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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
fc47::/16
First address
fc47::
Last address
fc47: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
fc47:0000:0000:0000:0000:0000:0000:0000
Type
Unique local (ULA) fc00::/7
Private IPv6, like RFC 1918; usually fd00::/8
Reverse DNS zone
7.4.c.f.ip6.arpa
Split into smaller subnets/28
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

fc47::/16 makes 4,096 subnets of /28; the first 256 are listed.

Subnets
#SubnetLast address
1fc47::/28fc47:f:ffff:ffff:ffff:ffff:ffff:ffff
2fc47:10::/28fc47:1f:ffff:ffff:ffff:ffff:ffff:ffff
3fc47:20::/28fc47:2f:ffff:ffff:ffff:ffff:ffff:ffff
4fc47:30::/28fc47:3f:ffff:ffff:ffff:ffff:ffff:ffff
5fc47:40::/28fc47:4f:ffff:ffff:ffff:ffff:ffff:ffff
6fc47:50::/28fc47:5f:ffff:ffff:ffff:ffff:ffff:ffff
7fc47:60::/28fc47:6f:ffff:ffff:ffff:ffff:ffff:ffff
8fc47:70::/28fc47:7f:ffff:ffff:ffff:ffff:ffff:ffff
9fc47:80::/28fc47:8f:ffff:ffff:ffff:ffff:ffff:ffff
10fc47:90::/28fc47:9f:ffff:ffff:ffff:ffff:ffff:ffff
11fc47:a0::/28fc47:af:ffff:ffff:ffff:ffff:ffff:ffff
12fc47:b0::/28fc47:bf:ffff:ffff:ffff:ffff:ffff:ffff
13fc47:c0::/28fc47:cf:ffff:ffff:ffff:ffff:ffff:ffff
14fc47:d0::/28fc47:df:ffff:ffff:ffff:ffff:ffff:ffff
15fc47:e0::/28fc47:ef:ffff:ffff:ffff:ffff:ffff:ffff
16fc47:f0::/28fc47:ff:ffff:ffff:ffff:ffff:ffff:ffff
17fc47:100::/28fc47:10f:ffff:ffff:ffff:ffff:ffff:ffff
18fc47:110::/28fc47:11f:ffff:ffff:ffff:ffff:ffff:ffff
19fc47:120::/28fc47:12f:ffff:ffff:ffff:ffff:ffff:ffff
20fc47:130::/28fc47:13f:ffff:ffff:ffff:ffff:ffff:ffff
21fc47:140::/28fc47:14f:ffff:ffff:ffff:ffff:ffff:ffff
22fc47:150::/28fc47:15f:ffff:ffff:ffff:ffff:ffff:ffff
23fc47:160::/28fc47:16f:ffff:ffff:ffff:ffff:ffff:ffff
24fc47:170::/28fc47:17f:ffff:ffff:ffff:ffff:ffff:ffff
25fc47:180::/28fc47:18f:ffff:ffff:ffff:ffff:ffff:ffff
26fc47:190::/28fc47:19f:ffff:ffff:ffff:ffff:ffff:ffff
27fc47:1a0::/28fc47:1af:ffff:ffff:ffff:ffff:ffff:ffff
28fc47:1b0::/28fc47:1bf:ffff:ffff:ffff:ffff:ffff:ffff
29fc47:1c0::/28fc47:1cf:ffff:ffff:ffff:ffff:ffff:ffff
30fc47:1d0::/28fc47:1df:ffff:ffff:ffff:ffff:ffff:ffff
31fc47:1e0::/28fc47:1ef:ffff:ffff:ffff:ffff:ffff:ffff
32fc47:1f0::/28fc47:1ff:ffff:ffff:ffff:ffff:ffff:ffff
33fc47:200::/28fc47:20f:ffff:ffff:ffff:ffff:ffff:ffff
34fc47:210::/28fc47:21f:ffff:ffff:ffff:ffff:ffff:ffff
35fc47:220::/28fc47:22f:ffff:ffff:ffff:ffff:ffff:ffff
36fc47:230::/28fc47:23f:ffff:ffff:ffff:ffff:ffff:ffff
