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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
fc76::/16
First address
fc76::
Last address
fc76: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
fc76:0000:0000:0000:0000:0000:0000:0000
Type
Unique local (ULA) fc00::/7
Private IPv6, like RFC 1918; usually fd00::/8
Reverse DNS zone
6.7.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)

fc76::/16 makes 4,096 subnets of /28; the first 256 are listed.

Subnets
#SubnetLast address
1fc76::/28fc76:f:ffff:ffff:ffff:ffff:ffff:ffff
2fc76:10::/28fc76:1f:ffff:ffff:ffff:ffff:ffff:ffff
3fc76:20::/28fc76:2f:ffff:ffff:ffff:ffff:ffff:ffff
4fc76:30::/28fc76:3f:ffff:ffff:ffff:ffff:ffff:ffff
5fc76:40::/28fc76:4f:ffff:ffff:ffff:ffff:ffff:ffff
6fc76:50::/28fc76:5f:ffff:ffff:ffff:ffff:ffff:ffff
7fc76:60::/28fc76:6f:ffff:ffff:ffff:ffff:ffff:ffff
8fc76:70::/28fc76:7f:ffff:ffff:ffff:ffff:ffff:ffff
9fc76:80::/28fc76:8f:ffff:ffff:ffff:ffff:ffff:ffff
10fc76:90::/28fc76:9f:ffff:ffff:ffff:ffff:ffff:ffff
11fc76:a0::/28fc76:af:ffff:ffff:ffff:ffff:ffff:ffff
12fc76:b0::/28fc76:bf:ffff:ffff:ffff:ffff:ffff:ffff
13fc76:c0::/28fc76:cf:ffff:ffff:ffff:ffff:ffff:ffff
14fc76:d0::/28fc76:df:ffff:ffff:ffff:ffff:ffff:ffff
15fc76:e0::/28fc76:ef:ffff:ffff:ffff:ffff:ffff:ffff
16fc76:f0::/28fc76:ff:ffff:ffff:ffff:ffff:ffff:ffff
17fc76:100::/28fc76:10f:ffff:ffff:ffff:ffff:ffff:ffff
18fc76:110::/28fc76:11f:ffff:ffff:ffff:ffff:ffff:ffff
19fc76:120::/28fc76:12f:ffff:ffff:ffff:ffff:ffff:ffff
20fc76:130::/28fc76:13f:ffff:ffff:ffff:ffff:ffff:ffff
21fc76:140::/28fc76:14f:ffff:ffff:ffff:ffff:ffff:ffff
22fc76:150::/28fc76:15f:ffff:ffff:ffff:ffff:ffff:ffff
23fc76:160::/28fc76:16f:ffff:ffff:ffff:ffff:ffff:ffff
24fc76:170::/28fc76:17f:ffff:ffff:ffff:ffff:ffff:ffff
25fc76:180::/28fc76:18f:ffff:ffff:ffff:ffff:ffff:ffff
26fc76:190::/28fc76:19f:ffff:ffff:ffff:ffff:ffff:ffff
27fc76:1a0::/28fc76:1af:ffff:ffff:ffff:ffff:ffff:ffff
28fc76:1b0::/28fc76:1bf:ffff:ffff:ffff:ffff:ffff:ffff
29fc76:1c0::/28fc76:1cf:ffff:ffff:ffff:ffff:ffff:ffff
30fc76:1d0::/28fc76:1df:ffff:ffff:ffff:ffff:ffff:ffff
31fc76:1e0::/28fc76:1ef:ffff:ffff:ffff:ffff:ffff:ffff
32fc76:1f0::/28fc76:1ff:ffff:ffff:ffff:ffff:ffff:ffff
33fc76:200::/28fc76:20f:ffff:ffff:ffff:ffff:ffff:ffff
34fc76:210::/28fc76:21f:ffff:ffff:ffff:ffff:ffff:ffff
35fc76:220::/28fc76:22f:ffff:ffff:ffff:ffff:ffff:ffff
36fc76:230::/28fc76:23f:ffff:ffff:ffff:ffff:ffff:ffff
