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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
fc50::/16
First address
fc50::
Last address
fc50: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
fc50:0000:0000:0000:0000:0000:0000:0000
Type
Unique local (ULA) fc00::/7
Private IPv6, like RFC 1918; usually fd00::/8
Reverse DNS zone
0.5.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)

fc50::/16 makes 65,536 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
1fc50::/32fc50:0:ffff:ffff:ffff:ffff:ffff:ffff
2fc50:1::/32fc50:1:ffff:ffff:ffff:ffff:ffff:ffff
3fc50:2::/32fc50:2:ffff:ffff:ffff:ffff:ffff:ffff
4fc50:3::/32fc50:3:ffff:ffff:ffff:ffff:ffff:ffff
5fc50:4::/32fc50:4:ffff:ffff:ffff:ffff:ffff:ffff
6fc50:5::/32fc50:5:ffff:ffff:ffff:ffff:ffff:ffff
7fc50:6::/32fc50:6:ffff:ffff:ffff:ffff:ffff:ffff
8fc50:7::/32fc50:7:ffff:ffff:ffff:ffff:ffff:ffff
9fc50:8::/32fc50:8:ffff:ffff:ffff:ffff:ffff:ffff
10fc50:9::/32fc50:9:ffff:ffff:ffff:ffff:ffff:ffff
11fc50:a::/32fc50:a:ffff:ffff:ffff:ffff:ffff:ffff
12fc50:b::/32fc50:b:ffff:ffff:ffff:ffff:ffff:ffff
13fc50:c::/32fc50:c:ffff:ffff:ffff:ffff:ffff:ffff
14fc50:d::/32fc50:d:ffff:ffff:ffff:ffff:ffff:ffff
15fc50:e::/32fc50:e:ffff:ffff:ffff:ffff:ffff:ffff
16fc50:f::/32fc50:f:ffff:ffff:ffff:ffff:ffff:ffff
17fc50:10::/32fc50:10:ffff:ffff:ffff:ffff:ffff:ffff
18fc50:11::/32fc50:11:ffff:ffff:ffff:ffff:ffff:ffff
19fc50:12::/32fc50:12:ffff:ffff:ffff:ffff:ffff:ffff
20fc50:13::/32fc50:13:ffff:ffff:ffff:ffff:ffff:ffff
21fc50:14::/32fc50:14:ffff:ffff:ffff:ffff:ffff:ffff
22fc50:15::/32fc50:15:ffff:ffff:ffff:ffff:ffff:ffff
23fc50:16::/32fc50:16:ffff:ffff:ffff:ffff:ffff:ffff
24fc50:17::/32fc50:17:ffff:ffff:ffff:ffff:ffff:ffff
25fc50:18::/32fc50:18:ffff:ffff:ffff:ffff:ffff:ffff
26fc50:19::/32fc50:19:ffff:ffff:ffff:ffff:ffff:ffff
27fc50:1a::/32fc50:1a:ffff:ffff:ffff:ffff:ffff:ffff
28fc50:1b::/32fc50:1b:ffff:ffff:ffff:ffff:ffff:ffff
29fc50:1c::/32fc50:1c:ffff:ffff:ffff:ffff:ffff:ffff
30fc50:1d::/32fc50:1d:ffff:ffff:ffff:ffff:ffff:ffff
31fc50:1e::/32fc50:1e:ffff:ffff:ffff:ffff:ffff:ffff
32fc50:1f::/32fc50:1f:ffff:ffff:ffff:ffff:ffff:ffff
33fc50:20::/32fc50:20:ffff:ffff:ffff:ffff:ffff:ffff
34fc50:21::/32fc50:21:ffff:ffff:ffff:ffff:ffff:ffff
35fc50:22::/32fc50:22:ffff:ffff:ffff:ffff:ffff:ffff
36fc50:23::/32fc50:23:ffff:ffff:ffff:ffff:ffff:ffff
