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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
fc49::/16
First address
fc49::
Last address
fc49: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
fc49:0000:0000:0000:0000:0000:0000:0000
Type
Unique local (ULA) fc00::/7
Private IPv6, like RFC 1918; usually fd00::/8
Reverse DNS zone
9.4.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)

fc49::/16 makes 65,536 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
1fc49::/32fc49:0:ffff:ffff:ffff:ffff:ffff:ffff
2fc49:1::/32fc49:1:ffff:ffff:ffff:ffff:ffff:ffff
3fc49:2::/32fc49:2:ffff:ffff:ffff:ffff:ffff:ffff
4fc49:3::/32fc49:3:ffff:ffff:ffff:ffff:ffff:ffff
5fc49:4::/32fc49:4:ffff:ffff:ffff:ffff:ffff:ffff
6fc49:5::/32fc49:5:ffff:ffff:ffff:ffff:ffff:ffff
7fc49:6::/32fc49:6:ffff:ffff:ffff:ffff:ffff:ffff
8fc49:7::/32fc49:7:ffff:ffff:ffff:ffff:ffff:ffff
9fc49:8::/32fc49:8:ffff:ffff:ffff:ffff:ffff:ffff
10fc49:9::/32fc49:9:ffff:ffff:ffff:ffff:ffff:ffff
11fc49:a::/32fc49:a:ffff:ffff:ffff:ffff:ffff:ffff
12fc49:b::/32fc49:b:ffff:ffff:ffff:ffff:ffff:ffff
13fc49:c::/32fc49:c:ffff:ffff:ffff:ffff:ffff:ffff
14fc49:d::/32fc49:d:ffff:ffff:ffff:ffff:ffff:ffff
15fc49:e::/32fc49:e:ffff:ffff:ffff:ffff:ffff:ffff
16fc49:f::/32fc49:f:ffff:ffff:ffff:ffff:ffff:ffff
17fc49:10::/32fc49:10:ffff:ffff:ffff:ffff:ffff:ffff
18fc49:11::/32fc49:11:ffff:ffff:ffff:ffff:ffff:ffff
19fc49:12::/32fc49:12:ffff:ffff:ffff:ffff:ffff:ffff
20fc49:13::/32fc49:13:ffff:ffff:ffff:ffff:ffff:ffff
21fc49:14::/32fc49:14:ffff:ffff:ffff:ffff:ffff:ffff
22fc49:15::/32fc49:15:ffff:ffff:ffff:ffff:ffff:ffff
23fc49:16::/32fc49:16:ffff:ffff:ffff:ffff:ffff:ffff
24fc49:17::/32fc49:17:ffff:ffff:ffff:ffff:ffff:ffff
25fc49:18::/32fc49:18:ffff:ffff:ffff:ffff:ffff:ffff
26fc49:19::/32fc49:19:ffff:ffff:ffff:ffff:ffff:ffff
27fc49:1a::/32fc49:1a:ffff:ffff:ffff:ffff:ffff:ffff
28fc49:1b::/32fc49:1b:ffff:ffff:ffff:ffff:ffff:ffff
29fc49:1c::/32fc49:1c:ffff:ffff:ffff:ffff:ffff:ffff
30fc49:1d::/32fc49:1d:ffff:ffff:ffff:ffff:ffff:ffff
31fc49:1e::/32fc49:1e:ffff:ffff:ffff:ffff:ffff:ffff
32fc49:1f::/32fc49:1f:ffff:ffff:ffff:ffff:ffff:ffff
33fc49:20::/32fc49:20:ffff:ffff:ffff:ffff:ffff:ffff
34fc49:21::/32fc49:21:ffff:ffff:ffff:ffff:ffff:ffff
35fc49:22::/32fc49:22:ffff:ffff:ffff:ffff:ffff:ffff
36fc49:23::/32fc49:23:ffff:ffff:ffff:ffff:ffff:ffff
