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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
fc84::/16
First address
fc84::
Last address
fc84: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
fc84:0000:0000:0000:0000:0000:0000:0000
Type
Unique local (ULA) fc00::/7
Private IPv6, like RFC 1918; usually fd00::/8
Reverse DNS zone
4.8.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)

fc84::/16 makes 65,536 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
1fc84::/32fc84:0:ffff:ffff:ffff:ffff:ffff:ffff
2fc84:1::/32fc84:1:ffff:ffff:ffff:ffff:ffff:ffff
3fc84:2::/32fc84:2:ffff:ffff:ffff:ffff:ffff:ffff
4fc84:3::/32fc84:3:ffff:ffff:ffff:ffff:ffff:ffff
5fc84:4::/32fc84:4:ffff:ffff:ffff:ffff:ffff:ffff
6fc84:5::/32fc84:5:ffff:ffff:ffff:ffff:ffff:ffff
7fc84:6::/32fc84:6:ffff:ffff:ffff:ffff:ffff:ffff
8fc84:7::/32fc84:7:ffff:ffff:ffff:ffff:ffff:ffff
9fc84:8::/32fc84:8:ffff:ffff:ffff:ffff:ffff:ffff
10fc84:9::/32fc84:9:ffff:ffff:ffff:ffff:ffff:ffff
11fc84:a::/32fc84:a:ffff:ffff:ffff:ffff:ffff:ffff
12fc84:b::/32fc84:b:ffff:ffff:ffff:ffff:ffff:ffff
13fc84:c::/32fc84:c:ffff:ffff:ffff:ffff:ffff:ffff
14fc84:d::/32fc84:d:ffff:ffff:ffff:ffff:ffff:ffff
15fc84:e::/32fc84:e:ffff:ffff:ffff:ffff:ffff:ffff
16fc84:f::/32fc84:f:ffff:ffff:ffff:ffff:ffff:ffff
17fc84:10::/32fc84:10:ffff:ffff:ffff:ffff:ffff:ffff
18fc84:11::/32fc84:11:ffff:ffff:ffff:ffff:ffff:ffff
19fc84:12::/32fc84:12:ffff:ffff:ffff:ffff:ffff:ffff
20fc84:13::/32fc84:13:ffff:ffff:ffff:ffff:ffff:ffff
21fc84:14::/32fc84:14:ffff:ffff:ffff:ffff:ffff:ffff
22fc84:15::/32fc84:15:ffff:ffff:ffff:ffff:ffff:ffff
23fc84:16::/32fc84:16:ffff:ffff:ffff:ffff:ffff:ffff
24fc84:17::/32fc84:17:ffff:ffff:ffff:ffff:ffff:ffff
25fc84:18::/32fc84:18:ffff:ffff:ffff:ffff:ffff:ffff
26fc84:19::/32fc84:19:ffff:ffff:ffff:ffff:ffff:ffff
27fc84:1a::/32fc84:1a:ffff:ffff:ffff:ffff:ffff:ffff
28fc84:1b::/32fc84:1b:ffff:ffff:ffff:ffff:ffff:ffff
29fc84:1c::/32fc84:1c:ffff:ffff:ffff:ffff:ffff:ffff
30fc84:1d::/32fc84:1d:ffff:ffff:ffff:ffff:ffff:ffff
31fc84:1e::/32fc84:1e:ffff:ffff:ffff:ffff:ffff:ffff
32fc84:1f::/32fc84:1f:ffff:ffff:ffff:ffff:ffff:ffff
33fc84:20::/32fc84:20:ffff:ffff:ffff:ffff:ffff:ffff
34fc84:21::/32fc84:21:ffff:ffff:ffff:ffff:ffff:ffff
35fc84:22::/32fc84:22:ffff:ffff:ffff:ffff:ffff:ffff
36fc84:23::/32fc84:23:ffff:ffff:ffff:ffff:ffff:ffff
