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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
fc7a::/16
First address
fc7a::
Last address
fc7a: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
fc7a:0000:0000:0000:0000:0000:0000:0000
Type
Unique local (ULA) fc00::/7
Private IPv6, like RFC 1918; usually fd00::/8
Reverse DNS zone
a.7.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)

fc7a::/16 makes 65,536 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
1fc7a::/32fc7a:0:ffff:ffff:ffff:ffff:ffff:ffff
2fc7a:1::/32fc7a:1:ffff:ffff:ffff:ffff:ffff:ffff
3fc7a:2::/32fc7a:2:ffff:ffff:ffff:ffff:ffff:ffff
4fc7a:3::/32fc7a:3:ffff:ffff:ffff:ffff:ffff:ffff
5fc7a:4::/32fc7a:4:ffff:ffff:ffff:ffff:ffff:ffff
6fc7a:5::/32fc7a:5:ffff:ffff:ffff:ffff:ffff:ffff
7fc7a:6::/32fc7a:6:ffff:ffff:ffff:ffff:ffff:ffff
8fc7a:7::/32fc7a:7:ffff:ffff:ffff:ffff:ffff:ffff
9fc7a:8::/32fc7a:8:ffff:ffff:ffff:ffff:ffff:ffff
10fc7a:9::/32fc7a:9:ffff:ffff:ffff:ffff:ffff:ffff
11fc7a:a::/32fc7a:a:ffff:ffff:ffff:ffff:ffff:ffff
12fc7a:b::/32fc7a:b:ffff:ffff:ffff:ffff:ffff:ffff
13fc7a:c::/32fc7a:c:ffff:ffff:ffff:ffff:ffff:ffff
14fc7a:d::/32fc7a:d:ffff:ffff:ffff:ffff:ffff:ffff
15fc7a:e::/32fc7a:e:ffff:ffff:ffff:ffff:ffff:ffff
16fc7a:f::/32fc7a:f:ffff:ffff:ffff:ffff:ffff:ffff
17fc7a:10::/32fc7a:10:ffff:ffff:ffff:ffff:ffff:ffff
18fc7a:11::/32fc7a:11:ffff:ffff:ffff:ffff:ffff:ffff
19fc7a:12::/32fc7a:12:ffff:ffff:ffff:ffff:ffff:ffff
20fc7a:13::/32fc7a:13:ffff:ffff:ffff:ffff:ffff:ffff
21fc7a:14::/32fc7a:14:ffff:ffff:ffff:ffff:ffff:ffff
22fc7a:15::/32fc7a:15:ffff:ffff:ffff:ffff:ffff:ffff
23fc7a:16::/32fc7a:16:ffff:ffff:ffff:ffff:ffff:ffff
24fc7a:17::/32fc7a:17:ffff:ffff:ffff:ffff:ffff:ffff
25fc7a:18::/32fc7a:18:ffff:ffff:ffff:ffff:ffff:ffff
26fc7a:19::/32fc7a:19:ffff:ffff:ffff:ffff:ffff:ffff
27fc7a:1a::/32fc7a:1a:ffff:ffff:ffff:ffff:ffff:ffff
28fc7a:1b::/32fc7a:1b:ffff:ffff:ffff:ffff:ffff:ffff
29fc7a:1c::/32fc7a:1c:ffff:ffff:ffff:ffff:ffff:ffff
30fc7a:1d::/32fc7a:1d:ffff:ffff:ffff:ffff:ffff:ffff