37fc76:240::/28fc76:24f:ffff:ffff:ffff:ffff:ffff:ffff
38fc76:250::/28fc76:25f:ffff:ffff:ffff:ffff:ffff:ffff
39fc76:260::/28fc76:26f:ffff:ffff:ffff:ffff:ffff:ffff
40fc76:270::/28fc76:27f:ffff:ffff:ffff:ffff:ffff:ffff
41fc76:280::/28fc76:28f:ffff:ffff:ffff:ffff:ffff:ffff
42fc76:290::/28fc76:29f:ffff:ffff:ffff:ffff:ffff:ffff
43fc76:2a0::/28fc76:2af:ffff:ffff:ffff:ffff:ffff:ffff
44fc76:2b0::/28fc76:2bf:ffff:ffff:ffff:ffff:ffff:ffff
45fc76:2c0::/28fc76:2cf:ffff:ffff:ffff:ffff:ffff:ffff
46fc76:2d0::/28fc76:2df:ffff:ffff:ffff:ffff:ffff:ffff
47fc76:2e0::/28fc76:2ef:ffff:ffff:ffff:ffff:ffff:ffff
48fc76:2f0::/28fc76:2ff:ffff:ffff:ffff:ffff:ffff:ffff
49fc76:300::/28fc76:30f:ffff:ffff:ffff:ffff:ffff:ffff
50fc76:310::/28fc76:31f:ffff:ffff:ffff:ffff:ffff:ffff
51fc76:320::/28fc76:32f:ffff:ffff:ffff:ffff:ffff:ffff
52fc76:330::/28fc76:33f:ffff:ffff:ffff:ffff:ffff:ffff
53fc76:340::/28fc76:34f:ffff:ffff:ffff:ffff:ffff:ffff
54fc76:350::/28fc76:35f:ffff:ffff:ffff:ffff:ffff:ffff
55fc76:360::/28fc76:36f:ffff:ffff:ffff:ffff:ffff:ffff
56fc76:370::/28fc76:37f:ffff:ffff:ffff:ffff:ffff:ffff
57fc76:380::/28fc76:38f:ffff:ffff:ffff:ffff:ffff:ffff
58fc76:390::/28fc76:39f:ffff:ffff:ffff:ffff:ffff:ffff
59fc76:3a0::/28fc76:3af:ffff:ffff:ffff:ffff:ffff:ffff
60fc76:3b0::/28fc76:3bf:ffff:ffff:ffff:ffff:ffff:ffff
61fc76:3c0::/28fc76:3cf:ffff:ffff:ffff:ffff:ffff:ffff
62fc76:3d0::/28fc76:3df:ffff:ffff:ffff:ffff:ffff:ffff
63fc76:3e0::/28fc76:3ef:ffff:ffff:ffff:ffff:ffff:ffff
64fc76:3f0::/28fc76:3ff:ffff:ffff:ffff:ffff:ffff:ffff
65fc76:400::/28fc76:40f:ffff:ffff:ffff:ffff:ffff:ffff
66fc76:410::/28fc76:41f:ffff:ffff:ffff:ffff:ffff:ffff
67fc76:420::/28fc76:42f:ffff:ffff:ffff:ffff:ffff:ffff
68fc76:430::/28fc76:43f:ffff:ffff:ffff:ffff:ffff:ffff
69fc76:440::/28fc76:44f:ffff:ffff:ffff:ffff:ffff:ffff
70fc76:450::/28fc76:45f:ffff:ffff:ffff:ffff:ffff:ffff
71fc76:460::/28fc76:46f:ffff:ffff:ffff:ffff:ffff:ffff
72fc76:470::/28fc76:47f:ffff:ffff:ffff:ffff:ffff:ffff
73fc76:480::/28fc76:48f:ffff:ffff:ffff:ffff:ffff:ffff
74fc76:490::/28fc76:49f:ffff:ffff:ffff:ffff:ffff:ffff
75fc76:4a0::/28fc76:4af:ffff:ffff:ffff:ffff:ffff:ffff
76fc76:4b0::/28fc76:4bf:ffff:ffff:ffff:ffff:ffff:ffff
77fc76:4c0::/28fc76:4cf:ffff:ffff:ffff:ffff:ffff:ffff
78fc76:4d0::/28fc76:4df:ffff:ffff:ffff:ffff:ffff:ffff
79fc76:4e0::/28fc76:4ef:ffff:ffff:ffff:ffff:ffff:ffff
80fc76:4f0::/28fc76:4ff:ffff:ffff:ffff:ffff:ffff:ffff
81fc76:500::/28fc76:50f:ffff:ffff:ffff:ffff:ffff:ffff
