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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
fc13::/16
First address
fc13::
Last address
fc13: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
fc13:0000:0000:0000:0000:0000:0000:0000
Type
Unique local (ULA) fc00::/7
Private IPv6, like RFC 1918; usually fd00::/8
Reverse DNS zone
3.1.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)

fc13::/16 makes 256 subnets of /24.

Subnets
#SubnetLast address
1fc13::/24fc13:ff:ffff:ffff:ffff:ffff:ffff:ffff
2fc13:100::/24fc13:1ff:ffff:ffff:ffff:ffff:ffff:ffff
3fc13:200::/24fc13:2ff:ffff:ffff:ffff:ffff:ffff:ffff
4fc13:300::/24fc13:3ff:ffff:ffff:ffff:ffff:ffff:ffff
5fc13:400::/24fc13:4ff:ffff:ffff:ffff:ffff:ffff:ffff
6fc13:500::/24fc13:5ff:ffff:ffff:ffff:ffff:ffff:ffff
7fc13:600::/24fc13:6ff:ffff:ffff:ffff:ffff:ffff:ffff
8fc13:700::/24fc13:7ff:ffff:ffff:ffff:ffff:ffff:ffff
9fc13:800::/24fc13:8ff:ffff:ffff:ffff:ffff:ffff:ffff
10fc13:900::/24fc13:9ff:ffff:ffff:ffff:ffff:ffff:ffff
11fc13:a00::/24fc13:aff:ffff:ffff:ffff:ffff:ffff:ffff
12fc13:b00::/24fc13:bff:ffff:ffff:ffff:ffff:ffff:ffff
13fc13:c00::/24fc13:cff:ffff:ffff:ffff:ffff:ffff:ffff
14fc13:d00::/24fc13:dff:ffff:ffff:ffff:ffff:ffff:ffff
15fc13:e00::/24fc13:eff:ffff:ffff:ffff:ffff:ffff:ffff
16fc13:f00::/24fc13:fff:ffff:ffff:ffff:ffff:ffff:ffff
17fc13:1000::/24fc13:10ff:ffff:ffff:ffff:ffff:ffff:ffff
18fc13:1100::/24fc13:11ff:ffff:ffff:ffff:ffff:ffff:ffff
19fc13:1200::/24fc13:12ff:ffff:ffff:ffff:ffff:ffff:ffff
20fc13:1300::/24fc13:13ff:ffff:ffff:ffff:ffff:ffff:ffff
21fc13:1400::/24fc13:14ff:ffff:ffff:ffff:ffff:ffff:ffff
22fc13:1500::/24fc13:15ff:ffff:ffff:ffff:ffff:ffff:ffff
23fc13:1600::/24fc13:16ff:ffff:ffff:ffff:ffff:ffff:ffff
24fc13:1700::/24fc13:17ff:ffff:ffff:ffff:ffff:ffff:ffff
25fc13:1800::/24fc13:18ff:ffff:ffff:ffff:ffff:ffff:ffff
26fc13:1900::/24fc13:19ff:ffff:ffff:ffff:ffff:ffff:ffff
27fc13:1a00::/24fc13:1aff:ffff:ffff:ffff:ffff:ffff:ffff
28fc13:1b00::/24fc13:1bff:ffff:ffff:ffff:ffff:ffff:ffff
29fc13:1c00::/24fc13:1cff:ffff:ffff:ffff:ffff:ffff:ffff
30fc13:1d00::/24fc13:1dff:ffff:ffff:ffff:ffff:ffff:ffff
31fc13:1e00::/24fc13:1eff:ffff:ffff:ffff:ffff:ffff:ffff
