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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/12
Addresses2^116
/64 networks2^52
Network
ff30::/12
First address
ff30::
Last address
ff3f:ffff:ffff:ffff:ffff:ffff:ffff:ffff
Addresses
83,076,749,736,557,242,056,487,941,267,521,536 (2^116)
/64 networks (LANs)
4,503,599,627,370,496 (2^52)
Full form
ff30:0000:0000:0000:0000:0000:0000:0000
Type
Multicast ff00::/8
One-to-many traffic; replaces broadcast
Reverse DNS zone
3.f.f.ip6.arpa
Split into smaller subnets/20
/13 (2)/14 (4)/15 (8)/16 (16)/20 (256)/24 (4,096)/28 (65,536)

ff30::/12 makes 256 subnets of /20.

Subnets
#SubnetLast address
1ff30::/20ff30:fff:ffff:ffff:ffff:ffff:ffff:ffff
2ff30:1000::/20ff30:1fff:ffff:ffff:ffff:ffff:ffff:ffff
3ff30:2000::/20ff30:2fff:ffff:ffff:ffff:ffff:ffff:ffff
4ff30:3000::/20ff30:3fff:ffff:ffff:ffff:ffff:ffff:ffff
5ff30:4000::/20ff30:4fff:ffff:ffff:ffff:ffff:ffff:ffff
6ff30:5000::/20ff30:5fff:ffff:ffff:ffff:ffff:ffff:ffff
7ff30:6000::/20ff30:6fff:ffff:ffff:ffff:ffff:ffff:ffff
8ff30:7000::/20ff30:7fff:ffff:ffff:ffff:ffff:ffff:ffff
9ff30:8000::/20ff30:8fff:ffff:ffff:ffff:ffff:ffff:ffff
10ff30:9000::/20ff30:9fff:ffff:ffff:ffff:ffff:ffff:ffff
11ff30:a000::/20ff30:afff:ffff:ffff:ffff:ffff:ffff:ffff
12ff30:b000::/20ff30:bfff:ffff:ffff:ffff:ffff:ffff:ffff
13ff30:c000::/20ff30:cfff:ffff:ffff:ffff:ffff:ffff:ffff
14ff30:d000::/20ff30:dfff:ffff:ffff:ffff:ffff:ffff:ffff
15ff30:e000::/20ff30:efff:ffff:ffff:ffff:ffff:ffff:ffff
16ff30:f000::/20ff30:ffff:ffff:ffff:ffff:ffff:ffff:ffff
17ff31::/20ff31:fff:ffff:ffff:ffff:ffff:ffff:ffff
18ff31:1000::/20ff31:1fff:ffff:ffff:ffff:ffff:ffff:ffff
19ff31:2000::/20ff31:2fff:ffff:ffff:ffff:ffff:ffff:ffff
20ff31:3000::/20ff31:3fff:ffff:ffff:ffff:ffff:ffff:ffff
21ff31:4000::/20ff31:4fff:ffff:ffff:ffff:ffff:ffff:ffff
22ff31:5000::/20ff31:5fff:ffff:ffff:ffff:ffff:ffff:ffff
23ff31:6000::/20ff31:6fff:ffff:ffff:ffff:ffff:ffff:ffff
24ff31:7000::/20ff31:7fff:ffff:ffff:ffff:ffff:ffff:ffff
25ff31:8000::/20ff31:8fff:ffff:ffff:ffff:ffff:ffff:ffff
26ff31:9000::/20ff31:9fff:ffff:ffff:ffff:ffff:ffff:ffff
27ff31:a000::/20ff31:afff:ffff:ffff:ffff:ffff:ffff:ffff
