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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
fc22::/16
First address
fc22::
Last address
fc22: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
fc22:0000:0000:0000:0000:0000:0000:0000
Type
Unique local (ULA) fc00::/7
Private IPv6, like RFC 1918; usually fd00::/8
Reverse DNS zone
2.2.c.f.ip6.arpa
Split into smaller subnets/32
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

fc22::/16 makes 65,536 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
1fc22::/32fc22:0:ffff:ffff:ffff:ffff:ffff:ffff
2fc22:1::/32fc22:1:ffff:ffff:ffff:ffff:ffff:ffff
3fc22:2::/32fc22:2:ffff:ffff:ffff:ffff:ffff:ffff
4fc22:3::/32fc22:3:ffff:ffff:ffff:ffff:ffff:ffff
5fc22:4::/32fc22:4:ffff:ffff:ffff:ffff:ffff:ffff
6fc22:5::/32fc22:5:ffff:ffff:ffff:ffff:ffff:ffff
7fc22:6::/32fc22:6:ffff:ffff:ffff:ffff:ffff:ffff
8fc22:7::/32fc22:7:ffff:ffff:ffff:ffff:ffff:ffff
9fc22:8::/32fc22:8:ffff:ffff:ffff:ffff:ffff:ffff
10fc22:9::/32fc22:9:ffff:ffff:ffff:ffff:ffff:ffff
11fc22:a::/32fc22:a:ffff:ffff:ffff:ffff:ffff:ffff
12fc22:b::/32fc22:b:ffff:ffff:ffff:ffff:ffff:ffff
13fc22:c::/32fc22:c:ffff:ffff:ffff:ffff:ffff:ffff
14fc22:d::/32fc22:d:ffff:ffff:ffff:ffff:ffff:ffff
15fc22:e::/32fc22:e:ffff:ffff:ffff:ffff:ffff:ffff
16fc22:f::/32fc22:f:ffff:ffff:ffff:ffff:ffff:ffff
17fc22:10::/32fc22:10:ffff:ffff:ffff:ffff:ffff:ffff
18fc22:11::/32fc22:11:ffff:ffff:ffff:ffff:ffff:ffff
19fc22:12::/32fc22:12:ffff:ffff:ffff:ffff:ffff:ffff
20fc22:13::/32fc22:13:ffff:ffff:ffff:ffff:ffff:ffff
21fc22:14::/32fc22:14:ffff:ffff:ffff:ffff:ffff:ffff
22fc22:15::/32fc22:15:ffff:ffff:ffff:ffff:ffff:ffff
23fc22:16::/32fc22:16:ffff:ffff:ffff:ffff:ffff:ffff
24fc22:17::/32fc22:17:ffff:ffff:ffff:ffff:ffff:ffff
25fc22:18::/32fc22:18:ffff:ffff:ffff:ffff:ffff:ffff
26fc22:19::/32fc22:19:ffff:ffff:ffff:ffff:ffff:ffff
27fc22:1a::/32fc22:1a:ffff:ffff:ffff:ffff:ffff:ffff
28fc22:1b::/32fc22:1b:ffff:ffff:ffff:ffff:ffff:ffff
29fc22:1c::/32fc22:1c:ffff:ffff:ffff:ffff:ffff:ffff
30fc22:1d::/32fc22:1d:ffff:ffff:ffff:ffff:ffff:ffff
31fc22:1e::/32fc22:1e:ffff:ffff:ffff:ffff:ffff:ffff
32fc22:1f::/32fc22:1f:ffff:ffff:ffff:ffff:ffff:ffff
33fc22:20::/32fc22:20:ffff:ffff:ffff:ffff:ffff:ffff
34fc22:21::/32fc22:21:ffff:ffff:ffff:ffff:ffff:ffff
35fc22:22::/32fc22:22:ffff:ffff:ffff:ffff:ffff:ffff
36fc22:23::/32fc22:23:ffff:ffff:ffff:ffff:ffff:ffff
