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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.

Network178.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
178.0.0.0
Broadcast address
179.255.255.255
First usable
178.0.0.1
Last usable
179.255.255.254
Usable hosts
33,554,430 (33,554,432 less the network and broadcast addresses)
Subnet mask
254.0.0.0
Wildcard mask
1.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/7
Type
Public public
Old class
B (default /16)
As numbers
Hex B2000000 · Integer 2986344448 to 3019898879
Reverse DNS zones
178.in-addr.arpa
179.in-addr.arpa
/7 is not on a 8-bit boundary, so it takes 2 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10110010.00000000.00000000.00000000178.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network10110010.00000000.00000000.00000000178.0.0.0
Broadcast10110011.11111111.11111111.11111111179.255.255.255
Split into smaller subnets/16
/8 (2)/9 (4)/10 (8)/11 (16)/12 (32)/13 (64)/14 (128)/15 (256)/16 (512)/17 (1,024)/18 (2,048)/19 (4,096)

178.0.0.0/7 makes 512 subnets of /16; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1178.0.0.0/16178.0.0.1 to 178.0.255.254178.0.255.25565,534
2178.1.0.0/16178.1.0.1 to 178.1.255.254178.1.255.25565,534
3178.2.0.0/16178.2.0.1 to 178.2.255.254178.2.255.25565,534
4178.3.0.0/16178.3.0.1 to 178.3.255.254178.3.255.25565,534
5178.4.0.0/16178.4.0.1 to 178.4.255.254178.4.255.25565,534
6178.5.0.0/16178.5.0.1 to 178.5.255.254178.5.255.25565,534
7178.6.0.0/16178.6.0.1 to 178.6.255.254178.6.255.25565,534
8178.7.0.0/16178.7.0.1 to 178.7.255.254178.7.255.25565,534
9178.8.0.0/16178.8.0.1 to 178.8.255.254178.8.255.25565,534
10178.9.0.0/16178.9.0.1 to 178.9.255.254178.9.255.25565,534
11178.10.0.0/16178.10.0.1 to 178.10.255.254178.10.255.25565,534
12178.11.0.0/16178.11.0.1 to 178.11.255.254178.11.255.25565,534
13178.12.0.0/16178.12.0.1 to 178.12.255.254178.12.255.25565,534
14178.13.0.0/16178.13.0.1 to 178.13.255.254178.13.255.25565,534
15178.14.0.0/16178.14.0.1 to 178.14.255.254178.14.255.25565,534
16178.15.0.0/16178.15.0.1 to 178.15.255.254178.15.255.25565,534
17178.16.0.0/16178.16.0.1 to 178.16.255.254178.16.255.25565,534
18178.17.0.0/16178.17.0.1 to 178.17.255.254178.17.255.25565,534
19178.18.0.0/16178.18.0.1 to 178.18.255.254178.18.255.25565,534
20178.19.0.0/16178.19.0.1 to 178.19.255.254178.19.255.25565,534
21178.20.0.0/16178.20.0.1 to 178.20.255.254178.20.255.25565,534
22178.21.0.0/16178.21.0.1 to 178.21.255.254178.21.255.25565,534
23178.22.0.0/16178.22.0.1 to 178.22.255.254178.22.255.25565,534
24178.23.0.0/16178.23.0.1 to 178.23.255.254178.23.255.25565,534
25178.24.0.0/16178.24.0.1 to 178.24.255.254178.24.255.25565,534
26178.25.0.0/16178.25.0.1 to 178.25.255.254178.25.255.25565,534
27178.26.0.0/16178.26.0.1 to 178.26.255.254178.26.255.25565,534
28178.27.0.0/16178.27.0.1 to 178.27.255.254178.27.255.25565,534
29178.28.0.0/16178.28.0.1 to 178.28.255.254178.28.255.25565,534
30178.29.0.0/16178.29.0.1 to 178.29.255.254178.29.255.25565,534
31178.30.0.0/16178.30.0.1 to 178.30.255.254178.30.255.25565,534
