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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.

Network152.0.0.0/6
Usable hosts67,108,862
Subnet mask252.0.0.0
Addresses67,108,864
Network address
152.0.0.0
Broadcast address
155.255.255.255
First usable
152.0.0.1
Last usable
155.255.255.254
Usable hosts
67,108,862 (67,108,864 less the network and broadcast addresses)
Subnet mask
252.0.0.0
Wildcard mask
3.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/6
Type
Public public
Old class
B (default /16)
As numbers
Hex 98000000 · Integer 2550136832 to 2617245695
Reverse DNS zones
152.in-addr.arpa
153.in-addr.arpa
154.in-addr.arpa
155.in-addr.arpa
/6 is not on a 8-bit boundary, so it takes 4 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10011000.00000000.00000000.00000000152.0.0.0
Subnet mask11111100.00000000.00000000.00000000252.0.0.0
Network10011000.00000000.00000000.00000000152.0.0.0
Broadcast10011011.11111111.11111111.11111111155.255.255.255
Split into smaller subnets/16
/7 (2)/8 (4)/9 (8)/10 (16)/11 (32)/12 (64)/13 (128)/14 (256)/15 (512)/16 (1,024)/17 (2,048)/18 (4,096)

152.0.0.0/6 makes 1,024 subnets of /16; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1152.0.0.0/16152.0.0.1 to 152.0.255.254152.0.255.25565,534
2152.1.0.0/16152.1.0.1 to 152.1.255.254152.1.255.25565,534
3152.2.0.0/16152.2.0.1 to 152.2.255.254152.2.255.25565,534
4152.3.0.0/16152.3.0.1 to 152.3.255.254152.3.255.25565,534
5152.4.0.0/16152.4.0.1 to 152.4.255.254152.4.255.25565,534
6152.5.0.0/16152.5.0.1 to 152.5.255.254152.5.255.25565,534
7152.6.0.0/16152.6.0.1 to 152.6.255.254152.6.255.25565,534
8152.7.0.0/16152.7.0.1 to 152.7.255.254152.7.255.25565,534
9152.8.0.0/16152.8.0.1 to 152.8.255.254152.8.255.25565,534
10152.9.0.0/16152.9.0.1 to 152.9.255.254152.9.255.25565,534
11152.10.0.0/16152.10.0.1 to 152.10.255.254152.10.255.25565,534
12152.11.0.0/16152.11.0.1 to 152.11.255.254152.11.255.25565,534
13152.12.0.0/16152.12.0.1 to 152.12.255.254152.12.255.25565,534
14152.13.0.0/16152.13.0.1 to 152.13.255.254152.13.255.25565,534
15152.14.0.0/16152.14.0.1 to 152.14.255.254152.14.255.25565,534
16152.15.0.0/16152.15.0.1 to 152.15.255.254152.15.255.25565,534
17152.16.0.0/16152.16.0.1 to 152.16.255.254152.16.255.25565,534
18152.17.0.0/16152.17.0.1 to 152.17.255.254152.17.255.25565,534
19152.18.0.0/16152.18.0.1 to 152.18.255.254152.18.255.25565,534
20152.19.0.0/16152.19.0.1 to 152.19.255.254152.19.255.25565,534
21152.20.0.0/16152.20.0.1 to 152.20.255.254152.20.255.25565,534
22152.21.0.0/16152.21.0.1 to 152.21.255.254152.21.255.25565,534
23152.22.0.0/16152.22.0.1 to 152.22.255.254152.22.255.25565,534
24152.23.0.0/16152.23.0.1 to 152.23.255.254152.23.255.25565,534
25152.24.0.0/16152.24.0.1 to 152.24.255.254152.24.255.25565,534
26152.25.0.0/16152.25.0.1 to 152.25.255.254152.25.255.25565,534
