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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.

Network176.0.0.0/4
Usable hosts268,435,454
Subnet mask240.0.0.0
Addresses268,435,456
Network address
176.0.0.0
Broadcast address
191.255.255.255
First usable
176.0.0.1
Last usable
191.255.255.254
Usable hosts
268,435,454 (268,435,456 less the network and broadcast addresses)
Subnet mask
240.0.0.0
Wildcard mask
15.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/4
Type
Public public
Old class
B (default /16)
As numbers
Hex B0000000 · Integer 2952790016 to 3221225471
Reverse DNS zones
176.in-addr.arpa
177.in-addr.arpa
178.in-addr.arpa
179.in-addr.arpa
180.in-addr.arpa
181.in-addr.arpa
182.in-addr.arpa
183.in-addr.arpa
184.in-addr.arpa
185.in-addr.arpa
186.in-addr.arpa
187.in-addr.arpa
188.in-addr.arpa
189.in-addr.arpa
190.in-addr.arpa
191.in-addr.arpa
/4 is not on a 8-bit boundary, so it takes 16 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10110000.00000000.00000000.00000000176.0.0.0
Subnet mask11110000.00000000.00000000.00000000240.0.0.0
Network10110000.00000000.00000000.00000000176.0.0.0
Broadcast10111111.11111111.11111111.11111111191.255.255.255
Split into smaller subnets/12
/5 (2)/6 (4)/7 (8)/8 (16)/9 (32)/10 (64)/11 (128)/12 (256)/13 (512)/14 (1,024)/15 (2,048)/16 (4,096)

176.0.0.0/4 makes 256 subnets of /12.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1176.0.0.0/12176.0.0.1 to 176.15.255.254176.15.255.2551,048,574
2176.16.0.0/12176.16.0.1 to 176.31.255.254176.31.255.2551,048,574
3176.32.0.0/12176.32.0.1 to 176.47.255.254176.47.255.2551,048,574
4176.48.0.0/12176.48.0.1 to 176.63.255.254176.63.255.2551,048,574
5176.64.0.0/12176.64.0.1 to 176.79.255.254176.79.255.2551,048,574
6176.80.0.0/12176.80.0.1 to 176.95.255.254176.95.255.2551,048,574
7176.96.0.0/12176.96.0.1 to 176.111.255.254176.111.255.2551,048,574
8176.112.0.0/12176.112.0.1 to 176.127.255.254176.127.255.2551,048,574
9176.128.0.0/12176.128.0.1 to 176.143.255.254176.143.255.2551,048,574
10176.144.0.0/12176.144.0.1 to 176.159.255.254176.159.255.2551,048,574
11176.160.0.0/12176.160.0.1 to 176.175.255.254176.175.255.2551,048,574
12176.176.0.0/12176.176.0.1 to 176.191.255.254176.191.255.2551,048,574
13176.192.0.0/12176.192.0.1 to 176.207.255.254176.207.255.2551,048,574
14176.208.0.0/12176.208.0.1 to 176.223.255.254176.223.255.2551,048,574
15176.224.0.0/12176.224.0.1 to 176.239.255.254176.239.255.2551,048,574
16176.240.0.0/12176.240.0.1 to 176.255.255.254176.255.255.2551,048,574
17177.0.0.0/12177.0.0.1 to 177.15.255.254177.15.255.2551,048,574
18177.16.0.0/12177.16.0.1 to 177.31.255.254177.31.255.2551,048,574
19177.32.0.0/12177.32.0.1 to 177.47.255.254177.47.255.2551,048,574
20177.48.0.0/12177.48.0.1 to 177.63.255.254177.63.255.2551,048,574