32178.31.0.0/16178.31.0.1 to 178.31.255.254178.31.255.25565,534
33178.32.0.0/16178.32.0.1 to 178.32.255.254178.32.255.25565,534
34178.33.0.0/16178.33.0.1 to 178.33.255.254178.33.255.25565,534
35178.34.0.0/16178.34.0.1 to 178.34.255.254178.34.255.25565,534
36178.35.0.0/16178.35.0.1 to 178.35.255.254178.35.255.25565,534
37178.36.0.0/16178.36.0.1 to 178.36.255.254178.36.255.25565,534
38178.37.0.0/16178.37.0.1 to 178.37.255.254178.37.255.25565,534
39178.38.0.0/16178.38.0.1 to 178.38.255.254178.38.255.25565,534
40178.39.0.0/16178.39.0.1 to 178.39.255.254178.39.255.25565,534
41178.40.0.0/16178.40.0.1 to 178.40.255.254178.40.255.25565,534
42178.41.0.0/16178.41.0.1 to 178.41.255.254178.41.255.25565,534
43178.42.0.0/16178.42.0.1 to 178.42.255.254178.42.255.25565,534
44178.43.0.0/16178.43.0.1 to 178.43.255.254178.43.255.25565,534
45178.44.0.0/16178.44.0.1 to 178.44.255.254178.44.255.25565,534
46178.45.0.0/16178.45.0.1 to 178.45.255.254178.45.255.25565,534
47178.46.0.0/16178.46.0.1 to 178.46.255.254178.46.255.25565,534
48178.47.0.0/16178.47.0.1 to 178.47.255.254178.47.255.25565,534
49178.48.0.0/16178.48.0.1 to 178.48.255.254178.48.255.25565,534
50178.49.0.0/16178.49.0.1 to 178.49.255.254178.49.255.25565,534
51178.50.0.0/16178.50.0.1 to 178.50.255.254178.50.255.25565,534
52178.51.0.0/16178.51.0.1 to 178.51.255.254178.51.255.25565,534
53178.52.0.0/16178.52.0.1 to 178.52.255.254178.52.255.25565,534
54178.53.0.0/16178.53.0.1 to 178.53.255.254178.53.255.25565,534
55178.54.0.0/16178.54.0.1 to 178.54.255.254178.54.255.25565,534
56178.55.0.0/16178.55.0.1 to 178.55.255.254178.55.255.25565,534
57178.56.0.0/16178.56.0.1 to 178.56.255.254178.56.255.25565,534
58178.57.0.0/16178.57.0.1 to 178.57.255.254178.57.255.25565,534
59178.58.0.0/16178.58.0.1 to 178.58.255.254178.58.255.25565,534
60178.59.0.0/16178.59.0.1 to 178.59.255.254178.59.255.25565,534
61178.60.0.0/16178.60.0.1 to 178.60.255.254178.60.255.25565,534
62178.61.0.0/16178.61.0.1 to 178.61.255.254178.61.255.25565,534
63178.62.0.0/16178.62.0.1 to 178.62.255.254178.62.255.25565,534
64178.63.0.0/16178.63.0.1 to 178.63.255.254178.63.255.25565,534
65178.64.0.0/16178.64.0.1 to 178.64.255.254178.64.255.25565,534
66178.65.0.0/16178.65.0.1 to 178.65.255.254178.65.255.25565,534
67178.66.0.0/16178.66.0.1 to 178.66.255.254178.66.255.25565,534
68178.67.0.0/16178.67.0.1 to 178.67.255.254178.67.255.25565,534
69178.68.0.0/16178.68.0.1 to 178.68.255.254178.68.255.25565,534
70178.69.0.0/16178.69.0.1 to 178.69.255.254178.69.255.25565,534
71178.70.0.0/16178.70.0.1 to 178.70.255.254178.70.255.25565,534
72178.71.0.0/16178.71.0.1 to 178.71.255.254178.71.255.25565,534
73178.72.0.0/16178.72.0.1 to 178.72.255.254178.72.255.25565,534
74178.73.0.0/16178.73.0.1 to 178.73.255.254178.73.255.25565,534
75178.74.0.0/16178.74.0.1 to 178.74.255.254178.74.255.25565,534
76178.75.0.0/16178.75.0.1 to 178.75.255.254178.75.255.25565,534
77178.76.0.0/16178.76.0.1 to 178.76.255.254178.76.255.25565,534
78178.77.0.0/16178.77.0.1 to 178.77.255.254178.77.255.25565,534