37fc84:24::/32fc84:24:ffff:ffff:ffff:ffff:ffff:ffff
38fc84:25::/32fc84:25:ffff:ffff:ffff:ffff:ffff:ffff
39fc84:26::/32fc84:26:ffff:ffff:ffff:ffff:ffff:ffff
40fc84:27::/32fc84:27:ffff:ffff:ffff:ffff:ffff:ffff
41fc84:28::/32fc84:28:ffff:ffff:ffff:ffff:ffff:ffff
42fc84:29::/32fc84:29:ffff:ffff:ffff:ffff:ffff:ffff
43fc84:2a::/32fc84:2a:ffff:ffff:ffff:ffff:ffff:ffff
44fc84:2b::/32fc84:2b:ffff:ffff:ffff:ffff:ffff:ffff
45fc84:2c::/32fc84:2c:ffff:ffff:ffff:ffff:ffff:ffff
46fc84:2d::/32fc84:2d:ffff:ffff:ffff:ffff:ffff:ffff
47fc84:2e::/32fc84:2e:ffff:ffff:ffff:ffff:ffff:ffff
48fc84:2f::/32fc84:2f:ffff:ffff:ffff:ffff:ffff:ffff
49fc84:30::/32fc84:30:ffff:ffff:ffff:ffff:ffff:ffff
50fc84:31::/32fc84:31:ffff:ffff:ffff:ffff:ffff:ffff
51fc84:32::/32fc84:32:ffff:ffff:ffff:ffff:ffff:ffff
52fc84:33::/32fc84:33:ffff:ffff:ffff:ffff:ffff:ffff
53fc84:34::/32fc84:34:ffff:ffff:ffff:ffff:ffff:ffff
54fc84:35::/32fc84:35:ffff:ffff:ffff:ffff:ffff:ffff
55fc84:36::/32fc84:36:ffff:ffff:ffff:ffff:ffff:ffff
56fc84:37::/32fc84:37:ffff:ffff:ffff:ffff:ffff:ffff
57fc84:38::/32fc84:38:ffff:ffff:ffff:ffff:ffff:ffff
58fc84:39::/32fc84:39:ffff:ffff:ffff:ffff:ffff:ffff
59fc84:3a::/32fc84:3a:ffff:ffff:ffff:ffff:ffff:ffff
60fc84:3b::/32fc84:3b:ffff:ffff:ffff:ffff:ffff:ffff
61fc84:3c::/32fc84:3c:ffff:ffff:ffff:ffff:ffff:ffff
62fc84:3d::/32fc84:3d:ffff:ffff:ffff:ffff:ffff:ffff
63fc84:3e::/32fc84:3e:ffff:ffff:ffff:ffff:ffff:ffff
64fc84:3f::/32fc84:3f:ffff:ffff:ffff:ffff:ffff:ffff
65fc84:40::/32fc84:40:ffff:ffff:ffff:ffff:ffff:ffff
66fc84:41::/32fc84:41:ffff:ffff:ffff:ffff:ffff:ffff
67fc84:42::/32fc84:42:ffff:ffff:ffff:ffff:ffff:ffff
68fc84:43::/32fc84:43:ffff:ffff:ffff:ffff:ffff:ffff
69fc84:44::/32fc84:44:ffff:ffff:ffff:ffff:ffff:ffff
70fc84:45::/32fc84:45:ffff:ffff:ffff:ffff:ffff:ffff
71fc84:46::/32fc84:46:ffff:ffff:ffff:ffff:ffff:ffff
72fc84:47::/32fc84:47:ffff:ffff:ffff:ffff:ffff:ffff
73fc84:48::/32fc84:48:ffff:ffff:ffff:ffff:ffff:ffff
74fc84:49::/32fc84:49:ffff:ffff:ffff:ffff:ffff:ffff
75fc84:4a::/32fc84:4a:ffff:ffff:ffff:ffff:ffff:ffff
76fc84:4b::/32fc84:4b:ffff:ffff:ffff:ffff:ffff:ffff
77fc84:4c::/32fc84:4c:ffff:ffff:ffff:ffff:ffff:ffff
78fc84:4d::/32fc84:4d:ffff:ffff:ffff:ffff:ffff:ffff
79fc84:4e::/32fc84:4e:ffff:ffff:ffff:ffff:ffff:ffff
80fc84:4f::/32fc84:4f:ffff:ffff:ffff:ffff:ffff:ffff
81fc84:50::/32fc84:50:ffff:ffff:ffff:ffff:ffff:ffff