21177.64.0.0/12177.64.0.1 to 177.79.255.254177.79.255.2551,048,574
22177.80.0.0/12177.80.0.1 to 177.95.255.254177.95.255.2551,048,574
23177.96.0.0/12177.96.0.1 to 177.111.255.254177.111.255.2551,048,574
24177.112.0.0/12177.112.0.1 to 177.127.255.254177.127.255.2551,048,574
25177.128.0.0/12177.128.0.1 to 177.143.255.254177.143.255.2551,048,574
26177.144.0.0/12177.144.0.1 to 177.159.255.254177.159.255.2551,048,574
27177.160.0.0/12177.160.0.1 to 177.175.255.254177.175.255.2551,048,574
28177.176.0.0/12177.176.0.1 to 177.191.255.254177.191.255.2551,048,574
29177.192.0.0/12177.192.0.1 to 177.207.255.254177.207.255.2551,048,574
30177.208.0.0/12177.208.0.1 to 177.223.255.254177.223.255.2551,048,574
31177.224.0.0/12177.224.0.1 to 177.239.255.254177.239.255.2551,048,574
32177.240.0.0/12177.240.0.1 to 177.255.255.254177.255.255.2551,048,574
33178.0.0.0/12178.0.0.1 to 178.15.255.254178.15.255.2551,048,574
34178.16.0.0/12178.16.0.1 to 178.31.255.254178.31.255.2551,048,574
35178.32.0.0/12178.32.0.1 to 178.47.255.254178.47.255.2551,048,574
36178.48.0.0/12178.48.0.1 to 178.63.255.254178.63.255.2551,048,574
37178.64.0.0/12178.64.0.1 to 178.79.255.254178.79.255.2551,048,574
38178.80.0.0/12178.80.0.1 to 178.95.255.254178.95.255.2551,048,574
39178.96.0.0/12178.96.0.1 to 178.111.255.254178.111.255.2551,048,574
40178.112.0.0/12178.112.0.1 to 178.127.255.254178.127.255.2551,048,574
41178.128.0.0/12178.128.0.1 to 178.143.255.254178.143.255.2551,048,574
42178.144.0.0/12178.144.0.1 to 178.159.255.254178.159.255.2551,048,574
43178.160.0.0/12178.160.0.1 to 178.175.255.254178.175.255.2551,048,574
44178.176.0.0/12178.176.0.1 to 178.191.255.254178.191.255.2551,048,574
45178.192.0.0/12178.192.0.1 to 178.207.255.254178.207.255.2551,048,574
46178.208.0.0/12178.208.0.1 to 178.223.255.254178.223.255.2551,048,574
47178.224.0.0/12178.224.0.1 to 178.239.255.254178.239.255.2551,048,574
48178.240.0.0/12178.240.0.1 to 178.255.255.254178.255.255.2551,048,574
49179.0.0.0/12179.0.0.1 to 179.15.255.254179.15.255.2551,048,574
50179.16.0.0/12179.16.0.1 to 179.31.255.254179.31.255.2551,048,574
51179.32.0.0/12179.32.0.1 to 179.47.255.254179.47.255.2551,048,574
52179.48.0.0/12179.48.0.1 to 179.63.255.254179.63.255.2551,048,574
53179.64.0.0/12179.64.0.1 to 179.79.255.254179.79.255.2551,048,574
54179.80.0.0/12179.80.0.1 to 179.95.255.254179.95.255.2551,048,574
55179.96.0.0/12179.96.0.1 to 179.111.255.254179.111.255.2551,048,574
56179.112.0.0/12179.112.0.1 to 179.127.255.254179.127.255.2551,048,574
57179.128.0.0/12179.128.0.1 to 179.143.255.254179.143.255.2551,048,574
58179.144.0.0/12179.144.0.1 to 179.159.255.254179.159.255.2551,048,574
59179.160.0.0/12179.160.0.1 to 179.175.255.254179.175.255.2551,048,574
60179.176.0.0/12179.176.0.1 to 179.191.255.254179.191.255.2551,048,574