32fc13:1f00::/24fc13:1fff:ffff:ffff:ffff:ffff:ffff:ffff
33fc13:2000::/24fc13:20ff:ffff:ffff:ffff:ffff:ffff:ffff
34fc13:2100::/24fc13:21ff:ffff:ffff:ffff:ffff:ffff:ffff
35fc13:2200::/24fc13:22ff:ffff:ffff:ffff:ffff:ffff:ffff
36fc13:2300::/24fc13:23ff:ffff:ffff:ffff:ffff:ffff:ffff
37fc13:2400::/24fc13:24ff:ffff:ffff:ffff:ffff:ffff:ffff
38fc13:2500::/24fc13:25ff:ffff:ffff:ffff:ffff:ffff:ffff
39fc13:2600::/24fc13:26ff:ffff:ffff:ffff:ffff:ffff:ffff
40fc13:2700::/24fc13:27ff:ffff:ffff:ffff:ffff:ffff:ffff
41fc13:2800::/24fc13:28ff:ffff:ffff:ffff:ffff:ffff:ffff
42fc13:2900::/24fc13:29ff:ffff:ffff:ffff:ffff:ffff:ffff
43fc13:2a00::/24fc13:2aff:ffff:ffff:ffff:ffff:ffff:ffff
44fc13:2b00::/24fc13:2bff:ffff:ffff:ffff:ffff:ffff:ffff
45fc13:2c00::/24fc13:2cff:ffff:ffff:ffff:ffff:ffff:ffff
46fc13:2d00::/24fc13:2dff:ffff:ffff:ffff:ffff:ffff:ffff
47fc13:2e00::/24fc13:2eff:ffff:ffff:ffff:ffff:ffff:ffff
48fc13:2f00::/24fc13:2fff:ffff:ffff:ffff:ffff:ffff:ffff
49fc13:3000::/24fc13:30ff:ffff:ffff:ffff:ffff:ffff:ffff
50fc13:3100::/24fc13:31ff:ffff:ffff:ffff:ffff:ffff:ffff
51fc13:3200::/24fc13:32ff:ffff:ffff:ffff:ffff:ffff:ffff
52fc13:3300::/24fc13:33ff:ffff:ffff:ffff:ffff:ffff:ffff
53fc13:3400::/24fc13:34ff:ffff:ffff:ffff:ffff:ffff:ffff
54fc13:3500::/24fc13:35ff:ffff:ffff:ffff:ffff:ffff:ffff
55fc13:3600::/24fc13:36ff:ffff:ffff:ffff:ffff:ffff:ffff
56fc13:3700::/24fc13:37ff:ffff:ffff:ffff:ffff:ffff:ffff
57fc13:3800::/24fc13:38ff:ffff:ffff:ffff:ffff:ffff:ffff
58fc13:3900::/24fc13:39ff:ffff:ffff:ffff:ffff:ffff:ffff
59fc13:3a00::/24fc13:3aff:ffff:ffff:ffff:ffff:ffff:ffff
60fc13:3b00::/24fc13:3bff:ffff:ffff:ffff:ffff:ffff:ffff
61fc13:3c00::/24fc13:3cff:ffff:ffff:ffff:ffff:ffff:ffff
62fc13:3d00::/24fc13:3dff:ffff:ffff:ffff:ffff:ffff:ffff
63fc13:3e00::/24fc13:3eff:ffff:ffff:ffff:ffff:ffff:ffff
64fc13:3f00::/24fc13:3fff:ffff:ffff:ffff:ffff:ffff:ffff
65fc13:4000::/24fc13:40ff:ffff:ffff:ffff:ffff:ffff:ffff
66fc13:4100::/24fc13:41ff:ffff:ffff:ffff:ffff:ffff:ffff
67fc13:4200::/24fc13:42ff:ffff:ffff:ffff:ffff:ffff:ffff
68fc13:4300::/24fc13:43ff:ffff:ffff:ffff:ffff:ffff:ffff
69fc13:4400::/24fc13:44ff:ffff:ffff:ffff:ffff:ffff:ffff