82fc84:51::/32fc84:51:ffff:ffff:ffff:ffff:ffff:ffff
83fc84:52::/32fc84:52:ffff:ffff:ffff:ffff:ffff:ffff
84fc84:53::/32fc84:53:ffff:ffff:ffff:ffff:ffff:ffff
85fc84:54::/32fc84:54:ffff:ffff:ffff:ffff:ffff:ffff
86fc84:55::/32fc84:55:ffff:ffff:ffff:ffff:ffff:ffff
87fc84:56::/32fc84:56:ffff:ffff:ffff:ffff:ffff:ffff
88fc84:57::/32fc84:57:ffff:ffff:ffff:ffff:ffff:ffff
89fc84:58::/32fc84:58:ffff:ffff:ffff:ffff:ffff:ffff
90fc84:59::/32fc84:59:ffff:ffff:ffff:ffff:ffff:ffff
91fc84:5a::/32fc84:5a:ffff:ffff:ffff:ffff:ffff:ffff
92fc84:5b::/32fc84:5b:ffff:ffff:ffff:ffff:ffff:ffff
93fc84:5c::/32fc84:5c:ffff:ffff:ffff:ffff:ffff:ffff
94fc84:5d::/32fc84:5d:ffff:ffff:ffff:ffff:ffff:ffff
95fc84:5e::/32fc84:5e:ffff:ffff:ffff:ffff:ffff:ffff
96fc84:5f::/32fc84:5f:ffff:ffff:ffff:ffff:ffff:ffff
97fc84:60::/32fc84:60:ffff:ffff:ffff:ffff:ffff:ffff
98fc84:61::/32fc84:61:ffff:ffff:ffff:ffff:ffff:ffff
99fc84:62::/32fc84:62:ffff:ffff:ffff:ffff:ffff:ffff
100fc84:63::/32fc84:63:ffff:ffff:ffff:ffff:ffff:ffff
101fc84:64::/32fc84:64:ffff:ffff:ffff:ffff:ffff:ffff
102fc84:65::/32fc84:65:ffff:ffff:ffff:ffff:ffff:ffff
103fc84:66::/32fc84:66:ffff:ffff:ffff:ffff:ffff:ffff
104fc84:67::/32fc84:67:ffff:ffff:ffff:ffff:ffff:ffff
105fc84:68::/32fc84:68:ffff:ffff:ffff:ffff:ffff:ffff
106fc84:69::/32fc84:69:ffff:ffff:ffff:ffff:ffff:ffff
107fc84:6a::/32fc84:6a:ffff:ffff:ffff:ffff:ffff:ffff
108fc84:6b::/32fc84:6b:ffff:ffff:ffff:ffff:ffff:ffff
109fc84:6c::/32fc84:6c:ffff:ffff:ffff:ffff:ffff:ffff
110fc84:6d::/32fc84:6d:ffff:ffff:ffff:ffff:ffff:ffff
111fc84:6e::/32fc84:6e:ffff:ffff:ffff:ffff:ffff:ffff
112fc84:6f::/32fc84:6f:ffff:ffff:ffff:ffff:ffff:ffff
113fc84:70::/32fc84:70:ffff:ffff:ffff:ffff:ffff:ffff
114fc84:71::/32fc84:71:ffff:ffff:ffff:ffff:ffff:ffff
115fc84:72::/32fc84:72:ffff:ffff:ffff:ffff:ffff:ffff
116fc84:73::/32fc84:73:ffff:ffff:ffff:ffff:ffff:ffff
117fc84:74::/32fc84:74:ffff:ffff:ffff:ffff:ffff:ffff
118fc84:75::/32fc84:75:ffff:ffff:ffff:ffff:ffff:ffff
119fc84:76::/32fc84:76:ffff:ffff:ffff:ffff:ffff:ffff
120fc84:77::/32fc84:77:ffff:ffff:ffff:ffff:ffff:ffff
121fc84:78::/32fc84:78:ffff:ffff:ffff:ffff:ffff:ffff
122fc84:79::/32fc84:79:ffff:ffff:ffff:ffff:ffff:ffff
123fc84:7a::/32fc84:7a:ffff:ffff:ffff:ffff:ffff:ffff
124fc84:7b::/32fc84:7b:ffff:ffff:ffff:ffff:ffff:ffff
125fc84:7c::/32fc84:7c:ffff:ffff:ffff:ffff:ffff:ffff