37fc50:24::/32fc50:24:ffff:ffff:ffff:ffff:ffff:ffff
38fc50:25::/32fc50:25:ffff:ffff:ffff:ffff:ffff:ffff
39fc50:26::/32fc50:26:ffff:ffff:ffff:ffff:ffff:ffff
40fc50:27::/32fc50:27:ffff:ffff:ffff:ffff:ffff:ffff
41fc50:28::/32fc50:28:ffff:ffff:ffff:ffff:ffff:ffff
42fc50:29::/32fc50:29:ffff:ffff:ffff:ffff:ffff:ffff
43fc50:2a::/32fc50:2a:ffff:ffff:ffff:ffff:ffff:ffff
44fc50:2b::/32fc50:2b:ffff:ffff:ffff:ffff:ffff:ffff
45fc50:2c::/32fc50:2c:ffff:ffff:ffff:ffff:ffff:ffff
46fc50:2d::/32fc50:2d:ffff:ffff:ffff:ffff:ffff:ffff
47fc50:2e::/32fc50:2e:ffff:ffff:ffff:ffff:ffff:ffff
48fc50:2f::/32fc50:2f:ffff:ffff:ffff:ffff:ffff:ffff
49fc50:30::/32fc50:30:ffff:ffff:ffff:ffff:ffff:ffff
50fc50:31::/32fc50:31:ffff:ffff:ffff:ffff:ffff:ffff
51fc50:32::/32fc50:32:ffff:ffff:ffff:ffff:ffff:ffff
52fc50:33::/32fc50:33:ffff:ffff:ffff:ffff:ffff:ffff
53fc50:34::/32fc50:34:ffff:ffff:ffff:ffff:ffff:ffff
54fc50:35::/32fc50:35:ffff:ffff:ffff:ffff:ffff:ffff
55fc50:36::/32fc50:36:ffff:ffff:ffff:ffff:ffff:ffff
56fc50:37::/32fc50:37:ffff:ffff:ffff:ffff:ffff:ffff
57fc50:38::/32fc50:38:ffff:ffff:ffff:ffff:ffff:ffff
58fc50:39::/32fc50:39:ffff:ffff:ffff:ffff:ffff:ffff
59fc50:3a::/32fc50:3a:ffff:ffff:ffff:ffff:ffff:ffff
60fc50:3b::/32fc50:3b:ffff:ffff:ffff:ffff:ffff:ffff
61fc50:3c::/32fc50:3c:ffff:ffff:ffff:ffff:ffff:ffff
62fc50:3d::/32fc50:3d:ffff:ffff:ffff:ffff:ffff:ffff
63fc50:3e::/32fc50:3e:ffff:ffff:ffff:ffff:ffff:ffff
64fc50:3f::/32fc50:3f:ffff:ffff:ffff:ffff:ffff:ffff
65fc50:40::/32fc50:40:ffff:ffff:ffff:ffff:ffff:ffff
66fc50:41::/32fc50:41:ffff:ffff:ffff:ffff:ffff:ffff
67fc50:42::/32fc50:42:ffff:ffff:ffff:ffff:ffff:ffff
68fc50:43::/32fc50:43:ffff:ffff:ffff:ffff:ffff:ffff
69fc50:44::/32fc50:44:ffff:ffff:ffff:ffff:ffff:ffff
70fc50:45::/32fc50:45:ffff:ffff:ffff:ffff:ffff:ffff
71fc50:46::/32fc50:46:ffff:ffff:ffff:ffff:ffff:ffff
72fc50:47::/32fc50:47:ffff:ffff:ffff:ffff:ffff:ffff
73fc50:48::/32fc50:48:ffff:ffff:ffff:ffff:ffff:ffff
74fc50:49::/32fc50:49:ffff:ffff:ffff:ffff:ffff:ffff
75fc50:4a::/32fc50:4a:ffff:ffff:ffff:ffff:ffff:ffff
76fc50:4b::/32fc50:4b:ffff:ffff:ffff:ffff:ffff:ffff
77fc50:4c::/32fc50:4c:ffff:ffff:ffff:ffff:ffff:ffff
78fc50:4d::/32fc50:4d:ffff:ffff:ffff:ffff:ffff:ffff
79fc50:4e::/32fc50:4e:ffff:ffff:ffff:ffff:ffff:ffff
80fc50:4f::/32fc50:4f:ffff:ffff:ffff:ffff:ffff:ffff
81fc50:50::/32fc50:50:ffff:ffff:ffff:ffff:ffff:ffff
