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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
fc90::/16
First address
fc90::
Last address
fc90: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
fc90:0000:0000:0000:0000:0000:0000:0000
Type
Unique local (ULA) fc00::/7
Private IPv6, like RFC 1918; usually fd00::/8
Reverse DNS zone
0.9.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)

fc90::/16 makes 256 subnets of /24.

Subnets
#SubnetLast address
1fc90::/24fc90:ff:ffff:ffff:ffff:ffff:ffff:ffff
2fc90:100::/24fc90:1ff:ffff:ffff:ffff:ffff:ffff:ffff
3fc90:200::/24fc90:2ff:ffff:ffff:ffff:ffff:ffff:ffff
4fc90:300::/24fc90:3ff:ffff:ffff:ffff:ffff:ffff:ffff
5fc90:400::/24fc90:4ff:ffff:ffff:ffff:ffff:ffff:ffff
6fc90:500::/24fc90:5ff:ffff:ffff:ffff:ffff:ffff:ffff
7fc90:600::/24fc90:6ff:ffff:ffff:ffff:ffff:ffff:ffff
8fc90:700::/24fc90:7ff:ffff:ffff:ffff:ffff:ffff:ffff
9fc90:800::/24fc90:8ff:ffff:ffff:ffff:ffff:ffff:ffff
10fc90:900::/24fc90:9ff:ffff:ffff:ffff:ffff:ffff:ffff
11fc90:a00::/24fc90:aff:ffff:ffff:ffff:ffff:ffff:ffff
12fc90:b00::/24fc90:bff:ffff:ffff:ffff:ffff:ffff:ffff
13fc90:c00::/24fc90:cff:ffff:ffff:ffff:ffff:ffff:ffff
14fc90:d00::/24fc90:dff:ffff:ffff:ffff:ffff:ffff:ffff
15fc90:e00::/24fc90:eff:ffff:ffff:ffff:ffff:ffff:ffff
16fc90:f00::/24fc90:fff:ffff:ffff:ffff:ffff:ffff:ffff
17fc90:1000::/24fc90:10ff:ffff:ffff:ffff:ffff:ffff:ffff
18fc90:1100::/24fc90:11ff:ffff:ffff:ffff:ffff:ffff:ffff
19fc90:1200::/24fc90:12ff:ffff:ffff:ffff:ffff:ffff:ffff
20fc90:1300::/24fc90:13ff:ffff:ffff:ffff:ffff:ffff:ffff
21fc90:1400::/24fc90:14ff:ffff:ffff:ffff:ffff:ffff:ffff
22fc90:1500::/24fc90:15ff:ffff:ffff:ffff:ffff:ffff:ffff
23fc90:1600::/24fc90:16ff:ffff:ffff:ffff:ffff:ffff:ffff
24fc90:1700::/24fc90:17ff:ffff:ffff:ffff:ffff:ffff:ffff
25fc90:1800::/24fc90:18ff:ffff:ffff:ffff:ffff:ffff:ffff
26fc90:1900::/24fc90:19ff:ffff:ffff:ffff:ffff:ffff:ffff
27fc90:1a00::/24fc90:1aff:ffff:ffff:ffff:ffff:ffff:ffff
28fc90:1b00::/24fc90:1bff:ffff:ffff:ffff:ffff:ffff:ffff
29fc90:1c00::/24fc90:1cff:ffff:ffff:ffff:ffff:ffff:ffff
30fc90:1d00::/24fc90:1dff:ffff:ffff:ffff:ffff:ffff:ffff
31fc90:1e00::/24fc90:1eff:ffff:ffff:ffff:ffff:ffff:ffff