37fc49:24::/32fc49:24:ffff:ffff:ffff:ffff:ffff:ffff
38fc49:25::/32fc49:25:ffff:ffff:ffff:ffff:ffff:ffff
39fc49:26::/32fc49:26:ffff:ffff:ffff:ffff:ffff:ffff
40fc49:27::/32fc49:27:ffff:ffff:ffff:ffff:ffff:ffff
41fc49:28::/32fc49:28:ffff:ffff:ffff:ffff:ffff:ffff
42fc49:29::/32fc49:29:ffff:ffff:ffff:ffff:ffff:ffff
43fc49:2a::/32fc49:2a:ffff:ffff:ffff:ffff:ffff:ffff
44fc49:2b::/32fc49:2b:ffff:ffff:ffff:ffff:ffff:ffff
45fc49:2c::/32fc49:2c:ffff:ffff:ffff:ffff:ffff:ffff
46fc49:2d::/32fc49:2d:ffff:ffff:ffff:ffff:ffff:ffff
47fc49:2e::/32fc49:2e:ffff:ffff:ffff:ffff:ffff:ffff
48fc49:2f::/32fc49:2f:ffff:ffff:ffff:ffff:ffff:ffff
49fc49:30::/32fc49:30:ffff:ffff:ffff:ffff:ffff:ffff
50fc49:31::/32fc49:31:ffff:ffff:ffff:ffff:ffff:ffff
51fc49:32::/32fc49:32:ffff:ffff:ffff:ffff:ffff:ffff
52fc49:33::/32fc49:33:ffff:ffff:ffff:ffff:ffff:ffff
53fc49:34::/32fc49:34:ffff:ffff:ffff:ffff:ffff:ffff
54fc49:35::/32fc49:35:ffff:ffff:ffff:ffff:ffff:ffff
55fc49:36::/32fc49:36:ffff:ffff:ffff:ffff:ffff:ffff
56fc49:37::/32fc49:37:ffff:ffff:ffff:ffff:ffff:ffff
57fc49:38::/32fc49:38:ffff:ffff:ffff:ffff:ffff:ffff
58fc49:39::/32fc49:39:ffff:ffff:ffff:ffff:ffff:ffff
59fc49:3a::/32fc49:3a:ffff:ffff:ffff:ffff:ffff:ffff
60fc49:3b::/32fc49:3b:ffff:ffff:ffff:ffff:ffff:ffff
61fc49:3c::/32fc49:3c:ffff:ffff:ffff:ffff:ffff:ffff
62fc49:3d::/32fc49:3d:ffff:ffff:ffff:ffff:ffff:ffff
63fc49:3e::/32fc49:3e:ffff:ffff:ffff:ffff:ffff:ffff
64fc49:3f::/32fc49:3f:ffff:ffff:ffff:ffff:ffff:ffff
65fc49:40::/32fc49:40:ffff:ffff:ffff:ffff:ffff:ffff
66fc49:41::/32fc49:41:ffff:ffff:ffff:ffff:ffff:ffff
67fc49:42::/32fc49:42:ffff:ffff:ffff:ffff:ffff:ffff
68fc49:43::/32fc49:43:ffff:ffff:ffff:ffff:ffff:ffff
69fc49:44::/32fc49:44:ffff:ffff:ffff:ffff:ffff:ffff
70fc49:45::/32fc49:45:ffff:ffff:ffff:ffff:ffff:ffff
71fc49:46::/32fc49:46:ffff:ffff:ffff:ffff:ffff:ffff
72fc49:47::/32fc49:47:ffff:ffff:ffff:ffff:ffff:ffff
73fc49:48::/32fc49:48:ffff:ffff:ffff:ffff:ffff:ffff
74fc49:49::/32fc49:49:ffff:ffff:ffff:ffff:ffff:ffff
75fc49:4a::/32fc49:4a:ffff:ffff:ffff:ffff:ffff:ffff
76fc49:4b::/32fc49:4b:ffff:ffff:ffff:ffff:ffff:ffff
77fc49:4c::/32fc49:4c:ffff:ffff:ffff:ffff:ffff:ffff
78fc49:4d::/32fc49:4d:ffff:ffff:ffff:ffff:ffff:ffff
79fc49:4e::/32fc49:4e:ffff:ffff:ffff:ffff:ffff:ffff
80fc49:4f::/32fc49:4f:ffff:ffff:ffff:ffff:ffff:ffff
81fc49:50::/32fc49:50:ffff:ffff:ffff:ffff:ffff:ffff
