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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
fcfe::/16
First address
fcfe::
Last address
fcfe: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
fcfe:0000:0000:0000:0000:0000:0000:0000
Type
Unique local (ULA) fc00::/7
Private IPv6, like RFC 1918; usually fd00::/8
Reverse DNS zone
e.f.c.f.ip6.arpa
Split into smaller subnets/24
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

fcfe::/16 makes 256 subnets of /24.

Subnets
#SubnetLast address
1fcfe::/24fcfe:ff:ffff:ffff:ffff:ffff:ffff:ffff
2fcfe:100::/24fcfe:1ff:ffff:ffff:ffff:ffff:ffff:ffff
3fcfe:200::/24fcfe:2ff:ffff:ffff:ffff:ffff:ffff:ffff
4fcfe:300::/24fcfe:3ff:ffff:ffff:ffff:ffff:ffff:ffff
5fcfe:400::/24fcfe:4ff:ffff:ffff:ffff:ffff:ffff:ffff
6fcfe:500::/24fcfe:5ff:ffff:ffff:ffff:ffff:ffff:ffff
7fcfe:600::/24fcfe:6ff:ffff:ffff:ffff:ffff:ffff:ffff
8fcfe:700::/24fcfe:7ff:ffff:ffff:ffff:ffff:ffff:ffff
9fcfe:800::/24fcfe:8ff:ffff:ffff:ffff:ffff:ffff:ffff
10fcfe:900::/24fcfe:9ff:ffff:ffff:ffff:ffff:ffff:ffff
11fcfe:a00::/24fcfe:aff:ffff:ffff:ffff:ffff:ffff:ffff
12fcfe:b00::/24fcfe:bff:ffff:ffff:ffff:ffff:ffff:ffff
13fcfe:c00::/24fcfe:cff:ffff:ffff:ffff:ffff:ffff:ffff
14fcfe:d00::/24fcfe:dff:ffff:ffff:ffff:ffff:ffff:ffff
15fcfe:e00::/24fcfe:eff:ffff:ffff:ffff:ffff:ffff:ffff
16fcfe:f00::/24fcfe:fff:ffff:ffff:ffff:ffff:ffff:ffff
17fcfe:1000::/24fcfe:10ff:ffff:ffff:ffff:ffff:ffff:ffff
18fcfe:1100::/24fcfe:11ff:ffff:ffff:ffff:ffff:ffff:ffff
19fcfe:1200::/24fcfe:12ff:ffff:ffff:ffff:ffff:ffff:ffff
20fcfe:1300::/24fcfe:13ff:ffff:ffff:ffff:ffff:ffff:ffff
21fcfe:1400::/24fcfe:14ff:ffff:ffff:ffff:ffff:ffff:ffff
22fcfe:1500::/24fcfe:15ff:ffff:ffff:ffff:ffff:ffff:ffff
23fcfe:1600::/24fcfe:16ff:ffff:ffff:ffff:ffff:ffff:ffff
24fcfe:1700::/24fcfe:17ff:ffff:ffff:ffff:ffff:ffff:ffff
25fcfe:1800::/24fcfe:18ff:ffff:ffff:ffff:ffff:ffff:ffff
26fcfe:1900::/24fcfe:19ff:ffff:ffff:ffff:ffff:ffff:ffff
27fcfe:1a00::/24fcfe:1aff:ffff:ffff:ffff:ffff:ffff:ffff
28fcfe:1b00::/24fcfe:1bff:ffff:ffff:ffff:ffff:ffff:ffff
29fcfe:1c00::/24fcfe:1cff:ffff:ffff:ffff:ffff:ffff:ffff
30fcfe:1d00::/24fcfe:1dff:ffff:ffff:ffff:ffff:ffff:ffff