37fc22:24::/32fc22:24:ffff:ffff:ffff:ffff:ffff:ffff
38fc22:25::/32fc22:25:ffff:ffff:ffff:ffff:ffff:ffff
39fc22:26::/32fc22:26:ffff:ffff:ffff:ffff:ffff:ffff
40fc22:27::/32fc22:27:ffff:ffff:ffff:ffff:ffff:ffff
41fc22:28::/32fc22:28:ffff:ffff:ffff:ffff:ffff:ffff
42fc22:29::/32fc22:29:ffff:ffff:ffff:ffff:ffff:ffff
43fc22:2a::/32fc22:2a:ffff:ffff:ffff:ffff:ffff:ffff
44fc22:2b::/32fc22:2b:ffff:ffff:ffff:ffff:ffff:ffff
45fc22:2c::/32fc22:2c:ffff:ffff:ffff:ffff:ffff:ffff
46fc22:2d::/32fc22:2d:ffff:ffff:ffff:ffff:ffff:ffff
47fc22:2e::/32fc22:2e:ffff:ffff:ffff:ffff:ffff:ffff
48fc22:2f::/32fc22:2f:ffff:ffff:ffff:ffff:ffff:ffff
49fc22:30::/32fc22:30:ffff:ffff:ffff:ffff:ffff:ffff
50fc22:31::/32fc22:31:ffff:ffff:ffff:ffff:ffff:ffff
51fc22:32::/32fc22:32:ffff:ffff:ffff:ffff:ffff:ffff
52fc22:33::/32fc22:33:ffff:ffff:ffff:ffff:ffff:ffff
53fc22:34::/32fc22:34:ffff:ffff:ffff:ffff:ffff:ffff
54fc22:35::/32fc22:35:ffff:ffff:ffff:ffff:ffff:ffff
55fc22:36::/32fc22:36:ffff:ffff:ffff:ffff:ffff:ffff
56fc22:37::/32fc22:37:ffff:ffff:ffff:ffff:ffff:ffff
57fc22:38::/32fc22:38:ffff:ffff:ffff:ffff:ffff:ffff
58fc22:39::/32fc22:39:ffff:ffff:ffff:ffff:ffff:ffff
59fc22:3a::/32fc22:3a:ffff:ffff:ffff:ffff:ffff:ffff
60fc22:3b::/32fc22:3b:ffff:ffff:ffff:ffff:ffff:ffff
61fc22:3c::/32fc22:3c:ffff:ffff:ffff:ffff:ffff:ffff
62fc22:3d::/32fc22:3d:ffff:ffff:ffff:ffff:ffff:ffff
63fc22:3e::/32fc22:3e:ffff:ffff:ffff:ffff:ffff:ffff
64fc22:3f::/32fc22:3f:ffff:ffff:ffff:ffff:ffff:ffff
65fc22:40::/32fc22:40:ffff:ffff:ffff:ffff:ffff:ffff
66fc22:41::/32fc22:41:ffff:ffff:ffff:ffff:ffff:ffff
67fc22:42::/32fc22:42:ffff:ffff:ffff:ffff:ffff:ffff
68fc22:43::/32fc22:43:ffff:ffff:ffff:ffff:ffff:ffff
69fc22:44::/32fc22:44:ffff:ffff:ffff:ffff:ffff:ffff
70fc22:45::/32fc22:45:ffff:ffff:ffff:ffff:ffff:ffff
71fc22:46::/32fc22:46:ffff:ffff:ffff:ffff:ffff:ffff
72fc22:47::/32fc22:47:ffff:ffff:ffff:ffff:ffff:ffff
73fc22:48::/32fc22:48:ffff:ffff:ffff:ffff:ffff:ffff
74fc22:49::/32fc22:49:ffff:ffff:ffff:ffff:ffff:ffff
75fc22:4a::/32fc22:4a:ffff:ffff:ffff:ffff:ffff:ffff
76fc22:4b::/32fc22:4b:ffff:ffff:ffff:ffff:ffff:ffff
77fc22:4c::/32fc22:4c:ffff:ffff:ffff:ffff:ffff:ffff
78fc22:4d::/32fc22:4d:ffff:ffff:ffff:ffff:ffff:ffff
79fc22:4e::/32fc22:4e:ffff:ffff:ffff:ffff:ffff:ffff
80fc22:4f::/32fc22:4f:ffff:ffff:ffff:ffff:ffff:ffff