126fc84:7d::/32fc84:7d:ffff:ffff:ffff:ffff:ffff:ffff
127fc84:7e::/32fc84:7e:ffff:ffff:ffff:ffff:ffff:ffff
128fc84:7f::/32fc84:7f:ffff:ffff:ffff:ffff:ffff:ffff
129fc84:80::/32fc84:80:ffff:ffff:ffff:ffff:ffff:ffff
130fc84:81::/32fc84:81:ffff:ffff:ffff:ffff:ffff:ffff
131fc84:82::/32fc84:82:ffff:ffff:ffff:ffff:ffff:ffff
132fc84:83::/32fc84:83:ffff:ffff:ffff:ffff:ffff:ffff
133fc84:84::/32fc84:84:ffff:ffff:ffff:ffff:ffff:ffff
134fc84:85::/32fc84:85:ffff:ffff:ffff:ffff:ffff:ffff
135fc84:86::/32fc84:86:ffff:ffff:ffff:ffff:ffff:ffff
136fc84:87::/32fc84:87:ffff:ffff:ffff:ffff:ffff:ffff
137fc84:88::/32fc84:88:ffff:ffff:ffff:ffff:ffff:ffff
138fc84:89::/32fc84:89:ffff:ffff:ffff:ffff:ffff:ffff
139fc84:8a::/32fc84:8a:ffff:ffff:ffff:ffff:ffff:ffff
140fc84:8b::/32fc84:8b:ffff:ffff:ffff:ffff:ffff:ffff
141fc84:8c::/32fc84:8c:ffff:ffff:ffff:ffff:ffff:ffff
142fc84:8d::/32fc84:8d:ffff:ffff:ffff:ffff:ffff:ffff
143fc84:8e::/32fc84:8e:ffff:ffff:ffff:ffff:ffff:ffff
144fc84:8f::/32fc84:8f:ffff:ffff:ffff:ffff:ffff:ffff
145fc84:90::/32fc84:90:ffff:ffff:ffff:ffff:ffff:ffff
146fc84:91::/32fc84:91:ffff:ffff:ffff:ffff:ffff:ffff
147fc84:92::/32fc84:92:ffff:ffff:ffff:ffff:ffff:ffff
148fc84:93::/32fc84:93:ffff:ffff:ffff:ffff:ffff:ffff
149fc84:94::/32fc84:94:ffff:ffff:ffff:ffff:ffff:ffff
150fc84:95::/32fc84:95:ffff:ffff:ffff:ffff:ffff:ffff
151fc84:96::/32fc84:96:ffff:ffff:ffff:ffff:ffff:ffff
152fc84:97::/32fc84:97:ffff:ffff:ffff:ffff:ffff:ffff
153fc84:98::/32fc84:98:ffff:ffff:ffff:ffff:ffff:ffff
154fc84:99::/32fc84:99:ffff:ffff:ffff:ffff:ffff:ffff
155fc84:9a::/32fc84:9a:ffff:ffff:ffff:ffff:ffff:ffff
156fc84:9b::/32fc84:9b:ffff:ffff:ffff:ffff:ffff:ffff
157fc84:9c::/32fc84:9c:ffff:ffff:ffff:ffff:ffff:ffff
158fc84:9d::/32fc84:9d:ffff:ffff:ffff:ffff:ffff:ffff
159fc84:9e::/32fc84:9e:ffff:ffff:ffff:ffff:ffff:ffff
160fc84:9f::/32fc84:9f:ffff:ffff:ffff:ffff:ffff:ffff
161fc84:a0::/32fc84:a0:ffff:ffff:ffff:ffff:ffff:ffff
162fc84:a1::/32fc84:a1:ffff:ffff:ffff:ffff:ffff:ffff
163fc84:a2::/32fc84:a2:ffff:ffff:ffff:ffff:ffff:ffff
164fc84:a3::/32fc84:a3:ffff:ffff:ffff:ffff:ffff:ffff
165fc84:a4::/32fc84:a4:ffff:ffff:ffff:ffff:ffff:ffff
166fc84:a5::/32fc84:a5:ffff:ffff:ffff:ffff:ffff:ffff
167fc84:a6::/32fc84:a6:ffff:ffff:ffff:ffff:ffff:ffff
168fc84:a7::/32fc84:a7:ffff:ffff:ffff:ffff:ffff:ffff
169fc84:a8::/32fc84:a8:ffff:ffff:ffff:ffff:ffff:ffff