82fc50:51::/32fc50:51:ffff:ffff:ffff:ffff:ffff:ffff
83fc50:52::/32fc50:52:ffff:ffff:ffff:ffff:ffff:ffff
84fc50:53::/32fc50:53:ffff:ffff:ffff:ffff:ffff:ffff
85fc50:54::/32fc50:54:ffff:ffff:ffff:ffff:ffff:ffff
86fc50:55::/32fc50:55:ffff:ffff:ffff:ffff:ffff:ffff
87fc50:56::/32fc50:56:ffff:ffff:ffff:ffff:ffff:ffff
88fc50:57::/32fc50:57:ffff:ffff:ffff:ffff:ffff:ffff
89fc50:58::/32fc50:58:ffff:ffff:ffff:ffff:ffff:ffff
90fc50:59::/32fc50:59:ffff:ffff:ffff:ffff:ffff:ffff
91fc50:5a::/32fc50:5a:ffff:ffff:ffff:ffff:ffff:ffff
92fc50:5b::/32fc50:5b:ffff:ffff:ffff:ffff:ffff:ffff
93fc50:5c::/32fc50:5c:ffff:ffff:ffff:ffff:ffff:ffff
94fc50:5d::/32fc50:5d:ffff:ffff:ffff:ffff:ffff:ffff
95fc50:5e::/32fc50:5e:ffff:ffff:ffff:ffff:ffff:ffff
96fc50:5f::/32fc50:5f:ffff:ffff:ffff:ffff:ffff:ffff
97fc50:60::/32fc50:60:ffff:ffff:ffff:ffff:ffff:ffff
98fc50:61::/32fc50:61:ffff:ffff:ffff:ffff:ffff:ffff
99fc50:62::/32fc50:62:ffff:ffff:ffff:ffff:ffff:ffff
100fc50:63::/32fc50:63:ffff:ffff:ffff:ffff:ffff:ffff
101fc50:64::/32fc50:64:ffff:ffff:ffff:ffff:ffff:ffff
102fc50:65::/32fc50:65:ffff:ffff:ffff:ffff:ffff:ffff
103fc50:66::/32fc50:66:ffff:ffff:ffff:ffff:ffff:ffff
104fc50:67::/32fc50:67:ffff:ffff:ffff:ffff:ffff:ffff
105fc50:68::/32fc50:68:ffff:ffff:ffff:ffff:ffff:ffff
106fc50:69::/32fc50:69:ffff:ffff:ffff:ffff:ffff:ffff
107fc50:6a::/32fc50:6a:ffff:ffff:ffff:ffff:ffff:ffff
108fc50:6b::/32fc50:6b:ffff:ffff:ffff:ffff:ffff:ffff
109fc50:6c::/32fc50:6c:ffff:ffff:ffff:ffff:ffff:ffff
110fc50:6d::/32fc50:6d:ffff:ffff:ffff:ffff:ffff:ffff
111fc50:6e::/32fc50:6e:ffff:ffff:ffff:ffff:ffff:ffff
112fc50:6f::/32fc50:6f:ffff:ffff:ffff:ffff:ffff:ffff
113fc50:70::/32fc50:70:ffff:ffff:ffff:ffff:ffff:ffff
114fc50:71::/32fc50:71:ffff:ffff:ffff:ffff:ffff:ffff
115fc50:72::/32fc50:72:ffff:ffff:ffff:ffff:ffff:ffff
116fc50:73::/32fc50:73:ffff:ffff:ffff:ffff:ffff:ffff
117fc50:74::/32fc50:74:ffff:ffff:ffff:ffff:ffff:ffff
118fc50:75::/32fc50:75:ffff:ffff:ffff:ffff:ffff:ffff
119fc50:76::/32fc50:76:ffff:ffff:ffff:ffff:ffff:ffff
120fc50:77::/32fc50:77:ffff:ffff:ffff:ffff:ffff:ffff
121fc50:78::/32fc50:78:ffff:ffff:ffff:ffff:ffff:ffff
122fc50:79::/32fc50:79:ffff:ffff:ffff:ffff:ffff:ffff
123fc50:7a::/32fc50:7a:ffff:ffff:ffff:ffff:ffff:ffff
124fc50:7b::/32fc50:7b:ffff:ffff:ffff:ffff:ffff:ffff
125fc50:7c::/32fc50:7c:ffff:ffff:ffff:ffff:ffff:ffff