81fc22:50::/32fc22:50:ffff:ffff:ffff:ffff:ffff:ffff
82fc22:51::/32fc22:51:ffff:ffff:ffff:ffff:ffff:ffff
83fc22:52::/32fc22:52:ffff:ffff:ffff:ffff:ffff:ffff
84fc22:53::/32fc22:53:ffff:ffff:ffff:ffff:ffff:ffff
85fc22:54::/32fc22:54:ffff:ffff:ffff:ffff:ffff:ffff
86fc22:55::/32fc22:55:ffff:ffff:ffff:ffff:ffff:ffff
87fc22:56::/32fc22:56:ffff:ffff:ffff:ffff:ffff:ffff
88fc22:57::/32fc22:57:ffff:ffff:ffff:ffff:ffff:ffff
89fc22:58::/32fc22:58:ffff:ffff:ffff:ffff:ffff:ffff
90fc22:59::/32fc22:59:ffff:ffff:ffff:ffff:ffff:ffff
91fc22:5a::/32fc22:5a:ffff:ffff:ffff:ffff:ffff:ffff
92fc22:5b::/32fc22:5b:ffff:ffff:ffff:ffff:ffff:ffff
93fc22:5c::/32fc22:5c:ffff:ffff:ffff:ffff:ffff:ffff
94fc22:5d::/32fc22:5d:ffff:ffff:ffff:ffff:ffff:ffff
95fc22:5e::/32fc22:5e:ffff:ffff:ffff:ffff:ffff:ffff
96fc22:5f::/32fc22:5f:ffff:ffff:ffff:ffff:ffff:ffff
97fc22:60::/32fc22:60:ffff:ffff:ffff:ffff:ffff:ffff
98fc22:61::/32fc22:61:ffff:ffff:ffff:ffff:ffff:ffff
99fc22:62::/32fc22:62:ffff:ffff:ffff:ffff:ffff:ffff
100fc22:63::/32fc22:63:ffff:ffff:ffff:ffff:ffff:ffff
101fc22:64::/32fc22:64:ffff:ffff:ffff:ffff:ffff:ffff
102fc22:65::/32fc22:65:ffff:ffff:ffff:ffff:ffff:ffff
103fc22:66::/32fc22:66:ffff:ffff:ffff:ffff:ffff:ffff
104fc22:67::/32fc22:67:ffff:ffff:ffff:ffff:ffff:ffff
105fc22:68::/32fc22:68:ffff:ffff:ffff:ffff:ffff:ffff
106fc22:69::/32fc22:69:ffff:ffff:ffff:ffff:ffff:ffff
107fc22:6a::/32fc22:6a:ffff:ffff:ffff:ffff:ffff:ffff
108fc22:6b::/32fc22:6b:ffff:ffff:ffff:ffff:ffff:ffff
109fc22:6c::/32fc22:6c:ffff:ffff:ffff:ffff:ffff:ffff
110fc22:6d::/32fc22:6d:ffff:ffff:ffff:ffff:ffff:ffff
111fc22:6e::/32fc22:6e:ffff:ffff:ffff:ffff:ffff:ffff
112fc22:6f::/32fc22:6f:ffff:ffff:ffff:ffff:ffff:ffff
113fc22:70::/32fc22:70:ffff:ffff:ffff:ffff:ffff:ffff
114fc22:71::/32fc22:71:ffff:ffff:ffff:ffff:ffff:ffff
115fc22:72::/32fc22:72:ffff:ffff:ffff:ffff:ffff:ffff
116fc22:73::/32fc22:73:ffff:ffff:ffff:ffff:ffff:ffff
117fc22:74::/32fc22:74:ffff:ffff:ffff:ffff:ffff:ffff
118fc22:75::/32fc22:75:ffff:ffff:ffff:ffff:ffff:ffff
119fc22:76::/32fc22:76:ffff:ffff:ffff:ffff:ffff:ffff
120fc22:77::/32fc22:77:ffff:ffff:ffff:ffff:ffff:ffff
121fc22:78::/32fc22:78:ffff:ffff:ffff:ffff:ffff:ffff
122fc22:79::/32fc22:79:ffff:ffff:ffff:ffff:ffff:ffff
123fc22:7a::/32fc22:7a:ffff:ffff:ffff:ffff:ffff:ffff
124fc22:7b::/32fc22:7b:ffff:ffff:ffff:ffff:ffff:ffff
125fc22:7c::/32fc22:7c:ffff:ffff:ffff:ffff:ffff:ffff