31fc7a:1e::/32fc7a:1e:ffff:ffff:ffff:ffff:ffff:ffff
32fc7a:1f::/32fc7a:1f:ffff:ffff:ffff:ffff:ffff:ffff
33fc7a:20::/32fc7a:20:ffff:ffff:ffff:ffff:ffff:ffff
34fc7a:21::/32fc7a:21:ffff:ffff:ffff:ffff:ffff:ffff
35fc7a:22::/32fc7a:22:ffff:ffff:ffff:ffff:ffff:ffff
36fc7a:23::/32fc7a:23:ffff:ffff:ffff:ffff:ffff:ffff
37fc7a:24::/32fc7a:24:ffff:ffff:ffff:ffff:ffff:ffff
38fc7a:25::/32fc7a:25:ffff:ffff:ffff:ffff:ffff:ffff
39fc7a:26::/32fc7a:26:ffff:ffff:ffff:ffff:ffff:ffff
40fc7a:27::/32fc7a:27:ffff:ffff:ffff:ffff:ffff:ffff
41fc7a:28::/32fc7a:28:ffff:ffff:ffff:ffff:ffff:ffff
42fc7a:29::/32fc7a:29:ffff:ffff:ffff:ffff:ffff:ffff
43fc7a:2a::/32fc7a:2a:ffff:ffff:ffff:ffff:ffff:ffff
44fc7a:2b::/32fc7a:2b:ffff:ffff:ffff:ffff:ffff:ffff
45fc7a:2c::/32fc7a:2c:ffff:ffff:ffff:ffff:ffff:ffff
46fc7a:2d::/32fc7a:2d:ffff:ffff:ffff:ffff:ffff:ffff
47fc7a:2e::/32fc7a:2e:ffff:ffff:ffff:ffff:ffff:ffff
48fc7a:2f::/32fc7a:2f:ffff:ffff:ffff:ffff:ffff:ffff
49fc7a:30::/32fc7a:30:ffff:ffff:ffff:ffff:ffff:ffff
50fc7a:31::/32fc7a:31:ffff:ffff:ffff:ffff:ffff:ffff
51fc7a:32::/32fc7a:32:ffff:ffff:ffff:ffff:ffff:ffff
52fc7a:33::/32fc7a:33:ffff:ffff:ffff:ffff:ffff:ffff
53fc7a:34::/32fc7a:34:ffff:ffff:ffff:ffff:ffff:ffff
54fc7a:35::/32fc7a:35:ffff:ffff:ffff:ffff:ffff:ffff
55fc7a:36::/32fc7a:36:ffff:ffff:ffff:ffff:ffff:ffff
56fc7a:37::/32fc7a:37:ffff:ffff:ffff:ffff:ffff:ffff
57fc7a:38::/32fc7a:38:ffff:ffff:ffff:ffff:ffff:ffff
58fc7a:39::/32fc7a:39:ffff:ffff:ffff:ffff:ffff:ffff
59fc7a:3a::/32fc7a:3a:ffff:ffff:ffff:ffff:ffff:ffff
60fc7a:3b::/32fc7a:3b:ffff:ffff:ffff:ffff:ffff:ffff
61fc7a:3c::/32fc7a:3c:ffff:ffff:ffff:ffff:ffff:ffff
62fc7a:3d::/32fc7a:3d:ffff:ffff:ffff:ffff:ffff:ffff
63fc7a:3e::/32fc7a:3e:ffff:ffff:ffff:ffff:ffff:ffff
64fc7a:3f::/32fc7a:3f:ffff:ffff:ffff:ffff:ffff:ffff
65fc7a:40::/32fc7a:40:ffff:ffff:ffff:ffff:ffff:ffff
66fc7a:41::/32fc7a:41:ffff:ffff:ffff:ffff:ffff:ffff
67fc7a:42::/32fc7a:42:ffff:ffff:ffff:ffff:ffff:ffff
68fc7a:43::/32fc7a:43:ffff:ffff:ffff:ffff:ffff:ffff