170fc84:a9::/32fc84:a9:ffff:ffff:ffff:ffff:ffff:ffff
171fc84:aa::/32fc84:aa:ffff:ffff:ffff:ffff:ffff:ffff
172fc84:ab::/32fc84:ab:ffff:ffff:ffff:ffff:ffff:ffff
173fc84:ac::/32fc84:ac:ffff:ffff:ffff:ffff:ffff:ffff
174fc84:ad::/32fc84:ad:ffff:ffff:ffff:ffff:ffff:ffff
175fc84:ae::/32fc84:ae:ffff:ffff:ffff:ffff:ffff:ffff
176fc84:af::/32fc84:af:ffff:ffff:ffff:ffff:ffff:ffff
177fc84:b0::/32fc84:b0:ffff:ffff:ffff:ffff:ffff:ffff
178fc84:b1::/32fc84:b1:ffff:ffff:ffff:ffff:ffff:ffff
179fc84:b2::/32fc84:b2:ffff:ffff:ffff:ffff:ffff:ffff
180fc84:b3::/32fc84:b3:ffff:ffff:ffff:ffff:ffff:ffff
181fc84:b4::/32fc84:b4:ffff:ffff:ffff:ffff:ffff:ffff
182fc84:b5::/32fc84:b5:ffff:ffff:ffff:ffff:ffff:ffff
183fc84:b6::/32fc84:b6:ffff:ffff:ffff:ffff:ffff:ffff
184fc84:b7::/32fc84:b7:ffff:ffff:ffff:ffff:ffff:ffff
185fc84:b8::/32fc84:b8:ffff:ffff:ffff:ffff:ffff:ffff
186fc84:b9::/32fc84:b9:ffff:ffff:ffff:ffff:ffff:ffff
187fc84:ba::/32fc84:ba:ffff:ffff:ffff:ffff:ffff:ffff
188fc84:bb::/32fc84:bb:ffff:ffff:ffff:ffff:ffff:ffff
189fc84:bc::/32fc84:bc:ffff:ffff:ffff:ffff:ffff:ffff
190fc84:bd::/32fc84:bd:ffff:ffff:ffff:ffff:ffff:ffff
191fc84:be::/32fc84:be:ffff:ffff:ffff:ffff:ffff:ffff
192fc84:bf::/32fc84:bf:ffff:ffff:ffff:ffff:ffff:ffff
193fc84:c0::/32fc84:c0:ffff:ffff:ffff:ffff:ffff:ffff
194fc84:c1::/32fc84:c1:ffff:ffff:ffff:ffff:ffff:ffff
195fc84:c2::/32fc84:c2:ffff:ffff:ffff:ffff:ffff:ffff
196fc84:c3::/32fc84:c3:ffff:ffff:ffff:ffff:ffff:ffff
197fc84:c4::/32fc84:c4:ffff:ffff:ffff:ffff:ffff:ffff
198fc84:c5::/32fc84:c5:ffff:ffff:ffff:ffff:ffff:ffff
199fc84:c6::/32fc84:c6:ffff:ffff:ffff:ffff:ffff:ffff
200fc84:c7::/32fc84:c7:ffff:ffff:ffff:ffff:ffff:ffff
201fc84:c8::/32fc84:c8:ffff:ffff:ffff:ffff:ffff:ffff
202fc84:c9::/32fc84:c9:ffff:ffff:ffff:ffff:ffff:ffff
203fc84:ca::/32fc84:ca:ffff:ffff:ffff:ffff:ffff:ffff
204fc84:cb::/32fc84:cb:ffff:ffff:ffff:ffff:ffff:ffff
205fc84:cc::/32fc84:cc:ffff:ffff:ffff:ffff:ffff:ffff
206fc84:cd::/32fc84:cd:ffff:ffff:ffff:ffff:ffff:ffff
207fc84:ce::/32fc84:ce:ffff:ffff:ffff:ffff:ffff:ffff
208fc84:cf::/32fc84:cf:ffff:ffff:ffff:ffff:ffff:ffff
209fc84:d0::/32fc84:d0:ffff:ffff:ffff:ffff:ffff:ffff
210fc84:d1::/32fc84:d1:ffff:ffff:ffff:ffff:ffff:ffff
211fc84:d2::/32fc84:d2:ffff:ffff:ffff:ffff:ffff:ffff
212fc84:d3::/32fc84:d3:ffff:ffff:ffff:ffff:ffff:ffff
213fc84:d4::/32fc84:d4:ffff:ffff:ffff:ffff:ffff:ffff