126fc22:7d::/32fc22:7d:ffff:ffff:ffff:ffff:ffff:ffff
127fc22:7e::/32fc22:7e:ffff:ffff:ffff:ffff:ffff:ffff
128fc22:7f::/32fc22:7f:ffff:ffff:ffff:ffff:ffff:ffff
129fc22:80::/32fc22:80:ffff:ffff:ffff:ffff:ffff:ffff
130fc22:81::/32fc22:81:ffff:ffff:ffff:ffff:ffff:ffff
131fc22:82::/32fc22:82:ffff:ffff:ffff:ffff:ffff:ffff
132fc22:83::/32fc22:83:ffff:ffff:ffff:ffff:ffff:ffff
133fc22:84::/32fc22:84:ffff:ffff:ffff:ffff:ffff:ffff
134fc22:85::/32fc22:85:ffff:ffff:ffff:ffff:ffff:ffff
135fc22:86::/32fc22:86:ffff:ffff:ffff:ffff:ffff:ffff
136fc22:87::/32fc22:87:ffff:ffff:ffff:ffff:ffff:ffff
137fc22:88::/32fc22:88:ffff:ffff:ffff:ffff:ffff:ffff
138fc22:89::/32fc22:89:ffff:ffff:ffff:ffff:ffff:ffff
139fc22:8a::/32fc22:8a:ffff:ffff:ffff:ffff:ffff:ffff
140fc22:8b::/32fc22:8b:ffff:ffff:ffff:ffff:ffff:ffff
141fc22:8c::/32fc22:8c:ffff:ffff:ffff:ffff:ffff:ffff
142fc22:8d::/32fc22:8d:ffff:ffff:ffff:ffff:ffff:ffff
143fc22:8e::/32fc22:8e:ffff:ffff:ffff:ffff:ffff:ffff
144fc22:8f::/32fc22:8f:ffff:ffff:ffff:ffff:ffff:ffff
145fc22:90::/32fc22:90:ffff:ffff:ffff:ffff:ffff:ffff
146fc22:91::/32fc22:91:ffff:ffff:ffff:ffff:ffff:ffff
147fc22:92::/32fc22:92:ffff:ffff:ffff:ffff:ffff:ffff
148fc22:93::/32fc22:93:ffff:ffff:ffff:ffff:ffff:ffff
149fc22:94::/32fc22:94:ffff:ffff:ffff:ffff:ffff:ffff
150fc22:95::/32fc22:95:ffff:ffff:ffff:ffff:ffff:ffff
151fc22:96::/32fc22:96:ffff:ffff:ffff:ffff:ffff:ffff
152fc22:97::/32fc22:97:ffff:ffff:ffff:ffff:ffff:ffff
153fc22:98::/32fc22:98:ffff:ffff:ffff:ffff:ffff:ffff
154fc22:99::/32fc22:99:ffff:ffff:ffff:ffff:ffff:ffff
155fc22:9a::/32fc22:9a:ffff:ffff:ffff:ffff:ffff:ffff
156fc22:9b::/32fc22:9b:ffff:ffff:ffff:ffff:ffff:ffff
157fc22:9c::/32fc22:9c:ffff:ffff:ffff:ffff:ffff:ffff
158fc22:9d::/32fc22:9d:ffff:ffff:ffff:ffff:ffff:ffff
159fc22:9e::/32fc22:9e:ffff:ffff:ffff:ffff:ffff:ffff
160fc22:9f::/32fc22:9f:ffff:ffff:ffff:ffff:ffff:ffff
161fc22:a0::/32fc22:a0:ffff:ffff:ffff:ffff:ffff:ffff
162fc22:a1::/32fc22:a1:ffff:ffff:ffff:ffff:ffff:ffff
163fc22:a2::/32fc22:a2:ffff:ffff:ffff:ffff:ffff:ffff
164fc22:a3::/32fc22:a3:ffff:ffff:ffff:ffff:ffff:ffff
165fc22:a4::/32fc22:a4:ffff:ffff:ffff:ffff:ffff:ffff
166fc22:a5::/32fc22:a5:ffff:ffff:ffff:ffff:ffff:ffff
167fc22:a6::/32fc22:a6:ffff:ffff:ffff:ffff:ffff:ffff
168fc22:a7::/32fc22:a7:ffff:ffff:ffff:ffff:ffff:ffff
169fc22:a8::/32fc22:a8:ffff:ffff:ffff:ffff:ffff:ffff