69fc7a:44::/32fc7a:44:ffff:ffff:ffff:ffff:ffff:ffff
70fc7a:45::/32fc7a:45:ffff:ffff:ffff:ffff:ffff:ffff
71fc7a:46::/32fc7a:46:ffff:ffff:ffff:ffff:ffff:ffff
72fc7a:47::/32fc7a:47:ffff:ffff:ffff:ffff:ffff:ffff
73fc7a:48::/32fc7a:48:ffff:ffff:ffff:ffff:ffff:ffff
74fc7a:49::/32fc7a:49:ffff:ffff:ffff:ffff:ffff:ffff
75fc7a:4a::/32fc7a:4a:ffff:ffff:ffff:ffff:ffff:ffff
76fc7a:4b::/32fc7a:4b:ffff:ffff:ffff:ffff:ffff:ffff
77fc7a:4c::/32fc7a:4c:ffff:ffff:ffff:ffff:ffff:ffff
78fc7a:4d::/32fc7a:4d:ffff:ffff:ffff:ffff:ffff:ffff
79fc7a:4e::/32fc7a:4e:ffff:ffff:ffff:ffff:ffff:ffff
80fc7a:4f::/32fc7a:4f:ffff:ffff:ffff:ffff:ffff:ffff
81fc7a:50::/32fc7a:50:ffff:ffff:ffff:ffff:ffff:ffff
82fc7a:51::/32fc7a:51:ffff:ffff:ffff:ffff:ffff:ffff
83fc7a:52::/32fc7a:52:ffff:ffff:ffff:ffff:ffff:ffff
84fc7a:53::/32fc7a:53:ffff:ffff:ffff:ffff:ffff:ffff
85fc7a:54::/32fc7a:54:ffff:ffff:ffff:ffff:ffff:ffff
86fc7a:55::/32fc7a:55:ffff:ffff:ffff:ffff:ffff:ffff
87fc7a:56::/32fc7a:56:ffff:ffff:ffff:ffff:ffff:ffff
88fc7a:57::/32fc7a:57:ffff:ffff:ffff:ffff:ffff:ffff
89fc7a:58::/32fc7a:58:ffff:ffff:ffff:ffff:ffff:ffff
90fc7a:59::/32fc7a:59:ffff:ffff:ffff:ffff:ffff:ffff
91fc7a:5a::/32fc7a:5a:ffff:ffff:ffff:ffff:ffff:ffff
92fc7a:5b::/32fc7a:5b:ffff:ffff:ffff:ffff:ffff:ffff
93fc7a:5c::/32fc7a:5c:ffff:ffff:ffff:ffff:ffff:ffff
94fc7a:5d::/32fc7a:5d:ffff:ffff:ffff:ffff:ffff:ffff
95fc7a:5e::/32fc7a:5e:ffff:ffff:ffff:ffff:ffff:ffff
96fc7a:5f::/32fc7a:5f:ffff:ffff:ffff:ffff:ffff:ffff
97fc7a:60::/32fc7a:60:ffff:ffff:ffff:ffff:ffff:ffff
98fc7a:61::/32fc7a:61:ffff:ffff:ffff:ffff:ffff:ffff
99fc7a:62::/32fc7a:62:ffff:ffff:ffff:ffff:ffff:ffff
100fc7a:63::/32fc7a:63:ffff:ffff:ffff:ffff:ffff:ffff
101fc7a:64::/32fc7a:64:ffff:ffff:ffff:ffff:ffff:ffff
102fc7a:65::/32fc7a:65:ffff:ffff:ffff:ffff:ffff:ffff
103fc7a:66::/32fc7a:66:ffff:ffff:ffff:ffff:ffff:ffff
104fc7a:67::/32fc7a:67:ffff:ffff:ffff:ffff:ffff:ffff
105fc7a:68::/32fc7a:68:ffff:ffff:ffff:ffff:ffff:ffff
106fc7a:69::/32fc7a:69:ffff:ffff:ffff:ffff:ffff:ffff