61179.192.0.0/12179.192.0.1 to 179.207.255.254179.207.255.2551,048,574
62179.208.0.0/12179.208.0.1 to 179.223.255.254179.223.255.2551,048,574
63179.224.0.0/12179.224.0.1 to 179.239.255.254179.239.255.2551,048,574
64179.240.0.0/12179.240.0.1 to 179.255.255.254179.255.255.2551,048,574
65180.0.0.0/12180.0.0.1 to 180.15.255.254180.15.255.2551,048,574
66180.16.0.0/12180.16.0.1 to 180.31.255.254180.31.255.2551,048,574
67180.32.0.0/12180.32.0.1 to 180.47.255.254180.47.255.2551,048,574
68180.48.0.0/12180.48.0.1 to 180.63.255.254180.63.255.2551,048,574
69180.64.0.0/12180.64.0.1 to 180.79.255.254180.79.255.2551,048,574
70180.80.0.0/12180.80.0.1 to 180.95.255.254180.95.255.2551,048,574
71180.96.0.0/12180.96.0.1 to 180.111.255.254180.111.255.2551,048,574
72180.112.0.0/12180.112.0.1 to 180.127.255.254180.127.255.2551,048,574
73180.128.0.0/12180.128.0.1 to 180.143.255.254180.143.255.2551,048,574
74180.144.0.0/12180.144.0.1 to 180.159.255.254180.159.255.2551,048,574
75180.160.0.0/12180.160.0.1 to 180.175.255.254180.175.255.2551,048,574
76180.176.0.0/12180.176.0.1 to 180.191.255.254180.191.255.2551,048,574
77180.192.0.0/12180.192.0.1 to 180.207.255.254180.207.255.2551,048,574
78180.208.0.0/12180.208.0.1 to 180.223.255.254180.223.255.2551,048,574
79180.224.0.0/12180.224.0.1 to 180.239.255.254180.239.255.2551,048,574
80180.240.0.0/12180.240.0.1 to 180.255.255.254180.255.255.2551,048,574
81181.0.0.0/12181.0.0.1 to 181.15.255.254181.15.255.2551,048,574
82181.16.0.0/12181.16.0.1 to 181.31.255.254181.31.255.2551,048,574
83181.32.0.0/12181.32.0.1 to 181.47.255.254181.47.255.2551,048,574
84181.48.0.0/12181.48.0.1 to 181.63.255.254181.63.255.2551,048,574
85181.64.0.0/12181.64.0.1 to 181.79.255.254181.79.255.2551,048,574
86181.80.0.0/12181.80.0.1 to 181.95.255.254181.95.255.2551,048,574
87181.96.0.0/12181.96.0.1 to 181.111.255.254181.111.255.2551,048,574
88181.112.0.0/12181.112.0.1 to 181.127.255.254181.127.255.2551,048,574
89181.128.0.0/12181.128.0.1 to 181.143.255.254181.143.255.2551,048,574
90181.144.0.0/12181.144.0.1 to 181.159.255.254181.159.255.2551,048,574
91181.160.0.0/12181.160.0.1 to 181.175.255.254181.175.255.2551,048,574
92181.176.0.0/12181.176.0.1 to 181.191.255.254181.191.255.2551,048,574
93181.192.0.0/12181.192.0.1 to 181.207.255.254181.207.255.2551,048,574
94181.208.0.0/12181.208.0.1 to 181.223.255.254181.223.255.2551,048,574
95181.224.0.0/12181.224.0.1 to 181.239.255.254181.239.255.2551,048,574
96181.240.0.0/12181.240.0.1 to 181.255.255.254181.255.255.2551,048,574
97182.0.0.0/12182.0.0.1 to 182.15.255.254182.15.255.2551,048,574
98182.16.0.0/12182.16.0.1 to 182.31.255.254182.31.255.2551,048,574
99182.32.0.0/12182.32.0.1 to 182.47.255.254182.47.255.2551,048,574
100182.48.0.0/12182.48.0.1 to 182.63.255.254182.63.255.2551,048,574
