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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
fc53::/16
First address
fc53::
Last address
fc53: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
fc53:0000:0000:0000:0000:0000:0000:0000
Type
Unique local (ULA) fc00::/7
Private IPv6, like RFC 1918; usually fd00::/8
Reverse DNS zone
3.5.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)

fc53::/16 makes 65,536 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
1fc53::/32fc53:0:ffff:ffff:ffff:ffff:ffff:ffff
2fc53:1::/32fc53:1:ffff:ffff:ffff:ffff:ffff:ffff
3fc53:2::/32fc53:2:ffff:ffff:ffff:ffff:ffff:ffff
4fc53:3::/32fc53:3:ffff:ffff:ffff:ffff:ffff:ffff
5fc53:4::/32fc53:4:ffff:ffff:ffff:ffff:ffff:ffff
6fc53:5::/32fc53:5:ffff:ffff:ffff:ffff:ffff:ffff
7fc53:6::/32fc53:6:ffff:ffff:ffff:ffff:ffff:ffff
8fc53:7::/32fc53:7:ffff:ffff:ffff:ffff:ffff:ffff
9fc53:8::/32fc53:8:ffff:ffff:ffff:ffff:ffff:ffff
10fc53:9::/32fc53:9:ffff:ffff:ffff:ffff:ffff:ffff
11fc53:a::/32fc53:a:ffff:ffff:ffff:ffff:ffff:ffff
12fc53:b::/32fc53:b:ffff:ffff:ffff:ffff:ffff:ffff
13fc53:c::/32fc53:c:ffff:ffff:ffff:ffff:ffff:ffff
14fc53:d::/32fc53:d:ffff:ffff:ffff:ffff:ffff:ffff
15fc53:e::/32fc53:e:ffff:ffff:ffff:ffff:ffff:ffff
16fc53:f::/32fc53:f:ffff:ffff:ffff:ffff:ffff:ffff
17fc53:10::/32fc53:10:ffff:ffff:ffff:ffff:ffff:ffff
18fc53:11::/32fc53:11:ffff:ffff:ffff:ffff:ffff:ffff
19fc53:12::/32fc53:12:ffff:ffff:ffff:ffff:ffff:ffff
20fc53:13::/32fc53:13:ffff:ffff:ffff:ffff:ffff:ffff
21fc53:14::/32fc53:14:ffff:ffff:ffff:ffff:ffff:ffff
22fc53:15::/32fc53:15:ffff:ffff:ffff:ffff:ffff:ffff
23fc53:16::/32fc53:16:ffff:ffff:ffff:ffff:ffff:ffff
24fc53:17::/32fc53:17:ffff:ffff:ffff:ffff:ffff:ffff
25fc53:18::/32fc53:18:ffff:ffff:ffff:ffff:ffff:ffff
26fc53:19::/32fc53:19:ffff:ffff:ffff:ffff:ffff:ffff
27fc53:1a::/32fc53:1a:ffff:ffff:ffff:ffff:ffff:ffff
28fc53:1b::/32fc53:1b:ffff:ffff:ffff:ffff:ffff:ffff
29fc53:1c::/32fc53:1c:ffff:ffff:ffff:ffff:ffff:ffff
30fc53:1d::/32fc53:1d:ffff:ffff:ffff:ffff:ffff:ffff
31fc53:1e::/32fc53:1e:ffff:ffff:ffff:ffff:ffff:ffff
32fc53:1f::/32fc53:1f:ffff:ffff:ffff:ffff:ffff:ffff
33fc53:20::/32fc53:20:ffff:ffff:ffff:ffff:ffff:ffff
34fc53:21::/32fc53:21:ffff:ffff:ffff:ffff:ffff:ffff
35fc53:22::/32fc53:22:ffff:ffff:ffff:ffff:ffff:ffff
36fc53:23::/32fc53:23:ffff:ffff:ffff:ffff:ffff:ffff