28ff31:b000::/20ff31:bfff:ffff:ffff:ffff:ffff:ffff:ffff
29ff31:c000::/20ff31:cfff:ffff:ffff:ffff:ffff:ffff:ffff
30ff31:d000::/20ff31:dfff:ffff:ffff:ffff:ffff:ffff:ffff
31ff31:e000::/20ff31:efff:ffff:ffff:ffff:ffff:ffff:ffff
32ff31:f000::/20ff31:ffff:ffff:ffff:ffff:ffff:ffff:ffff
33ff32::/20ff32:fff:ffff:ffff:ffff:ffff:ffff:ffff
34ff32:1000::/20ff32:1fff:ffff:ffff:ffff:ffff:ffff:ffff
35ff32:2000::/20ff32:2fff:ffff:ffff:ffff:ffff:ffff:ffff
36ff32:3000::/20ff32:3fff:ffff:ffff:ffff:ffff:ffff:ffff
37ff32:4000::/20ff32:4fff:ffff:ffff:ffff:ffff:ffff:ffff
38ff32:5000::/20ff32:5fff:ffff:ffff:ffff:ffff:ffff:ffff
39ff32:6000::/20ff32:6fff:ffff:ffff:ffff:ffff:ffff:ffff
40ff32:7000::/20ff32:7fff:ffff:ffff:ffff:ffff:ffff:ffff
41ff32:8000::/20ff32:8fff:ffff:ffff:ffff:ffff:ffff:ffff
42ff32:9000::/20ff32:9fff:ffff:ffff:ffff:ffff:ffff:ffff
43ff32:a000::/20ff32:afff:ffff:ffff:ffff:ffff:ffff:ffff
44ff32:b000::/20ff32:bfff:ffff:ffff:ffff:ffff:ffff:ffff
45ff32:c000::/20ff32:cfff:ffff:ffff:ffff:ffff:ffff:ffff
46ff32:d000::/20ff32:dfff:ffff:ffff:ffff:ffff:ffff:ffff
47ff32:e000::/20ff32:efff:ffff:ffff:ffff:ffff:ffff:ffff
48ff32:f000::/20ff32:ffff:ffff:ffff:ffff:ffff:ffff:ffff
49ff33::/20ff33:fff:ffff:ffff:ffff:ffff:ffff:ffff
50ff33:1000::/20ff33:1fff:ffff:ffff:ffff:ffff:ffff:ffff
51ff33:2000::/20ff33:2fff:ffff:ffff:ffff:ffff:ffff:ffff
52ff33:3000::/20ff33:3fff:ffff:ffff:ffff:ffff:ffff:ffff
53ff33:4000::/20ff33:4fff:ffff:ffff:ffff:ffff:ffff:ffff
54ff33:5000::/20ff33:5fff:ffff:ffff:ffff:ffff:ffff:ffff
55ff33:6000::/20ff33:6fff:ffff:ffff:ffff:ffff:ffff:ffff
56ff33:7000::/20ff33:7fff:ffff:ffff:ffff:ffff:ffff:ffff
57ff33:8000::/20ff33:8fff:ffff:ffff:ffff:ffff:ffff:ffff
58ff33:9000::/20ff33:9fff:ffff:ffff:ffff:ffff:ffff:ffff
59ff33:a000::/20ff33:afff:ffff:ffff:ffff:ffff:ffff:ffff
60ff33:b000::/20ff33:bfff:ffff:ffff:ffff:ffff:ffff:ffff
61ff33:c000::/20ff33:cfff:ffff:ffff:ffff:ffff:ffff:ffff
62ff33:d000::/20ff33:dfff:ffff:ffff:ffff:ffff:ffff:ffff
63ff33:e000::/20ff33:efff:ffff:ffff:ffff:ffff:ffff:ffff
64ff33:f000::/20ff33:ffff:ffff:ffff:ffff:ffff:ffff:ffff
65ff34::/20ff34:fff:ffff:ffff:ffff:ffff:ffff:ffff
66ff34:1000::/20ff34:1fff:ffff:ffff:ffff:ffff:ffff:ffff