82fc76:510::/28fc76:51f:ffff:ffff:ffff:ffff:ffff:ffff
83fc76:520::/28fc76:52f:ffff:ffff:ffff:ffff:ffff:ffff
84fc76:530::/28fc76:53f:ffff:ffff:ffff:ffff:ffff:ffff
85fc76:540::/28fc76:54f:ffff:ffff:ffff:ffff:ffff:ffff
86fc76:550::/28fc76:55f:ffff:ffff:ffff:ffff:ffff:ffff
87fc76:560::/28fc76:56f:ffff:ffff:ffff:ffff:ffff:ffff
88fc76:570::/28fc76:57f:ffff:ffff:ffff:ffff:ffff:ffff
89fc76:580::/28fc76:58f:ffff:ffff:ffff:ffff:ffff:ffff
90fc76:590::/28fc76:59f:ffff:ffff:ffff:ffff:ffff:ffff
91fc76:5a0::/28fc76:5af:ffff:ffff:ffff:ffff:ffff:ffff
92fc76:5b0::/28fc76:5bf:ffff:ffff:ffff:ffff:ffff:ffff
93fc76:5c0::/28fc76:5cf:ffff:ffff:ffff:ffff:ffff:ffff
94fc76:5d0::/28fc76:5df:ffff:ffff:ffff:ffff:ffff:ffff
95fc76:5e0::/28fc76:5ef:ffff:ffff:ffff:ffff:ffff:ffff
96fc76:5f0::/28fc76:5ff:ffff:ffff:ffff:ffff:ffff:ffff
97fc76:600::/28fc76:60f:ffff:ffff:ffff:ffff:ffff:ffff
98fc76:610::/28fc76:61f:ffff:ffff:ffff:ffff:ffff:ffff
99fc76:620::/28fc76:62f:ffff:ffff:ffff:ffff:ffff:ffff
100fc76:630::/28fc76:63f:ffff:ffff:ffff:ffff:ffff:ffff
101fc76:640::/28fc76:64f:ffff:ffff:ffff:ffff:ffff:ffff
102fc76:650::/28fc76:65f:ffff:ffff:ffff:ffff:ffff:ffff
103fc76:660::/28fc76:66f:ffff:ffff:ffff:ffff:ffff:ffff
104fc76:670::/28fc76:67f:ffff:ffff:ffff:ffff:ffff:ffff
105fc76:680::/28fc76:68f:ffff:ffff:ffff:ffff:ffff:ffff
106fc76:690::/28fc76:69f:ffff:ffff:ffff:ffff:ffff:ffff
107fc76:6a0::/28fc76:6af:ffff:ffff:ffff:ffff:ffff:ffff
108fc76:6b0::/28fc76:6bf:ffff:ffff:ffff:ffff:ffff:ffff
109fc76:6c0::/28fc76:6cf:ffff:ffff:ffff:ffff:ffff:ffff
110fc76:6d0::/28fc76:6df:ffff:ffff:ffff:ffff:ffff:ffff
111fc76:6e0::/28fc76:6ef:ffff:ffff:ffff:ffff:ffff:ffff
112fc76:6f0::/28fc76:6ff:ffff:ffff:ffff:ffff:ffff:ffff
113fc76:700::/28fc76:70f:ffff:ffff:ffff:ffff:ffff:ffff
114fc76:710::/28fc76:71f:ffff:ffff:ffff:ffff:ffff:ffff
115fc76:720::/28fc76:72f:ffff:ffff:ffff:ffff:ffff:ffff
116fc76:730::/28fc76:73f:ffff:ffff:ffff:ffff:ffff:ffff
117fc76:740::/28fc76:74f:ffff:ffff:ffff:ffff:ffff:ffff
118fc76:750::/28fc76:75f:ffff:ffff:ffff:ffff:ffff:ffff
119fc76:760::/28fc76:76f:ffff:ffff:ffff:ffff:ffff:ffff
120fc76:770::/28fc76:77f:ffff:ffff:ffff:ffff:ffff:ffff
121fc76:780::/28fc76:78f:ffff:ffff:ffff:ffff:ffff:ffff
122fc76:790::/28fc76:79f:ffff:ffff:ffff:ffff:ffff:ffff
123fc76:7a0::/28fc76:7af:ffff:ffff:ffff:ffff:ffff:ffff
124fc76:7b0::/28fc76:7bf:ffff:ffff:ffff:ffff:ffff:ffff
125fc76:7c0::/28fc76:7cf:ffff:ffff:ffff:ffff:ffff:ffff