37fc47:240::/28fc47:24f:ffff:ffff:ffff:ffff:ffff:ffff
38fc47:250::/28fc47:25f:ffff:ffff:ffff:ffff:ffff:ffff
39fc47:260::/28fc47:26f:ffff:ffff:ffff:ffff:ffff:ffff
40fc47:270::/28fc47:27f:ffff:ffff:ffff:ffff:ffff:ffff
41fc47:280::/28fc47:28f:ffff:ffff:ffff:ffff:ffff:ffff
42fc47:290::/28fc47:29f:ffff:ffff:ffff:ffff:ffff:ffff
43fc47:2a0::/28fc47:2af:ffff:ffff:ffff:ffff:ffff:ffff
44fc47:2b0::/28fc47:2bf:ffff:ffff:ffff:ffff:ffff:ffff
45fc47:2c0::/28fc47:2cf:ffff:ffff:ffff:ffff:ffff:ffff
46fc47:2d0::/28fc47:2df:ffff:ffff:ffff:ffff:ffff:ffff
47fc47:2e0::/28fc47:2ef:ffff:ffff:ffff:ffff:ffff:ffff
48fc47:2f0::/28fc47:2ff:ffff:ffff:ffff:ffff:ffff:ffff
49fc47:300::/28fc47:30f:ffff:ffff:ffff:ffff:ffff:ffff
50fc47:310::/28fc47:31f:ffff:ffff:ffff:ffff:ffff:ffff
51fc47:320::/28fc47:32f:ffff:ffff:ffff:ffff:ffff:ffff
52fc47:330::/28fc47:33f:ffff:ffff:ffff:ffff:ffff:ffff
53fc47:340::/28fc47:34f:ffff:ffff:ffff:ffff:ffff:ffff
54fc47:350::/28fc47:35f:ffff:ffff:ffff:ffff:ffff:ffff
55fc47:360::/28fc47:36f:ffff:ffff:ffff:ffff:ffff:ffff
56fc47:370::/28fc47:37f:ffff:ffff:ffff:ffff:ffff:ffff
57fc47:380::/28fc47:38f:ffff:ffff:ffff:ffff:ffff:ffff
58fc47:390::/28fc47:39f:ffff:ffff:ffff:ffff:ffff:ffff
59fc47:3a0::/28fc47:3af:ffff:ffff:ffff:ffff:ffff:ffff
60fc47:3b0::/28fc47:3bf:ffff:ffff:ffff:ffff:ffff:ffff
61fc47:3c0::/28fc47:3cf:ffff:ffff:ffff:ffff:ffff:ffff
62fc47:3d0::/28fc47:3df:ffff:ffff:ffff:ffff:ffff:ffff
63fc47:3e0::/28fc47:3ef:ffff:ffff:ffff:ffff:ffff:ffff
64fc47:3f0::/28fc47:3ff:ffff:ffff:ffff:ffff:ffff:ffff
65fc47:400::/28fc47:40f:ffff:ffff:ffff:ffff:ffff:ffff
66fc47:410::/28fc47:41f:ffff:ffff:ffff:ffff:ffff:ffff
67fc47:420::/28fc47:42f:ffff:ffff:ffff:ffff:ffff:ffff
68fc47:430::/28fc47:43f:ffff:ffff:ffff:ffff:ffff:ffff
69fc47:440::/28fc47:44f:ffff:ffff:ffff:ffff:ffff:ffff
70fc47:450::/28fc47:45f:ffff:ffff:ffff:ffff:ffff:ffff
71fc47:460::/28fc47:46f:ffff:ffff:ffff:ffff:ffff:ffff
72fc47:470::/28fc47:47f:ffff:ffff:ffff:ffff:ffff:ffff
73fc47:480::/28fc47:48f:ffff:ffff:ffff:ffff:ffff:ffff
74fc47:490::/28fc47:49f:ffff:ffff:ffff:ffff:ffff:ffff
75fc47:4a0::/28fc47:4af:ffff:ffff:ffff:ffff:ffff:ffff
76fc47:4b0::/28fc47:4bf:ffff:ffff:ffff:ffff:ffff:ffff
77fc47:4c0::/28fc47:4cf:ffff:ffff:ffff:ffff:ffff:ffff
78fc47:4d0::/28fc47:4df:ffff:ffff:ffff:ffff:ffff:ffff
79fc47:4e0::/28fc47:4ef:ffff:ffff:ffff:ffff:ffff:ffff
80fc47:4f0::/28fc47:4ff:ffff:ffff:ffff:ffff:ffff:ffff
