ffff:ffff:ffff:ffff:ffff
158ff47:9d::/32ff47:9d:ffff:ffff:ffff:ffff:ffff:ffff
159ff47:9e::/32ff47:9e:ffff:ffff:ffff:ffff:ffff:ffff
160ff47:9f::/32ff47:9f:ffff:ffff:ffff:ffff:ffff:ffff
161ff47:a0::/32ff47:a0:ffff:ffff:ffff:ffff:ffff:ffff
162ff47:a1::/32ff47:a1:ffff:ffff:ffff:ffff:ffff:ffff
163ff47:a2::/32ff47:a2:ffff:ffff:ffff:ffff:ffff:ffff
164ff47:a3::/32ff47:a3:ffff:ffff:ffff:ffff:ffff:ffff
165ff47:a4::/32ff47:a4:ffff:ffff:ffff:ffff:ffff:ffff
166ff47:a5::/32ff47:a5:ffff:ffff:ffff:ffff:ffff:ffff
167ff47:a6::/32ff47:a6:ffff:ffff:ffff:ffff:ffff:ffff
168ff47:a7::/32ff47:a7:ffff:ffff:ffff:ffff:ffff:ffff
169ff47:a8::/32ff47:a8:ffff:ffff:ffff:ffff:ffff:ffff
170ff47:a9::/32ff47:a9:ffff:ffff:ffff:ffff:ffff:ffff
171ff47:aa::/32ff47:aa:ffff:ffff:ffff:ffff:ffff:ffff
172ff47:ab::/32ff47:ab:ffff:ffff:ffff:ffff:ffff:ffff
173ff47:ac::/32ff47:ac:ffff:ffff:ffff:ffff:ffff:ffff
174ff47:ad::/32ff47:ad:ffff:ffff:ffff:ffff:ffff:ffff
175ff47:ae::/32ff47:ae:ffff:ffff:ffff:ffff:ffff:ffff
176ff47:af::/32ff47:af:ffff:ffff:ffff:ffff:ffff:ffff
177ff47:b0::/32ff47:b0:ffff:ffff:ffff:ffff:ffff:ffff
178ff47:b1::/32ff47:b1:ffff:ffff:ffff:ffff:ffff:ffff
179ff47:b2::/32ff47:b2:ffff:ffff:ffff:ffff:ffff:ffff
180ff47:b3::/32ff47:b3:ffff:ffff:ffff:ffff:ffff:ffff
181ff47:b4::/32ff47:b4:ffff:ffff:ffff:ffff:ffff:ffff
182ff47:b5::/32ff47:b5:ffff:ffff:ffff:ffff:ffff:ffff
183ff47:b6::/32ff47:b6:ffff:ffff:ffff:ffff:ffff:ffff
184ff47:b7::/32ff47:b7:ffff:ffff:ffff:ffff:ffff:ffff
185ff47:b8::/32ff47:b8:ffff:ffff:ffff:ffff:ffff:ffff
186ff47:b9::/32ff47:b9:ffff:ffff:ffff:ffff:ffff:ffff
187ff47:ba::/32ff47:ba:ffff:ffff:ffff:ffff:ffff:ffff
188ff47:bb::/32ff47:bb:ffff:ffff:ffff:ffff:ffff:ffff
189ff47:bc::/32ff47:bc:ffff:ffff:ffff:ffff:ffff:ffff
190ff47:bd::/32ff47:bd:ffff:ffff:ffff:ffff:ffff:ffff
191ff47:be::/32ff47:be:ffff:ffff:ffff:ffff:ffff:ffff
192ff47:bf::/32ff47:bf:ffff:ffff:ffff:ffff:ffff:ffff
193ff47:c0::/32ff47:c0:ffff:ffff:ffff:ffff:ffff:ffff
194ff47:c1::/32ff47:c1:ffff:ffff:ffff:ffff:ffff:ffff
195ff47:c2::/32ff47:c2:ffff:ffff:ffff:ffff:ffff:ffff
196ff47:c3::/32ff47:c3:ffff:ffff:ffff:ffff:ffff:ffff
197ff47:c4::/32ff47:c4:ffff:ffff:ffff:ffff:ffff:ffff
198ff47:c5::/32ff47:c5:ffff:ffff:ffff:ffff:ffff:ffff
199ff47:c6::/32ff47:c6:ffff:ffff:ffff:ffff:ffff:ffff
200ff47:c7::/32ff47:c7:ffff:ffff:ffff:ffff:ffff:ffff
201ff47:c8::/32ff47:c8:ffff:ffff:ffff:ffff:ffff:ffff
202ff47:c9::/32ff47:c9:ffff:ffff:ffff:ffff:ffff:ffff
203ff47:ca::/32ff47:ca:ffff:ffff:ffff:ffff:ffff:ffff
204ff47:cb::/32ff47:cb:ffff:ffff:ffff:ffff:ffff:ffff
205ff47:cc::/32ff47:cc:ffff:ffff:ffff:ffff:ffff:ffff
206ff47:cd::/32ff47:cd:ffff:ffff:ffff:ffff:ffff:ffff