37fc53:24::/32fc53:24:ffff:ffff:ffff:ffff:ffff:ffff
38fc53:25::/32fc53:25:ffff:ffff:ffff:ffff:ffff:ffff
39fc53:26::/32fc53:26:ffff:ffff:ffff:ffff:ffff:ffff
40fc53:27::/32fc53:27:ffff:ffff:ffff:ffff:ffff:ffff
41fc53:28::/32fc53:28:ffff:ffff:ffff:ffff:ffff:ffff
42fc53:29::/32fc53:29:ffff:ffff:ffff:ffff:ffff:ffff
43fc53:2a::/32fc53:2a:ffff:ffff:ffff:ffff:ffff:ffff
44fc53:2b::/32fc53:2b:ffff:ffff:ffff:ffff:ffff:ffff
45fc53:2c::/32fc53:2c:ffff:ffff:ffff:ffff:ffff:ffff
46fc53:2d::/32fc53:2d:ffff:ffff:ffff:ffff:ffff:ffff
47fc53:2e::/32fc53:2e:ffff:ffff:ffff:ffff:ffff:ffff
48fc53:2f::/32fc53:2f:ffff:ffff:ffff:ffff:ffff:ffff
49fc53:30::/32fc53:30:ffff:ffff:ffff:ffff:ffff:ffff
50fc53:31::/32fc53:31:ffff:ffff:ffff:ffff:ffff:ffff
51fc53:32::/32fc53:32:ffff:ffff:ffff:ffff:ffff:ffff
52fc53:33::/32fc53:33:ffff:ffff:ffff:ffff:ffff:ffff
53fc53:34::/32fc53:34:ffff:ffff:ffff:ffff:ffff:ffff
54fc53:35::/32fc53:35:ffff:ffff:ffff:ffff:ffff:ffff
55fc53:36::/32fc53:36:ffff:ffff:ffff:ffff:ffff:ffff
56fc53:37::/32fc53:37:ffff:ffff:ffff:ffff:ffff:ffff
57fc53:38::/32fc53:38:ffff:ffff:ffff:ffff:ffff:ffff
58fc53:39::/32fc53:39:ffff:ffff:ffff:ffff:ffff:ffff
59fc53:3a::/32fc53:3a:ffff:ffff:ffff:ffff:ffff:ffff
60fc53:3b::/32fc53:3b:ffff:ffff:ffff:ffff:ffff:ffff
61fc53:3c::/32fc53:3c:ffff:ffff:ffff:ffff:ffff:ffff
62fc53:3d::/32fc53:3d:ffff:ffff:ffff:ffff:ffff:ffff
63fc53:3e::/32fc53:3e:ffff:ffff:ffff:ffff:ffff:ffff
64fc53:3f::/32fc53:3f:ffff:ffff:ffff:ffff:ffff:ffff
65fc53:40::/32fc53:40:ffff:ffff:ffff:ffff:ffff:ffff
66fc53:41::/32fc53:41:ffff:ffff:ffff:ffff:ffff:ffff
67fc53:42::/32fc53:42:ffff:ffff:ffff:ffff:ffff:ffff
68fc53:43::/32fc53:43:ffff:ffff:ffff:ffff:ffff:ffff
69fc53:44::/32fc53:44:ffff:ffff:ffff:ffff:ffff:ffff
70fc53:45::/32fc53:45:ffff:ffff:ffff:ffff:ffff:ffff
71fc53:46::/32fc53:46:ffff:ffff:ffff:ffff:ffff:ffff
72fc53:47::/32fc53:47:ffff:ffff:ffff:ffff:ffff:ffff
73fc53:48::/32fc53:48:ffff:ffff:ffff:ffff:ffff:ffff
74fc53:49::/32fc53:49:ffff:ffff:ffff:ffff:ffff:ffff
75fc53:4a::/32fc53:4a:ffff:ffff:ffff:ffff:ffff:ffff
76fc53:4b::/32fc53:4b:ffff:ffff:ffff:ffff:ffff:ffff
77fc53:4c::/32fc53:4c:ffff:ffff:ffff:ffff:ffff:ffff
78fc53:4d::/32fc53:4d:ffff:ffff:ffff:ffff:ffff:ffff
79fc53:4e::/32fc53:4e:ffff:ffff:ffff:ffff:ffff:ffff
80fc53:4f::/32fc53:4f:ffff:ffff:ffff:ffff:ffff:ffff
81fc53:50::/32fc53:50:ffff:ffff:ffff:ffff:ffff:ffff