170fc22:a9::/32fc22:a9:ffff:ffff:ffff:ffff:ffff:ffff
171fc22:aa::/32fc22:aa:ffff:ffff:ffff:ffff:ffff:ffff
172fc22:ab::/32fc22:ab:ffff:ffff:ffff:ffff:ffff:ffff
173fc22:ac::/32fc22:ac:ffff:ffff:ffff:ffff:ffff:ffff
174fc22:ad::/32fc22:ad:ffff:ffff:ffff:ffff:ffff:ffff
175fc22:ae::/32fc22:ae:ffff:ffff:ffff:ffff:ffff:ffff
176fc22:af::/32fc22:af:ffff:ffff:ffff:ffff:ffff:ffff
177fc22:b0::/32fc22:b0:ffff:ffff:ffff:ffff:ffff:ffff
178fc22:b1::/32fc22:b1:ffff:ffff:ffff:ffff:ffff:ffff
179fc22:b2::/32fc22:b2:ffff:ffff:ffff:ffff:ffff:ffff
180fc22:b3::/32fc22:b3:ffff:ffff:ffff:ffff:ffff:ffff
181fc22:b4::/32fc22:b4:ffff:ffff:ffff:ffff:ffff:ffff
182fc22:b5::/32fc22:b5:ffff:ffff:ffff:ffff:ffff:ffff
183fc22:b6::/32fc22:b6:ffff:ffff:ffff:ffff:ffff:ffff
184fc22:b7::/32fc22:b7:ffff:ffff:ffff:ffff:ffff:ffff
185fc22:b8::/32fc22:b8:ffff:ffff:ffff:ffff:ffff:ffff
186fc22:b9::/32fc22:b9:ffff:ffff:ffff:ffff:ffff:ffff
187fc22:ba::/32fc22:ba:ffff:ffff:ffff:ffff:ffff:ffff
188fc22:bb::/32fc22:bb:ffff:ffff:ffff:ffff:ffff:ffff
189fc22:bc::/32fc22:bc:ffff:ffff:ffff:ffff:ffff:ffff
190fc22:bd::/32fc22:bd:ffff:ffff:ffff:ffff:ffff:ffff
191fc22:be::/32fc22:be:ffff:ffff:ffff:ffff:ffff:ffff
192fc22:bf::/32fc22:bf:ffff:ffff:ffff:ffff:ffff:ffff
193fc22:c0::/32fc22:c0:ffff:ffff:ffff:ffff:ffff:ffff
194fc22:c1::/32fc22:c1:ffff:ffff:ffff:ffff:ffff:ffff
195fc22:c2::/32fc22:c2:ffff:ffff:ffff:ffff:ffff:ffff
196fc22:c3::/32fc22:c3:ffff:ffff:ffff:ffff:ffff:ffff
197fc22:c4::/32fc22:c4:ffff:ffff:ffff:ffff:ffff:ffff
198fc22:c5::/32fc22:c5:ffff:ffff:ffff:ffff:ffff:ffff
199fc22:c6::/32fc22:c6:ffff:ffff:ffff:ffff:ffff:ffff
200fc22:c7::/32fc22:c7:ffff:ffff:ffff:ffff:ffff:ffff
201fc22:c8::/32fc22:c8:ffff:ffff:ffff:ffff:ffff:ffff
202fc22:c9::/32fc22:c9:ffff:ffff:ffff:ffff:ffff:ffff
203fc22:ca::/32fc22:ca:ffff:ffff:ffff:ffff:ffff:ffff
204fc22:cb::/32fc22:cb:ffff:ffff:ffff:ffff:ffff:ffff
205fc22:cc::/32fc22:cc:ffff:ffff:ffff:ffff:ffff:ffff
206fc22:cd::/32fc22:cd:ffff:ffff:ffff:ffff:ffff:ffff
207fc22:ce::/32fc22:ce:ffff:ffff:ffff:ffff:ffff:ffff
208fc22:cf::/32fc22:cf:ffff:ffff:ffff:ffff:ffff:ffff
209fc22:d0::/32fc22:d0:ffff:ffff:ffff:ffff:ffff:ffff
210fc22:d1::/32fc22:d1:ffff:ffff:ffff:ffff:ffff:ffff
211fc22:d2::/32fc22:d2:ffff:ffff:ffff:ffff:ffff:ffff
212fc22:d3::/32fc22:d3:ffff:ffff:ffff:ffff:ffff:ffff