70fc13:4500::/24fc13:45ff:ffff:ffff:ffff:ffff:ffff:ffff
71fc13:4600::/24fc13:46ff:ffff:ffff:ffff:ffff:ffff:ffff
72fc13:4700::/24fc13:47ff:ffff:ffff:ffff:ffff:ffff:ffff
73fc13:4800::/24fc13:48ff:ffff:ffff:ffff:ffff:ffff:ffff
74fc13:4900::/24fc13:49ff:ffff:ffff:ffff:ffff:ffff:ffff
75fc13:4a00::/24fc13:4aff:ffff:ffff:ffff:ffff:ffff:ffff
76fc13:4b00::/24fc13:4bff:ffff:ffff:ffff:ffff:ffff:ffff
77fc13:4c00::/24fc13:4cff:ffff:ffff:ffff:ffff:ffff:ffff
78fc13:4d00::/24fc13:4dff:ffff:ffff:ffff:ffff:ffff:ffff
79fc13:4e00::/24fc13:4eff:ffff:ffff:ffff:ffff:ffff:ffff
80fc13:4f00::/24fc13:4fff:ffff:ffff:ffff:ffff:ffff:ffff
81fc13:5000::/24fc13:50ff:ffff:ffff:ffff:ffff:ffff:ffff
82fc13:5100::/24fc13:51ff:ffff:ffff:ffff:ffff:ffff:ffff
83fc13:5200::/24fc13:52ff:ffff:ffff:ffff:ffff:ffff:ffff
84fc13:5300::/24fc13:53ff:ffff:ffff:ffff:ffff:ffff:ffff
85fc13:5400::/24fc13:54ff:ffff:ffff:ffff:ffff:ffff:ffff
86fc13:5500::/24fc13:55ff:ffff:ffff:ffff:ffff:ffff:ffff
87fc13:5600::/24fc13:56ff:ffff:ffff:ffff:ffff:ffff:ffff
88fc13:5700::/24fc13:57ff:ffff:ffff:ffff:ffff:ffff:ffff
89fc13:5800::/24fc13:58ff:ffff:ffff:ffff:ffff:ffff:ffff
90fc13:5900::/24fc13:59ff:ffff:ffff:ffff:ffff:ffff:ffff
91fc13:5a00::/24fc13:5aff:ffff:ffff:ffff:ffff:ffff:ffff
92fc13:5b00::/24fc13:5bff:ffff:ffff:ffff:ffff:ffff:ffff
93fc13:5c00::/24fc13:5cff:ffff:ffff:ffff:ffff:ffff:ffff
94fc13:5d00::/24fc13:5dff:ffff:ffff:ffff:ffff:ffff:ffff
95fc13:5e00::/24fc13:5eff:ffff:ffff:ffff:ffff:ffff:ffff
96fc13:5f00::/24fc13:5fff:ffff:ffff:ffff:ffff:ffff:ffff
97fc13:6000::/24fc13:60ff:ffff:ffff:ffff:ffff:ffff:ffff
98fc13:6100::/24fc13:61ff:ffff:ffff:ffff:ffff:ffff:ffff
99fc13:6200::/24fc13:62ff:ffff:ffff:ffff:ffff:ffff:ffff
100fc13:6300::/24fc13:63ff:ffff:ffff:ffff:ffff:ffff:ffff
101fc13:6400::/24fc13:64ff:ffff:ffff:ffff:ffff:ffff:ffff
102fc13:6500::/24fc13:65ff:ffff:ffff:ffff:ffff:ffff:ffff
103fc13:6600::/24fc13:66ff:ffff:ffff:ffff:ffff:ffff:ffff
104fc13:6700::/24fc13:67ff:ffff:ffff:ffff:ffff:ffff:ffff
105fc13:6800::/24fc13:68ff:ffff:ffff:ffff:ffff:ffff:ffff
106fc13:6900::/24fc13:69ff:ffff:ffff:ffff:ffff:ffff:ffff
107fc13:6a00::/24fc13:6aff:ffff:ffff:ffff:ffff:ffff:ffff