107fc7a:6a::/32fc7a:6a:ffff:ffff:ffff:ffff:ffff:ffff
108fc7a:6b::/32fc7a:6b:ffff:ffff:ffff:ffff:ffff:ffff
109fc7a:6c::/32fc7a:6c:ffff:ffff:ffff:ffff:ffff:ffff
110fc7a:6d::/32fc7a:6d:ffff:ffff:ffff:ffff:ffff:ffff
111fc7a:6e::/32fc7a:6e:ffff:ffff:ffff:ffff:ffff:ffff
112fc7a:6f::/32fc7a:6f:ffff:ffff:ffff:ffff:ffff:ffff
113fc7a:70::/32fc7a:70:ffff:ffff:ffff:ffff:ffff:ffff
114fc7a:71::/32fc7a:71:ffff:ffff:ffff:ffff:ffff:ffff
115fc7a:72::/32fc7a:72:ffff:ffff:ffff:ffff:ffff:ffff
116fc7a:73::/32fc7a:73:ffff:ffff:ffff:ffff:ffff:ffff
117fc7a:74::/32fc7a:74:ffff:ffff:ffff:ffff:ffff:ffff
118fc7a:75::/32fc7a:75:ffff:ffff:ffff:ffff:ffff:ffff
119fc7a:76::/32fc7a:76:ffff:ffff:ffff:ffff:ffff:ffff
120fc7a:77::/32fc7a:77:ffff:ffff:ffff:ffff:ffff:ffff
121fc7a:78::/32fc7a:78:ffff:ffff:ffff:ffff:ffff:ffff
122fc7a:79::/32fc7a:79:ffff:ffff:ffff:ffff:ffff:ffff
123fc7a:7a::/32fc7a:7a:ffff:ffff:ffff:ffff:ffff:ffff
124fc7a:7b::/32fc7a:7b:ffff:ffff:ffff:ffff:ffff:ffff
125fc7a:7c::/32fc7a:7c:ffff:ffff:ffff:ffff:ffff:ffff
126fc7a:7d::/32fc7a:7d:ffff:ffff:ffff:ffff:ffff:ffff
127fc7a:7e::/32fc7a:7e:ffff:ffff:ffff:ffff:ffff:ffff
128fc7a:7f::/32fc7a:7f:ffff:ffff:ffff:ffff:ffff:ffff
129fc7a:80::/32fc7a:80:ffff:ffff:ffff:ffff:ffff:ffff
130fc7a:81::/32fc7a:81:ffff:ffff:ffff:ffff:ffff:ffff
131fc7a:82::/32fc7a:82:ffff:ffff:ffff:ffff:ffff:ffff
132fc7a:83::/32fc7a:83:ffff:ffff:ffff:ffff:ffff:ffff
133fc7a:84::/32fc7a:84:ffff:ffff:ffff:ffff:ffff:ffff
134fc7a:85::/32fc7a:85:ffff:ffff:ffff:ffff:ffff:ffff
135fc7a:86::/32fc7a:86:ffff:ffff:ffff:ffff:ffff:ffff
136fc7a:87::/32fc7a:87:ffff:ffff:ffff:ffff:ffff:ffff
137fc7a:88::/32fc7a:88:ffff:ffff:ffff:ffff:ffff:ffff
138fc7a:89::/32fc7a:89:ffff:ffff:ffff:ffff:ffff:ffff
139fc7a:8a::/32fc7a:8a:ffff:ffff:ffff:ffff:ffff:ffff
140fc7a:8b::/32fc7a:8b:ffff:ffff:ffff:ffff:ffff:ffff
141fc7a:8c::/32fc7a:8c:ffff:ffff:ffff:ffff:ffff:ffff
142fc7a:8d::/32fc7a:8d:ffff:ffff:ffff:ffff:ffff:ffff
143fc7a:8e::/32fc7a:8e:ffff:ffff:ffff:ffff:ffff:ffff
144fc7a:8f::/32fc7a:8f:ffff:ffff:ffff:ffff:ffff:ffff