31fcfe:1e00::/24fcfe:1eff:ffff:ffff:ffff:ffff:ffff:ffff
32fcfe:1f00::/24fcfe:1fff:ffff:ffff:ffff:ffff:ffff:ffff
33fcfe:2000::/24fcfe:20ff:ffff:ffff:ffff:ffff:ffff:ffff
34fcfe:2100::/24fcfe:21ff:ffff:ffff:ffff:ffff:ffff:ffff
35fcfe:2200::/24fcfe:22ff:ffff:ffff:ffff:ffff:ffff:ffff
36fcfe:2300::/24fcfe:23ff:ffff:ffff:ffff:ffff:ffff:ffff
37fcfe:2400::/24fcfe:24ff:ffff:ffff:ffff:ffff:ffff:ffff
38fcfe:2500::/24fcfe:25ff:ffff:ffff:ffff:ffff:ffff:ffff
39fcfe:2600::/24fcfe:26ff:ffff:ffff:ffff:ffff:ffff:ffff
40fcfe:2700::/24fcfe:27ff:ffff:ffff:ffff:ffff:ffff:ffff
41fcfe:2800::/24fcfe:28ff:ffff:ffff:ffff:ffff:ffff:ffff
42fcfe:2900::/24fcfe:29ff:ffff:ffff:ffff:ffff:ffff:ffff
43fcfe:2a00::/24fcfe:2aff:ffff:ffff:ffff:ffff:ffff:ffff
44fcfe:2b00::/24fcfe:2bff:ffff:ffff:ffff:ffff:ffff:ffff
45fcfe:2c00::/24fcfe:2cff:ffff:ffff:ffff:ffff:ffff:ffff
46fcfe:2d00::/24fcfe:2dff:ffff:ffff:ffff:ffff:ffff:ffff
47fcfe:2e00::/24fcfe:2eff:ffff:ffff:ffff:ffff:ffff:ffff
48fcfe:2f00::/24fcfe:2fff:ffff:ffff:ffff:ffff:ffff:ffff
49fcfe:3000::/24fcfe:30ff:ffff:ffff:ffff:ffff:ffff:ffff
50fcfe:3100::/24fcfe:31ff:ffff:ffff:ffff:ffff:ffff:ffff
51fcfe:3200::/24fcfe:32ff:ffff:ffff:ffff:ffff:ffff:ffff
52fcfe:3300::/24fcfe:33ff:ffff:ffff:ffff:ffff:ffff:ffff
53fcfe:3400::/24fcfe:34ff:ffff:ffff:ffff:ffff:ffff:ffff
54fcfe:3500::/24fcfe:35ff:ffff:ffff:ffff:ffff:ffff:ffff
55fcfe:3600::/24fcfe:36ff:ffff:ffff:ffff:ffff:ffff:ffff
56fcfe:3700::/24fcfe:37ff:ffff:ffff:ffff:ffff:ffff:ffff
57fcfe:3800::/24fcfe:38ff:ffff:ffff:ffff:ffff:ffff:ffff
58fcfe:3900::/24fcfe:39ff:ffff:ffff:ffff:ffff:ffff:ffff
59fcfe:3a00::/24fcfe:3aff:ffff:ffff:ffff:ffff:ffff:ffff
60fcfe:3b00::/24fcfe:3bff:ffff:ffff:ffff:ffff:ffff:ffff
61fcfe:3c00::/24fcfe:3cff:ffff:ffff:ffff:ffff:ffff:ffff
62fcfe:3d00::/24fcfe:3dff:ffff:ffff:ffff:ffff:ffff:ffff
63fcfe:3e00::/24fcfe:3eff:ffff:ffff:ffff:ffff:ffff:ffff
64fcfe:3f00::/24fcfe:3fff:ffff:ffff:ffff:ffff:ffff:ffff
65fcfe:4000::/24fcfe:40ff:ffff:ffff:ffff:ffff:ffff:ffff
66fcfe:4100::/24fcfe:41ff:ffff:ffff:ffff:ffff:ffff:ffff
67fcfe:4200::/24fcfe:42ff:ffff:ffff:ffff:ffff:ffff:ffff
68fcfe:4300::/24fcfe:43ff:ffff:ffff:ffff:ffff:ffff:ffff