82fc49:51::/32fc49:51:ffff:ffff:ffff:ffff:ffff:ffff
83fc49:52::/32fc49:52:ffff:ffff:ffff:ffff:ffff:ffff
84fc49:53::/32fc49:53:ffff:ffff:ffff:ffff:ffff:ffff
85fc49:54::/32fc49:54:ffff:ffff:ffff:ffff:ffff:ffff
86fc49:55::/32fc49:55:ffff:ffff:ffff:ffff:ffff:ffff
87fc49:56::/32fc49:56:ffff:ffff:ffff:ffff:ffff:ffff
88fc49:57::/32fc49:57:ffff:ffff:ffff:ffff:ffff:ffff
89fc49:58::/32fc49:58:ffff:ffff:ffff:ffff:ffff:ffff
90fc49:59::/32fc49:59:ffff:ffff:ffff:ffff:ffff:ffff
91fc49:5a::/32fc49:5a:ffff:ffff:ffff:ffff:ffff:ffff
92fc49:5b::/32fc49:5b:ffff:ffff:ffff:ffff:ffff:ffff
93fc49:5c::/32fc49:5c:ffff:ffff:ffff:ffff:ffff:ffff
94fc49:5d::/32fc49:5d:ffff:ffff:ffff:ffff:ffff:ffff
95fc49:5e::/32fc49:5e:ffff:ffff:ffff:ffff:ffff:ffff
96fc49:5f::/32fc49:5f:ffff:ffff:ffff:ffff:ffff:ffff
97fc49:60::/32fc49:60:ffff:ffff:ffff:ffff:ffff:ffff
98fc49:61::/32fc49:61:ffff:ffff:ffff:ffff:ffff:ffff
99fc49:62::/32fc49:62:ffff:ffff:ffff:ffff:ffff:ffff
100fc49:63::/32fc49:63:ffff:ffff:ffff:ffff:ffff:ffff
101fc49:64::/32fc49:64:ffff:ffff:ffff:ffff:ffff:ffff
102fc49:65::/32fc49:65:ffff:ffff:ffff:ffff:ffff:ffff
103fc49:66::/32fc49:66:ffff:ffff:ffff:ffff:ffff:ffff
104fc49:67::/32fc49:67:ffff:ffff:ffff:ffff:ffff:ffff
105fc49:68::/32fc49:68:ffff:ffff:ffff:ffff:ffff:ffff
106fc49:69::/32fc49:69:ffff:ffff:ffff:ffff:ffff:ffff
107fc49:6a::/32fc49:6a:ffff:ffff:ffff:ffff:ffff:ffff
108fc49:6b::/32fc49:6b:ffff:ffff:ffff:ffff:ffff:ffff
109fc49:6c::/32fc49:6c:ffff:ffff:ffff:ffff:ffff:ffff
110fc49:6d::/32fc49:6d:ffff:ffff:ffff:ffff:ffff:ffff
111fc49:6e::/32fc49:6e:ffff:ffff:ffff:ffff:ffff:ffff
112fc49:6f::/32fc49:6f:ffff:ffff:ffff:ffff:ffff:ffff
113fc49:70::/32fc49:70:ffff:ffff:ffff:ffff:ffff:ffff
114fc49:71::/32fc49:71:ffff:ffff:ffff:ffff:ffff:ffff
115fc49:72::/32fc49:72:ffff:ffff:ffff:ffff:ffff:ffff
116fc49:73::/32fc49:73:ffff:ffff:ffff:ffff:ffff:ffff
117fc49:74::/32fc49:74:ffff:ffff:ffff:ffff:ffff:ffff
118fc49:75::/32fc49:75:ffff:ffff:ffff:ffff:ffff:ffff
119fc49:76::/32fc49:76:ffff:ffff:ffff:ffff:ffff:ffff
120fc49:77::/32fc49:77:ffff:ffff:ffff:ffff:ffff:ffff
121fc49:78::/32fc49:78:ffff:ffff:ffff:ffff:ffff:ffff
122fc49:79::/32fc49:79:ffff:ffff:ffff:ffff:ffff:ffff
123fc49:7a::/32fc49:7a:ffff:ffff:ffff:ffff:ffff:ffff
124fc49:7b::/32fc49:7b:ffff:ffff:ffff:ffff:ffff:ffff
125fc49:7c::/32fc49:7c:ffff:ffff:ffff:ffff:ffff:ffff