108fc13:6b00::/24fc13:6bff:ffff:ffff:ffff:ffff:ffff:ffff
109fc13:6c00::/24fc13:6cff:ffff:ffff:ffff:ffff:ffff:ffff
110fc13:6d00::/24fc13:6dff:ffff:ffff:ffff:ffff:ffff:ffff
111fc13:6e00::/24fc13:6eff:ffff:ffff:ffff:ffff:ffff:ffff
112fc13:6f00::/24fc13:6fff:ffff:ffff:ffff:ffff:ffff:ffff
113fc13:7000::/24fc13:70ff:ffff:ffff:ffff:ffff:ffff:ffff
114fc13:7100::/24fc13:71ff:ffff:ffff:ffff:ffff:ffff:ffff
115fc13:7200::/24fc13:72ff:ffff:ffff:ffff:ffff:ffff:ffff
116fc13:7300::/24fc13:73ff:ffff:ffff:ffff:ffff:ffff:ffff
117fc13:7400::/24fc13:74ff:ffff:ffff:ffff:ffff:ffff:ffff
118fc13:7500::/24fc13:75ff:ffff:ffff:ffff:ffff:ffff:ffff
119fc13:7600::/24fc13:76ff:ffff:ffff:ffff:ffff:ffff:ffff
120fc13:7700::/24fc13:77ff:ffff:ffff:ffff:ffff:ffff:ffff
121fc13:7800::/24fc13:78ff:ffff:ffff:ffff:ffff:ffff:ffff
122fc13:7900::/24fc13:79ff:ffff:ffff:ffff:ffff:ffff:ffff
123fc13:7a00::/24fc13:7aff:ffff:ffff:ffff:ffff:ffff:ffff
124fc13:7b00::/24fc13:7bff:ffff:ffff:ffff:ffff:ffff:ffff
125fc13:7c00::/24fc13:7cff:ffff:ffff:ffff:ffff:ffff:ffff
126fc13:7d00::/24fc13:7dff:ffff:ffff:ffff:ffff:ffff:ffff
127fc13:7e00::/24fc13:7eff:ffff:ffff:ffff:ffff:ffff:ffff
128fc13:7f00::/24fc13:7fff:ffff:ffff:ffff:ffff:ffff:ffff
129fc13:8000::/24fc13:80ff:ffff:ffff:ffff:ffff:ffff:ffff
130fc13:8100::/24fc13:81ff:ffff:ffff:ffff:ffff:ffff:ffff
131fc13:8200::/24fc13:82ff:ffff:ffff:ffff:ffff:ffff:ffff
132fc13:8300::/24fc13:83ff:ffff:ffff:ffff:ffff:ffff:ffff
133fc13:8400::/24fc13:84ff:ffff:ffff:ffff:ffff:ffff:ffff
134fc13:8500::/24fc13:85ff:ffff:ffff:ffff:ffff:ffff:ffff
135fc13:8600::/24fc13:86ff:ffff:ffff:ffff:ffff:ffff:ffff
136fc13:8700::/24fc13:87ff:ffff:ffff:ffff:ffff:ffff:ffff
137fc13:8800::/24fc13:88ff:ffff:ffff:ffff:ffff:ffff:ffff
138fc13:8900::/24fc13:89ff:ffff:ffff:ffff:ffff:ffff:ffff
139fc13:8a00::/24fc13:8aff:ffff:ffff:ffff:ffff:ffff:ffff
140fc13:8b00::/24fc13:8bff:ffff:ffff:ffff:ffff:ffff:ffff
141fc13:8c00::/24fc13:8cff:ffff:ffff:ffff:ffff:ffff:ffff
142fc13:8d00::/24fc13:8dff:ffff:ffff:ffff:ffff:ffff:ffff
143fc13:8e00::/24fc13:8eff:ffff:ffff:ffff:ffff:ffff:ffff
144fc13:8f00::/24fc13:8fff:ffff:ffff:ffff:ffff:ffff:ffff