69fcfe:4400::/24fcfe:44ff:ffff:ffff:ffff:ffff:ffff:ffff
70fcfe:4500::/24fcfe:45ff:ffff:ffff:ffff:ffff:ffff:ffff
71fcfe:4600::/24fcfe:46ff:ffff:ffff:ffff:ffff:ffff:ffff
72fcfe:4700::/24fcfe:47ff:ffff:ffff:ffff:ffff:ffff:ffff
73fcfe:4800::/24fcfe:48ff:ffff:ffff:ffff:ffff:ffff:ffff
74fcfe:4900::/24fcfe:49ff:ffff:ffff:ffff:ffff:ffff:ffff
75fcfe:4a00::/24fcfe:4aff:ffff:ffff:ffff:ffff:ffff:ffff
76fcfe:4b00::/24fcfe:4bff:ffff:ffff:ffff:ffff:ffff:ffff
77fcfe:4c00::/24fcfe:4cff:ffff:ffff:ffff:ffff:ffff:ffff
78fcfe:4d00::/24fcfe:4dff:ffff:ffff:ffff:ffff:ffff:ffff
79fcfe:4e00::/24fcfe:4eff:ffff:ffff:ffff:ffff:ffff:ffff
80fcfe:4f00::/24fcfe:4fff:ffff:ffff:ffff:ffff:ffff:ffff
81fcfe:5000::/24fcfe:50ff:ffff:ffff:ffff:ffff:ffff:ffff
82fcfe:5100::/24fcfe:51ff:ffff:ffff:ffff:ffff:ffff:ffff
83fcfe:5200::/24fcfe:52ff:ffff:ffff:ffff:ffff:ffff:ffff
84fcfe:5300::/24fcfe:53ff:ffff:ffff:ffff:ffff:ffff:ffff
85fcfe:5400::/24fcfe:54ff:ffff:ffff:ffff:ffff:ffff:ffff
86fcfe:5500::/24fcfe:55ff:ffff:ffff:ffff:ffff:ffff:ffff
87fcfe:5600::/24fcfe:56ff:ffff:ffff:ffff:ffff:ffff:ffff
88fcfe:5700::/24fcfe:57ff:ffff:ffff:ffff:ffff:ffff:ffff
89fcfe:5800::/24fcfe:58ff:ffff:ffff:ffff:ffff:ffff:ffff
90fcfe:5900::/24fcfe:59ff:ffff:ffff:ffff:ffff:ffff:ffff
91fcfe:5a00::/24fcfe:5aff:ffff:ffff:ffff:ffff:ffff:ffff
92fcfe:5b00::/24fcfe:5bff:ffff:ffff:ffff:ffff:ffff:ffff
93fcfe:5c00::/24fcfe:5cff:ffff:ffff:ffff:ffff:ffff:ffff
94fcfe:5d00::/24fcfe:5dff:ffff:ffff:ffff:ffff:ffff:ffff
95fcfe:5e00::/24fcfe:5eff:ffff:ffff:ffff:ffff:ffff:ffff
96fcfe:5f00::/24fcfe:5fff:ffff:ffff:ffff:ffff:ffff:ffff
97fcfe:6000::/24fcfe:60ff:ffff:ffff:ffff:ffff:ffff:ffff
98fcfe:6100::/24fcfe:61ff:ffff:ffff:ffff:ffff:ffff:ffff
99fcfe:6200::/24fcfe:62ff:ffff:ffff:ffff:ffff:ffff:ffff
100fcfe:6300::/24fcfe:63ff:ffff:ffff:ffff:ffff:ffff:ffff
101fcfe:6400::/24fcfe:64ff:ffff:ffff:ffff:ffff:ffff:ffff
102fcfe:6500::/24fcfe:65ff:ffff:ffff:ffff:ffff:ffff:ffff
103fcfe:6600::/24fcfe:66ff:ffff:ffff:ffff:ffff:ffff:ffff
104fcfe:6700::/24fcfe:67ff:ffff:ffff:ffff:ffff:ffff:ffff
105fcfe:6800::/24fcfe:68ff:ffff:ffff:ffff:ffff:ffff:ffff
106fcfe:6900::/24fcfe:69ff:ffff:ffff:ffff:ffff:ffff:ffff