32fc90:1f00::/24fc90:1fff:ffff:ffff:ffff:ffff:ffff:ffff
33fc90:2000::/24fc90:20ff:ffff:ffff:ffff:ffff:ffff:ffff
34fc90:2100::/24fc90:21ff:ffff:ffff:ffff:ffff:ffff:ffff
35fc90:2200::/24fc90:22ff:ffff:ffff:ffff:ffff:ffff:ffff
36fc90:2300::/24fc90:23ff:ffff:ffff:ffff:ffff:ffff:ffff
37fc90:2400::/24fc90:24ff:ffff:ffff:ffff:ffff:ffff:ffff
38fc90:2500::/24fc90:25ff:ffff:ffff:ffff:ffff:ffff:ffff
39fc90:2600::/24fc90:26ff:ffff:ffff:ffff:ffff:ffff:ffff
40fc90:2700::/24fc90:27ff:ffff:ffff:ffff:ffff:ffff:ffff
41fc90:2800::/24fc90:28ff:ffff:ffff:ffff:ffff:ffff:ffff
42fc90:2900::/24fc90:29ff:ffff:ffff:ffff:ffff:ffff:ffff
43fc90:2a00::/24fc90:2aff:ffff:ffff:ffff:ffff:ffff:ffff
44fc90:2b00::/24fc90:2bff:ffff:ffff:ffff:ffff:ffff:ffff
45fc90:2c00::/24fc90:2cff:ffff:ffff:ffff:ffff:ffff:ffff
46fc90:2d00::/24fc90:2dff:ffff:ffff:ffff:ffff:ffff:ffff
47fc90:2e00::/24fc90:2eff:ffff:ffff:ffff:ffff:ffff:ffff
48fc90:2f00::/24fc90:2fff:ffff:ffff:ffff:ffff:ffff:ffff
49fc90:3000::/24fc90:30ff:ffff:ffff:ffff:ffff:ffff:ffff
50fc90:3100::/24fc90:31ff:ffff:ffff:ffff:ffff:ffff:ffff
51fc90:3200::/24fc90:32ff:ffff:ffff:ffff:ffff:ffff:ffff
52fc90:3300::/24fc90:33ff:ffff:ffff:ffff:ffff:ffff:ffff
53fc90:3400::/24fc90:34ff:ffff:ffff:ffff:ffff:ffff:ffff
54fc90:3500::/24fc90:35ff:ffff:ffff:ffff:ffff:ffff:ffff
55fc90:3600::/24fc90:36ff:ffff:ffff:ffff:ffff:ffff:ffff
56fc90:3700::/24fc90:37ff:ffff:ffff:ffff:ffff:ffff:ffff
57fc90:3800::/24fc90:38ff:ffff:ffff:ffff:ffff:ffff:ffff
58fc90:3900::/24fc90:39ff:ffff:ffff:ffff:ffff:ffff:ffff
59fc90:3a00::/24fc90:3aff:ffff:ffff:ffff:ffff:ffff:ffff
60fc90:3b00::/24fc90:3bff:ffff:ffff:ffff:ffff:ffff:ffff
61fc90:3c00::/24fc90:3cff:ffff:ffff:ffff:ffff:ffff:ffff
62fc90:3d00::/24fc90:3dff:ffff:ffff:ffff:ffff:ffff:ffff
63fc90:3e00::/24fc90:3eff:ffff:ffff:ffff:ffff:ffff:ffff
64fc90:3f00::/24fc90:3fff:ffff:ffff:ffff:ffff:ffff:ffff
65fc90:4000::/24fc90:40ff:ffff:ffff:ffff:ffff:ffff:ffff
66fc90:4100::/24fc90:41ff:ffff:ffff:ffff:ffff:ffff:ffff
67fc90:4200::/24fc90:42ff:ffff:ffff:ffff:ffff:ffff:ffff
68fc90:4300::/24fc90:43ff:ffff:ffff:ffff:ffff:ffff:ffff
69fc90:4400::/24fc90:44ff:ffff:ffff:ffff:ffff:ffff:ffff