145fc7a:90::/32fc7a:90:ffff:ffff:ffff:ffff:ffff:ffff
146fc7a:91::/32fc7a:91:ffff:ffff:ffff:ffff:ffff:ffff
147fc7a:92::/32fc7a:92:ffff:ffff:ffff:ffff:ffff:ffff
148fc7a:93::/32fc7a:93:ffff:ffff:ffff:ffff:ffff:ffff
149fc7a:94::/32fc7a:94:ffff:ffff:ffff:ffff:ffff:ffff
150fc7a:95::/32fc7a:95:ffff:ffff:ffff:ffff:ffff:ffff
151fc7a:96::/32fc7a:96:ffff:ffff:ffff:ffff:ffff:ffff
152fc7a:97::/32fc7a:97:ffff:ffff:ffff:ffff:ffff:ffff
153fc7a:98::/32fc7a:98:ffff:ffff:ffff:ffff:ffff:ffff
154fc7a:99::/32fc7a:99:ffff:ffff:ffff:ffff:ffff:ffff
155fc7a:9a::/32fc7a:9a:ffff:ffff:ffff:ffff:ffff:ffff
156fc7a:9b::/32fc7a:9b:ffff:ffff:ffff:ffff:ffff:ffff
157fc7a:9c::/32fc7a:9c:ffff:ffff:ffff:ffff:ffff:ffff
158fc7a:9d::/32fc7a:9d:ffff:ffff:ffff:ffff:ffff:ffff
159fc7a:9e::/32fc7a:9e:ffff:ffff:ffff:ffff:ffff:ffff
160fc7a:9f::/32fc7a:9f:ffff:ffff:ffff:ffff:ffff:ffff
161fc7a:a0::/32fc7a:a0:ffff:ffff:ffff:ffff:ffff:ffff
162fc7a:a1::/32fc7a:a1:ffff:ffff:ffff:ffff:ffff:ffff
163fc7a:a2::/32fc7a:a2:ffff:ffff:ffff:ffff:ffff:ffff
164fc7a:a3::/32fc7a:a3:ffff:ffff:ffff:ffff:ffff:ffff
165fc7a:a4::/32fc7a:a4:ffff:ffff:ffff:ffff:ffff:ffff
166fc7a:a5::/32fc7a:a5:ffff:ffff:ffff:ffff:ffff:ffff
167fc7a:a6::/32fc7a:a6:ffff:ffff:ffff:ffff:ffff:ffff
168fc7a:a7::/32fc7a:a7:ffff:ffff:ffff:ffff:ffff:ffff
169fc7a:a8::/32fc7a:a8:ffff:ffff:ffff:ffff:ffff:ffff
170fc7a:a9::/32fc7a:a9:ffff:ffff:ffff:ffff:ffff:ffff
171fc7a:aa::/32fc7a:aa:ffff:ffff:ffff:ffff:ffff:ffff
172fc7a:ab::/32fc7a:ab:ffff:ffff:ffff:ffff:ffff:ffff
173fc7a:ac::/32fc7a:ac:ffff:ffff:ffff:ffff:ffff:ffff
174fc7a:ad::/32fc7a:ad:ffff:ffff:ffff:ffff:ffff:ffff
175fc7a:ae::/32fc7a:ae:ffff:ffff:ffff:ffff:ffff:ffff
176fc7a:af::/32fc7a:af:ffff:ffff:ffff:ffff:ffff:ffff
177fc7a:b0::/32fc7a:b0:ffff:ffff:ffff:ffff:ffff:ffff
178fc7a:b1::/32fc7a:b1:ffff:ffff:ffff:ffff:ffff:ffff
179fc7a:b2::/32fc7a:b2:ffff:ffff:ffff:ffff:ffff:ffff
180fc7a:b3::/32fc7a:b3:ffff:ffff:ffff:ffff:ffff:ffff
181fc7a:b4::/32fc7a:b4:ffff:ffff:ffff:ffff:ffff:ffff