67ff34:2000::/20ff34:2fff:ffff:ffff:ffff:ffff:ffff:ffff
68ff34:3000::/20ff34:3fff:ffff:ffff:ffff:ffff:ffff:ffff
69ff34:4000::/20ff34:4fff:ffff:ffff:ffff:ffff:ffff:ffff
70ff34:5000::/20ff34:5fff:ffff:ffff:ffff:ffff:ffff:ffff
71ff34:6000::/20ff34:6fff:ffff:ffff:ffff:ffff:ffff:ffff
72ff34:7000::/20ff34:7fff:ffff:ffff:ffff:ffff:ffff:ffff
73ff34:8000::/20ff34:8fff:ffff:ffff:ffff:ffff:ffff:ffff
74ff34:9000::/20ff34:9fff:ffff:ffff:ffff:ffff:ffff:ffff
75ff34:a000::/20ff34:afff:ffff:ffff:ffff:ffff:ffff:ffff
76ff34:b000::/20ff34:bfff:ffff:ffff:ffff:ffff:ffff:ffff
77ff34:c000::/20ff34:cfff:ffff:ffff:ffff:ffff:ffff:ffff
78ff34:d000::/20ff34:dfff:ffff:ffff:ffff:ffff:ffff:ffff
79ff34:e000::/20ff34:efff:ffff:ffff:ffff:ffff:ffff:ffff
80ff34:f000::/20ff34:ffff:ffff:ffff:ffff:ffff:ffff:ffff
81ff35::/20ff35:fff:ffff:ffff:ffff:ffff:ffff:ffff
82ff35:1000::/20ff35:1fff:ffff:ffff:ffff:ffff:ffff:ffff
83ff35:2000::/20ff35:2fff:ffff:ffff:ffff:ffff:ffff:ffff
84ff35:3000::/20ff35:3fff:ffff:ffff:ffff:ffff:ffff:ffff
85ff35:4000::/20ff35:4fff:ffff:ffff:ffff:ffff:ffff:ffff
86ff35:5000::/20ff35:5fff:ffff:ffff:ffff:ffff:ffff:ffff
87ff35:6000::/20ff35:6fff:ffff:ffff:ffff:ffff:ffff:ffff
88ff35:7000::/20ff35:7fff:ffff:ffff:ffff:ffff:ffff:ffff
89ff35:8000::/20ff35:8fff:ffff:ffff:ffff:ffff:ffff:ffff
90ff35:9000::/20ff35:9fff:ffff:ffff:ffff:ffff:ffff:ffff
91ff35:a000::/20ff35:afff:ffff:ffff:ffff:ffff:ffff:ffff
92ff35:b000::/20ff35:bfff:ffff:ffff:ffff:ffff:ffff:ffff
93ff35:c000::/20ff35:cfff:ffff:ffff:ffff:ffff:ffff:ffff
94ff35:d000::/20ff35:dfff:ffff:ffff:ffff:ffff:ffff:ffff
95ff35:e000::/20ff35:efff:ffff:ffff:ffff:ffff:ffff:ffff
96ff35:f000::/20ff35:ffff:ffff:ffff:ffff:ffff:ffff:ffff
97ff36::/20ff36:fff:ffff:ffff:ffff:ffff:ffff:ffff
98ff36:1000::/20ff36:1fff:ffff:ffff:ffff:ffff:ffff:ffff
99ff36:2000::/20ff36:2fff:ffff:ffff:ffff:ffff:ffff:ffff
100ff36:3000::/20ff36:3fff:ffff:ffff:ffff:ffff:ffff:ffff
101ff36:4000::/20ff36:4fff:ffff:ffff:ffff:ffff:ffff:ffff
102ff36:5000::/20ff36:5fff:ffff:ffff:ffff:ffff:ffff:ffff
103ff36:6000::/20ff36:6fff:ffff:ffff:ffff:ffff:ffff:ffff
104ff36:7000::/20ff36:7fff:ffff:ffff:ffff:ffff:ffff:ffff