81fc47:500::/28fc47:50f:ffff:ffff:ffff:ffff:ffff:ffff
82fc47:510::/28fc47:51f:ffff:ffff:ffff:ffff:ffff:ffff
83fc47:520::/28fc47:52f:ffff:ffff:ffff:ffff:ffff:ffff
84fc47:530::/28fc47:53f:ffff:ffff:ffff:ffff:ffff:ffff
85fc47:540::/28fc47:54f:ffff:ffff:ffff:ffff:ffff:ffff
86fc47:550::/28fc47:55f:ffff:ffff:ffff:ffff:ffff:ffff
87fc47:560::/28fc47:56f:ffff:ffff:ffff:ffff:ffff:ffff
88fc47:570::/28fc47:57f:ffff:ffff:ffff:ffff:ffff:ffff
89fc47:580::/28fc47:58f:ffff:ffff:ffff:ffff:ffff:ffff
90fc47:590::/28fc47:59f:ffff:ffff:ffff:ffff:ffff:ffff
91fc47:5a0::/28fc47:5af:ffff:ffff:ffff:ffff:ffff:ffff
92fc47:5b0::/28fc47:5bf:ffff:ffff:ffff:ffff:ffff:ffff
93fc47:5c0::/28fc47:5cf:ffff:ffff:ffff:ffff:ffff:ffff
94fc47:5d0::/28fc47:5df:ffff:ffff:ffff:ffff:ffff:ffff
95fc47:5e0::/28fc47:5ef:ffff:ffff:ffff:ffff:ffff:ffff
96fc47:5f0::/28fc47:5ff:ffff:ffff:ffff:ffff:ffff:ffff
97fc47:600::/28fc47:60f:ffff:ffff:ffff:ffff:ffff:ffff
98fc47:610::/28fc47:61f:ffff:ffff:ffff:ffff:ffff:ffff
99fc47:620::/28fc47:62f:ffff:ffff:ffff:ffff:ffff:ffff
100fc47:630::/28fc47:63f:ffff:ffff:ffff:ffff:ffff:ffff
101fc47:640::/28fc47:64f:ffff:ffff:ffff:ffff:ffff:ffff
102fc47:650::/28fc47:65f:ffff:ffff:ffff:ffff:ffff:ffff
103fc47:660::/28fc47:66f:ffff:ffff:ffff:ffff:ffff:ffff
104fc47:670::/28fc47:67f:ffff:ffff:ffff:ffff:ffff:ffff
105fc47:680::/28fc47:68f:ffff:ffff:ffff:ffff:ffff:ffff
106fc47:690::/28fc47:69f:ffff:ffff:ffff:ffff:ffff:ffff
107fc47:6a0::/28fc47:6af:ffff:ffff:ffff:ffff:ffff:ffff
108fc47:6b0::/28fc47:6bf:ffff:ffff:ffff:ffff:ffff:ffff
109fc47:6c0::/28fc47:6cf:ffff:ffff:ffff:ffff:ffff:ffff
110fc47:6d0::/28fc47:6df:ffff:ffff:ffff:ffff:ffff:ffff
111fc47:6e0::/28fc47:6ef:ffff:ffff:ffff:ffff:ffff:ffff
112fc47:6f0::/28fc47:6ff:ffff:ffff:ffff:ffff:ffff:ffff
113fc47:700::/28fc47:70f:ffff:ffff:ffff:ffff:ffff:ffff
114fc47:710::/28fc47:71f:ffff:ffff:ffff:ffff:ffff:ffff
115fc47:720::/28fc47:72f:ffff:ffff:ffff:ffff:ffff:ffff
116fc47:730::/28fc47:73f:ffff:ffff:ffff:ffff:ffff:ffff
117fc47:740::/28fc47:74f:ffff:ffff:ffff:ffff:ffff:ffff
118fc47:750::/28fc47:75f:ffff:ffff:ffff:ffff:ffff:ffff
119fc47:760::/28fc47:76f:ffff:ffff:ffff:ffff:ffff:ffff
120fc47:770::/28fc47:77f:ffff:ffff:ffff:ffff:ffff:ffff
121fc47:780::/28fc47:78f:ffff:ffff:ffff:ffff:ffff:ffff
122fc47:790::/28fc47:79f:ffff:ffff:ffff:ffff:ffff:ffff
123fc47:7a0::/28fc47:7af:ffff:ffff:ffff:ffff:ffff:ffff
124fc47:7b0::/28fc47:7bf:ffff:ffff:ffff:ffff:ffff:ffff
125fc47:7c0::/28fc47:7cf:ffff:ffff:ffff:ffff:ffff:ffff