79178.78.0.0/16178.78.0.1 to 178.78.255.254178.78.255.25565,534
80178.79.0.0/16178.79.0.1 to 178.79.255.254178.79.255.25565,534
81178.80.0.0/16178.80.0.1 to 178.80.255.254178.80.255.25565,534
82178.81.0.0/16178.81.0.1 to 178.81.255.254178.81.255.25565,534
83178.82.0.0/16178.82.0.1 to 178.82.255.254178.82.255.25565,534
84178.83.0.0/16178.83.0.1 to 178.83.255.254178.83.255.25565,534
85178.84.0.0/16178.84.0.1 to 178.84.255.254178.84.255.25565,534
86178.85.0.0/16178.85.0.1 to 178.85.255.254178.85.255.25565,534
87178.86.0.0/16178.86.0.1 to 178.86.255.254178.86.255.25565,534
88178.87.0.0/16178.87.0.1 to 178.87.255.254178.87.255.25565,534
89178.88.0.0/16178.88.0.1 to 178.88.255.254178.88.255.25565,534
90178.89.0.0/16178.89.0.1 to 178.89.255.254178.89.255.25565,534
91178.90.0.0/16178.90.0.1 to 178.90.255.254178.90.255.25565,534
92178.91.0.0/16178.91.0.1 to 178.91.255.254178.91.255.25565,534
93178.92.0.0/16178.92.0.1 to 178.92.255.254178.92.255.25565,534
94178.93.0.0/16178.93.0.1 to 178.93.255.254178.93.255.25565,534
95178.94.0.0/16178.94.0.1 to 178.94.255.254178.94.255.25565,534
96178.95.0.0/16178.95.0.1 to 178.95.255.254178.95.255.25565,534
97178.96.0.0/16178.96.0.1 to 178.96.255.254178.96.255.25565,534
98178.97.0.0/16178.97.0.1 to 178.97.255.254178.97.255.25565,534
99178.98.0.0/16178.98.0.1 to 178.98.255.254178.98.255.25565,534
100178.99.0.0/16178.99.0.1 to 178.99.255.254178.99.255.25565,534
101178.100.0.0/16178.100.0.1 to 178.100.255.254178.100.255.25565,534
102178.101.0.0/16178.101.0.1 to 178.101.255.254178.101.255.25565,534
103178.102.0.0/16178.102.0.1 to 178.102.255.254178.102.255.25565,534
104178.103.0.0/16178.103.0.1 to 178.103.255.254178.103.255.25565,534
105178.104.0.0/16178.104.0.1 to 178.104.255.254178.104.255.25565,534
106178.105.0.0/16178.105.0.1 to 178.105.255.254178.105.255.25565,534
107178.106.0.0/16178.106.0.1 to 178.106.255.254178.106.255.25565,534
108178.107.0.0/16178.107.0.1 to 178.107.255.254178.107.255.25565,534
109178.108.0.0/16178.108.0.1 to 178.108.255.254178.108.255.25565,534
110178.109.0.0/16178.109.0.1 to 178.109.255.254178.109.255.25565,534
111178.110.0.0/16178.110.0.1 to 178.110.255.254178.110.255.25565,534
112178.111.0.0/16178.111.0.1 to 178.111.255.254178.111.255.25565,534
113178.112.0.0/16178.112.0.1 to 178.112.255.254178.112.255.25565,534
114178.113.0.0/16178.113.0.1 to 178.113.255.254178.113.255.25565,534
115178.114.0.0/16178.114.0.1 to 178.114.255.254178.114.255.25565,534
116178.115.0.0/16178.115.0.1 to 178.115.255.254178.115.255.25565,534
117178.116.0.0/16178.116.0.1 to 178.116.255.254178.116.255.25565,534
118178.117.0.0/16178.117.0.1 to 178.117.255.254178.117.255.25565,534
119178.118.0.0/16178.118.0.1 to 178.118.255.254178.118.255.25565,534
120178.119.0.0/16178.119.0.1 to 178.119.255.254178.119.255.25565,534
121178.120.0.0/16178.120.0.1 to 178.120.255.254178.120.255.25565,534
122178.121.0.0/16178.121.0.1 to 178.121.255.254178.121.255.25565,534
123178.122.0.0/16178.122.0.1 to 178.122.255.254178.122.255.25565,534
124178.123.0.0/16178.123.0.1 to 178.123.255.254178.123.255.25565,534