207ff47:ce::/32ff47:ce:ffff:ffff:ffff:ffff:ffff:ffff
208ff47:cf::/32ff47:cf:ffff:ffff:ffff:ffff:ffff:ffff
209ff47:d0::/32ff47:d0:ffff:ffff:ffff:ffff:ffff:ffff
210ff47:d1::/32ff47:d1:ffff:ffff:ffff:ffff:ffff:ffff
211ff47:d2::/32ff47:d2:ffff:ffff:ffff:ffff:ffff:ffff
212ff47:d3::/32ff47:d3:ffff:ffff:ffff:ffff:ffff:ffff
213ff47:d4::/32ff47:d4:ffff:ffff:ffff:ffff:ffff:ffff
214ff47:d5::/32ff47:d5:ffff:ffff:ffff:ffff:ffff:ffff
215ff47:d6::/32ff47:d6:ffff:ffff:ffff:ffff:ffff:ffff
216ff47:d7::/32ff47:d7:ffff:ffff:ffff:ffff:ffff:ffff
217ff47:d8::/32ff47:d8:ffff:ffff:ffff:ffff:ffff:ffff
218ff47:d9::/32ff47:d9:ffff:ffff:ffff:ffff:ffff:ffff
219ff47:da::/32ff47:da:ffff:ffff:ffff:ffff:ffff:ffff
220ff47:db::/32ff47:db:ffff:ffff:ffff:ffff:ffff:ffff
221ff47:dc::/32ff47:dc:ffff:ffff:ffff:ffff:ffff:ffff
222ff47:dd::/32ff47:dd:ffff:ffff:ffff:ffff:ffff:ffff
223ff47:de::/32ff47:de:ffff:ffff:ffff:ffff:ffff:ffff
224ff47:df::/32ff47:df:ffff:ffff:ffff:ffff:ffff:ffff
225ff47:e0::/32ff47:e0:ffff:ffff:ffff:ffff:ffff:ffff
226ff47:e1::/32ff47:e1:ffff:ffff:ffff:ffff:ffff:ffff
227ff47:e2::/32ff47:e2:ffff:ffff:ffff:ffff:ffff:ffff
228ff47:e3::/32ff47:e3:ffff:ffff:ffff:ffff:ffff:ffff
229ff47:e4::/32ff47:e4:ffff:ffff:ffff:ffff:ffff:ffff
230ff47:e5::/32ff47:e5:ffff:ffff:ffff:ffff:ffff:ffff
231ff47:e6::/32ff47:e6:ffff:ffff:ffff:ffff:ffff:ffff
232ff47:e7::/32ff47:e7:ffff:ffff:ffff:ffff:ffff:ffff
233ff47:e8::/32ff47:e8:ffff:ffff:ffff:ffff:ffff:ffff
234ff47:e9::/32ff47:e9:ffff:ffff:ffff:ffff:ffff:ffff
235ff47:ea::/32ff47:ea:ffff:ffff:ffff:ffff:ffff:ffff
236ff47:eb::/32ff47:eb:ffff:ffff:ffff:ffff:ffff:ffff
237ff47:ec::/32ff47:ec:ffff:ffff:ffff:ffff:ffff:ffff
238ff47:ed::/32ff47:ed:ffff:ffff:ffff:ffff:ffff:ffff
239ff47:ee::/32ff47:ee:ffff:ffff:ffff:ffff:ffff:ffff
240ff47:ef::/32ff47:ef:ffff:ffff:ffff:ffff:ffff:ffff
241ff47:f0::/32ff47:f0:ffff:ffff:ffff:ffff:ffff:ffff
242ff47:f1::/32ff47:f1:ffff:ffff:ffff:ffff:ffff:ffff
243ff47:f2::/32ff47:f2:ffff:ffff:ffff:ffff:ffff:ffff
244ff47:f3::/32ff47:f3:ffff:ffff:ffff:ffff:ffff:ffff
245ff47:f4::/32ff47:f4:ffff:ffff:ffff:ffff:ffff:ffff
246ff47:f5::/32ff47:f5:ffff:ffff:ffff:ffff:ffff:ffff
247ff47:f6::/32ff47:f6:ffff:ffff:ffff:ffff:ffff:ffff
248ff47:f7::/32ff47:f7:ffff:ffff:ffff:ffff:ffff:ffff
249ff47:f8::/32ff47:f8:ffff:ffff:ffff:ffff:ffff:ffff
250ff47:f9::/32ff47:f9:ffff:ffff:ffff:ffff:ffff:ffff
251ff47:fa::/32ff47:fa:ffff:ffff:ffff:ffff:ffff:ffff
252ff47:fb::/32ff47:fb:ffff:ffff:ffff:ffff:ffff:ffff
253ff47:fc::/32ff47:fc:ffff:ffff:ffff:ffff:ffff:ffff
254ff47:fd::/32ff47:fd:ffff:ffff:ffff:ffff:ffff:ffff
255ff47:fe::/32ff47:fe:ffff:ffff:ffff:ffff:ffff:ffff
256ff47:ff::/32ff47: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.