82fc53:51::/32fc53:51:ffff:ffff:ffff:ffff:ffff:ffff
83fc53:52::/32fc53:52:ffff:ffff:ffff:ffff:ffff:ffff
84fc53:53::/32fc53:53:ffff:ffff:ffff:ffff:ffff:ffff
85fc53:54::/32fc53:54:ffff:ffff:ffff:ffff:ffff:ffff
86fc53:55::/32fc53:55:ffff:ffff:ffff:ffff:ffff:ffff
87fc53:56::/32fc53:56:ffff:ffff:ffff:ffff:ffff:ffff
88fc53:57::/32fc53:57:ffff:ffff:ffff:ffff:ffff:ffff
89fc53:58::/32fc53:58:ffff:ffff:ffff:ffff:ffff:ffff
90fc53:59::/32fc53:59:ffff:ffff:ffff:ffff:ffff:ffff
91fc53:5a::/32fc53:5a:ffff:ffff:ffff:ffff:ffff:ffff
92fc53:5b::/32fc53:5b:ffff:ffff:ffff:ffff:ffff:ffff
93fc53:5c::/32fc53:5c:ffff:ffff:ffff:ffff:ffff:ffff
94fc53:5d::/32fc53:5d:ffff:ffff:ffff:ffff:ffff:ffff
95fc53:5e::/32fc53:5e:ffff:ffff:ffff:ffff:ffff:ffff
96fc53:5f::/32fc53:5f:ffff:ffff:ffff:ffff:ffff:ffff
97fc53:60::/32fc53:60:ffff:ffff:ffff:ffff:ffff:ffff
98fc53:61::/32fc53:61:ffff:ffff:ffff:ffff:ffff:ffff
99fc53:62::/32fc53:62:ffff:ffff:ffff:ffff:ffff:ffff
100fc53:63::/32fc53:63:ffff:ffff:ffff:ffff:ffff:ffff
101fc53:64::/32fc53:64:ffff:ffff:ffff:ffff:ffff:ffff
102fc53:65::/32fc53:65:ffff:ffff:ffff:ffff:ffff:ffff
103fc53:66::/32fc53:66:ffff:ffff:ffff:ffff:ffff:ffff
104fc53:67::/32fc53:67:ffff:ffff:ffff:ffff:ffff:ffff
105fc53:68::/32fc53:68:ffff:ffff:ffff:ffff:ffff:ffff
106fc53:69::/32fc53:69:ffff:ffff:ffff:ffff:ffff:ffff
107fc53:6a::/32fc53:6a:ffff:ffff:ffff:ffff:ffff:ffff
108fc53:6b::/32fc53:6b:ffff:ffff:ffff:ffff:ffff:ffff
109fc53:6c::/32fc53:6c:ffff:ffff:ffff:ffff:ffff:ffff
110fc53:6d::/32fc53:6d:ffff:ffff:ffff:ffff:ffff:ffff
111fc53:6e::/32fc53:6e:ffff:ffff:ffff:ffff:ffff:ffff
112fc53:6f::/32fc53:6f:ffff:ffff:ffff:ffff:ffff:ffff
113fc53:70::/32fc53:70:ffff:ffff:ffff:ffff:ffff:ffff
114fc53:71::/32fc53:71:ffff:ffff:ffff:ffff:ffff:ffff
115fc53:72::/32fc53:72:ffff:ffff:ffff:ffff:ffff:ffff
116fc53:73::/32fc53:73:ffff:ffff:ffff:ffff:ffff:ffff
117fc53:74::/32fc53:74:ffff:ffff:ffff:ffff:ffff:ffff
118fc53:75::/32fc53:75:ffff:ffff:ffff:ffff:ffff:ffff
119fc53:76::/32fc53:76:ffff:ffff:ffff:ffff:ffff:ffff
120fc53:77::/32fc53:77:ffff:ffff:ffff:ffff:ffff:ffff
121fc53:78::/32fc53:78:ffff:ffff:ffff:ffff:ffff:ffff
122fc53:79::/32fc53:79:ffff:ffff:ffff:ffff:ffff:ffff
123fc53:7a::/32fc53:7a:ffff:ffff:ffff:ffff:ffff:ffff
124fc53:7b::/32fc53:7b:ffff:ffff:ffff:ffff:ffff:ffff
125fc53:7c::/32fc53:7c:ffff:ffff:ffff:ffff:ffff:ffff