145fc13:9000::/24fc13:90ff:ffff:ffff:ffff:ffff:ffff:ffff
146fc13:9100::/24fc13:91ff:ffff:ffff:ffff:ffff:ffff:ffff
147fc13:9200::/24fc13:92ff:ffff:ffff:ffff:ffff:ffff:ffff
148fc13:9300::/24fc13:93ff:ffff:ffff:ffff:ffff:ffff:ffff
149fc13:9400::/24fc13:94ff:ffff:ffff:ffff:ffff:ffff:ffff
150fc13:9500::/24fc13:95ff:ffff:ffff:ffff:ffff:ffff:ffff
151fc13:9600::/24fc13:96ff:ffff:ffff:ffff:ffff:ffff:ffff
152fc13:9700::/24fc13:97ff:ffff:ffff:ffff:ffff:ffff:ffff
153fc13:9800::/24fc13:98ff:ffff:ffff:ffff:ffff:ffff:ffff
154fc13:9900::/24fc13:99ff:ffff:ffff:ffff:ffff:ffff:ffff
155fc13:9a00::/24fc13:9aff:ffff:ffff:ffff:ffff:ffff:ffff
156fc13:9b00::/24fc13:9bff:ffff:ffff:ffff:ffff:ffff:ffff
157fc13:9c00::/24fc13:9cff:ffff:ffff:ffff:ffff:ffff:ffff
158fc13:9d00::/24fc13:9dff:ffff:ffff:ffff:ffff:ffff:ffff
159fc13:9e00::/24fc13:9eff:ffff:ffff:ffff:ffff:ffff:ffff
160fc13:9f00::/24fc13:9fff:ffff:ffff:ffff:ffff:ffff:ffff
161fc13:a000::/24fc13:a0ff:ffff:ffff:ffff:ffff:ffff:ffff
162fc13:a100::/24fc13:a1ff:ffff:ffff:ffff:ffff:ffff:ffff
163fc13:a200::/24fc13:a2ff:ffff:ffff:ffff:ffff:ffff:ffff
164fc13:a300::/24fc13:a3ff:ffff:ffff:ffff:ffff:ffff:ffff
165fc13:a400::/24fc13:a4ff:ffff:ffff:ffff:ffff:ffff:ffff
166fc13:a500::/24fc13:a5ff:ffff:ffff:ffff:ffff:ffff:ffff
167fc13:a600::/24fc13:a6ff:ffff:ffff:ffff:ffff:ffff:ffff
168fc13:a700::/24fc13:a7ff:ffff:ffff:ffff:ffff:ffff:ffff
169fc13:a800::/24fc13:a8ff:ffff:ffff:ffff:ffff:ffff:ffff
170fc13:a900::/24fc13:a9ff:ffff:ffff:ffff:ffff:ffff:ffff
171fc13:aa00::/24fc13:aaff:ffff:ffff:ffff:ffff:ffff:ffff
172fc13:ab00::/24fc13:abff:ffff:ffff:ffff:ffff:ffff:ffff
173fc13:ac00::/24fc13:acff:ffff:ffff:ffff:ffff:ffff:ffff
174fc13:ad00::/24fc13:adff:ffff:ffff:ffff:ffff:ffff:ffff
175fc13:ae00::/24fc13:aeff:ffff:ffff:ffff:ffff:ffff:ffff
176fc13:af00::/24fc13:afff:ffff:ffff:ffff:ffff:ffff:ffff
177fc13:b000::/24fc13:b0ff:ffff:ffff:ffff:ffff:ffff:ffff
178fc13:b100::/24fc13:b1ff:ffff:ffff:ffff:ffff:ffff:ffff
179fc13:b200::/24fc13:b2ff:ffff:ffff:ffff:ffff:ffff:ffff
180fc13:b300::/24fc13:b3ff:ffff:ffff:ffff:ffff:ffff:ffff
181fc13:b400::/24fc13:b4ff:ffff:ffff:ffff:ffff:ffff:ffff