126fc50:7d::/32fc50:7d:ffff:ffff:ffff:ffff:ffff:ffff
127fc50:7e::/32fc50:7e:ffff:ffff:ffff:ffff:ffff:ffff
128fc50:7f::/32fc50:7f:ffff:ffff:ffff:ffff:ffff:ffff
129fc50:80::/32fc50:80:ffff:ffff:ffff:ffff:ffff:ffff
130fc50:81::/32fc50:81:ffff:ffff:ffff:ffff:ffff:ffff
131fc50:82::/32fc50:82:ffff:ffff:ffff:ffff:ffff:ffff
132fc50:83::/32fc50:83:ffff:ffff:ffff:ffff:ffff:ffff
133fc50:84::/32fc50:84:ffff:ffff:ffff:ffff:ffff:ffff
134fc50:85::/32fc50:85:ffff:ffff:ffff:ffff:ffff:ffff
135fc50:86::/32fc50:86:ffff:ffff:ffff:ffff:ffff:ffff
136fc50:87::/32fc50:87:ffff:ffff:ffff:ffff:ffff:ffff
137fc50:88::/32fc50:88:ffff:ffff:ffff:ffff:ffff:ffff
138fc50:89::/32fc50:89:ffff:ffff:ffff:ffff:ffff:ffff
139fc50:8a::/32fc50:8a:ffff:ffff:ffff:ffff:ffff:ffff
140fc50:8b::/32fc50:8b:ffff:ffff:ffff:ffff:ffff:ffff
141fc50:8c::/32fc50:8c:ffff:ffff:ffff:ffff:ffff:ffff
142fc50:8d::/32fc50:8d:ffff:ffff:ffff:ffff:ffff:ffff
143fc50:8e::/32fc50:8e:ffff:ffff:ffff:ffff:ffff:ffff
144fc50:8f::/32fc50:8f:ffff:ffff:ffff:ffff:ffff:ffff
145fc50:90::/32fc50:90:ffff:ffff:ffff:ffff:ffff:ffff
146fc50:91::/32fc50:91:ffff:ffff:ffff:ffff:ffff:ffff
147fc50:92::/32fc50:92:ffff:ffff:ffff:ffff:ffff:ffff
148fc50:93::/32fc50:93:ffff:ffff:ffff:ffff:ffff:ffff
149fc50:94::/32fc50:94:ffff:ffff:ffff:ffff:ffff:ffff
150fc50:95::/32fc50:95:ffff:ffff:ffff:ffff:ffff:ffff
151fc50:96::/32fc50:96:ffff:ffff:ffff:ffff:ffff:ffff
152fc50:97::/32fc50:97:ffff:ffff:ffff:ffff:ffff:ffff
153fc50:98::/32fc50:98:ffff:ffff:ffff:ffff:ffff:ffff
154fc50:99::/32fc50:99:ffff:ffff:ffff:ffff:ffff:ffff
155fc50:9a::/32fc50:9a:ffff:ffff:ffff:ffff:ffff:ffff
156fc50:9b::/32fc50:9b:ffff:ffff:ffff:ffff:ffff:ffff
157fc50:9c::/32fc50:9c:ffff:ffff:ffff:ffff:ffff:ffff
158fc50:9d::/32fc50:9d:ffff:ffff:ffff:ffff:ffff:ffff
159fc50:9e::/32fc50:9e:ffff:ffff:ffff:ffff:ffff:ffff
160fc50:9f::/32fc50:9f:ffff:ffff:ffff:ffff:ffff:ffff
161fc50:a0::/32fc50:a0:ffff:ffff:ffff:ffff:ffff:ffff
162fc50:a1::/32fc50:a1:ffff:ffff:ffff:ffff:ffff:ffff
163fc50:a2::/32fc50:a2:ffff:ffff:ffff:ffff:ffff:ffff
164fc50:a3::/32fc50:a3:ffff:ffff:ffff:ffff:ffff:ffff
165fc50:a4::/32fc50:a4:ffff:ffff:ffff:ffff:ffff:ffff
166fc50:a5::/32fc50:a5:ffff:ffff:ffff:ffff:ffff:ffff
167fc50:a6::/32fc50:a6:ffff:ffff:ffff:ffff:ffff:ffff
168fc50:a7::/32fc50:a7:ffff:ffff:ffff:ffff:ffff:ffff
169fc50:a8::/32fc50:a8:ffff:ffff:ffff:ffff:ffff:ffff