214fc84:d5::/32fc84:d5:ffff:ffff:ffff:ffff:ffff:ffff
215fc84:d6::/32fc84:d6:ffff:ffff:ffff:ffff:ffff:ffff
216fc84:d7::/32fc84:d7:ffff:ffff:ffff:ffff:ffff:ffff
217fc84:d8::/32fc84:d8:ffff:ffff:ffff:ffff:ffff:ffff
218fc84:d9::/32fc84:d9:ffff:ffff:ffff:ffff:ffff:ffff
219fc84:da::/32fc84:da:ffff:ffff:ffff:ffff:ffff:ffff
220fc84:db::/32fc84:db:ffff:ffff:ffff:ffff:ffff:ffff
221fc84:dc::/32fc84:dc:ffff:ffff:ffff:ffff:ffff:ffff
222fc84:dd::/32fc84:dd:ffff:ffff:ffff:ffff:ffff:ffff
223fc84:de::/32fc84:de:ffff:ffff:ffff:ffff:ffff:ffff
224fc84:df::/32fc84:df:ffff:ffff:ffff:ffff:ffff:ffff
225fc84:e0::/32fc84:e0:ffff:ffff:ffff:ffff:ffff:ffff
226fc84:e1::/32fc84:e1:ffff:ffff:ffff:ffff:ffff:ffff
227fc84:e2::/32fc84:e2:ffff:ffff:ffff:ffff:ffff:ffff
228fc84:e3::/32fc84:e3:ffff:ffff:ffff:ffff:ffff:ffff
229fc84:e4::/32fc84:e4:ffff:ffff:ffff:ffff:ffff:ffff
230fc84:e5::/32fc84:e5:ffff:ffff:ffff:ffff:ffff:ffff
231fc84:e6::/32fc84:e6:ffff:ffff:ffff:ffff:ffff:ffff
232fc84:e7::/32fc84:e7:ffff:ffff:ffff:ffff:ffff:ffff
233fc84:e8::/32fc84:e8:ffff:ffff:ffff:ffff:ffff:ffff
234fc84:e9::/32fc84:e9:ffff:ffff:ffff:ffff:ffff:ffff
235fc84:ea::/32fc84:ea:ffff:ffff:ffff:ffff:ffff:ffff
236fc84:eb::/32fc84:eb:ffff:ffff:ffff:ffff:ffff:ffff
237fc84:ec::/32fc84:ec:ffff:ffff:ffff:ffff:ffff:ffff
238fc84:ed::/32fc84:ed:ffff:ffff:ffff:ffff:ffff:ffff
239fc84:ee::/32fc84:ee:ffff:ffff:ffff:ffff:ffff:ffff
240fc84:ef::/32fc84:ef:ffff:ffff:ffff:ffff:ffff:ffff
241fc84:f0::/32fc84:f0:ffff:ffff:ffff:ffff:ffff:ffff
242fc84:f1::/32fc84:f1:ffff:ffff:ffff:ffff:ffff:ffff
243fc84:f2::/32fc84:f2:ffff:ffff:ffff:ffff:ffff:ffff
244fc84:f3::/32fc84:f3:ffff:ffff:ffff:ffff:ffff:ffff
245fc84:f4::/32fc84:f4:ffff:ffff:ffff:ffff:ffff:ffff
246fc84:f5::/32fc84:f5:ffff:ffff:ffff:ffff:ffff:ffff
247fc84:f6::/32fc84:f6:ffff:ffff:ffff:ffff:ffff:ffff
248fc84:f7::/32fc84:f7:ffff:ffff:ffff:ffff:ffff:ffff
249fc84:f8::/32fc84:f8:ffff:ffff:ffff:ffff:ffff:ffff
250fc84:f9::/32fc84:f9:ffff:ffff:ffff:ffff:ffff:ffff
251fc84:fa::/32fc84:fa:ffff:ffff:ffff:ffff:ffff:ffff
252fc84:fb::/32fc84:fb:ffff:ffff:ffff:ffff:ffff:ffff
253fc84:fc::/32fc84:fc:ffff:ffff:ffff:ffff:ffff:ffff
254fc84:fd::/32fc84:fd:ffff:ffff:ffff:ffff:ffff:ffff
255fc84:fe::/32fc84:fe:ffff:ffff:ffff:ffff:ffff:ffff
256fc84:ff::/32fc84: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.