101182.64.0.0/12182.64.0.1 to 182.79.255.254182.79.255.2551,048,574
102182.80.0.0/12182.80.0.1 to 182.95.255.254182.95.255.2551,048,574
103182.96.0.0/12182.96.0.1 to 182.111.255.254182.111.255.2551,048,574
104182.112.0.0/12182.112.0.1 to 182.127.255.254182.127.255.2551,048,574
105182.128.0.0/12182.128.0.1 to 182.143.255.254182.143.255.2551,048,574
106182.144.0.0/12182.144.0.1 to 182.159.255.254182.159.255.2551,048,574
107182.160.0.0/12182.160.0.1 to 182.175.255.254182.175.255.2551,048,574
108182.176.0.0/12182.176.0.1 to 182.191.255.254182.191.255.2551,048,574
109182.192.0.0/12182.192.0.1 to 182.207.255.254182.207.255.2551,048,574
110182.208.0.0/12182.208.0.1 to 182.223.255.254182.223.255.2551,048,574
111182.224.0.0/12182.224.0.1 to 182.239.255.254182.239.255.2551,048,574
112182.240.0.0/12182.240.0.1 to 182.255.255.254182.255.255.2551,048,574
113183.0.0.0/12183.0.0.1 to 183.15.255.254183.15.255.2551,048,574
114183.16.0.0/12183.16.0.1 to 183.31.255.254183.31.255.2551,048,574
115183.32.0.0/12183.32.0.1 to 183.47.255.254183.47.255.2551,048,574
116183.48.0.0/12183.48.0.1 to 183.63.255.254183.63.255.2551,048,574
117183.64.0.0/12183.64.0.1 to 183.79.255.254183.79.255.2551,048,574
118183.80.0.0/12183.80.0.1 to 183.95.255.254183.95.255.2551,048,574
119183.96.0.0/12183.96.0.1 to 183.111.255.254183.111.255.2551,048,574
120183.112.0.0/12183.112.0.1 to 183.127.255.254183.127.255.2551,048,574
121183.128.0.0/12183.128.0.1 to 183.143.255.254183.143.255.2551,048,574
122183.144.0.0/12183.144.0.1 to 183.159.255.254183.159.255.2551,048,574
123183.160.0.0/12183.160.0.1 to 183.175.255.254183.175.255.2551,048,574
124183.176.0.0/12183.176.0.1 to 183.191.255.254183.191.255.2551,048,574
125183.192.0.0/12183.192.0.1 to 183.207.255.254183.207.255.2551,048,574
126183.208.0.0/12183.208.0.1 to 183.223.255.254183.223.255.2551,048,574
127183.224.0.0/12183.224.0.1 to 183.239.255.254183.239.255.2551,048,574
128183.240.0.0/12183.240.0.1 to 183.255.255.254183.255.255.2551,048,574
129184.0.0.0/12184.0.0.1 to 184.15.255.254184.15.255.2551,048,574
130184.16.0.0/12184.16.0.1 to 184.31.255.254184.31.255.2551,048,574
131184.32.0.0/12184.32.0.1 to 184.47.255.254184.47.255.2551,048,574
132184.48.0.0/12184.48.0.1 to 184.63.255.254184.63.255.2551,048,574
133184.64.0.0/12184.64.0.1 to 184.79.255.254184.79.255.2551,048,574
134184.80.0.0/12184.80.0.1 to 184.95.255.254184.95.255.2551,048,574
135184.96.0.0/12184.96.0.1 to 184.111.255.254184.111.255.2551,048,574
136184.112.0.0/12184.112.0.1 to 184.127.255.254184.127.255.2551,048,574
137184.128.0.0/12184.128.0.1 to 184.143.255.254184.143.255.2551,048,574
138184.144.0.0/12184.144.0.1 to 184.159.255.254184.159.255.2551,048,574
139184.160.0.0/12184.160.0.1 to 184.175.255.254184.175.255.2551,048,574