105ff36:8000::/20ff36:8fff:ffff:ffff:ffff:ffff:ffff:ffff
106ff36:9000::/20ff36:9fff:ffff:ffff:ffff:ffff:ffff:ffff
107ff36:a000::/20ff36:afff:ffff:ffff:ffff:ffff:ffff:ffff
108ff36:b000::/20ff36:bfff:ffff:ffff:ffff:ffff:ffff:ffff
109ff36:c000::/20ff36:cfff:ffff:ffff:ffff:ffff:ffff:ffff
110ff36:d000::/20ff36:dfff:ffff:ffff:ffff:ffff:ffff:ffff
111ff36:e000::/20ff36:efff:ffff:ffff:ffff:ffff:ffff:ffff
112ff36:f000::/20ff36:ffff:ffff:ffff:ffff:ffff:ffff:ffff
113ff37::/20ff37:fff:ffff:ffff:ffff:ffff:ffff:ffff
114ff37:1000::/20ff37:1fff:ffff:ffff:ffff:ffff:ffff:ffff
115ff37:2000::/20ff37:2fff:ffff:ffff:ffff:ffff:ffff:ffff
116ff37:3000::/20ff37:3fff:ffff:ffff:ffff:ffff:ffff:ffff
117ff37:4000::/20ff37:4fff:ffff:ffff:ffff:ffff:ffff:ffff
118ff37:5000::/20ff37:5fff:ffff:ffff:ffff:ffff:ffff:ffff
119ff37:6000::/20ff37:6fff:ffff:ffff:ffff:ffff:ffff:ffff
120ff37:7000::/20ff37:7fff:ffff:ffff:ffff:ffff:ffff:ffff
121ff37:8000::/20ff37:8fff:ffff:ffff:ffff:ffff:ffff:ffff
122ff37:9000::/20ff37:9fff:ffff:ffff:ffff:ffff:ffff:ffff
123ff37:a000::/20ff37:afff:ffff:ffff:ffff:ffff:ffff:ffff
124ff37:b000::/20ff37:bfff:ffff:ffff:ffff:ffff:ffff:ffff
125ff37:c000::/20ff37:cfff:ffff:ffff:ffff:ffff:ffff:ffff
126ff37:d000::/20ff37:dfff:ffff:ffff:ffff:ffff:ffff:ffff
127ff37:e000::/20ff37:efff:ffff:ffff:ffff:ffff:ffff:ffff
128ff37:f000::/20ff37:ffff:ffff:ffff:ffff:ffff:ffff:ffff
129ff38::/20ff38:fff:ffff:ffff:ffff:ffff:ffff:ffff
130ff38:1000::/20ff38:1fff:ffff:ffff:ffff:ffff:ffff:ffff
131ff38:2000::/20ff38:2fff:ffff:ffff:ffff:ffff:ffff:ffff
132ff38:3000::/20ff38:3fff:ffff:ffff:ffff:ffff:ffff:ffff
133ff38:4000::/20ff38:4fff:ffff:ffff:ffff:ffff:ffff:ffff
134ff38:5000::/20ff38:5fff:ffff:ffff:ffff:ffff:ffff:ffff
135ff38:6000::/20ff38:6fff:ffff:ffff:ffff:ffff:ffff:ffff
136ff38:7000::/20ff38:7fff:ffff:ffff:ffff:ffff:ffff:ffff
137ff38:8000::/20ff38:8fff:ffff:ffff:ffff:ffff:ffff:ffff
138ff38:9000::/20ff38:9fff:ffff:ffff:ffff:ffff:ffff:ffff
139ff38:a000::/20ff38:afff:ffff:ffff:ffff:ffff:ffff:ffff
140ff38:b000::/20ff38:bfff:ffff:ffff:ffff:ffff:ffff:ffff
141ff38:c000::/20ff38:cfff:ffff:ffff:ffff:ffff:ffff:ffff
142ff38:d000::/20ff38:dfff:ffff:ffff:ffff:ffff:ffff:ffff