170fc50:a9::/32fc50:a9:ffff:ffff:ffff:ffff:ffff:ffff
171fc50:aa::/32fc50:aa:ffff:ffff:ffff:ffff:ffff:ffff
172fc50:ab::/32fc50:ab:ffff:ffff:ffff:ffff:ffff:ffff
173fc50:ac::/32fc50:ac:ffff:ffff:ffff:ffff:ffff:ffff
174fc50:ad::/32fc50:ad:ffff:ffff:ffff:ffff:ffff:ffff
175fc50:ae::/32fc50:ae:ffff:ffff:ffff:ffff:ffff:ffff
176fc50:af::/32fc50:af:ffff:ffff:ffff:ffff:ffff:ffff
177fc50:b0::/32fc50:b0:ffff:ffff:ffff:ffff:ffff:ffff
178fc50:b1::/32fc50:b1:ffff:ffff:ffff:ffff:ffff:ffff
179fc50:b2::/32fc50:b2:ffff:ffff:ffff:ffff:ffff:ffff
180fc50:b3::/32fc50:b3:ffff:ffff:ffff:ffff:ffff:ffff
181fc50:b4::/32fc50:b4:ffff:ffff:ffff:ffff:ffff:ffff
182fc50:b5::/32fc50:b5:ffff:ffff:ffff:ffff:ffff:ffff
183fc50:b6::/32fc50:b6:ffff:ffff:ffff:ffff:ffff:ffff
184fc50:b7::/32fc50:b7:ffff:ffff:ffff:ffff:ffff:ffff
185fc50:b8::/32fc50:b8:ffff:ffff:ffff:ffff:ffff:ffff
186fc50:b9::/32fc50:b9:ffff:ffff:ffff:ffff:ffff:ffff
187fc50:ba::/32fc50:ba:ffff:ffff:ffff:ffff:ffff:ffff
188fc50:bb::/32fc50:bb:ffff:ffff:ffff:ffff:ffff:ffff
189fc50:bc::/32fc50:bc:ffff:ffff:ffff:ffff:ffff:ffff
190fc50:bd::/32fc50:bd:ffff:ffff:ffff:ffff:ffff:ffff
191fc50:be::/32fc50:be:ffff:ffff:ffff:ffff:ffff:ffff
192fc50:bf::/32fc50:bf:ffff:ffff:ffff:ffff:ffff:ffff
193fc50:c0::/32fc50:c0:ffff:ffff:ffff:ffff:ffff:ffff
194fc50:c1::/32fc50:c1:ffff:ffff:ffff:ffff:ffff:ffff
195fc50:c2::/32fc50:c2:ffff:ffff:ffff:ffff:ffff:ffff
196fc50:c3::/32fc50:c3:ffff:ffff:ffff:ffff:ffff:ffff
197fc50:c4::/32fc50:c4:ffff:ffff:ffff:ffff:ffff:ffff
198fc50:c5::/32fc50:c5:ffff:ffff:ffff:ffff:ffff:ffff
199fc50:c6::/32fc50:c6:ffff:ffff:ffff:ffff:ffff:ffff
200fc50:c7::/32fc50:c7:ffff:ffff:ffff:ffff:ffff:ffff
201fc50:c8::/32fc50:c8:ffff:ffff:ffff:ffff:ffff:ffff
202fc50:c9::/32fc50:c9:ffff:ffff:ffff:ffff:ffff:ffff
203fc50:ca::/32fc50:ca:ffff:ffff:ffff:ffff:ffff:ffff
204fc50:cb::/32fc50:cb:ffff:ffff:ffff:ffff:ffff:ffff
205fc50:cc::/32fc50:cc:ffff:ffff:ffff:ffff:ffff:ffff
206fc50:cd::/32fc50:cd:ffff:ffff:ffff:ffff:ffff:ffff
207fc50:ce::/32fc50:ce:ffff:ffff:ffff:ffff:ffff:ffff
208fc50:cf::/32fc50:cf:ffff:ffff:ffff:ffff:ffff:ffff
209fc50:d0::/32fc50:d0:ffff:ffff:ffff:ffff:ffff:ffff
210fc50:d1::/32fc50:d1:ffff:ffff:ffff:ffff:ffff:ffff
211fc50:d2::/32fc50:d2:ffff:ffff:ffff:ffff:ffff:ffff
212fc50:d3::/32fc50:d3:ffff:ffff:ffff:ffff:ffff:ffff
213fc50:d4::/32fc50:d4:ffff:ffff:ffff:ffff:ffff:ffff