125178.124.0.0/16178.124.0.1 to 178.124.255.254178.124.255.25565,534
126178.125.0.0/16178.125.0.1 to 178.125.255.254178.125.255.25565,534
127178.126.0.0/16178.126.0.1 to 178.126.255.254178.126.255.25565,534
128178.127.0.0/16178.127.0.1 to 178.127.255.254178.127.255.25565,534
129178.128.0.0/16178.128.0.1 to 178.128.255.254178.128.255.25565,534
130178.129.0.0/16178.129.0.1 to 178.129.255.254178.129.255.25565,534
131178.130.0.0/16178.130.0.1 to 178.130.255.254178.130.255.25565,534
132178.131.0.0/16178.131.0.1 to 178.131.255.254178.131.255.25565,534
133178.132.0.0/16178.132.0.1 to 178.132.255.254178.132.255.25565,534
134178.133.0.0/16178.133.0.1 to 178.133.255.254178.133.255.25565,534
135178.134.0.0/16178.134.0.1 to 178.134.255.254178.134.255.25565,534
136178.135.0.0/16178.135.0.1 to 178.135.255.254178.135.255.25565,534
137178.136.0.0/16178.136.0.1 to 178.136.255.254178.136.255.25565,534
138178.137.0.0/16178.137.0.1 to 178.137.255.254178.137.255.25565,534
139178.138.0.0/16178.138.0.1 to 178.138.255.254178.138.255.25565,534
140178.139.0.0/16178.139.0.1 to 178.139.255.254178.139.255.25565,534
141178.140.0.0/16178.140.0.1 to 178.140.255.254178.140.255.25565,534
142178.141.0.0/16178.141.0.1 to 178.141.255.254178.141.255.25565,534
143178.142.0.0/16178.142.0.1 to 178.142.255.254178.142.255.25565,534
144178.143.0.0/16178.143.0.1 to 178.143.255.254178.143.255.25565,534
145178.144.0.0/16178.144.0.1 to 178.144.255.254178.144.255.25565,534
146178.145.0.0/16178.145.0.1 to 178.145.255.254178.145.255.25565,534
147178.146.0.0/16178.146.0.1 to 178.146.255.254178.146.255.25565,534
148178.147.0.0/16178.147.0.1 to 178.147.255.254178.147.255.25565,534
149178.148.0.0/16178.148.0.1 to 178.148.255.254178.148.255.25565,534
150178.149.0.0/16178.149.0.1 to 178.149.255.254178.149.255.25565,534
151178.150.0.0/16178.150.0.1 to 178.150.255.254178.150.255.25565,534
152178.151.0.0/16178.151.0.1 to 178.151.255.254178.151.255.25565,534
153178.152.0.0/16178.152.0.1 to 178.152.255.254178.152.255.25565,534
154178.153.0.0/16178.153.0.1 to 178.153.255.254178.153.255.25565,534
155178.154.0.0/16178.154.0.1 to 178.154.255.254178.154.255.25565,534
156178.155.0.0/16178.155.0.1 to 178.155.255.254178.155.255.25565,534
157178.156.0.0/16178.156.0.1 to 178.156.255.254178.156.255.25565,534
158178.157.0.0/16178.157.0.1 to 178.157.255.254178.157.255.25565,534
159178.158.0.0/16178.158.0.1 to 178.158.255.254178.158.255.25565,534
160178.159.0.0/16178.159.0.1 to 178.159.255.254178.159.255.25565,534
161178.160.0.0/16178.160.0.1 to 178.160.255.254178.160.255.25565,534
162178.161.0.0/16178.161.0.1 to 178.161.255.254178.161.255.25565,534
163178.162.0.0/16178.162.0.1 to 178.162.255.254178.162.255.25565,534
164178.163.0.0/16178.163.0.1 to 178.163.255.254178.163.255.25565,534
165178.164.0.0/16178.164.0.1 to 178.164.255.254178.164.255.25565,534
166178.165.0.0/16178.165.0.1 to 178.165.255.254178.165.255.25565,534
167178.166.0.0/16178.166.0.1 to 178.166.255.254178.166.255.25565,534
168178.167.0.0/16178.167.0.1 to 178.167.255.254178.167.255.25565,534