70fc90:4500::/24fc90:45ff:ffff:ffff:ffff:ffff:ffff:ffff
71fc90:4600::/24fc90:46ff:ffff:ffff:ffff:ffff:ffff:ffff
72fc90:4700::/24fc90:47ff:ffff:ffff:ffff:ffff:ffff:ffff
73fc90:4800::/24fc90:48ff:ffff:ffff:ffff:ffff:ffff:ffff
74fc90:4900::/24fc90:49ff:ffff:ffff:ffff:ffff:ffff:ffff
75fc90:4a00::/24fc90:4aff:ffff:ffff:ffff:ffff:ffff:ffff
76fc90:4b00::/24fc90:4bff:ffff:ffff:ffff:ffff:ffff:ffff
77fc90:4c00::/24fc90:4cff:ffff:ffff:ffff:ffff:ffff:ffff
78fc90:4d00::/24fc90:4dff:ffff:ffff:ffff:ffff:ffff:ffff
79fc90:4e00::/24fc90:4eff:ffff:ffff:ffff:ffff:ffff:ffff
80fc90:4f00::/24fc90:4fff:ffff:ffff:ffff:ffff:ffff:ffff
81fc90:5000::/24fc90:50ff:ffff:ffff:ffff:ffff:ffff:ffff
82fc90:5100::/24fc90:51ff:ffff:ffff:ffff:ffff:ffff:ffff
83fc90:5200::/24fc90:52ff:ffff:ffff:ffff:ffff:ffff:ffff
84fc90:5300::/24fc90:53ff:ffff:ffff:ffff:ffff:ffff:ffff
85fc90:5400::/24fc90:54ff:ffff:ffff:ffff:ffff:ffff:ffff
86fc90:5500::/24fc90:55ff:ffff:ffff:ffff:ffff:ffff:ffff
87fc90:5600::/24fc90:56ff:ffff:ffff:ffff:ffff:ffff:ffff
88fc90:5700::/24fc90:57ff:ffff:ffff:ffff:ffff:ffff:ffff
89fc90:5800::/24fc90:58ff:ffff:ffff:ffff:ffff:ffff:ffff
90fc90:5900::/24fc90:59ff:ffff:ffff:ffff:ffff:ffff:ffff
91fc90:5a00::/24fc90:5aff:ffff:ffff:ffff:ffff:ffff:ffff
92fc90:5b00::/24fc90:5bff:ffff:ffff:ffff:ffff:ffff:ffff
93fc90:5c00::/24fc90:5cff:ffff:ffff:ffff:ffff:ffff:ffff
94fc90:5d00::/24fc90:5dff:ffff:ffff:ffff:ffff:ffff:ffff
95fc90:5e00::/24fc90:5eff:ffff:ffff:ffff:ffff:ffff:ffff
96fc90:5f00::/24fc90:5fff:ffff:ffff:ffff:ffff:ffff:ffff
97fc90:6000::/24fc90:60ff:ffff:ffff:ffff:ffff:ffff:ffff
98fc90:6100::/24fc90:61ff:ffff:ffff:ffff:ffff:ffff:ffff
99fc90:6200::/24fc90:62ff:ffff:ffff:ffff:ffff:ffff:ffff
100fc90:6300::/24fc90:63ff:ffff:ffff:ffff:ffff:ffff:ffff
101fc90:6400::/24fc90:64ff:ffff:ffff:ffff:ffff:ffff:ffff
102fc90:6500::/24fc90:65ff:ffff:ffff:ffff:ffff:ffff:ffff
103fc90:6600::/24fc90:66ff:ffff:ffff:ffff:ffff:ffff:ffff
104fc90:6700::/24fc90:67ff:ffff:ffff:ffff:ffff:ffff:ffff
105fc90:6800::/24fc90:68ff:ffff:ffff:ffff:ffff:ffff:ffff
106fc90:6900::/24fc90:69ff:ffff:ffff:ffff:ffff:ffff:ffff
107fc90:6a00::/24fc90:6aff:ffff:ffff:ffff:ffff:ffff:ffff