214fc50:d5::/32fc50:d5:ffff:ffff:ffff:ffff:ffff:ffff
215fc50:d6::/32fc50:d6:ffff:ffff:ffff:ffff:ffff:ffff
216fc50:d7::/32fc50:d7:ffff:ffff:ffff:ffff:ffff:ffff
217fc50:d8::/32fc50:d8:ffff:ffff:ffff:ffff:ffff:ffff
218fc50:d9::/32fc50:d9:ffff:ffff:ffff:ffff:ffff:ffff
219fc50:da::/32fc50:da:ffff:ffff:ffff:ffff:ffff:ffff
220fc50:db::/32fc50:db:ffff:ffff:ffff:ffff:ffff:ffff
221fc50:dc::/32fc50:dc:ffff:ffff:ffff:ffff:ffff:ffff
222fc50:dd::/32fc50:dd:ffff:ffff:ffff:ffff:ffff:ffff
223fc50:de::/32fc50:de:ffff:ffff:ffff:ffff:ffff:ffff
224fc50:df::/32fc50:df:ffff:ffff:ffff:ffff:ffff:ffff
225fc50:e0::/32fc50:e0:ffff:ffff:ffff:ffff:ffff:ffff
226fc50:e1::/32fc50:e1:ffff:ffff:ffff:ffff:ffff:ffff
227fc50:e2::/32fc50:e2:ffff:ffff:ffff:ffff:ffff:ffff
228fc50:e3::/32fc50:e3:ffff:ffff:ffff:ffff:ffff:ffff
229fc50:e4::/32fc50:e4:ffff:ffff:ffff:ffff:ffff:ffff
230fc50:e5::/32fc50:e5:ffff:ffff:ffff:ffff:ffff:ffff
231fc50:e6::/32fc50:e6:ffff:ffff:ffff:ffff:ffff:ffff
232fc50:e7::/32fc50:e7:ffff:ffff:ffff:ffff:ffff:ffff
233fc50:e8::/32fc50:e8:ffff:ffff:ffff:ffff:ffff:ffff
234fc50:e9::/32fc50:e9:ffff:ffff:ffff:ffff:ffff:ffff
235fc50:ea::/32fc50:ea:ffff:ffff:ffff:ffff:ffff:ffff
236fc50:eb::/32fc50:eb:ffff:ffff:ffff:ffff:ffff:ffff
237fc50:ec::/32fc50:ec:ffff:ffff:ffff:ffff:ffff:ffff
238fc50:ed::/32fc50:ed:ffff:ffff:ffff:ffff:ffff:ffff
239fc50:ee::/32fc50:ee:ffff:ffff:ffff:ffff:ffff:ffff
240fc50:ef::/32fc50:ef:ffff:ffff:ffff:ffff:ffff:ffff
241fc50:f0::/32fc50:f0:ffff:ffff:ffff:ffff:ffff:ffff
242fc50:f1::/32fc50:f1:ffff:ffff:ffff:ffff:ffff:ffff
243fc50:f2::/32fc50:f2:ffff:ffff:ffff:ffff:ffff:ffff
244fc50:f3::/32fc50:f3:ffff:ffff:ffff:ffff:ffff:ffff
245fc50:f4::/32fc50:f4:ffff:ffff:ffff:ffff:ffff:ffff
246fc50:f5::/32fc50:f5:ffff:ffff:ffff:ffff:ffff:ffff
247fc50:f6::/32fc50:f6:ffff:ffff:ffff:ffff:ffff:ffff
248fc50:f7::/32fc50:f7:ffff:ffff:ffff:ffff:ffff:ffff
249fc50:f8::/32fc50:f8:ffff:ffff:ffff:ffff:ffff:ffff
250fc50:f9::/32fc50:f9:ffff:ffff:ffff:ffff:ffff:ffff
251fc50:fa::/32fc50:fa:ffff:ffff:ffff:ffff:ffff:ffff
252fc50:fb::/32fc50:fb:ffff:ffff:ffff:ffff:ffff:ffff
253fc50:fc::/32fc50:fc:ffff:ffff:ffff:ffff:ffff:ffff
254fc50:fd::/32fc50:fd:ffff:ffff:ffff:ffff:ffff:ffff
255fc50:fe::/32fc50:fe:ffff:ffff:ffff:ffff:ffff:ffff
256fc50:ff::/32fc50: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.