126fc47:7d0::/28fc47:7df:ffff:ffff:ffff:ffff:ffff:ffff
127fc47:7e0::/28fc47:7ef:ffff:ffff:ffff:ffff:ffff:ffff
128fc47:7f0::/28fc47:7ff:ffff:ffff:ffff:ffff:ffff:ffff
129fc47:800::/28fc47:80f:ffff:ffff:ffff:ffff:ffff:ffff
130fc47:810::/28fc47:81f:ffff:ffff:ffff:ffff:ffff:ffff
131fc47:820::/28fc47:82f:ffff:ffff:ffff:ffff:ffff:ffff
132fc47:830::/28fc47:83f:ffff:ffff:ffff:ffff:ffff:ffff
133fc47:840::/28fc47:84f:ffff:ffff:ffff:ffff:ffff:ffff
134fc47:850::/28fc47:85f:ffff:ffff:ffff:ffff:ffff:ffff
135fc47:860::/28fc47:86f:ffff:ffff:ffff:ffff:ffff:ffff
136fc47:870::/28fc47:87f:ffff:ffff:ffff:ffff:ffff:ffff
137fc47:880::/28fc47:88f:ffff:ffff:ffff:ffff:ffff:ffff
138fc47:890::/28fc47:89f:ffff:ffff:ffff:ffff:ffff:ffff
139fc47:8a0::/28fc47:8af:ffff:ffff:ffff:ffff:ffff:ffff
140fc47:8b0::/28fc47:8bf:ffff:ffff:ffff:ffff:ffff:ffff
141fc47:8c0::/28fc47:8cf:ffff:ffff:ffff:ffff:ffff:ffff
142fc47:8d0::/28fc47:8df:ffff:ffff:ffff:ffff:ffff:ffff
143fc47:8e0::/28fc47:8ef:ffff:ffff:ffff:ffff:ffff:ffff
144fc47:8f0::/28fc47:8ff:ffff:ffff:ffff:ffff:ffff:ffff
145fc47:900::/28fc47:90f:ffff:ffff:ffff:ffff:ffff:ffff
146fc47:910::/28fc47:91f:ffff:ffff:ffff:ffff:ffff:ffff
147fc47:920::/28fc47:92f:ffff:ffff:ffff:ffff:ffff:ffff
148fc47:930::/28fc47:93f:ffff:ffff:ffff:ffff:ffff:ffff
149fc47:940::/28fc47:94f:ffff:ffff:ffff:ffff:ffff:ffff
150fc47:950::/28fc47:95f:ffff:ffff:ffff:ffff:ffff:ffff
151fc47:960::/28fc47:96f:ffff:ffff:ffff:ffff:ffff:ffff
152fc47:970::/28fc47:97f:ffff:ffff:ffff:ffff:ffff:ffff
153fc47:980::/28fc47:98f:ffff:ffff:ffff:ffff:ffff:ffff
154fc47:990::/28fc47:99f:ffff:ffff:ffff:ffff:ffff:ffff
155fc47:9a0::/28fc47:9af:ffff:ffff:ffff:ffff:ffff:ffff
156fc47:9b0::/28fc47:9bf:ffff:ffff:ffff:ffff:ffff:ffff
157fc47:9c0::/28fc47:9cf:ffff:ffff:ffff:ffff:ffff:ffff
158fc47:9d0::/28fc47:9df:ffff:ffff:ffff:ffff:ffff:ffff
159fc47:9e0::/28fc47:9ef:ffff:ffff:ffff:ffff:ffff:ffff
160fc47:9f0::/28fc47:9ff:ffff:ffff:ffff:ffff:ffff:ffff
161fc47:a00::/28fc47:a0f:ffff:ffff:ffff:ffff:ffff:ffff
162fc47:a10::/28fc47:a1f:ffff:ffff:ffff:ffff:ffff:ffff
163fc47:a20::/28fc47:a2f:ffff:ffff:ffff:ffff:ffff:ffff
164fc47:a30::/28fc47:a3f:ffff:ffff:ffff:ffff:ffff:ffff
165fc47:a40::/28fc47:a4f:ffff:ffff:ffff:ffff:ffff:ffff
166fc47:a50::/28fc47:a5f:ffff:ffff:ffff:ffff:ffff:ffff
167fc47:a60::/28fc47:a6f:ffff:ffff:ffff:ffff:ffff:ffff
168fc47:a70::/28fc47:a7f:ffff:ffff:ffff:ffff:ffff:ffff
169fc47:a80::/28fc47:a8f:ffff:ffff:ffff:ffff:ffff:ffff