126fc53:7d::/32fc53:7d:ffff:ffff:ffff:ffff:ffff:ffff
127fc53:7e::/32fc53:7e:ffff:ffff:ffff:ffff:ffff:ffff
128fc53:7f::/32fc53:7f:ffff:ffff:ffff:ffff:ffff:ffff
129fc53:80::/32fc53:80:ffff:ffff:ffff:ffff:ffff:ffff
130fc53:81::/32fc53:81:ffff:ffff:ffff:ffff:ffff:ffff
131fc53:82::/32fc53:82:ffff:ffff:ffff:ffff:ffff:ffff
132fc53:83::/32fc53:83:ffff:ffff:ffff:ffff:ffff:ffff
133fc53:84::/32fc53:84:ffff:ffff:ffff:ffff:ffff:ffff
134fc53:85::/32fc53:85:ffff:ffff:ffff:ffff:ffff:ffff
135fc53:86::/32fc53:86:ffff:ffff:ffff:ffff:ffff:ffff
136fc53:87::/32fc53:87:ffff:ffff:ffff:ffff:ffff:ffff
137fc53:88::/32fc53:88:ffff:ffff:ffff:ffff:ffff:ffff
138fc53:89::/32fc53:89:ffff:ffff:ffff:ffff:ffff:ffff
139fc53:8a::/32fc53:8a:ffff:ffff:ffff:ffff:ffff:ffff
140fc53:8b::/32fc53:8b:ffff:ffff:ffff:ffff:ffff:ffff
141fc53:8c::/32fc53:8c:ffff:ffff:ffff:ffff:ffff:ffff
142fc53:8d::/32fc53:8d:ffff:ffff:ffff:ffff:ffff:ffff
143fc53:8e::/32fc53:8e:ffff:ffff:ffff:ffff:ffff:ffff
144fc53:8f::/32fc53:8f:ffff:ffff:ffff:ffff:ffff:ffff
145fc53:90::/32fc53:90:ffff:ffff:ffff:ffff:ffff:ffff
146fc53:91::/32fc53:91:ffff:ffff:ffff:ffff:ffff:ffff
147fc53:92::/32fc53:92:ffff:ffff:ffff:ffff:ffff:ffff
148fc53:93::/32fc53:93:ffff:ffff:ffff:ffff:ffff:ffff
149fc53:94::/32fc53:94:ffff:ffff:ffff:ffff:ffff:ffff
150fc53:95::/32fc53:95:ffff:ffff:ffff:ffff:ffff:ffff
151fc53:96::/32fc53:96:ffff:ffff:ffff:ffff:ffff:ffff
152fc53:97::/32fc53:97:ffff:ffff:ffff:ffff:ffff:ffff
153fc53:98::/32fc53:98:ffff:ffff:ffff:ffff:ffff:ffff
154fc53:99::/32fc53:99:ffff:ffff:ffff:ffff:ffff:ffff
155fc53:9a::/32fc53:9a:ffff:ffff:ffff:ffff:ffff:ffff
156fc53:9b::/32fc53:9b:ffff:ffff:ffff:ffff:ffff:ffff
157fc53:9c::/32fc53:9c:ffff:ffff:ffff:ffff:ffff:ffff
158fc53:9d::/32fc53:9d:ffff:ffff:ffff:ffff:ffff:ffff
159fc53:9e::/32fc53:9e:ffff:ffff:ffff:ffff:ffff:ffff
160fc53:9f::/32fc53:9f:ffff:ffff:ffff:ffff:ffff:ffff
161fc53:a0::/32fc53:a0:ffff:ffff:ffff:ffff:ffff:ffff
162fc53:a1::/32fc53:a1:ffff:ffff:ffff:ffff:ffff:ffff
163fc53:a2::/32fc53:a2:ffff:ffff:ffff:ffff:ffff:ffff
164fc53:a3::/32fc53:a3:ffff:ffff:ffff:ffff:ffff:ffff
165fc53:a4::/32fc53:a4:ffff:ffff:ffff:ffff:ffff:ffff
166fc53:a5::/32fc53:a5:ffff:ffff:ffff:ffff:ffff:ffff
167fc53:a6::/32fc53:a6:ffff:ffff:ffff:ffff:ffff:ffff
168fc53:a7::/32fc53:a7:ffff:ffff:ffff:ffff:ffff:ffff
169fc53:a8::/32fc53:a8:ffff:ffff:ffff:ffff:ffff:ffff