143ff38:e000::/20ff38:efff:ffff:ffff:ffff:ffff:ffff:ffff
144ff38:f000::/20ff38:ffff:ffff:ffff:ffff:ffff:ffff:ffff
145ff39::/20ff39:fff:ffff:ffff:ffff:ffff:ffff:ffff
146ff39:1000::/20ff39:1fff:ffff:ffff:ffff:ffff:ffff:ffff
147ff39:2000::/20ff39:2fff:ffff:ffff:ffff:ffff:ffff:ffff
148ff39:3000::/20ff39:3fff:ffff:ffff:ffff:ffff:ffff:ffff
149ff39:4000::/20ff39:4fff:ffff:ffff:ffff:ffff:ffff:ffff
150ff39:5000::/20ff39:5fff:ffff:ffff:ffff:ffff:ffff:ffff
151ff39:6000::/20ff39:6fff:ffff:ffff:ffff:ffff:ffff:ffff
152ff39:7000::/20ff39:7fff:ffff:ffff:ffff:ffff:ffff:ffff
153ff39:8000::/20ff39:8fff:ffff:ffff:ffff:ffff:ffff:ffff
154ff39:9000::/20ff39:9fff:ffff:ffff:ffff:ffff:ffff:ffff
155ff39:a000::/20ff39:afff:ffff:ffff:ffff:ffff:ffff:ffff
156ff39:b000::/20ff39:bfff:ffff:ffff:ffff:ffff:ffff:ffff
157ff39:c000::/20ff39:cfff:ffff:ffff:ffff:ffff:ffff:ffff
158ff39:d000::/20ff39:dfff:ffff:ffff:ffff:ffff:ffff:ffff
159ff39:e000::/20ff39:efff:ffff:ffff:ffff:ffff:ffff:ffff
160ff39:f000::/20ff39:ffff:ffff:ffff:ffff:ffff:ffff:ffff
161ff3a::/20ff3a:fff:ffff:ffff:ffff:ffff:ffff:ffff
162ff3a:1000::/20ff3a:1fff:ffff:ffff:ffff:ffff:ffff:ffff
163ff3a:2000::/20ff3a:2fff:ffff:ffff:ffff:ffff:ffff:ffff
164ff3a:3000::/20ff3a:3fff:ffff:ffff:ffff:ffff:ffff:ffff
165ff3a:4000::/20ff3a:4fff:ffff:ffff:ffff:ffff:ffff:ffff
166ff3a:5000::/20ff3a:5fff:ffff:ffff:ffff:ffff:ffff:ffff
167ff3a:6000::/20ff3a:6fff:ffff:ffff:ffff:ffff:ffff:ffff
168ff3a:7000::/20ff3a:7fff:ffff:ffff:ffff:ffff:ffff:ffff
169ff3a:8000::/20ff3a:8fff:ffff:ffff:ffff:ffff:ffff:ffff
170ff3a:9000::/20ff3a:9fff:ffff:ffff:ffff:ffff:ffff:ffff
171ff3a:a000::/20ff3a:afff:ffff:ffff:ffff:ffff:ffff:ffff
172ff3a:b000::/20ff3a:bfff:ffff:ffff:ffff:ffff:ffff:ffff
173ff3a:c000::/20ff3a:cfff:ffff:ffff:ffff:ffff:ffff:ffff
174ff3a:d000::/20ff3a:dfff:ffff:ffff:ffff:ffff:ffff:ffff
175ff3a:e000::/20ff3a:efff:ffff:ffff:ffff:ffff:ffff:ffff
176ff3a:f000::/20ff3a:ffff:ffff:ffff:ffff:ffff:ffff:ffff
177ff3b::/20ff3b:fff:ffff:ffff:ffff:ffff:ffff:ffff
178ff3b:1000::/20ff3b:1fff:ffff:ffff:ffff:ffff:ffff:ffff
179ff3b:2000::/20ff3b:2fff:ffff:ffff:ffff:ffff:ffff:ffff
180ff3b:3000::/20ff3b:3fff:ffff:ffff:ffff:ffff:ffff:ffff