170fc47:a90::/28fc47:a9f:ffff:ffff:ffff:ffff:ffff:ffff
171fc47:aa0::/28fc47:aaf:ffff:ffff:ffff:ffff:ffff:ffff
172fc47:ab0::/28fc47:abf:ffff:ffff:ffff:ffff:ffff:ffff
173fc47:ac0::/28fc47:acf:ffff:ffff:ffff:ffff:ffff:ffff
174fc47:ad0::/28fc47:adf:ffff:ffff:ffff:ffff:ffff:ffff
175fc47:ae0::/28fc47:aef:ffff:ffff:ffff:ffff:ffff:ffff
176fc47:af0::/28fc47:aff:ffff:ffff:ffff:ffff:ffff:ffff
177fc47:b00::/28fc47:b0f:ffff:ffff:ffff:ffff:ffff:ffff
178fc47:b10::/28fc47:b1f:ffff:ffff:ffff:ffff:ffff:ffff
179fc47:b20::/28fc47:b2f:ffff:ffff:ffff:ffff:ffff:ffff
180fc47:b30::/28fc47:b3f:ffff:ffff:ffff:ffff:ffff:ffff
181fc47:b40::/28fc47:b4f:ffff:ffff:ffff:ffff:ffff:ffff
182fc47:b50::/28fc47:b5f:ffff:ffff:ffff:ffff:ffff:ffff
183fc47:b60::/28fc47:b6f:ffff:ffff:ffff:ffff:ffff:ffff
184fc47:b70::/28fc47:b7f:ffff:ffff:ffff:ffff:ffff:ffff
185fc47:b80::/28fc47:b8f:ffff:ffff:ffff:ffff:ffff:ffff
186fc47:b90::/28fc47:b9f:ffff:ffff:ffff:ffff:ffff:ffff
187fc47:ba0::/28fc47:baf:ffff:ffff:ffff:ffff:ffff:ffff
188fc47:bb0::/28fc47:bbf:ffff:ffff:ffff:ffff:ffff:ffff
189fc47:bc0::/28fc47:bcf:ffff:ffff:ffff:ffff:ffff:ffff
190fc47:bd0::/28fc47:bdf:ffff:ffff:ffff:ffff:ffff:ffff
191fc47:be0::/28fc47:bef:ffff:ffff:ffff:ffff:ffff:ffff
192fc47:bf0::/28fc47:bff:ffff:ffff:ffff:ffff:ffff:ffff
193fc47:c00::/28fc47:c0f:ffff:ffff:ffff:ffff:ffff:ffff
194fc47:c10::/28fc47:c1f:ffff:ffff:ffff:ffff:ffff:ffff
195fc47:c20::/28fc47:c2f:ffff:ffff:ffff:ffff:ffff:ffff
196fc47:c30::/28fc47:c3f:ffff:ffff:ffff:ffff:ffff:ffff
197fc47:c40::/28fc47:c4f:ffff:ffff:ffff:ffff:ffff:ffff
198fc47:c50::/28fc47:c5f:ffff:ffff:ffff:ffff:ffff:ffff
199fc47:c60::/28fc47:c6f:ffff:ffff:ffff:ffff:ffff:ffff
200fc47:c70::/28fc47:c7f:ffff:ffff:ffff:ffff:ffff:ffff
201fc47:c80::/28fc47:c8f:ffff:ffff:ffff:ffff:ffff:ffff
202fc47:c90::/28fc47:c9f:ffff:ffff:ffff:ffff:ffff:ffff
203fc47:ca0::/28fc47:caf:ffff:ffff:ffff:ffff:ffff:ffff
204fc47:cb0::/28fc47:cbf:ffff:ffff:ffff:ffff:ffff:ffff
205fc47:cc0::/28fc47:ccf:ffff:ffff:ffff:ffff:ffff:ffff
206fc47:cd0::/28fc47:cdf:ffff:ffff:ffff:ffff:ffff:ffff
207fc47:ce0::/28fc47:cef:ffff:ffff:ffff:ffff:ffff:ffff
208fc47:cf0::/28fc47:cff:ffff:ffff:ffff:ffff:ffff:ffff
209fc47:d00::/28fc47:d0f:ffff:ffff:ffff:ffff:ffff:ffff
210fc47:d10::/28fc47:d1f:ffff:ffff:ffff:ffff:ffff:ffff
211fc47:d20::/28fc47:d2f:ffff:ffff:ffff:ffff:ffff:ffff
212fc47:d30::/28fc47:d3f:ffff:ffff:ffff:ffff:ffff:ffff