126fc49:7d::/32fc49:7d:ffff:ffff:ffff:ffff:ffff:ffff
127fc49:7e::/32fc49:7e:ffff:ffff:ffff:ffff:ffff:ffff
128fc49:7f::/32fc49:7f:ffff:ffff:ffff:ffff:ffff:ffff
129fc49:80::/32fc49:80:ffff:ffff:ffff:ffff:ffff:ffff
130fc49:81::/32fc49:81:ffff:ffff:ffff:ffff:ffff:ffff
131fc49:82::/32fc49:82:ffff:ffff:ffff:ffff:ffff:ffff
132fc49:83::/32fc49:83:ffff:ffff:ffff:ffff:ffff:ffff
133fc49:84::/32fc49:84:ffff:ffff:ffff:ffff:ffff:ffff
134fc49:85::/32fc49:85:ffff:ffff:ffff:ffff:ffff:ffff
135fc49:86::/32fc49:86:ffff:ffff:ffff:ffff:ffff:ffff
136fc49:87::/32fc49:87:ffff:ffff:ffff:ffff:ffff:ffff
137fc49:88::/32fc49:88:ffff:ffff:ffff:ffff:ffff:ffff
138fc49:89::/32fc49:89:ffff:ffff:ffff:ffff:ffff:ffff
139fc49:8a::/32fc49:8a:ffff:ffff:ffff:ffff:ffff:ffff
140fc49:8b::/32fc49:8b:ffff:ffff:ffff:ffff:ffff:ffff
141fc49:8c::/32fc49:8c:ffff:ffff:ffff:ffff:ffff:ffff
142fc49:8d::/32fc49:8d:ffff:ffff:ffff:ffff:ffff:ffff
143fc49:8e::/32fc49:8e:ffff:ffff:ffff:ffff:ffff:ffff
144fc49:8f::/32fc49:8f:ffff:ffff:ffff:ffff:ffff:ffff
145fc49:90::/32fc49:90:ffff:ffff:ffff:ffff:ffff:ffff
146fc49:91::/32fc49:91:ffff:ffff:ffff:ffff:ffff:ffff
147fc49:92::/32fc49:92:ffff:ffff:ffff:ffff:ffff:ffff
148fc49:93::/32fc49:93:ffff:ffff:ffff:ffff:ffff:ffff
149fc49:94::/32fc49:94:ffff:ffff:ffff:ffff:ffff:ffff
150fc49:95::/32fc49:95:ffff:ffff:ffff:ffff:ffff:ffff
151fc49:96::/32fc49:96:ffff:ffff:ffff:ffff:ffff:ffff
152fc49:97::/32fc49:97:ffff:ffff:ffff:ffff:ffff:ffff
153fc49:98::/32fc49:98:ffff:ffff:ffff:ffff:ffff:ffff
154fc49:99::/32fc49:99:ffff:ffff:ffff:ffff:ffff:ffff
155fc49:9a::/32fc49:9a:ffff:ffff:ffff:ffff:ffff:ffff
156fc49:9b::/32fc49:9b:ffff:ffff:ffff:ffff:ffff:ffff
157fc49:9c::/32fc49:9c:ffff:ffff:ffff:ffff:ffff:ffff
158fc49:9d::/32fc49:9d:ffff:ffff:ffff:ffff:ffff:ffff
159fc49:9e::/32fc49:9e:ffff:ffff:ffff:ffff:ffff:ffff
160fc49:9f::/32fc49:9f:ffff:ffff:ffff:ffff:ffff:ffff
161fc49:a0::/32fc49:a0:ffff:ffff:ffff:ffff:ffff:ffff
162fc49:a1::/32fc49:a1:ffff:ffff:ffff:ffff:ffff:ffff
163fc49:a2::/32fc49:a2:ffff:ffff:ffff:ffff:ffff:ffff
164fc49:a3::/32fc49:a3:ffff:ffff:ffff:ffff:ffff:ffff
165fc49:a4::/32fc49:a4:ffff:ffff:ffff:ffff:ffff:ffff
166fc49:a5::/32fc49:a5:ffff:ffff:ffff:ffff:ffff:ffff
167fc49:a6::/32fc49:a6:ffff:ffff:ffff:ffff:ffff:ffff
168fc49:a7::/32fc49:a7:ffff:ffff:ffff:ffff:ffff:ffff
169fc49:a8::/32fc49:a8:ffff:ffff:ffff:ffff:ffff:ffff