181ff3b:4000::/20ff3b:4fff:ffff:ffff:ffff:ffff:ffff:ffff
182ff3b:5000::/20ff3b:5fff:ffff:ffff:ffff:ffff:ffff:ffff
183ff3b:6000::/20ff3b:6fff:ffff:ffff:ffff:ffff:ffff:ffff
184ff3b:7000::/20ff3b:7fff:ffff:ffff:ffff:ffff:ffff:ffff
185ff3b:8000::/20ff3b:8fff:ffff:ffff:ffff:ffff:ffff:ffff
186ff3b:9000::/20ff3b:9fff:ffff:ffff:ffff:ffff:ffff:ffff
187ff3b:a000::/20ff3b:afff:ffff:ffff:ffff:ffff:ffff:ffff
188ff3b:b000::/20ff3b:bfff:ffff:ffff:ffff:ffff:ffff:ffff
189ff3b:c000::/20ff3b:cfff:ffff:ffff:ffff:ffff:ffff:ffff
190ff3b:d000::/20ff3b:dfff:ffff:ffff:ffff:ffff:ffff:ffff
191ff3b:e000::/20ff3b:efff:ffff:ffff:ffff:ffff:ffff:ffff
192ff3b:f000::/20ff3b:ffff:ffff:ffff:ffff:ffff:ffff:ffff
193ff3c::/20ff3c:fff:ffff:ffff:ffff:ffff:ffff:ffff
194ff3c:1000::/20ff3c:1fff:ffff:ffff:ffff:ffff:ffff:ffff
195ff3c:2000::/20ff3c:2fff:ffff:ffff:ffff:ffff:ffff:ffff
196ff3c:3000::/20ff3c:3fff:ffff:ffff:ffff:ffff:ffff:ffff
197ff3c:4000::/20ff3c:4fff:ffff:ffff:ffff:ffff:ffff:ffff
198ff3c:5000::/20ff3c:5fff:ffff:ffff:ffff:ffff:ffff:ffff
199ff3c:6000::/20ff3c:6fff:ffff:ffff:ffff:ffff:ffff:ffff
200ff3c:7000::/20ff3c:7fff:ffff:ffff:ffff:ffff:ffff:ffff
201ff3c:8000::/20ff3c:8fff:ffff:ffff:ffff:ffff:ffff:ffff
202ff3c:9000::/20ff3c:9fff:ffff:ffff:ffff:ffff:ffff:ffff
203ff3c:a000::/20ff3c:afff:ffff:ffff:ffff:ffff:ffff:ffff
204ff3c:b000::/20ff3c:bfff:ffff:ffff:ffff:ffff:ffff:ffff
205ff3c:c000::/20ff3c:cfff:ffff:ffff:ffff:ffff:ffff:ffff
206ff3c:d000::/20ff3c:dfff:ffff:ffff:ffff:ffff:ffff:ffff
207ff3c:e000::/20ff3c:efff:ffff:ffff:ffff:ffff:ffff:ffff
208ff3c:f000::/20ff3c:ffff:ffff:ffff:ffff:ffff:ffff:ffff
209ff3d::/20ff3d:fff:ffff:ffff:ffff:ffff:ffff:ffff
210ff3d:1000::/20ff3d:1fff:ffff:ffff:ffff:ffff:ffff:ffff
211ff3d:2000::/20ff3d:2fff:ffff:ffff:ffff:ffff:ffff:ffff
212ff3d:3000::/20ff3d:3fff:ffff:ffff:ffff:ffff:ffff:ffff
213ff3d:4000::/20ff3d:4fff:ffff:ffff:ffff:ffff:ffff:ffff
214ff3d:5000::/20ff3d:5fff:ffff:ffff:ffff:ffff:ffff:ffff
215ff3d:6000::/20ff3d:6fff:ffff:ffff:ffff:ffff:ffff:ffff
216ff3d:7000::/20ff3d:7fff:ffff:ffff:ffff:ffff:ffff:ffff
217ff3d:8000::/20ff3d:8fff:ffff:ffff:ffff:ffff:ffff:ffff
218ff3d:9000::/20ff3d:9fff:ffff:ffff:ffff:ffff:ffff:ffff