108fc90:6b00::/24fc90:6bff:ffff:ffff:ffff:ffff:ffff:ffff
109fc90:6c00::/24fc90:6cff:ffff:ffff:ffff:ffff:ffff:ffff
110fc90:6d00::/24fc90:6dff:ffff:ffff:ffff:ffff:ffff:ffff
111fc90:6e00::/24fc90:6eff:ffff:ffff:ffff:ffff:ffff:ffff
112fc90:6f00::/24fc90:6fff:ffff:ffff:ffff:ffff:ffff:ffff
113fc90:7000::/24fc90:70ff:ffff:ffff:ffff:ffff:ffff:ffff
114fc90:7100::/24fc90:71ff:ffff:ffff:ffff:ffff:ffff:ffff
115fc90:7200::/24fc90:72ff:ffff:ffff:ffff:ffff:ffff:ffff
116fc90:7300::/24fc90:73ff:ffff:ffff:ffff:ffff:ffff:ffff
117fc90:7400::/24fc90:74ff:ffff:ffff:ffff:ffff:ffff:ffff
118fc90:7500::/24fc90:75ff:ffff:ffff:ffff:ffff:ffff:ffff
119fc90:7600::/24fc90:76ff:ffff:ffff:ffff:ffff:ffff:ffff
120fc90:7700::/24fc90:77ff:ffff:ffff:ffff:ffff:ffff:ffff
121fc90:7800::/24fc90:78ff:ffff:ffff:ffff:ffff:ffff:ffff
122fc90:7900::/24fc90:79ff:ffff:ffff:ffff:ffff:ffff:ffff
123fc90:7a00::/24fc90:7aff:ffff:ffff:ffff:ffff:ffff:ffff
124fc90:7b00::/24fc90:7bff:ffff:ffff:ffff:ffff:ffff:ffff
125fc90:7c00::/24fc90:7cff:ffff:ffff:ffff:ffff:ffff:ffff
126fc90:7d00::/24fc90:7dff:ffff:ffff:ffff:ffff:ffff:ffff
127fc90:7e00::/24fc90:7eff:ffff:ffff:ffff:ffff:ffff:ffff
128fc90:7f00::/24fc90:7fff:ffff:ffff:ffff:ffff:ffff:ffff
129fc90:8000::/24fc90:80ff:ffff:ffff:ffff:ffff:ffff:ffff
130fc90:8100::/24fc90:81ff:ffff:ffff:ffff:ffff:ffff:ffff
131fc90:8200::/24fc90:82ff:ffff:ffff:ffff:ffff:ffff:ffff
132fc90:8300::/24fc90:83ff:ffff:ffff:ffff:ffff:ffff:ffff
133fc90:8400::/24fc90:84ff:ffff:ffff:ffff:ffff:ffff:ffff
134fc90:8500::/24fc90:85ff:ffff:ffff:ffff:ffff:ffff:ffff
135fc90:8600::/24fc90:86ff:ffff:ffff:ffff:ffff:ffff:ffff
136fc90:8700::/24fc90:87ff:ffff:ffff:ffff:ffff:ffff:ffff
137fc90:8800::/24fc90:88ff:ffff:ffff:ffff:ffff:ffff:ffff
138fc90:8900::/24fc90:89ff:ffff:ffff:ffff:ffff:ffff:ffff
139fc90:8a00::/24fc90:8aff:ffff:ffff:ffff:ffff:ffff:ffff
140fc90:8b00::/24fc90:8bff:ffff:ffff:ffff:ffff:ffff:ffff
141fc90:8c00::/24fc90:8cff:ffff:ffff:ffff:ffff:ffff:ffff
142fc90:8d00::/24fc90:8dff:ffff:ffff:ffff:ffff:ffff:ffff
143fc90:8e00::/24fc90:8eff:ffff:ffff:ffff:ffff:ffff:ffff
144fc90:8f00::/24fc90:8fff:ffff:ffff:ffff:ffff:ffff:ffff