107fcfe:6a00::/24fcfe:6aff:ffff:ffff:ffff:ffff:ffff:ffff
108fcfe:6b00::/24fcfe:6bff:ffff:ffff:ffff:ffff:ffff:ffff
109fcfe:6c00::/24fcfe:6cff:ffff:ffff:ffff:ffff:ffff:ffff
110fcfe:6d00::/24fcfe:6dff:ffff:ffff:ffff:ffff:ffff:ffff
111fcfe:6e00::/24fcfe:6eff:ffff:ffff:ffff:ffff:ffff:ffff
112fcfe:6f00::/24fcfe:6fff:ffff:ffff:ffff:ffff:ffff:ffff
113fcfe:7000::/24fcfe:70ff:ffff:ffff:ffff:ffff:ffff:ffff
114fcfe:7100::/24fcfe:71ff:ffff:ffff:ffff:ffff:ffff:ffff
115fcfe:7200::/24fcfe:72ff:ffff:ffff:ffff:ffff:ffff:ffff
116fcfe:7300::/24fcfe:73ff:ffff:ffff:ffff:ffff:ffff:ffff
117fcfe:7400::/24fcfe:74ff:ffff:ffff:ffff:ffff:ffff:ffff
118fcfe:7500::/24fcfe:75ff:ffff:ffff:ffff:ffff:ffff:ffff
119fcfe:7600::/24fcfe:76ff:ffff:ffff:ffff:ffff:ffff:ffff
120fcfe:7700::/24fcfe:77ff:ffff:ffff:ffff:ffff:ffff:ffff
121fcfe:7800::/24fcfe:78ff:ffff:ffff:ffff:ffff:ffff:ffff
122fcfe:7900::/24fcfe:79ff:ffff:ffff:ffff:ffff:ffff:ffff
123fcfe:7a00::/24fcfe:7aff:ffff:ffff:ffff:ffff:ffff:ffff
124fcfe:7b00::/24fcfe:7bff:ffff:ffff:ffff:ffff:ffff:ffff
125fcfe:7c00::/24fcfe:7cff:ffff:ffff:ffff:ffff:ffff:ffff
126fcfe:7d00::/24fcfe:7dff:ffff:ffff:ffff:ffff:ffff:ffff
127fcfe:7e00::/24fcfe:7eff:ffff:ffff:ffff:ffff:ffff:ffff
128fcfe:7f00::/24fcfe:7fff:ffff:ffff:ffff:ffff:ffff:ffff
129fcfe:8000::/24fcfe:80ff:ffff:ffff:ffff:ffff:ffff:ffff
130fcfe:8100::/24fcfe:81ff:ffff:ffff:ffff:ffff:ffff:ffff
131fcfe:8200::/24fcfe:82ff:ffff:ffff:ffff:ffff:ffff:ffff
132fcfe:8300::/24fcfe:83ff:ffff:ffff:ffff:ffff:ffff:ffff
133fcfe:8400::/24fcfe:84ff:ffff:ffff:ffff:ffff:ffff:ffff
134fcfe:8500::/24fcfe:85ff:ffff:ffff:ffff:ffff:ffff:ffff
135fcfe:8600::/24fcfe:86ff:ffff:ffff:ffff:ffff:ffff:ffff
136fcfe:8700::/24fcfe:87ff:ffff:ffff:ffff:ffff:ffff:ffff
137fcfe:8800::/24fcfe:88ff:ffff:ffff:ffff:ffff:ffff:ffff
138fcfe:8900::/24fcfe:89ff:ffff:ffff:ffff:ffff:ffff:ffff
139fcfe:8a00::/24fcfe:8aff:ffff:ffff:ffff:ffff:ffff:ffff
140fcfe:8b00::/24fcfe:8bff:ffff:ffff:ffff:ffff:ffff:ffff
141fcfe:8c00::/24fcfe:8cff:ffff:ffff:ffff:ffff:ffff:ffff
142fcfe:8d00::/24fcfe:8dff:ffff:ffff:ffff:ffff:ffff:ffff
143fcfe:8e00::/24fcfe:8eff:ffff:ffff:ffff:ffff:ffff:ffff
144fcfe:8f00::/24fcfe:8fff:ffff:ffff:ffff:ffff:ffff:ffff