169178.168.0.0/16178.168.0.1 to 178.168.255.254178.168.255.25565,534
170178.169.0.0/16178.169.0.1 to 178.169.255.254178.169.255.25565,534
171178.170.0.0/16178.170.0.1 to 178.170.255.254178.170.255.25565,534
172178.171.0.0/16178.171.0.1 to 178.171.255.254178.171.255.25565,534
173178.172.0.0/16178.172.0.1 to 178.172.255.254178.172.255.25565,534
174178.173.0.0/16178.173.0.1 to 178.173.255.254178.173.255.25565,534
175178.174.0.0/16178.174.0.1 to 178.174.255.254178.174.255.25565,534
176178.175.0.0/16178.175.0.1 to 178.175.255.254178.175.255.25565,534
177178.176.0.0/16178.176.0.1 to 178.176.255.254178.176.255.25565,534
178178.177.0.0/16178.177.0.1 to 178.177.255.254178.177.255.25565,534
179178.178.0.0/16178.178.0.1 to 178.178.255.254178.178.255.25565,534
180178.179.0.0/16178.179.0.1 to 178.179.255.254178.179.255.25565,534
181178.180.0.0/16178.180.0.1 to 178.180.255.254178.180.255.25565,534
182178.181.0.0/16178.181.0.1 to 178.181.255.254178.181.255.25565,534
183178.182.0.0/16178.182.0.1 to 178.182.255.254178.182.255.25565,534
184178.183.0.0/16178.183.0.1 to 178.183.255.254178.183.255.25565,534
185178.184.0.0/16178.184.0.1 to 178.184.255.254178.184.255.25565,534
186178.185.0.0/16178.185.0.1 to 178.185.255.254178.185.255.25565,534
187178.186.0.0/16178.186.0.1 to 178.186.255.254178.186.255.25565,534
188178.187.0.0/16178.187.0.1 to 178.187.255.254178.187.255.25565,534
189178.188.0.0/16178.188.0.1 to 178.188.255.254178.188.255.25565,534
190178.189.0.0/16178.189.0.1 to 178.189.255.254178.189.255.25565,534
191178.190.0.0/16178.190.0.1 to 178.190.255.254178.190.255.25565,534
192178.191.0.0/16178.191.0.1 to 178.191.255.254178.191.255.25565,534
193178.192.0.0/16178.192.0.1 to 178.192.255.254178.192.255.25565,534
194178.193.0.0/16178.193.0.1 to 178.193.255.254178.193.255.25565,534
195178.194.0.0/16178.194.0.1 to 178.194.255.254178.194.255.25565,534
196178.195.0.0/16178.195.0.1 to 178.195.255.254178.195.255.25565,534
197178.196.0.0/16178.196.0.1 to 178.196.255.254178.196.255.25565,534
198178.197.0.0/16178.197.0.1 to 178.197.255.254178.197.255.25565,534
199178.198.0.0/16178.198.0.1 to 178.198.255.254178.198.255.25565,534
200178.199.0.0/16178.199.0.1 to 178.199.255.254178.199.255.25565,534
201178.200.0.0/16178.200.0.1 to 178.200.255.254178.200.255.25565,534
202178.201.0.0/16178.201.0.1 to 178.201.255.254178.201.255.25565,534
203178.202.0.0/16178.202.0.1 to 178.202.255.254178.202.255.25565,534
204178.203.0.0/16178.203.0.1 to 178.203.255.254178.203.255.25565,534
205178.204.0.0/16178.204.0.1 to 178.204.255.254178.204.255.25565,534
206178.205.0.0/16178.205.0.1 to 178.205.255.254178.205.255.25565,534
207178.206.0.0/16178.206.0.1 to 178.206.255.254178.206.255.25565,534
208178.207.0.0/16178.207.0.1 to 178.207.255.254178.207.255.25565,534
209178.208.0.0/16178.208.0.1 to 178.208.255.254178.208.255.25565,534
210178.209.0.0/16178.209.0.1 to 178.209.255.254178.209.255.25565,534
211178.210.0.0/16178.210.0.1 to 178.210.255.254178.210.255.25565,534
212178.211.0.0/16178.211.0.1 to 178.211.255.254178.211.255.25565,534
213178.212.0.0/16178.212.0.1 to 178.212.255.254178.212.255.25565,534