145fc90:9000::/24fc90:90ff:ffff:ffff:ffff:ffff:ffff:ffff
146fc90:9100::/24fc90:91ff:ffff:ffff:ffff:ffff:ffff:ffff
147fc90:9200::/24fc90:92ff:ffff:ffff:ffff:ffff:ffff:ffff
148fc90:9300::/24fc90:93ff:ffff:ffff:ffff:ffff:ffff:ffff
149fc90:9400::/24fc90:94ff:ffff:ffff:ffff:ffff:ffff:ffff
150fc90:9500::/24fc90:95ff:ffff:ffff:ffff:ffff:ffff:ffff
151fc90:9600::/24fc90:96ff:ffff:ffff:ffff:ffff:ffff:ffff
152fc90:9700::/24fc90:97ff:ffff:ffff:ffff:ffff:ffff:ffff
153fc90:9800::/24fc90:98ff:ffff:ffff:ffff:ffff:ffff:ffff
154fc90:9900::/24fc90:99ff:ffff:ffff:ffff:ffff:ffff:ffff
155fc90:9a00::/24fc90:9aff:ffff:ffff:ffff:ffff:ffff:ffff
156fc90:9b00::/24fc90:9bff:ffff:ffff:ffff:ffff:ffff:ffff
157fc90:9c00::/24fc90:9cff:ffff:ffff:ffff:ffff:ffff:ffff
158fc90:9d00::/24fc90:9dff:ffff:ffff:ffff:ffff:ffff:ffff
159fc90:9e00::/24fc90:9eff:ffff:ffff:ffff:ffff:ffff:ffff
160fc90:9f00::/24fc90:9fff:ffff:ffff:ffff:ffff:ffff:ffff
161fc90:a000::/24fc90:a0ff:ffff:ffff:ffff:ffff:ffff:ffff
162fc90:a100::/24fc90:a1ff:ffff:ffff:ffff:ffff:ffff:ffff
163fc90:a200::/24fc90:a2ff:ffff:ffff:ffff:ffff:ffff:ffff
164fc90:a300::/24fc90:a3ff:ffff:ffff:ffff:ffff:ffff:ffff
165fc90:a400::/24fc90:a4ff:ffff:ffff:ffff:ffff:ffff:ffff
166fc90:a500::/24fc90:a5ff:ffff:ffff:ffff:ffff:ffff:ffff
167fc90:a600::/24fc90:a6ff:ffff:ffff:ffff:ffff:ffff:ffff
168fc90:a700::/24fc90:a7ff:ffff:ffff:ffff:ffff:ffff:ffff
169fc90:a800::/24fc90:a8ff:ffff:ffff:ffff:ffff:ffff:ffff
170fc90:a900::/24fc90:a9ff:ffff:ffff:ffff:ffff:ffff:ffff
171fc90:aa00::/24fc90:aaff:ffff:ffff:ffff:ffff:ffff:ffff
172fc90:ab00::/24fc90:abff:ffff:ffff:ffff:ffff:ffff:ffff
173fc90:ac00::/24fc90:acff:ffff:ffff:ffff:ffff:ffff:ffff
174fc90:ad00::/24fc90:adff:ffff:ffff:ffff:ffff:ffff:ffff
175fc90:ae00::/24fc90:aeff:ffff:ffff:ffff:ffff:ffff:ffff
176fc90:af00::/24fc90:afff:ffff:ffff:ffff:ffff:ffff:ffff
177fc90:b000::/24fc90:b0ff:ffff:ffff:ffff:ffff:ffff:ffff
178fc90:b100::/24fc90:b1ff:ffff:ffff:ffff:ffff:ffff:ffff
179fc90:b200::/24fc90:b2ff:ffff:ffff:ffff:ffff:ffff:ffff
180fc90:b300::/24fc90:b3ff:ffff:ffff:ffff:ffff:ffff:ffff
181fc90:b400::/24fc90:b4ff:ffff:ffff:ffff:ffff:ffff:ffff