213fc22:d4::/32fc22:d4:ffff:ffff:ffff:ffff:ffff:ffff
214fc22:d5::/32fc22:d5:ffff:ffff:ffff:ffff:ffff:ffff
215fc22:d6::/32fc22:d6:ffff:ffff:ffff:ffff:ffff:ffff
216fc22:d7::/32fc22:d7:ffff:ffff:ffff:ffff:ffff:ffff
217fc22:d8::/32fc22:d8:ffff:ffff:ffff:ffff:ffff:ffff
218fc22:d9::/32fc22:d9:ffff:ffff:ffff:ffff:ffff:ffff
219fc22:da::/32fc22:da:ffff:ffff:ffff:ffff:ffff:ffff
220fc22:db::/32fc22:db:ffff:ffff:ffff:ffff:ffff:ffff
221fc22:dc::/32fc22:dc:ffff:ffff:ffff:ffff:ffff:ffff
222fc22:dd::/32fc22:dd:ffff:ffff:ffff:ffff:ffff:ffff
223fc22:de::/32fc22:de:ffff:ffff:ffff:ffff:ffff:ffff
224fc22:df::/32fc22:df:ffff:ffff:ffff:ffff:ffff:ffff
225fc22:e0::/32fc22:e0:ffff:ffff:ffff:ffff:ffff:ffff
226fc22:e1::/32fc22:e1:ffff:ffff:ffff:ffff:ffff:ffff
227fc22:e2::/32fc22:e2:ffff:ffff:ffff:ffff:ffff:ffff
228fc22:e3::/32fc22:e3:ffff:ffff:ffff:ffff:ffff:ffff
229fc22:e4::/32fc22:e4:ffff:ffff:ffff:ffff:ffff:ffff
230fc22:e5::/32fc22:e5:ffff:ffff:ffff:ffff:ffff:ffff
231fc22:e6::/32fc22:e6:ffff:ffff:ffff:ffff:ffff:ffff
232fc22:e7::/32fc22:e7:ffff:ffff:ffff:ffff:ffff:ffff
233fc22:e8::/32fc22:e8:ffff:ffff:ffff:ffff:ffff:ffff
234fc22:e9::/32fc22:e9:ffff:ffff:ffff:ffff:ffff:ffff
235fc22:ea::/32fc22:ea:ffff:ffff:ffff:ffff:ffff:ffff
236fc22:eb::/32fc22:eb:ffff:ffff:ffff:ffff:ffff:ffff
237fc22:ec::/32fc22:ec:ffff:ffff:ffff:ffff:ffff:ffff
238fc22:ed::/32fc22:ed:ffff:ffff:ffff:ffff:ffff:ffff
239fc22:ee::/32fc22:ee:ffff:ffff:ffff:ffff:ffff:ffff
240fc22:ef::/32fc22:ef:ffff:ffff:ffff:ffff:ffff:ffff
241fc22:f0::/32fc22:f0:ffff:ffff:ffff:ffff:ffff:ffff
242fc22:f1::/32fc22:f1:ffff:ffff:ffff:ffff:ffff:ffff
243fc22:f2::/32fc22:f2:ffff:ffff:ffff:ffff:ffff:ffff
244fc22:f3::/32fc22:f3:ffff:ffff:ffff:ffff:ffff:ffff
245fc22:f4::/32fc22:f4:ffff:ffff:ffff:ffff:ffff:ffff
246fc22:f5::/32fc22:f5:ffff:ffff:ffff:ffff:ffff:ffff
247fc22:f6::/32fc22:f6:ffff:ffff:ffff:ffff:ffff:ffff
248fc22:f7::/32fc22:f7:ffff:ffff:ffff:ffff:ffff:ffff
249fc22:f8::/32fc22:f8:ffff:ffff:ffff:ffff:ffff:ffff
250fc22:f9::/32fc22:f9:ffff:ffff:ffff:ffff:ffff:ffff
251fc22:fa::/32fc22:fa:ffff:ffff:ffff:ffff:ffff:ffff
252fc22:fb::/32fc22:fb:ffff:ffff:ffff:ffff:ffff:ffff
253fc22:fc::/32fc22:fc:ffff:ffff:ffff:ffff:ffff:ffff
254fc22:fd::/32fc22:fd:ffff:ffff:ffff:ffff:ffff:ffff
255fc22:fe::/32fc22:fe:ffff:ffff:ffff:ffff:ffff:ffff
256fc22:ff::/32fc22: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.