213fc47:d40::/28fc47:d4f:ffff:ffff:ffff:ffff:ffff:ffff
214fc47:d50::/28fc47:d5f:ffff:ffff:ffff:ffff:ffff:ffff
215fc47:d60::/28fc47:d6f:ffff:ffff:ffff:ffff:ffff:ffff
216fc47:d70::/28fc47:d7f:ffff:ffff:ffff:ffff:ffff:ffff
217fc47:d80::/28fc47:d8f:ffff:ffff:ffff:ffff:ffff:ffff
218fc47:d90::/28fc47:d9f:ffff:ffff:ffff:ffff:ffff:ffff
219fc47:da0::/28fc47:daf:ffff:ffff:ffff:ffff:ffff:ffff
220fc47:db0::/28fc47:dbf:ffff:ffff:ffff:ffff:ffff:ffff
221fc47:dc0::/28fc47:dcf:ffff:ffff:ffff:ffff:ffff:ffff
222fc47:dd0::/28fc47:ddf:ffff:ffff:ffff:ffff:ffff:ffff
223fc47:de0::/28fc47:def:ffff:ffff:ffff:ffff:ffff:ffff
224fc47:df0::/28fc47:dff:ffff:ffff:ffff:ffff:ffff:ffff
225fc47:e00::/28fc47:e0f:ffff:ffff:ffff:ffff:ffff:ffff
226fc47:e10::/28fc47:e1f:ffff:ffff:ffff:ffff:ffff:ffff
227fc47:e20::/28fc47:e2f:ffff:ffff:ffff:ffff:ffff:ffff
228fc47:e30::/28fc47:e3f:ffff:ffff:ffff:ffff:ffff:ffff
229fc47:e40::/28fc47:e4f:ffff:ffff:ffff:ffff:ffff:ffff
230fc47:e50::/28fc47:e5f:ffff:ffff:ffff:ffff:ffff:ffff
231fc47:e60::/28fc47:e6f:ffff:ffff:ffff:ffff:ffff:ffff
232fc47:e70::/28fc47:e7f:ffff:ffff:ffff:ffff:ffff:ffff
233fc47:e80::/28fc47:e8f:ffff:ffff:ffff:ffff:ffff:ffff
234fc47:e90::/28fc47:e9f:ffff:ffff:ffff:ffff:ffff:ffff
235fc47:ea0::/28fc47:eaf:ffff:ffff:ffff:ffff:ffff:ffff
236fc47:eb0::/28fc47:ebf:ffff:ffff:ffff:ffff:ffff:ffff
237fc47:ec0::/28fc47:ecf:ffff:ffff:ffff:ffff:ffff:ffff
238fc47:ed0::/28fc47:edf:ffff:ffff:ffff:ffff:ffff:ffff
239fc47:ee0::/28fc47:eef:ffff:ffff:ffff:ffff:ffff:ffff
240fc47:ef0::/28fc47:eff:ffff:ffff:ffff:ffff:ffff:ffff
241fc47:f00::/28fc47:f0f:ffff:ffff:ffff:ffff:ffff:ffff
242fc47:f10::/28fc47:f1f:ffff:ffff:ffff:ffff:ffff:ffff
243fc47:f20::/28fc47:f2f:ffff:ffff:ffff:ffff:ffff:ffff
244fc47:f30::/28fc47:f3f:ffff:ffff:ffff:ffff:ffff:ffff
245fc47:f40::/28fc47:f4f:ffff:ffff:ffff:ffff:ffff:ffff
246fc47:f50::/28fc47:f5f:ffff:ffff:ffff:ffff:ffff:ffff
247fc47:f60::/28fc47:f6f:ffff:ffff:ffff:ffff:ffff:ffff
248fc47:f70::/28fc47:f7f:ffff:ffff:ffff:ffff:ffff:ffff
249fc47:f80::/28fc47:f8f:ffff:ffff:ffff:ffff:ffff:ffff
250fc47:f90::/28fc47:f9f:ffff:ffff:ffff:ffff:ffff:ffff
251fc47:fa0::/28fc47:faf:ffff:ffff:ffff:ffff:ffff:ffff
252fc47:fb0::/28fc47:fbf:ffff:ffff:ffff:ffff:ffff:ffff
253fc47:fc0::/28fc47:fcf:ffff:ffff:ffff:ffff:ffff:ffff
254fc47:fd0::/28fc47:fdf:ffff:ffff:ffff:ffff:ffff:ffff
255fc47:fe0::/28fc47:fef:ffff:ffff:ffff:ffff:ffff:ffff
256fc47:ff0::/28fc47:fff: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.