182fc13:b500::/24fc13:b5ff:ffff:ffff:ffff:ffff:ffff:ffff
183fc13:b600::/24fc13:b6ff:ffff:ffff:ffff:ffff:ffff:ffff
184fc13:b700::/24fc13:b7ff:ffff:ffff:ffff:ffff:ffff:ffff
185fc13:b800::/24fc13:b8ff:ffff:ffff:ffff:ffff:ffff:ffff
186fc13:b900::/24fc13:b9ff:ffff:ffff:ffff:ffff:ffff:ffff
187fc13:ba00::/24fc13:baff:ffff:ffff:ffff:ffff:ffff:ffff
188fc13:bb00::/24fc13:bbff:ffff:ffff:ffff:ffff:ffff:ffff
189fc13:bc00::/24fc13:bcff:ffff:ffff:ffff:ffff:ffff:ffff
190fc13:bd00::/24fc13:bdff:ffff:ffff:ffff:ffff:ffff:ffff
191fc13:be00::/24fc13:beff:ffff:ffff:ffff:ffff:ffff:ffff
192fc13:bf00::/24fc13:bfff:ffff:ffff:ffff:ffff:ffff:ffff
193fc13:c000::/24fc13:c0ff:ffff:ffff:ffff:ffff:ffff:ffff
194fc13:c100::/24fc13:c1ff:ffff:ffff:ffff:ffff:ffff:ffff
195fc13:c200::/24fc13:c2ff:ffff:ffff:ffff:ffff:ffff:ffff
196fc13:c300::/24fc13:c3ff:ffff:ffff:ffff:ffff:ffff:ffff
197fc13:c400::/24fc13:c4ff:ffff:ffff:ffff:ffff:ffff:ffff
198fc13:c500::/24fc13:c5ff:ffff:ffff:ffff:ffff:ffff:ffff
199fc13:c600::/24fc13:c6ff:ffff:ffff:ffff:ffff:ffff:ffff
200fc13:c700::/24fc13:c7ff:ffff:ffff:ffff:ffff:ffff:ffff
201fc13:c800::/24fc13:c8ff:ffff:ffff:ffff:ffff:ffff:ffff
202fc13:c900::/24fc13:c9ff:ffff:ffff:ffff:ffff:ffff:ffff
203fc13:ca00::/24fc13:caff:ffff:ffff:ffff:ffff:ffff:ffff
204fc13:cb00::/24fc13:cbff:ffff:ffff:ffff:ffff:ffff:ffff
205fc13:cc00::/24fc13:ccff:ffff:ffff:ffff:ffff:ffff:ffff
206fc13:cd00::/24fc13:cdff:ffff:ffff:ffff:ffff:ffff:ffff
207fc13:ce00::/24fc13:ceff:ffff:ffff:ffff:ffff:ffff:ffff
208fc13:cf00::/24fc13:cfff:ffff:ffff:ffff:ffff:ffff:ffff
209fc13:d000::/24fc13:d0ff:ffff:ffff:ffff:ffff:ffff:ffff
210fc13:d100::/24fc13:d1ff:ffff:ffff:ffff:ffff:ffff:ffff
211fc13:d200::/24fc13:d2ff:ffff:ffff:ffff:ffff:ffff:ffff
212fc13:d300::/24fc13:d3ff:ffff:ffff:ffff:ffff:ffff:ffff
213fc13:d400::/24fc13:d4ff:ffff:ffff:ffff:ffff:ffff:ffff
214fc13:d500::/24fc13:d5ff:ffff:ffff:ffff:ffff:ffff:ffff
215fc13:d600::/24fc13:d6ff:ffff:ffff:ffff:ffff:ffff:ffff
216fc13:d700::/24fc13:d7ff:ffff:ffff:ffff:ffff:ffff:ffff
217fc13:d800::/24fc13:d8ff:ffff:ffff:ffff:ffff:ffff:ffff
218fc13:d900::/24fc13:d9ff:ffff:ffff:ffff:ffff:ffff:ffff
219fc13:da00::/24fc13:daff:ffff:ffff:ffff:ffff:ffff:ffff