170fc53:a9::/32fc53:a9:ffff:ffff:ffff:ffff:ffff:ffff
171fc53:aa::/32fc53:aa:ffff:ffff:ffff:ffff:ffff:ffff
172fc53:ab::/32fc53:ab:ffff:ffff:ffff:ffff:ffff:ffff
173fc53:ac::/32fc53:ac:ffff:ffff:ffff:ffff:ffff:ffff
174fc53:ad::/32fc53:ad:ffff:ffff:ffff:ffff:ffff:ffff
175fc53:ae::/32fc53:ae:ffff:ffff:ffff:ffff:ffff:ffff
176fc53:af::/32fc53:af:ffff:ffff:ffff:ffff:ffff:ffff
177fc53:b0::/32fc53:b0:ffff:ffff:ffff:ffff:ffff:ffff
178fc53:b1::/32fc53:b1:ffff:ffff:ffff:ffff:ffff:ffff
179fc53:b2::/32fc53:b2:ffff:ffff:ffff:ffff:ffff:ffff
180fc53:b3::/32fc53:b3:ffff:ffff:ffff:ffff:ffff:ffff
181fc53:b4::/32fc53:b4:ffff:ffff:ffff:ffff:ffff:ffff
182fc53:b5::/32fc53:b5:ffff:ffff:ffff:ffff:ffff:ffff
183fc53:b6::/32fc53:b6:ffff:ffff:ffff:ffff:ffff:ffff
184fc53:b7::/32fc53:b7:ffff:ffff:ffff:ffff:ffff:ffff
185fc53:b8::/32fc53:b8:ffff:ffff:ffff:ffff:ffff:ffff
186fc53:b9::/32fc53:b9:ffff:ffff:ffff:ffff:ffff:ffff
187fc53:ba::/32fc53:ba:ffff:ffff:ffff:ffff:ffff:ffff
188fc53:bb::/32fc53:bb:ffff:ffff:ffff:ffff:ffff:ffff
189fc53:bc::/32fc53:bc:ffff:ffff:ffff:ffff:ffff:ffff
190fc53:bd::/32fc53:bd:ffff:ffff:ffff:ffff:ffff:ffff
191fc53:be::/32fc53:be:ffff:ffff:ffff:ffff:ffff:ffff
192fc53:bf::/32fc53:bf:ffff:ffff:ffff:ffff:ffff:ffff
193fc53:c0::/32fc53:c0:ffff:ffff:ffff:ffff:ffff:ffff
194fc53:c1::/32fc53:c1:ffff:ffff:ffff:ffff:ffff:ffff
195fc53:c2::/32fc53:c2:ffff:ffff:ffff:ffff:ffff:ffff
196fc53:c3::/32fc53:c3:ffff:ffff:ffff:ffff:ffff:ffff
197fc53:c4::/32fc53:c4:ffff:ffff:ffff:ffff:ffff:ffff
198fc53:c5::/32fc53:c5:ffff:ffff:ffff:ffff:ffff:ffff
199fc53:c6::/32fc53:c6:ffff:ffff:ffff:ffff:ffff:ffff
200fc53:c7::/32fc53:c7:ffff:ffff:ffff:ffff:ffff:ffff
201fc53:c8::/32fc53:c8:ffff:ffff:ffff:ffff:ffff:ffff
202fc53:c9::/32fc53:c9:ffff:ffff:ffff:ffff:ffff:ffff
203fc53:ca::/32fc53:ca:ffff:ffff:ffff:ffff:ffff:ffff
204fc53:cb::/32fc53:cb:ffff:ffff:ffff:ffff:ffff:ffff
205fc53:cc::/32fc53:cc:ffff:ffff:ffff:ffff:ffff:ffff
206fc53:cd::/32fc53:cd:ffff:ffff:ffff:ffff:ffff:ffff
207fc53:ce::/32fc53:ce:ffff:ffff:ffff:ffff:ffff:ffff
208fc53:cf::/32fc53:cf:ffff:ffff:ffff:ffff:ffff:ffff
209fc53:d0::/32fc53:d0:ffff:ffff:ffff:ffff:ffff:ffff
210fc53:d1::/32fc53:d1:ffff:ffff:ffff:ffff:ffff:ffff
211fc53:d2::/32fc53:d2:ffff:ffff:ffff:ffff:ffff:ffff
212fc53:d3::/32fc53:d3:ffff:ffff:ffff:ffff:ffff:ffff
213fc53:d4::/32fc53:d4:ffff:ffff:ffff:ffff:ffff:ffff