126fc76:7d0::/28fc76:7df:ffff:ffff:ffff:ffff:ffff:ffff
127fc76:7e0::/28fc76:7ef:ffff:ffff:ffff:ffff:ffff:ffff
128fc76:7f0::/28fc76:7ff:ffff:ffff:ffff:ffff:ffff:ffff
129fc76:800::/28fc76:80f:ffff:ffff:ffff:ffff:ffff:ffff
130fc76:810::/28fc76:81f:ffff:ffff:ffff:ffff:ffff:ffff
131fc76:820::/28fc76:82f:ffff:ffff:ffff:ffff:ffff:ffff
132fc76:830::/28fc76:83f:ffff:ffff:ffff:ffff:ffff:ffff
133fc76:840::/28fc76:84f:ffff:ffff:ffff:ffff:ffff:ffff
134fc76:850::/28fc76:85f:ffff:ffff:ffff:ffff:ffff:ffff
135fc76:860::/28fc76:86f:ffff:ffff:ffff:ffff:ffff:ffff
136fc76:870::/28fc76:87f:ffff:ffff:ffff:ffff:ffff:ffff
137fc76:880::/28fc76:88f:ffff:ffff:ffff:ffff:ffff:ffff
138fc76:890::/28fc76:89f:ffff:ffff:ffff:ffff:ffff:ffff
139fc76:8a0::/28fc76:8af:ffff:ffff:ffff:ffff:ffff:ffff
140fc76:8b0::/28fc76:8bf:ffff:ffff:ffff:ffff:ffff:ffff
141fc76:8c0::/28fc76:8cf:ffff:ffff:ffff:ffff:ffff:ffff
142fc76:8d0::/28fc76:8df:ffff:ffff:ffff:ffff:ffff:ffff
143fc76:8e0::/28fc76:8ef:ffff:ffff:ffff:ffff:ffff:ffff
144fc76:8f0::/28fc76:8ff:ffff:ffff:ffff:ffff:ffff:ffff
145fc76:900::/28fc76:90f:ffff:ffff:ffff:ffff:ffff:ffff
146fc76:910::/28fc76:91f:ffff:ffff:ffff:ffff:ffff:ffff
147fc76:920::/28fc76:92f:ffff:ffff:ffff:ffff:ffff:ffff
148fc76:930::/28fc76:93f:ffff:ffff:ffff:ffff:ffff:ffff
149fc76:940::/28fc76:94f:ffff:ffff:ffff:ffff:ffff:ffff
150fc76:950::/28fc76:95f:ffff:ffff:ffff:ffff:ffff:ffff
151fc76:960::/28fc76:96f:ffff:ffff:ffff:ffff:ffff:ffff
152fc76:970::/28fc76:97f:ffff:ffff:ffff:ffff:ffff:ffff
153fc76:980::/28fc76:98f:ffff:ffff:ffff:ffff:ffff:ffff
154fc76:990::/28fc76:99f:ffff:ffff:ffff:ffff:ffff:ffff
155fc76:9a0::/28fc76:9af:ffff:ffff:ffff:ffff:ffff:ffff
156fc76:9b0::/28fc76:9bf:ffff:ffff:ffff:ffff:ffff:ffff
157fc76:9c0::/28fc76:9cf:ffff:ffff:ffff:ffff:ffff:ffff
158fc76:9d0::/28fc76:9df:ffff:ffff:ffff:ffff:ffff:ffff
159fc76:9e0::/28fc76:9ef:ffff:ffff:ffff:ffff:ffff:ffff
160fc76:9f0::/28fc76:9ff:ffff:ffff:ffff:ffff:ffff:ffff
161fc76:a00::/28fc76:a0f:ffff:ffff:ffff:ffff:ffff:ffff
162fc76:a10::/28fc76:a1f:ffff:ffff:ffff:ffff:ffff:ffff
163fc76:a20::/28fc76:a2f:ffff:ffff:ffff:ffff:ffff:ffff
164fc76:a30::/28fc76:a3f:ffff:ffff:ffff:ffff:ffff:ffff
165fc76:a40::/28fc76:a4f:ffff:ffff:ffff:ffff:ffff:ffff
166fc76:a50::/28fc76:a5f:ffff:ffff:ffff:ffff:ffff:ffff
167fc76:a60::/28fc76:a6f:ffff:ffff:ffff:ffff:ffff:ffff
168fc76:a70::/28fc76:a7f:ffff:ffff:ffff:ffff:ffff:ffff
169fc76:a80::/28fc76:a8f:ffff:ffff:ffff:ffff:ffff:ffff