170fc49:a9::/32fc49:a9:ffff:ffff:ffff:ffff:ffff:ffff
171fc49:aa::/32fc49:aa:ffff:ffff:ffff:ffff:ffff:ffff
172fc49:ab::/32fc49:ab:ffff:ffff:ffff:ffff:ffff:ffff
173fc49:ac::/32fc49:ac:ffff:ffff:ffff:ffff:ffff:ffff
174fc49:ad::/32fc49:ad:ffff:ffff:ffff:ffff:ffff:ffff
175fc49:ae::/32fc49:ae:ffff:ffff:ffff:ffff:ffff:ffff
176fc49:af::/32fc49:af:ffff:ffff:ffff:ffff:ffff:ffff
177fc49:b0::/32fc49:b0:ffff:ffff:ffff:ffff:ffff:ffff
178fc49:b1::/32fc49:b1:ffff:ffff:ffff:ffff:ffff:ffff
179fc49:b2::/32fc49:b2:ffff:ffff:ffff:ffff:ffff:ffff
180fc49:b3::/32fc49:b3:ffff:ffff:ffff:ffff:ffff:ffff
181fc49:b4::/32fc49:b4:ffff:ffff:ffff:ffff:ffff:ffff
182fc49:b5::/32fc49:b5:ffff:ffff:ffff:ffff:ffff:ffff
183fc49:b6::/32fc49:b6:ffff:ffff:ffff:ffff:ffff:ffff
184fc49:b7::/32fc49:b7:ffff:ffff:ffff:ffff:ffff:ffff
185fc49:b8::/32fc49:b8:ffff:ffff:ffff:ffff:ffff:ffff
186fc49:b9::/32fc49:b9:ffff:ffff:ffff:ffff:ffff:ffff
187fc49:ba::/32fc49:ba:ffff:ffff:ffff:ffff:ffff:ffff
188fc49:bb::/32fc49:bb:ffff:ffff:ffff:ffff:ffff:ffff
189fc49:bc::/32fc49:bc:ffff:ffff:ffff:ffff:ffff:ffff
190fc49:bd::/32fc49:bd:ffff:ffff:ffff:ffff:ffff:ffff
191fc49:be::/32fc49:be:ffff:ffff:ffff:ffff:ffff:ffff
192fc49:bf::/32fc49:bf:ffff:ffff:ffff:ffff:ffff:ffff
193fc49:c0::/32fc49:c0:ffff:ffff:ffff:ffff:ffff:ffff
194fc49:c1::/32fc49:c1:ffff:ffff:ffff:ffff:ffff:ffff
195fc49:c2::/32fc49:c2:ffff:ffff:ffff:ffff:ffff:ffff
196fc49:c3::/32fc49:c3:ffff:ffff:ffff:ffff:ffff:ffff
197fc49:c4::/32fc49:c4:ffff:ffff:ffff:ffff:ffff:ffff
198fc49:c5::/32fc49:c5:ffff:ffff:ffff:ffff:ffff:ffff
199fc49:c6::/32fc49:c6:ffff:ffff:ffff:ffff:ffff:ffff
200fc49:c7::/32fc49:c7:ffff:ffff:ffff:ffff:ffff:ffff
201fc49:c8::/32fc49:c8:ffff:ffff:ffff:ffff:ffff:ffff
202fc49:c9::/32fc49:c9:ffff:ffff:ffff:ffff:ffff:ffff
203fc49:ca::/32fc49:ca:ffff:ffff:ffff:ffff:ffff:ffff
204fc49:cb::/32fc49:cb:ffff:ffff:ffff:ffff:ffff:ffff
205fc49:cc::/32fc49:cc:ffff:ffff:ffff:ffff:ffff:ffff
206fc49:cd::/32fc49:cd:ffff:ffff:ffff:ffff:ffff:ffff
207fc49:ce::/32fc49:ce:ffff:ffff:ffff:ffff:ffff:ffff
208fc49:cf::/32fc49:cf:ffff:ffff:ffff:ffff:ffff:ffff
209fc49:d0::/32fc49:d0:ffff:ffff:ffff:ffff:ffff:ffff
210fc49:d1::/32fc49:d1:ffff:ffff:ffff:ffff:ffff:ffff
211fc49:d2::/32fc49:d2:ffff:ffff:ffff:ffff:ffff:ffff
212fc49:d3::/32fc49:d3:ffff:ffff:ffff:ffff:ffff:ffff
213fc49:d4::/32fc49:d4:ffff:ffff:ffff:ffff:ffff:ffff