140184.176.0.0/12184.176.0.1 to 184.191.255.254184.191.255.2551,048,574
141184.192.0.0/12184.192.0.1 to 184.207.255.254184.207.255.2551,048,574
142184.208.0.0/12184.208.0.1 to 184.223.255.254184.223.255.2551,048,574
143184.224.0.0/12184.224.0.1 to 184.239.255.254184.239.255.2551,048,574
144184.240.0.0/12184.240.0.1 to 184.255.255.254184.255.255.2551,048,574
145185.0.0.0/12185.0.0.1 to 185.15.255.254185.15.255.2551,048,574
146185.16.0.0/12185.16.0.1 to 185.31.255.254185.31.255.2551,048,574
147185.32.0.0/12185.32.0.1 to 185.47.255.254185.47.255.2551,048,574
148185.48.0.0/12185.48.0.1 to 185.63.255.254185.63.255.2551,048,574
149185.64.0.0/12185.64.0.1 to 185.79.255.254185.79.255.2551,048,574
150185.80.0.0/12185.80.0.1 to 185.95.255.254185.95.255.2551,048,574
151185.96.0.0/12185.96.0.1 to 185.111.255.254185.111.255.2551,048,574
152185.112.0.0/12185.112.0.1 to 185.127.255.254185.127.255.2551,048,574
153185.128.0.0/12185.128.0.1 to 185.143.255.254185.143.255.2551,048,574
154185.144.0.0/12185.144.0.1 to 185.159.255.254185.159.255.2551,048,574
155185.160.0.0/12185.160.0.1 to 185.175.255.254185.175.255.2551,048,574
156185.176.0.0/12185.176.0.1 to 185.191.255.254185.191.255.2551,048,574
157185.192.0.0/12185.192.0.1 to 185.207.255.254185.207.255.2551,048,574
158185.208.0.0/12185.208.0.1 to 185.223.255.254185.223.255.2551,048,574
159185.224.0.0/12185.224.0.1 to 185.239.255.254185.239.255.2551,048,574
160185.240.0.0/12185.240.0.1 to 185.255.255.254185.255.255.2551,048,574
161186.0.0.0/12186.0.0.1 to 186.15.255.254186.15.255.2551,048,574
162186.16.0.0/12186.16.0.1 to 186.31.255.254186.31.255.2551,048,574
163186.32.0.0/12186.32.0.1 to 186.47.255.254186.47.255.2551,048,574
164186.48.0.0/12186.48.0.1 to 186.63.255.254186.63.255.2551,048,574
165186.64.0.0/12186.64.0.1 to 186.79.255.254186.79.255.2551,048,574
166186.80.0.0/12186.80.0.1 to 186.95.255.254186.95.255.2551,048,574
167186.96.0.0/12186.96.0.1 to 186.111.255.254186.111.255.2551,048,574
168186.112.0.0/12186.112.0.1 to 186.127.255.254186.127.255.2551,048,574
169186.128.0.0/12186.128.0.1 to 186.143.255.254186.143.255.2551,048,574
170186.144.0.0/12186.144.0.1 to 186.159.255.254186.159.255.2551,048,574
171186.160.0.0/12186.160.0.1 to 186.175.255.254186.175.255.2551,048,574
172186.176.0.0/12186.176.0.1 to 186.191.255.254186.191.255.2551,048,574
173186.192.0.0/12186.192.0.1 to 186.207.255.254186.207.255.2551,048,574
174186.208.0.0/12186.208.0.1 to 186.223.255.254186.223.255.2551,048,574
175186.224.0.0/12186.224.0.1 to 186.239.255.254186.239.255.2551,048,574
176186.240.0.0/12186.240.0.1 to 186.255.255.254186.255.255.2551,048,574
177187.0.0.0/12187.0.0.1 to 187.15.255.254187.15.255.2551,048,574
178187.16.0.0/12187.16.0.1 to 187.31.255.254187.31.255.2551,048,574