182fc90:b500::/24fc90:b5ff:ffff:ffff:ffff:ffff:ffff:ffff
183fc90:b600::/24fc90:b6ff:ffff:ffff:ffff:ffff:ffff:ffff
184fc90:b700::/24fc90:b7ff:ffff:ffff:ffff:ffff:ffff:ffff
185fc90:b800::/24fc90:b8ff:ffff:ffff:ffff:ffff:ffff:ffff
186fc90:b900::/24fc90:b9ff:ffff:ffff:ffff:ffff:ffff:ffff
187fc90:ba00::/24fc90:baff:ffff:ffff:ffff:ffff:ffff:ffff
188fc90:bb00::/24fc90:bbff:ffff:ffff:ffff:ffff:ffff:ffff
189fc90:bc00::/24fc90:bcff:ffff:ffff:ffff:ffff:ffff:ffff
190fc90:bd00::/24fc90:bdff:ffff:ffff:ffff:ffff:ffff:ffff
191fc90:be00::/24fc90:beff:ffff:ffff:ffff:ffff:ffff:ffff
192fc90:bf00::/24fc90:bfff:ffff:ffff:ffff:ffff:ffff:ffff
193fc90:c000::/24fc90:c0ff:ffff:ffff:ffff:ffff:ffff:ffff
194fc90:c100::/24fc90:c1ff:ffff:ffff:ffff:ffff:ffff:ffff
195fc90:c200::/24fc90:c2ff:ffff:ffff:ffff:ffff:ffff:ffff
196fc90:c300::/24fc90:c3ff:ffff:ffff:ffff:ffff:ffff:ffff
197fc90:c400::/24fc90:c4ff:ffff:ffff:ffff:ffff:ffff:ffff
198fc90:c500::/24fc90:c5ff:ffff:ffff:ffff:ffff:ffff:ffff
199fc90:c600::/24fc90:c6ff:ffff:ffff:ffff:ffff:ffff:ffff
200fc90:c700::/24fc90:c7ff:ffff:ffff:ffff:ffff:ffff:ffff
201fc90:c800::/24fc90:c8ff:ffff:ffff:ffff:ffff:ffff:ffff
202fc90:c900::/24fc90:c9ff:ffff:ffff:ffff:ffff:ffff:ffff
203fc90:ca00::/24fc90:caff:ffff:ffff:ffff:ffff:ffff:ffff
204fc90:cb00::/24fc90:cbff:ffff:ffff:ffff:ffff:ffff:ffff
205fc90:cc00::/24fc90:ccff:ffff:ffff:ffff:ffff:ffff:ffff
206fc90:cd00::/24fc90:cdff:ffff:ffff:ffff:ffff:ffff:ffff
207fc90:ce00::/24fc90:ceff:ffff:ffff:ffff:ffff:ffff:ffff
208fc90:cf00::/24fc90:cfff:ffff:ffff:ffff:ffff:ffff:ffff
209fc90:d000::/24fc90:d0ff:ffff:ffff:ffff:ffff:ffff:ffff
210fc90:d100::/24fc90:d1ff:ffff:ffff:ffff:ffff:ffff:ffff
211fc90:d200::/24fc90:d2ff:ffff:ffff:ffff:ffff:ffff:ffff
212fc90:d300::/24fc90:d3ff:ffff:ffff:ffff:ffff:ffff:ffff
213fc90:d400::/24fc90:d4ff:ffff:ffff:ffff:ffff:ffff:ffff
214fc90:d500::/24fc90:d5ff:ffff:ffff:ffff:ffff:ffff:ffff
215fc90:d600::/24fc90:d6ff:ffff:ffff:ffff:ffff:ffff:ffff
216fc90:d700::/24fc90:d7ff:ffff:ffff:ffff:ffff:ffff:ffff
217fc90:d800::/24fc90:d8ff:ffff:ffff:ffff:ffff:ffff:ffff
218fc90:d900::/24fc90:d9ff:ffff:ffff:ffff:ffff:ffff:ffff
219fc90:da00::/24fc90:daff:ffff:ffff:ffff:ffff:ffff:ffff