214fc53:d5::/32fc53:d5:ffff:ffff:ffff:ffff:ffff:ffff
215fc53:d6::/32fc53:d6:ffff:ffff:ffff:ffff:ffff:ffff
216fc53:d7::/32fc53:d7:ffff:ffff:ffff:ffff:ffff:ffff
217fc53:d8::/32fc53:d8:ffff:ffff:ffff:ffff:ffff:ffff
218fc53:d9::/32fc53:d9:ffff:ffff:ffff:ffff:ffff:ffff
219fc53:da::/32fc53:da:ffff:ffff:ffff:ffff:ffff:ffff
220fc53:db::/32fc53:db:ffff:ffff:ffff:ffff:ffff:ffff
221fc53:dc::/32fc53:dc:ffff:ffff:ffff:ffff:ffff:ffff
222fc53:dd::/32fc53:dd:ffff:ffff:ffff:ffff:ffff:ffff
223fc53:de::/32fc53:de:ffff:ffff:ffff:ffff:ffff:ffff
224fc53:df::/32fc53:df:ffff:ffff:ffff:ffff:ffff:ffff
225fc53:e0::/32fc53:e0:ffff:ffff:ffff:ffff:ffff:ffff
226fc53:e1::/32fc53:e1:ffff:ffff:ffff:ffff:ffff:ffff
227fc53:e2::/32fc53:e2:ffff:ffff:ffff:ffff:ffff:ffff
228fc53:e3::/32fc53:e3:ffff:ffff:ffff:ffff:ffff:ffff
229fc53:e4::/32fc53:e4:ffff:ffff:ffff:ffff:ffff:ffff
230fc53:e5::/32fc53:e5:ffff:ffff:ffff:ffff:ffff:ffff
231fc53:e6::/32fc53:e6:ffff:ffff:ffff:ffff:ffff:ffff
232fc53:e7::/32fc53:e7:ffff:ffff:ffff:ffff:ffff:ffff
233fc53:e8::/32fc53:e8:ffff:ffff:ffff:ffff:ffff:ffff
234fc53:e9::/32fc53:e9:ffff:ffff:ffff:ffff:ffff:ffff
235fc53:ea::/32fc53:ea:ffff:ffff:ffff:ffff:ffff:ffff
236fc53:eb::/32fc53:eb:ffff:ffff:ffff:ffff:ffff:ffff
237fc53:ec::/32fc53:ec:ffff:ffff:ffff:ffff:ffff:ffff
238fc53:ed::/32fc53:ed:ffff:ffff:ffff:ffff:ffff:ffff
239fc53:ee::/32fc53:ee:ffff:ffff:ffff:ffff:ffff:ffff
240fc53:ef::/32fc53:ef:ffff:ffff:ffff:ffff:ffff:ffff
241fc53:f0::/32fc53:f0:ffff:ffff:ffff:ffff:ffff:ffff
242fc53:f1::/32fc53:f1:ffff:ffff:ffff:ffff:ffff:ffff
243fc53:f2::/32fc53:f2:ffff:ffff:ffff:ffff:ffff:ffff
244fc53:f3::/32fc53:f3:ffff:ffff:ffff:ffff:ffff:ffff
245fc53:f4::/32fc53:f4:ffff:ffff:ffff:ffff:ffff:ffff
246fc53:f5::/32fc53:f5:ffff:ffff:ffff:ffff:ffff:ffff
247fc53:f6::/32fc53:f6:ffff:ffff:ffff:ffff:ffff:ffff
248fc53:f7::/32fc53:f7:ffff:ffff:ffff:ffff:ffff:ffff
249fc53:f8::/32fc53:f8:ffff:ffff:ffff:ffff:ffff:ffff
250fc53:f9::/32fc53:f9:ffff:ffff:ffff:ffff:ffff:ffff
251fc53:fa::/32fc53:fa:ffff:ffff:ffff:ffff:ffff:ffff
252fc53:fb::/32fc53:fb:ffff:ffff:ffff:ffff:ffff:ffff
253fc53:fc::/32fc53:fc:ffff:ffff:ffff:ffff:ffff:ffff
254fc53:fd::/32fc53:fd:ffff:ffff:ffff:ffff:ffff:ffff
255fc53:fe::/32fc53:fe:ffff:ffff:ffff:ffff:ffff:ffff
256fc53:ff::/32fc53: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.