220fc13:db00::/24fc13:dbff:ffff:ffff:ffff:ffff:ffff:ffff
221fc13:dc00::/24fc13:dcff:ffff:ffff:ffff:ffff:ffff:ffff
222fc13:dd00::/24fc13:ddff:ffff:ffff:ffff:ffff:ffff:ffff
223fc13:de00::/24fc13:deff:ffff:ffff:ffff:ffff:ffff:ffff
224fc13:df00::/24fc13:dfff:ffff:ffff:ffff:ffff:ffff:ffff
225fc13:e000::/24fc13:e0ff:ffff:ffff:ffff:ffff:ffff:ffff
226fc13:e100::/24fc13:e1ff:ffff:ffff:ffff:ffff:ffff:ffff
227fc13:e200::/24fc13:e2ff:ffff:ffff:ffff:ffff:ffff:ffff
228fc13:e300::/24fc13:e3ff:ffff:ffff:ffff:ffff:ffff:ffff
229fc13:e400::/24fc13:e4ff:ffff:ffff:ffff:ffff:ffff:ffff
230fc13:e500::/24fc13:e5ff:ffff:ffff:ffff:ffff:ffff:ffff
231fc13:e600::/24fc13:e6ff:ffff:ffff:ffff:ffff:ffff:ffff
232fc13:e700::/24fc13:e7ff:ffff:ffff:ffff:ffff:ffff:ffff
233fc13:e800::/24fc13:e8ff:ffff:ffff:ffff:ffff:ffff:ffff
234fc13:e900::/24fc13:e9ff:ffff:ffff:ffff:ffff:ffff:ffff
235fc13:ea00::/24fc13:eaff:ffff:ffff:ffff:ffff:ffff:ffff
236fc13:eb00::/24fc13:ebff:ffff:ffff:ffff:ffff:ffff:ffff
237fc13:ec00::/24fc13:ecff:ffff:ffff:ffff:ffff:ffff:ffff
238fc13:ed00::/24fc13:edff:ffff:ffff:ffff:ffff:ffff:ffff
239fc13:ee00::/24fc13:eeff:ffff:ffff:ffff:ffff:ffff:ffff
240fc13:ef00::/24fc13:efff:ffff:ffff:ffff:ffff:ffff:ffff
241fc13:f000::/24fc13:f0ff:ffff:ffff:ffff:ffff:ffff:ffff
242fc13:f100::/24fc13:f1ff:ffff:ffff:ffff:ffff:ffff:ffff
243fc13:f200::/24fc13:f2ff:ffff:ffff:ffff:ffff:ffff:ffff
244fc13:f300::/24fc13:f3ff:ffff:ffff:ffff:ffff:ffff:ffff
245fc13:f400::/24fc13:f4ff:ffff:ffff:ffff:ffff:ffff:ffff
246fc13:f500::/24fc13:f5ff:ffff:ffff:ffff:ffff:ffff:ffff
247fc13:f600::/24fc13:f6ff:ffff:ffff:ffff:ffff:ffff:ffff
248fc13:f700::/24fc13:f7ff:ffff:ffff:ffff:ffff:ffff:ffff
249fc13:f800::/24fc13:f8ff:ffff:ffff:ffff:ffff:ffff:ffff
250fc13:f900::/24fc13:f9ff:ffff:ffff:ffff:ffff:ffff:ffff
251fc13:fa00::/24fc13:faff:ffff:ffff:ffff:ffff:ffff:ffff
252fc13:fb00::/24fc13:fbff:ffff:ffff:ffff:ffff:ffff:ffff
253fc13:fc00::/24fc13:fcff:ffff:ffff:ffff:ffff:ffff:ffff
254fc13:fd00::/24fc13:fdff:ffff:ffff:ffff:ffff:ffff:ffff
255fc13:fe00::/24fc13:feff:ffff:ffff:ffff:ffff:ffff:ffff
256fc13:ff00::/24fc13: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.