179187.32.0.0/12187.32.0.1 to 187.47.255.254187.47.255.2551,048,574
180187.48.0.0/12187.48.0.1 to 187.63.255.254187.63.255.2551,048,574
181187.64.0.0/12187.64.0.1 to 187.79.255.254187.79.255.2551,048,574
182187.80.0.0/12187.80.0.1 to 187.95.255.254187.95.255.2551,048,574
183187.96.0.0/12187.96.0.1 to 187.111.255.254187.111.255.2551,048,574
184187.112.0.0/12187.112.0.1 to 187.127.255.254187.127.255.2551,048,574
185187.128.0.0/12187.128.0.1 to 187.143.255.254187.143.255.2551,048,574
186187.144.0.0/12187.144.0.1 to 187.159.255.254187.159.255.2551,048,574
187187.160.0.0/12187.160.0.1 to 187.175.255.254187.175.255.2551,048,574
188187.176.0.0/12187.176.0.1 to 187.191.255.254187.191.255.2551,048,574
189187.192.0.0/12187.192.0.1 to 187.207.255.254187.207.255.2551,048,574
190187.208.0.0/12187.208.0.1 to 187.223.255.254187.223.255.2551,048,574
191187.224.0.0/12187.224.0.1 to 187.239.255.254187.239.255.2551,048,574
192187.240.0.0/12187.240.0.1 to 187.255.255.254187.255.255.2551,048,574
193188.0.0.0/12188.0.0.1 to 188.15.255.254188.15.255.2551,048,574
194188.16.0.0/12188.16.0.1 to 188.31.255.254188.31.255.2551,048,574
195188.32.0.0/12188.32.0.1 to 188.47.255.254188.47.255.2551,048,574
196188.48.0.0/12188.48.0.1 to 188.63.255.254188.63.255.2551,048,574
197188.64.0.0/12188.64.0.1 to 188.79.255.254188.79.255.2551,048,574
198188.80.0.0/12188.80.0.1 to 188.95.255.254188.95.255.2551,048,574
199188.96.0.0/12188.96.0.1 to 188.111.255.254188.111.255.2551,048,574
200188.112.0.0/12188.112.0.1 to 188.127.255.254188.127.255.2551,048,574
201188.128.0.0/12188.128.0.1 to 188.143.255.254188.143.255.2551,048,574
202188.144.0.0/12188.144.0.1 to 188.159.255.254188.159.255.2551,048,574
203188.160.0.0/12188.160.0.1 to 188.175.255.254188.175.255.2551,048,574
204188.176.0.0/12188.176.0.1 to 188.191.255.254188.191.255.2551,048,574
205188.192.0.0/12188.192.0.1 to 188.207.255.254188.207.255.2551,048,574
206188.208.0.0/12188.208.0.1 to 188.223.255.254188.223.255.2551,048,574
207188.224.0.0/12188.224.0.1 to 188.239.255.254188.239.255.2551,048,574
208188.240.0.0/12188.240.0.1 to 188.255.255.254188.255.255.2551,048,574
209189.0.0.0/12189.0.0.1 to 189.15.255.254189.15.255.2551,048,574
210189.16.0.0/12189.16.0.1 to 189.31.255.254189.31.255.2551,048,574
211189.32.0.0/12189.32.0.1 to 189.47.255.254189.47.255.2551,048,574
212189.48.0.0/12189.48.0.1 to 189.63.255.254189.63.255.2551,048,574
213189.64.0.0/12189.64.0.1 to 189.79.255.254189.79.255.2551,048,574
214189.80.0.0/12189.80.0.1 to 189.95.255.254189.95.255.2551,048,574
215189.96.0.0/12189.96.0.1 to 189.111.255.254189.111.255.2551,048,574
216189.112.0.0/12189.112.0.1 to 189.127.255.254189.127.255.2551,048,574
217189.128.0.0/12189.128.0.1 to 189.143.255.254189.143.255.2551,048,574
218189.144.0.0/12189.144.0.1 to 189.159.255.254189.159.255.2551,048,574