214fc49:d5::/32fc49:d5:ffff:ffff:ffff:ffff:ffff:ffff
215fc49:d6::/32fc49:d6:ffff:ffff:ffff:ffff:ffff:ffff
216fc49:d7::/32fc49:d7:ffff:ffff:ffff:ffff:ffff:ffff
217fc49:d8::/32fc49:d8:ffff:ffff:ffff:ffff:ffff:ffff
218fc49:d9::/32fc49:d9:ffff:ffff:ffff:ffff:ffff:ffff
219fc49:da::/32fc49:da:ffff:ffff:ffff:ffff:ffff:ffff
220fc49:db::/32fc49:db:ffff:ffff:ffff:ffff:ffff:ffff
221fc49:dc::/32fc49:dc:ffff:ffff:ffff:ffff:ffff:ffff
222fc49:dd::/32fc49:dd:ffff:ffff:ffff:ffff:ffff:ffff
223fc49:de::/32fc49:de:ffff:ffff:ffff:ffff:ffff:ffff
224fc49:df::/32fc49:df:ffff:ffff:ffff:ffff:ffff:ffff
225fc49:e0::/32fc49:e0:ffff:ffff:ffff:ffff:ffff:ffff
226fc49:e1::/32fc49:e1:ffff:ffff:ffff:ffff:ffff:ffff
227fc49:e2::/32fc49:e2:ffff:ffff:ffff:ffff:ffff:ffff
228fc49:e3::/32fc49:e3:ffff:ffff:ffff:ffff:ffff:ffff
229fc49:e4::/32fc49:e4:ffff:ffff:ffff:ffff:ffff:ffff
230fc49:e5::/32fc49:e5:ffff:ffff:ffff:ffff:ffff:ffff
231fc49:e6::/32fc49:e6:ffff:ffff:ffff:ffff:ffff:ffff
232fc49:e7::/32fc49:e7:ffff:ffff:ffff:ffff:ffff:ffff
233fc49:e8::/32fc49:e8:ffff:ffff:ffff:ffff:ffff:ffff
234fc49:e9::/32fc49:e9:ffff:ffff:ffff:ffff:ffff:ffff
235fc49:ea::/32fc49:ea:ffff:ffff:ffff:ffff:ffff:ffff
236fc49:eb::/32fc49:eb:ffff:ffff:ffff:ffff:ffff:ffff
237fc49:ec::/32fc49:ec:ffff:ffff:ffff:ffff:ffff:ffff
238fc49:ed::/32fc49:ed:ffff:ffff:ffff:ffff:ffff:ffff
239fc49:ee::/32fc49:ee:ffff:ffff:ffff:ffff:ffff:ffff
240fc49:ef::/32fc49:ef:ffff:ffff:ffff:ffff:ffff:ffff
241fc49:f0::/32fc49:f0:ffff:ffff:ffff:ffff:ffff:ffff
242fc49:f1::/32fc49:f1:ffff:ffff:ffff:ffff:ffff:ffff
243fc49:f2::/32fc49:f2:ffff:ffff:ffff:ffff:ffff:ffff
244fc49:f3::/32fc49:f3:ffff:ffff:ffff:ffff:ffff:ffff
245fc49:f4::/32fc49:f4:ffff:ffff:ffff:ffff:ffff:ffff
246fc49:f5::/32fc49:f5:ffff:ffff:ffff:ffff:ffff:ffff
247fc49:f6::/32fc49:f6:ffff:ffff:ffff:ffff:ffff:ffff
248fc49:f7::/32fc49:f7:ffff:ffff:ffff:ffff:ffff:ffff
249fc49:f8::/32fc49:f8:ffff:ffff:ffff:ffff:ffff:ffff
250fc49:f9::/32fc49:f9:ffff:ffff:ffff:ffff:ffff:ffff
251fc49:fa::/32fc49:fa:ffff:ffff:ffff:ffff:ffff:ffff
252fc49:fb::/32fc49:fb:ffff:ffff:ffff:ffff:ffff:ffff
253fc49:fc::/32fc49:fc:ffff:ffff:ffff:ffff:ffff:ffff
254fc49:fd::/32fc49:fd:ffff:ffff:ffff:ffff:ffff:ffff
255fc49:fe::/32fc49:fe:ffff:ffff:ffff:ffff:ffff:ffff
256fc49:ff::/32fc49: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.