145fcfe:9000::/24fcfe:90ff:ffff:ffff:ffff:ffff:ffff:ffff
146fcfe:9100::/24fcfe:91ff:ffff:ffff:ffff:ffff:ffff:ffff
147fcfe:9200::/24fcfe:92ff:ffff:ffff:ffff:ffff:ffff:ffff
148fcfe:9300::/24fcfe:93ff:ffff:ffff:ffff:ffff:ffff:ffff
149fcfe:9400::/24fcfe:94ff:ffff:ffff:ffff:ffff:ffff:ffff
150fcfe:9500::/24fcfe:95ff:ffff:ffff:ffff:ffff:ffff:ffff
151fcfe:9600::/24fcfe:96ff:ffff:ffff:ffff:ffff:ffff:ffff
152fcfe:9700::/24fcfe:97ff:ffff:ffff:ffff:ffff:ffff:ffff
153fcfe:9800::/24fcfe:98ff:ffff:ffff:ffff:ffff:ffff:ffff
154fcfe:9900::/24fcfe:99ff:ffff:ffff:ffff:ffff:ffff:ffff
155fcfe:9a00::/24fcfe:9aff:ffff:ffff:ffff:ffff:ffff:ffff
156fcfe:9b00::/24fcfe:9bff:ffff:ffff:ffff:ffff:ffff:ffff
157fcfe:9c00::/24fcfe:9cff:ffff:ffff:ffff:ffff:ffff:ffff
158fcfe:9d00::/24fcfe:9dff:ffff:ffff:ffff:ffff:ffff:ffff
159fcfe:9e00::/24fcfe:9eff:ffff:ffff:ffff:ffff:ffff:ffff
160fcfe:9f00::/24fcfe:9fff:ffff:ffff:ffff:ffff:ffff:ffff
161fcfe:a000::/24fcfe:a0ff:ffff:ffff:ffff:ffff:ffff:ffff
162fcfe:a100::/24fcfe:a1ff:ffff:ffff:ffff:ffff:ffff:ffff
163fcfe:a200::/24fcfe:a2ff:ffff:ffff:ffff:ffff:ffff:ffff
164fcfe:a300::/24fcfe:a3ff:ffff:ffff:ffff:ffff:ffff:ffff
165fcfe:a400::/24fcfe:a4ff:ffff:ffff:ffff:ffff:ffff:ffff
166fcfe:a500::/24fcfe:a5ff:ffff:ffff:ffff:ffff:ffff:ffff
167fcfe:a600::/24fcfe:a6ff:ffff:ffff:ffff:ffff:ffff:ffff
168fcfe:a700::/24fcfe:a7ff:ffff:ffff:ffff:ffff:ffff:ffff
169fcfe:a800::/24fcfe:a8ff:ffff:ffff:ffff:ffff:ffff:ffff
170fcfe:a900::/24fcfe:a9ff:ffff:ffff:ffff:ffff:ffff:ffff
171fcfe:aa00::/24fcfe:aaff:ffff:ffff:ffff:ffff:ffff:ffff
172fcfe:ab00::/24fcfe:abff:ffff:ffff:ffff:ffff:ffff:ffff
173fcfe:ac00::/24fcfe:acff:ffff:ffff:ffff:ffff:ffff:ffff
174fcfe:ad00::/24fcfe:adff:ffff:ffff:ffff:ffff:ffff:ffff
175fcfe:ae00::/24fcfe:aeff:ffff:ffff:ffff:ffff:ffff:ffff
176fcfe:af00::/24fcfe:afff:ffff:ffff:ffff:ffff:ffff:ffff
177fcfe:b000::/24fcfe:b0ff:ffff:ffff:ffff:ffff:ffff:ffff
178fcfe:b100::/24fcfe:b1ff:ffff:ffff:ffff:ffff:ffff:ffff
179fcfe:b200::/24fcfe:b2ff:ffff:ffff:ffff:ffff:ffff:ffff
180fcfe:b300::/24fcfe:b3ff:ffff:ffff:ffff:ffff:ffff:ffff
181fcfe:b400::/24fcfe:b4ff:ffff:ffff:ffff:ffff:ffff:ffff