220fc90:db00::/24fc90:dbff:ffff:ffff:ffff:ffff:ffff:ffff
221fc90:dc00::/24fc90:dcff:ffff:ffff:ffff:ffff:ffff:ffff
222fc90:dd00::/24fc90:ddff:ffff:ffff:ffff:ffff:ffff:ffff
223fc90:de00::/24fc90:deff:ffff:ffff:ffff:ffff:ffff:ffff
224fc90:df00::/24fc90:dfff:ffff:ffff:ffff:ffff:ffff:ffff
225fc90:e000::/24fc90:e0ff:ffff:ffff:ffff:ffff:ffff:ffff
226fc90:e100::/24fc90:e1ff:ffff:ffff:ffff:ffff:ffff:ffff
227fc90:e200::/24fc90:e2ff:ffff:ffff:ffff:ffff:ffff:ffff
228fc90:e300::/24fc90:e3ff:ffff:ffff:ffff:ffff:ffff:ffff
229fc90:e400::/24fc90:e4ff:ffff:ffff:ffff:ffff:ffff:ffff
230fc90:e500::/24fc90:e5ff:ffff:ffff:ffff:ffff:ffff:ffff
231fc90:e600::/24fc90:e6ff:ffff:ffff:ffff:ffff:ffff:ffff
232fc90:e700::/24fc90:e7ff:ffff:ffff:ffff:ffff:ffff:ffff
233fc90:e800::/24fc90:e8ff:ffff:ffff:ffff:ffff:ffff:ffff
234fc90:e900::/24fc90:e9ff:ffff:ffff:ffff:ffff:ffff:ffff
235fc90:ea00::/24fc90:eaff:ffff:ffff:ffff:ffff:ffff:ffff
236fc90:eb00::/24fc90:ebff:ffff:ffff:ffff:ffff:ffff:ffff
237fc90:ec00::/24fc90:ecff:ffff:ffff:ffff:ffff:ffff:ffff
238fc90:ed00::/24fc90:edff:ffff:ffff:ffff:ffff:ffff:ffff
239fc90:ee00::/24fc90:eeff:ffff:ffff:ffff:ffff:ffff:ffff
240fc90:ef00::/24fc90:efff:ffff:ffff:ffff:ffff:ffff:ffff
241fc90:f000::/24fc90:f0ff:ffff:ffff:ffff:ffff:ffff:ffff
242fc90:f100::/24fc90:f1ff:ffff:ffff:ffff:ffff:ffff:ffff
243fc90:f200::/24fc90:f2ff:ffff:ffff:ffff:ffff:ffff:ffff
244fc90:f300::/24fc90:f3ff:ffff:ffff:ffff:ffff:ffff:ffff
245fc90:f400::/24fc90:f4ff:ffff:ffff:ffff:ffff:ffff:ffff
246fc90:f500::/24fc90:f5ff:ffff:ffff:ffff:ffff:ffff:ffff
247fc90:f600::/24fc90:f6ff:ffff:ffff:ffff:ffff:ffff:ffff
248fc90:f700::/24fc90:f7ff:ffff:ffff:ffff:ffff:ffff:ffff
249fc90:f800::/24fc90:f8ff:ffff:ffff:ffff:ffff:ffff:ffff
250fc90:f900::/24fc90:f9ff:ffff:ffff:ffff:ffff:ffff:ffff
251fc90:fa00::/24fc90:faff:ffff:ffff:ffff:ffff:ffff:ffff
252fc90:fb00::/24fc90:fbff:ffff:ffff:ffff:ffff:ffff:ffff
253fc90:fc00::/24fc90:fcff:ffff:ffff:ffff:ffff:ffff:ffff
254fc90:fd00::/24fc90:fdff:ffff:ffff:ffff:ffff:ffff:ffff
255fc90:fe00::/24fc90:feff:ffff:ffff:ffff:ffff:ffff:ffff
256fc90:ff00::/24fc90: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.