219189.160.0.0/12189.160.0.1 to 189.175.255.254189.175.255.2551,048,574
220189.176.0.0/12189.176.0.1 to 189.191.255.254189.191.255.2551,048,574
221189.192.0.0/12189.192.0.1 to 189.207.255.254189.207.255.2551,048,574
222189.208.0.0/12189.208.0.1 to 189.223.255.254189.223.255.2551,048,574
223189.224.0.0/12189.224.0.1 to 189.239.255.254189.239.255.2551,048,574
224189.240.0.0/12189.240.0.1 to 189.255.255.254189.255.255.2551,048,574
225190.0.0.0/12190.0.0.1 to 190.15.255.254190.15.255.2551,048,574
226190.16.0.0/12190.16.0.1 to 190.31.255.254190.31.255.2551,048,574
227190.32.0.0/12190.32.0.1 to 190.47.255.254190.47.255.2551,048,574
228190.48.0.0/12190.48.0.1 to 190.63.255.254190.63.255.2551,048,574
229190.64.0.0/12190.64.0.1 to 190.79.255.254190.79.255.2551,048,574
230190.80.0.0/12190.80.0.1 to 190.95.255.254190.95.255.2551,048,574
231190.96.0.0/12190.96.0.1 to 190.111.255.254190.111.255.2551,048,574
232190.112.0.0/12190.112.0.1 to 190.127.255.254190.127.255.2551,048,574
233190.128.0.0/12190.128.0.1 to 190.143.255.254190.143.255.2551,048,574
234190.144.0.0/12190.144.0.1 to 190.159.255.254190.159.255.2551,048,574
235190.160.0.0/12190.160.0.1 to 190.175.255.254190.175.255.2551,048,574
236190.176.0.0/12190.176.0.1 to 190.191.255.254190.191.255.2551,048,574
237190.192.0.0/12190.192.0.1 to 190.207.255.254190.207.255.2551,048,574
238190.208.0.0/12190.208.0.1 to 190.223.255.254190.223.255.2551,048,574
239190.224.0.0/12190.224.0.1 to 190.239.255.254190.239.255.2551,048,574
240190.240.0.0/12190.240.0.1 to 190.255.255.254190.255.255.2551,048,574
241191.0.0.0/12191.0.0.1 to 191.15.255.254191.15.255.2551,048,574
242191.16.0.0/12191.16.0.1 to 191.31.255.254191.31.255.2551,048,574
243191.32.0.0/12191.32.0.1 to 191.47.255.254191.47.255.2551,048,574
244191.48.0.0/12191.48.0.1 to 191.63.255.254191.63.255.2551,048,574
245191.64.0.0/12191.64.0.1 to 191.79.255.254191.79.255.2551,048,574
246191.80.0.0/12191.80.0.1 to 191.95.255.254191.95.255.2551,048,574
247191.96.0.0/12191.96.0.1 to 191.111.255.254191.111.255.2551,048,574
248191.112.0.0/12191.112.0.1 to 191.127.255.254191.127.255.2551,048,574
249191.128.0.0/12191.128.0.1 to 191.143.255.254191.143.255.2551,048,574
250191.144.0.0/12191.144.0.1 to 191.159.255.254191.159.255.2551,048,574
251191.160.0.0/12191.160.0.1 to 191.175.255.254191.175.255.2551,048,574
252191.176.0.0/12191.176.0.1 to 191.191.255.254191.191.255.2551,048,574
253191.192.0.0/12191.192.0.1 to 191.207.255.254191.207.255.2551,048,574
254191.208.0.0/12191.208.0.1 to 191.223.255.254191.223.255.2551,048,574
255191.224.0.0/12191.224.0.1 to 191.239.255.254191.239.255.2551,048,574
256191.240.0.0/12191.240.0.1 to 191.255.255.254191.255.255.2551,048,574

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.