182fcfe:b500::/24fcfe:b5ff:ffff:ffff:ffff:ffff:ffff:ffff
183fcfe:b600::/24fcfe:b6ff:ffff:ffff:ffff:ffff:ffff:ffff
184fcfe:b700::/24fcfe:b7ff:ffff:ffff:ffff:ffff:ffff:ffff
185fcfe:b800::/24fcfe:b8ff:ffff:ffff:ffff:ffff:ffff:ffff
186fcfe:b900::/24fcfe:b9ff:ffff:ffff:ffff:ffff:ffff:ffff
187fcfe:ba00::/24fcfe:baff:ffff:ffff:ffff:ffff:ffff:ffff
188fcfe:bb00::/24fcfe:bbff:ffff:ffff:ffff:ffff:ffff:ffff
189fcfe:bc00::/24fcfe:bcff:ffff:ffff:ffff:ffff:ffff:ffff
190fcfe:bd00::/24fcfe:bdff:ffff:ffff:ffff:ffff:ffff:ffff
191fcfe:be00::/24fcfe:beff:ffff:ffff:ffff:ffff:ffff:ffff
192fcfe:bf00::/24fcfe:bfff:ffff:ffff:ffff:ffff:ffff:ffff
193fcfe:c000::/24fcfe:c0ff:ffff:ffff:ffff:ffff:ffff:ffff
194fcfe:c100::/24fcfe:c1ff:ffff:ffff:ffff:ffff:ffff:ffff
195fcfe:c200::/24fcfe:c2ff:ffff:ffff:ffff:ffff:ffff:ffff
196fcfe:c300::/24fcfe:c3ff:ffff:ffff:ffff:ffff:ffff:ffff
197fcfe:c400::/24fcfe:c4ff:ffff:ffff:ffff:ffff:ffff:ffff
198fcfe:c500::/24fcfe:c5ff:ffff:ffff:ffff:ffff:ffff:ffff
199fcfe:c600::/24fcfe:c6ff:ffff:ffff:ffff:ffff:ffff:ffff
200fcfe:c700::/24fcfe:c7ff:ffff:ffff:ffff:ffff:ffff:ffff
201fcfe:c800::/24fcfe:c8ff:ffff:ffff:ffff:ffff:ffff:ffff
202fcfe:c900::/24fcfe:c9ff:ffff:ffff:ffff:ffff:ffff:ffff
203fcfe:ca00::/24fcfe:caff:ffff:ffff:ffff:ffff:ffff:ffff
204fcfe:cb00::/24fcfe:cbff:ffff:ffff:ffff:ffff:ffff:ffff
205fcfe:cc00::/24fcfe:ccff:ffff:ffff:ffff:ffff:ffff:ffff
206fcfe:cd00::/24fcfe:cdff:ffff:ffff:ffff:ffff:ffff:ffff
207fcfe:ce00::/24fcfe:ceff:ffff:ffff:ffff:ffff:ffff:ffff
208fcfe:cf00::/24fcfe:cfff:ffff:ffff:ffff:ffff:ffff:ffff
209fcfe:d000::/24fcfe:d0ff:ffff:ffff:ffff:ffff:ffff:ffff
210fcfe:d100::/24fcfe:d1ff:ffff:ffff:ffff:ffff:ffff:ffff
211fcfe:d200::/24fcfe:d2ff:ffff:ffff:ffff:ffff:ffff:ffff
212fcfe:d300::/24fcfe:d3ff:ffff:ffff:ffff:ffff:ffff:ffff
213fcfe:d400::/24fcfe:d4ff:ffff:ffff:ffff:ffff:ffff:ffff
214fcfe:d500::/24fcfe:d5ff:ffff:ffff:ffff:ffff:ffff:ffff
215fcfe:d600::/24fcfe:d6ff:ffff:ffff:ffff:ffff:ffff:ffff
216fcfe:d700::/24fcfe:d7ff:ffff:ffff:ffff:ffff:ffff:ffff
217fcfe:d800::/24fcfe:d8ff:ffff:ffff:ffff:ffff:ffff:ffff
218fcfe:d900::/24fcfe:d9ff:ffff:ffff:ffff:ffff:ffff:ffff
219fcfe:da00::/24fcfe:daff:ffff:ffff:ffff:ffff:ffff:ffff