219ff3d:a000::/20ff3d:afff:ffff:ffff:ffff:ffff:ffff:ffff
220ff3d:b000::/20ff3d:bfff:ffff:ffff:ffff:ffff:ffff:ffff
221ff3d:c000::/20ff3d:cfff:ffff:ffff:ffff:ffff:ffff:ffff
222ff3d:d000::/20ff3d:dfff:ffff:ffff:ffff:ffff:ffff:ffff
223ff3d:e000::/20ff3d:efff:ffff:ffff:ffff:ffff:ffff:ffff
224ff3d:f000::/20ff3d:ffff:ffff:ffff:ffff:ffff:ffff:ffff
225ff3e::/20ff3e:fff:ffff:ffff:ffff:ffff:ffff:ffff
226ff3e:1000::/20ff3e:1fff:ffff:ffff:ffff:ffff:ffff:ffff
227ff3e:2000::/20ff3e:2fff:ffff:ffff:ffff:ffff:ffff:ffff
228ff3e:3000::/20ff3e:3fff:ffff:ffff:ffff:ffff:ffff:ffff
229ff3e:4000::/20ff3e:4fff:ffff:ffff:ffff:ffff:ffff:ffff
230ff3e:5000::/20ff3e:5fff:ffff:ffff:ffff:ffff:ffff:ffff
231ff3e:6000::/20ff3e:6fff:ffff:ffff:ffff:ffff:ffff:ffff
232ff3e:7000::/20ff3e:7fff:ffff:ffff:ffff:ffff:ffff:ffff
233ff3e:8000::/20ff3e:8fff:ffff:ffff:ffff:ffff:ffff:ffff
234ff3e:9000::/20ff3e:9fff:ffff:ffff:ffff:ffff:ffff:ffff
235ff3e:a000::/20ff3e:afff:ffff:ffff:ffff:ffff:ffff:ffff
236ff3e:b000::/20ff3e:bfff:ffff:ffff:ffff:ffff:ffff:ffff
237ff3e:c000::/20ff3e:cfff:ffff:ffff:ffff:ffff:ffff:ffff
238ff3e:d000::/20ff3e:dfff:ffff:ffff:ffff:ffff:ffff:ffff
239ff3e:e000::/20ff3e:efff:ffff:ffff:ffff:ffff:ffff:ffff
240ff3e:f000::/20ff3e:ffff:ffff:ffff:ffff:ffff:ffff:ffff
241ff3f::/20ff3f:fff:ffff:ffff:ffff:ffff:ffff:ffff
242ff3f:1000::/20ff3f:1fff:ffff:ffff:ffff:ffff:ffff:ffff
243ff3f:2000::/20ff3f:2fff:ffff:ffff:ffff:ffff:ffff:ffff
244ff3f:3000::/20ff3f:3fff:ffff:ffff:ffff:ffff:ffff:ffff
245ff3f:4000::/20ff3f:4fff:ffff:ffff:ffff:ffff:ffff:ffff
246ff3f:5000::/20ff3f:5fff:ffff:ffff:ffff:ffff:ffff:ffff
247ff3f:6000::/20ff3f:6fff:ffff:ffff:ffff:ffff:ffff:ffff
248ff3f:7000::/20ff3f:7fff:ffff:ffff:ffff:ffff:ffff:ffff
249ff3f:8000::/20ff3f:8fff:ffff:ffff:ffff:ffff:ffff:ffff
250ff3f:9000::/20ff3f:9fff:ffff:ffff:ffff:ffff:ffff:ffff
251ff3f:a000::/20ff3f:afff:ffff:ffff:ffff:ffff:ffff:ffff
252ff3f:b000::/20ff3f:bfff:ffff:ffff:ffff:ffff:ffff:ffff
253ff3f:c000::/20ff3f:cfff:ffff:ffff:ffff:ffff:ffff:ffff
254ff3f:d000::/20ff3f:dfff:ffff:ffff:ffff:ffff:ffff:ffff
255ff3f:e000::/20ff3f:efff:ffff:ffff:ffff:ffff:ffff:ffff
256ff3f:f000::/20ff3f:ffff: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.