214178.213.0.0/16178.213.0.1 to 178.213.255.254178.213.255.25565,534
215178.214.0.0/16178.214.0.1 to 178.214.255.254178.214.255.25565,534
216178.215.0.0/16178.215.0.1 to 178.215.255.254178.215.255.25565,534
217178.216.0.0/16178.216.0.1 to 178.216.255.254178.216.255.25565,534
218178.217.0.0/16178.217.0.1 to 178.217.255.254178.217.255.25565,534
219178.218.0.0/16178.218.0.1 to 178.218.255.254178.218.255.25565,534
220178.219.0.0/16178.219.0.1 to 178.219.255.254178.219.255.25565,534
221178.220.0.0/16178.220.0.1 to 178.220.255.254178.220.255.25565,534
222178.221.0.0/16178.221.0.1 to 178.221.255.254178.221.255.25565,534
223178.222.0.0/16178.222.0.1 to 178.222.255.254178.222.255.25565,534
224178.223.0.0/16178.223.0.1 to 178.223.255.254178.223.255.25565,534
225178.224.0.0/16178.224.0.1 to 178.224.255.254178.224.255.25565,534
226178.225.0.0/16178.225.0.1 to 178.225.255.254178.225.255.25565,534
227178.226.0.0/16178.226.0.1 to 178.226.255.254178.226.255.25565,534
228178.227.0.0/16178.227.0.1 to 178.227.255.254178.227.255.25565,534
229178.228.0.0/16178.228.0.1 to 178.228.255.254178.228.255.25565,534
230178.229.0.0/16178.229.0.1 to 178.229.255.254178.229.255.25565,534
231178.230.0.0/16178.230.0.1 to 178.230.255.254178.230.255.25565,534
232178.231.0.0/16178.231.0.1 to 178.231.255.254178.231.255.25565,534
233178.232.0.0/16178.232.0.1 to 178.232.255.254178.232.255.25565,534
234178.233.0.0/16178.233.0.1 to 178.233.255.254178.233.255.25565,534
235178.234.0.0/16178.234.0.1 to 178.234.255.254178.234.255.25565,534
236178.235.0.0/16178.235.0.1 to 178.235.255.254178.235.255.25565,534
237178.236.0.0/16178.236.0.1 to 178.236.255.254178.236.255.25565,534
238178.237.0.0/16178.237.0.1 to 178.237.255.254178.237.255.25565,534
239178.238.0.0/16178.238.0.1 to 178.238.255.254178.238.255.25565,534
240178.239.0.0/16178.239.0.1 to 178.239.255.254178.239.255.25565,534
241178.240.0.0/16178.240.0.1 to 178.240.255.254178.240.255.25565,534
242178.241.0.0/16178.241.0.1 to 178.241.255.254178.241.255.25565,534
243178.242.0.0/16178.242.0.1 to 178.242.255.254178.242.255.25565,534
244178.243.0.0/16178.243.0.1 to 178.243.255.254178.243.255.25565,534
245178.244.0.0/16178.244.0.1 to 178.244.255.254178.244.255.25565,534
246178.245.0.0/16178.245.0.1 to 178.245.255.254178.245.255.25565,534
247178.246.0.0/16178.246.0.1 to 178.246.255.254178.246.255.25565,534
248178.247.0.0/16178.247.0.1 to 178.247.255.254178.247.255.25565,534
249178.248.0.0/16178.248.0.1 to 178.248.255.254178.248.255.25565,534
250178.249.0.0/16178.249.0.1 to 178.249.255.254178.249.255.25565,534
251178.250.0.0/16178.250.0.1 to 178.250.255.254178.250.255.25565,534
252178.251.0.0/16178.251.0.1 to 178.251.255.254178.251.255.25565,534
253178.252.0.0/16178.252.0.1 to 178.252.255.254178.252.255.25565,534
254178.253.0.0/16178.253.0.1 to 178.253.255.254178.253.255.25565,534
255178.254.0.0/16178.254.0.1 to 178.254.255.254178.254.255.25565,534
256178.255.0.0/16178.255.0.1 to 178.255.255.254178.255.255.25565,534

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.