220fcfe:db00::/24fcfe:dbff:ffff:ffff:ffff:ffff:ffff:ffff
221fcfe:dc00::/24fcfe:dcff:ffff:ffff:ffff:ffff:ffff:ffff
222fcfe:dd00::/24fcfe:ddff:ffff:ffff:ffff:ffff:ffff:ffff
223fcfe:de00::/24fcfe:deff:ffff:ffff:ffff:ffff:ffff:ffff
224fcfe:df00::/24fcfe:dfff:ffff:ffff:ffff:ffff:ffff:ffff
225fcfe:e000::/24fcfe:e0ff:ffff:ffff:ffff:ffff:ffff:ffff
226fcfe:e100::/24fcfe:e1ff:ffff:ffff:ffff:ffff:ffff:ffff
227fcfe:e200::/24fcfe:e2ff:ffff:ffff:ffff:ffff:ffff:ffff
228fcfe:e300::/24fcfe:e3ff:ffff:ffff:ffff:ffff:ffff:ffff
229fcfe:e400::/24fcfe:e4ff:ffff:ffff:ffff:ffff:ffff:ffff
230fcfe:e500::/24fcfe:e5ff:ffff:ffff:ffff:ffff:ffff:ffff
231fcfe:e600::/24fcfe:e6ff:ffff:ffff:ffff:ffff:ffff:ffff
232fcfe:e700::/24fcfe:e7ff:ffff:ffff:ffff:ffff:ffff:ffff
233fcfe:e800::/24fcfe:e8ff:ffff:ffff:ffff:ffff:ffff:ffff
234fcfe:e900::/24fcfe:e9ff:ffff:ffff:ffff:ffff:ffff:ffff
235fcfe:ea00::/24fcfe:eaff:ffff:ffff:ffff:ffff:ffff:ffff
236fcfe:eb00::/24fcfe:ebff:ffff:ffff:ffff:ffff:ffff:ffff
237fcfe:ec00::/24fcfe:ecff:ffff:ffff:ffff:ffff:ffff:ffff
238fcfe:ed00::/24fcfe:edff:ffff:ffff:ffff:ffff:ffff:ffff
239fcfe:ee00::/24fcfe:eeff:ffff:ffff:ffff:ffff:ffff:ffff
240fcfe:ef00::/24fcfe:efff:ffff:ffff:ffff:ffff:ffff:ffff
241fcfe:f000::/24fcfe:f0ff:ffff:ffff:ffff:ffff:ffff:ffff
242fcfe:f100::/24fcfe:f1ff:ffff:ffff:ffff:ffff:ffff:ffff
243fcfe:f200::/24fcfe:f2ff:ffff:ffff:ffff:ffff:ffff:ffff
244fcfe:f300::/24fcfe:f3ff:ffff:ffff:ffff:ffff:ffff:ffff
245fcfe:f400::/24fcfe:f4ff:ffff:ffff:ffff:ffff:ffff:ffff
246fcfe:f500::/24fcfe:f5ff:ffff:ffff:ffff:ffff:ffff:ffff
247fcfe:f600::/24fcfe:f6ff:ffff:ffff:ffff:ffff:ffff:ffff
248fcfe:f700::/24fcfe:f7ff:ffff:ffff:ffff:ffff:ffff:ffff
249fcfe:f800::/24fcfe:f8ff:ffff:ffff:ffff:ffff:ffff:ffff
250fcfe:f900::/24fcfe:f9ff:ffff:ffff:ffff:ffff:ffff:ffff
251fcfe:fa00::/24fcfe:faff:ffff:ffff:ffff:ffff:ffff:ffff
252fcfe:fb00::/24fcfe:fbff:ffff:ffff:ffff:ffff:ffff:ffff
253fcfe:fc00::/24fcfe:fcff:ffff:ffff:ffff:ffff:ffff:ffff
254fcfe:fd00::/24fcfe:fdff:ffff:ffff:ffff:ffff:ffff:ffff
255fcfe:fe00::/24fcfe:feff:ffff:ffff:ffff:ffff:ffff:ffff
256fcfe:ff00::/24fcfe:ffff: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.