182fc7a:b5::/32fc7a:b5:ffff:ffff:ffff:ffff:ffff:ffff
183fc7a:b6::/32fc7a:b6:ffff:ffff:ffff:ffff:ffff:ffff
184fc7a:b7::/32fc7a:b7:ffff:ffff:ffff:ffff:ffff:ffff
185fc7a:b8::/32fc7a:b8:ffff:ffff:ffff:ffff:ffff:ffff
186fc7a:b9::/32fc7a:b9:ffff:ffff:ffff:ffff:ffff:ffff
187fc7a:ba::/32fc7a:ba:ffff:ffff:ffff:ffff:ffff:ffff
188fc7a:bb::/32fc7a:bb:ffff:ffff:ffff:ffff:ffff:ffff
189fc7a:bc::/32fc7a:bc:ffff:ffff:ffff:ffff:ffff:ffff
190fc7a:bd::/32fc7a:bd:ffff:ffff:ffff:ffff:ffff:ffff
191fc7a:be::/32fc7a:be:ffff:ffff:ffff:ffff:ffff:ffff
192fc7a:bf::/32fc7a:bf:ffff:ffff:ffff:ffff:ffff:ffff
193fc7a:c0::/32fc7a:c0:ffff:ffff:ffff:ffff:ffff:ffff
194fc7a:c1::/32fc7a:c1:ffff:ffff:ffff:ffff:ffff:ffff
195fc7a:c2::/32fc7a:c2:ffff:ffff:ffff:ffff:ffff:ffff
196fc7a:c3::/32fc7a:c3:ffff:ffff:ffff:ffff:ffff:ffff
197fc7a:c4::/32fc7a:c4:ffff:ffff:ffff:ffff:ffff:ffff
198fc7a:c5::/32fc7a:c5:ffff:ffff:ffff:ffff:ffff:ffff
199fc7a:c6::/32fc7a:c6:ffff:ffff:ffff:ffff:ffff:ffff
200fc7a:c7::/32fc7a:c7:ffff:ffff:ffff:ffff:ffff:ffff
201fc7a:c8::/32fc7a:c8:ffff:ffff:ffff:ffff:ffff:ffff
202fc7a:c9::/32fc7a:c9:ffff:ffff:ffff:ffff:ffff:ffff
203fc7a:ca::/32fc7a:ca:ffff:ffff:ffff:ffff:ffff:ffff
204fc7a:cb::/32fc7a:cb:ffff:ffff:ffff:ffff:ffff:ffff
205fc7a:cc::/32fc7a:cc:ffff:ffff:ffff:ffff:ffff:ffff
206fc7a:cd::/32fc7a:cd:ffff:ffff:ffff:ffff:ffff:ffff
207fc7a:ce::/32fc7a:ce:ffff:ffff:ffff:ffff:ffff:ffff
208fc7a:cf::/32fc7a:cf:ffff:ffff:ffff:ffff:ffff:ffff
209fc7a:d0::/32fc7a:d0:ffff:ffff:ffff:ffff:ffff:ffff
210fc7a:d1::/32fc7a:d1:ffff:ffff:ffff:ffff:ffff:ffff
211fc7a:d2::/32fc7a:d2:ffff:ffff:ffff:ffff:ffff:ffff
212fc7a:d3::/32fc7a:d3:ffff:ffff:ffff:ffff:ffff:ffff
213fc7a:d4::/32fc7a:d4:ffff:ffff:ffff:ffff:ffff:ffff
214fc7a:d5::/32fc7a:d5:ffff:ffff:ffff:ffff:ffff:ffff
215fc7a:d6::/32fc7a:d6:ffff:ffff:ffff:ffff:ffff:ffff
216fc7a:d7::/32fc7a:d7:ffff:ffff:ffff:ffff:ffff:ffff
217fc7a:d8::/32fc7a:d8:ffff:ffff:ffff:ffff:ffff:ffff
218fc7a:d9::/32fc7a:d9:ffff:ffff:ffff:ffff:ffff:ffff
219fc7a:da::/32fc7a:da:ffff:ffff:ffff:ffff:ffff:ffff