170fc76:a90::/28fc76:a9f:ffff:ffff:ffff:ffff:ffff:ffff
171fc76:aa0::/28fc76:aaf:ffff:ffff:ffff:ffff:ffff:ffff
172fc76:ab0::/28fc76:abf:ffff:ffff:ffff:ffff:ffff:ffff
173fc76:ac0::/28fc76:acf:ffff:ffff:ffff:ffff:ffff:ffff
174fc76:ad0::/28fc76:adf:ffff:ffff:ffff:ffff:ffff:ffff
175fc76:ae0::/28fc76:aef:ffff:ffff:ffff:ffff:ffff:ffff
176fc76:af0::/28fc76:aff:ffff:ffff:ffff:ffff:ffff:ffff
177fc76:b00::/28fc76:b0f:ffff:ffff:ffff:ffff:ffff:ffff
178fc76:b10::/28fc76:b1f:ffff:ffff:ffff:ffff:ffff:ffff
179fc76:b20::/28fc76:b2f:ffff:ffff:ffff:ffff:ffff:ffff
180fc76:b30::/28fc76:b3f:ffff:ffff:ffff:ffff:ffff:ffff
181fc76:b40::/28fc76:b4f:ffff:ffff:ffff:ffff:ffff:ffff
182fc76:b50::/28fc76:b5f:ffff:ffff:ffff:ffff:ffff:ffff
183fc76:b60::/28fc76:b6f:ffff:ffff:ffff:ffff:ffff:ffff
184fc76:b70::/28fc76:b7f:ffff:ffff:ffff:ffff:ffff:ffff
185fc76:b80::/28fc76:b8f:ffff:ffff:ffff:ffff:ffff:ffff
186fc76:b90::/28fc76:b9f:ffff:ffff:ffff:ffff:ffff:ffff
187fc76:ba0::/28fc76:baf:ffff:ffff:ffff:ffff:ffff:ffff
188fc76:bb0::/28fc76:bbf:ffff:ffff:ffff:ffff:ffff:ffff
189fc76:bc0::/28fc76:bcf:ffff:ffff:ffff:ffff:ffff:ffff
190fc76:bd0::/28fc76:bdf:ffff:ffff:ffff:ffff:ffff:ffff
191fc76:be0::/28fc76:bef:ffff:ffff:ffff:ffff:ffff:ffff
192fc76:bf0::/28fc76:bff:ffff:ffff:ffff:ffff:ffff:ffff
193fc76:c00::/28fc76:c0f:ffff:ffff:ffff:ffff:ffff:ffff
194fc76:c10::/28fc76:c1f:ffff:ffff:ffff:ffff:ffff:ffff
195fc76:c20::/28fc76:c2f:ffff:ffff:ffff:ffff:ffff:ffff
196fc76:c30::/28fc76:c3f:ffff:ffff:ffff:ffff:ffff:ffff
197fc76:c40::/28fc76:c4f:ffff:ffff:ffff:ffff:ffff:ffff
198fc76:c50::/28fc76:c5f:ffff:ffff:ffff:ffff:ffff:ffff
199fc76:c60::/28fc76:c6f:ffff:ffff:ffff:ffff:ffff:ffff
200fc76:c70::/28fc76:c7f:ffff:ffff:ffff:ffff:ffff:ffff
201fc76:c80::/28fc76:c8f:ffff:ffff:ffff:ffff:ffff:ffff
202fc76:c90::/28fc76:c9f:ffff:ffff:ffff:ffff:ffff:ffff
203fc76:ca0::/28fc76:caf:ffff:ffff:ffff:ffff:ffff:ffff
204fc76:cb0::/28fc76:cbf:ffff:ffff:ffff:ffff:ffff:ffff
205fc76:cc0::/28fc76:ccf:ffff:ffff:ffff:ffff:ffff:ffff
206fc76:cd0::/28fc76:cdf:ffff:ffff:ffff:ffff:ffff:ffff
207fc76:ce0::/28fc76:cef:ffff:ffff:ffff:ffff:ffff:ffff
208fc76:cf0::/28fc76:cff:ffff:ffff:ffff:ffff:ffff:ffff
209fc76:d00::/28fc76:d0f:ffff:ffff:ffff:ffff:ffff:ffff
210fc76:d10::/28fc76:d1f:ffff:ffff:ffff:ffff:ffff:ffff
211fc76:d20::/28fc76:d2f:ffff:ffff:ffff:ffff:ffff:ffff
212fc76:d30::/28fc76:d3f:ffff:ffff:ffff:ffff:ffff:ffff
213fc76:d40::/28fc76:d4f:ffff:ffff:ffff:ffff:ffff:ffff
214fc76:d50::/28fc76:d5f:ffff:ffff:ffff:ffff:ffff:ffff
215fc76:d60::/28fc76:d6f:ffff:ffff:ffff:ffff:ffff:ffff
216fc76:d70::/28fc76:d7f:ffff:ffff:ffff:ffff:ffff:ffff
217fc76:d80::/28fc76:d8f:ffff:ffff:ffff:ffff:ffff:ffff
218fc76:d90::/28fc76:d9f:ffff:ffff:ffff:ffff:ffff:ffff
219fc76:da0::/28fc76:daf:ffff:ffff:ffff:ffff:ffff:ffff
220fc76:db0::/28fc76:dbf:ffff:ffff:ffff:ffff:ffff:ffff
221fc76:dc0::/28fc76:dcf:ffff:ffff:ffff:ffff:ffff:ffff
222fc76:dd0::/28fc76:ddf:ffff:ffff:ffff:ffff:ffff:ffff
223fc76:de0::/28fc76:def:ffff:ffff:ffff:ffff:ffff:ffff
224fc76:df0::/28fc76:dff:ffff:ffff:ffff:ffff:ffff:ffff
225fc76:e00::/28fc76:e0f:ffff:ffff:ffff:ffff:ffff:ffff
226fc76:e10::/28fc76:e1f:ffff:ffff:ffff:ffff:ffff:ffff
227fc76:e20::/28fc76:e2f:ffff:ffff:ffff:ffff:ffff:ffff
228fc76:e30::/28fc76:e3f:ffff:ffff:ffff:ffff:ffff:ffff
229fc76:e40::/28fc76:e4f:ffff:ffff:ffff:ffff:ffff:ffff
230fc76:e50::/28fc76:e5f:ffff:ffff:ffff:ffff:ffff:ffff
231fc76:e60::/28fc76:e6f:ffff:ffff:ffff:ffff:ffff:ffff
232fc76:e70::/28fc76:e7f:ffff:ffff:ffff:ffff:ffff:ffff
233fc76:e80::/28fc76:e8f:ffff:ffff:ffff:ffff:ffff:ffff
234fc76:e90::/28fc76:e9f:ffff:ffff:ffff:ffff:ffff:ffff
235fc76:ea0::/28fc76:eaf:ffff:ffff:ffff:ffff:ffff:ffff
236fc76:eb0::/28fc76:ebf:ffff:ffff:ffff:ffff:ffff:ffff
237fc76:ec0::/28fc76:ecf:ffff:ffff:ffff:ffff:ffff:ffff
238fc76:ed0::/28fc76:edf:ffff:ffff:ffff:ffff:ffff:ffff
239fc76:ee0::/28fc76:eef:ffff:ffff:ffff:ffff:ffff:ffff
240fc76:ef0::/28fc76:eff:ffff:ffff:ffff:ffff:ffff:ffff
241fc76:f00::/28fc76:f0f:ffff:ffff:ffff:ffff:ffff:ffff
242fc76:f10::/28fc76:f1f:ffff:ffff:ffff:ffff:ffff:ffff
243fc76:f20::/28fc76:f2f:ffff:ffff:ffff:ffff:ffff:ffff
244fc76:f30::/28fc76:f3f:ffff:ffff:ffff:ffff:ffff:ffff
245fc76:f40::/28fc76:f4f:ffff:ffff:ffff:ffff:ffff:ffff
246fc76:f50::/28fc76:f5f:ffff:ffff:ffff:ffff:ffff:ffff
247fc76:f60::/28fc76:f6f:ffff:ffff:ffff:ffff:ffff:ffff
248fc76:f70::/28fc76:f7f:ffff:ffff:ffff:ffff:ffff:ffff
249fc76:f80::/28fc76:f8f:ffff:ffff:ffff:ffff:ffff:ffff
250fc76:f90::/28fc76:f9f:ffff:ffff:ffff:ffff:ffff:ffff
251fc76:fa0::/28fc76:faf:ffff:ffff:ffff:ffff:ffff:ffff
252fc76:fb0::/28fc76:fbf:ffff:ffff:ffff:ffff:ffff:ffff
253fc76:fc0::/28fc76:fcf:ffff:ffff:ffff:ffff:ffff:ffff
254fc76:fd0::/28fc76:fdf:ffff:ffff:ffff:ffff:ffff:ffff
255fc76:fe0::/28fc76:fef:ffff:ffff:ffff:ffff:ffff:ffff
256fc76:ff0::/28fc76: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.