220fc7a:db::/32fc7a:db:ffff:ffff:ffff:ffff:ffff:ffff
221fc7a:dc::/32fc7a:dc:ffff:ffff:ffff:ffff:ffff:ffff
222fc7a:dd::/32fc7a:dd:ffff:ffff:ffff:ffff:ffff:ffff
223fc7a:de::/32fc7a:de:ffff:ffff:ffff:ffff:ffff:ffff
224fc7a:df::/32fc7a:df:ffff:ffff:ffff:ffff:ffff:ffff
225fc7a:e0::/32fc7a:e0:ffff:ffff:ffff:ffff:ffff:ffff
226fc7a:e1::/32fc7a:e1:ffff:ffff:ffff:ffff:ffff:ffff
227fc7a:e2::/32fc7a:e2:ffff:ffff:ffff:ffff:ffff:ffff
228fc7a:e3::/32fc7a:e3:ffff:ffff:ffff:ffff:ffff:ffff
229fc7a:e4::/32fc7a:e4:ffff:ffff:ffff:ffff:ffff:ffff
230fc7a:e5::/32fc7a:e5:ffff:ffff:ffff:ffff:ffff:ffff
231fc7a:e6::/32fc7a:e6:ffff:ffff:ffff:ffff:ffff:ffff
232fc7a:e7::/32fc7a:e7:ffff:ffff:ffff:ffff:ffff:ffff
233fc7a:e8::/32fc7a:e8:ffff:ffff:ffff:ffff:ffff:ffff
234fc7a:e9::/32fc7a:e9:ffff:ffff:ffff:ffff:ffff:ffff
235fc7a:ea::/32fc7a:ea:ffff:ffff:ffff:ffff:ffff:ffff
236fc7a:eb::/32fc7a:eb:ffff:ffff:ffff:ffff:ffff:ffff
237fc7a:ec::/32fc7a:ec:ffff:ffff:ffff:ffff:ffff:ffff
238fc7a:ed::/32fc7a:ed:ffff:ffff:ffff:ffff:ffff:ffff
239fc7a:ee::/32fc7a:ee:ffff:ffff:ffff:ffff:ffff:ffff
240fc7a:ef::/32fc7a:ef:ffff:ffff:ffff:ffff:ffff:ffff
241fc7a:f0::/32fc7a:f0:ffff:ffff:ffff:ffff:ffff:ffff
242fc7a:f1::/32fc7a:f1:ffff:ffff:ffff:ffff:ffff:ffff
243fc7a:f2::/32fc7a:f2:ffff:ffff:ffff:ffff:ffff:ffff
244fc7a:f3::/32fc7a:f3:ffff:ffff:ffff:ffff:ffff:ffff
245fc7a:f4::/32fc7a:f4:ffff:ffff:ffff:ffff:ffff:ffff
246fc7a:f5::/32fc7a:f5:ffff:ffff:ffff:ffff:ffff:ffff
247fc7a:f6::/32fc7a:f6:ffff:ffff:ffff:ffff:ffff:ffff
248fc7a:f7::/32fc7a:f7:ffff:ffff:ffff:ffff:ffff:ffff
249fc7a:f8::/32fc7a:f8:ffff:ffff:ffff:ffff:ffff:ffff
250fc7a:f9::/32fc7a:f9:ffff:ffff:ffff:ffff:ffff:ffff
251fc7a:fa::/32fc7a:fa:ffff:ffff:ffff:ffff:ffff:ffff
252fc7a:fb::/32fc7a:fb:ffff:ffff:ffff:ffff:ffff:ffff
253fc7a:fc::/32fc7a:fc:ffff:ffff:ffff:ffff:ffff:ffff
254fc7a:fd::/32fc7a:fd:ffff:ffff:ffff:ffff:ffff:ffff
255fc7a:fe::/32fc7a:fe:ffff:ffff:ffff:ffff:ffff:ffff
256fc7a:ff::/32fc7a: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.