27152.26.0.0/16152.26.0.1 to 152.26.255.254152.26.255.25565,534
28152.27.0.0/16152.27.0.1 to 152.27.255.254152.27.255.25565,534
29152.28.0.0/16152.28.0.1 to 152.28.255.254152.28.255.25565,534
30152.29.0.0/16152.29.0.1 to 152.29.255.254152.29.255.25565,534
31152.30.0.0/16152.30.0.1 to 152.30.255.254152.30.255.25565,534
32152.31.0.0/16152.31.0.1 to 152.31.255.254152.31.255.25565,534
33152.32.0.0/16152.32.0.1 to 152.32.255.254152.32.255.25565,534
34152.33.0.0/16152.33.0.1 to 152.33.255.254152.33.255.25565,534
35152.34.0.0/16152.34.0.1 to 152.34.255.254152.34.255.25565,534
36152.35.0.0/16152.35.0.1 to 152.35.255.254152.35.255.25565,534
37152.36.0.0/16152.36.0.1 to 152.36.255.254152.36.255.25565,534
38152.37.0.0/16152.37.0.1 to 152.37.255.254152.37.255.25565,534
39152.38.0.0/16152.38.0.1 to 152.38.255.254152.38.255.25565,534
40152.39.0.0/16152.39.0.1 to 152.39.255.254152.39.255.25565,534
41152.40.0.0/16152.40.0.1 to 152.40.255.254152.40.255.25565,534
42152.41.0.0/16152.41.0.1 to 152.41.255.254152.41.255.25565,534
43152.42.0.0/16152.42.0.1 to 152.42.255.254152.42.255.25565,534
44152.43.0.0/16152.43.0.1 to 152.43.255.254152.43.255.25565,534
45152.44.0.0/16152.44.0.1 to 152.44.255.254152.44.255.25565,534
46152.45.0.0/16152.45.0.1 to 152.45.255.254152.45.255.25565,534
47152.46.0.0/16152.46.0.1 to 152.46.255.254152.46.255.25565,534
48152.47.0.0/16152.47.0.1 to 152.47.255.254152.47.255.25565,534
49152.48.0.0/16152.48.0.1 to 152.48.255.254152.48.255.25565,534
50152.49.0.0/16152.49.0.1 to 152.49.255.254152.49.255.25565,534
51152.50.0.0/16152.50.0.1 to 152.50.255.254152.50.255.25565,534
52152.51.0.0/16152.51.0.1 to 152.51.255.254152.51.255.25565,534
53152.52.0.0/16152.52.0.1 to 152.52.255.254152.52.255.25565,534
54152.53.0.0/16152.53.0.1 to 152.53.255.254152.53.255.25565,534
55152.54.0.0/16152.54.0.1 to 152.54.255.254152.54.255.25565,534
56152.55.0.0/16152.55.0.1 to 152.55.255.254152.55.255.25565,534
57152.56.0.0/16152.56.0.1 to 152.56.255.254152.56.255.25565,534
58152.57.0.0/16152.57.0.1 to 152.57.255.254152.57.255.25565,534
59152.58.0.0/16152.58.0.1 to 152.58.255.254152.58.255.25565,534
60152.59.0.0/16152.59.0.1 to 152.59.255.254152.59.255.25565,534
61152.60.0.0/16152.60.0.1 to 152.60.255.254152.60.255.25565,534
62152.61.0.0/16152.61.0.1 to 152.61.255.254152.61.255.25565,534
63152.62.0.0/16152.62.0.1 to 152.62.255.254152.62.255.25565,534
64152.63.0.0/16152.63.0.1 to 152.63.255.254152.63.255.25565,534
65152.64.0.0/16152.64.0.1 to 152.64.255.254152.64.255.25565,534
66152.65.0.0/16152.65.0.1 to 152.65.255.254152.65.255.25565,534
67152.66.0.0/16152.66.0.1 to 152.66.255.254152.66.255.25565,534
68152.67.0.0/16152.67.0.1 to 152.67.255.254152.67.255.25565,534
69152.68.0.0/16152.68.0.1 to 152.68.255.254152.68.255.25565,534
70152.69.0.0/16152.69.0.1 to 152.69.255.254152.69.255.25565,534
71152.70.0.0/16152.70.0.1 to 152.70.255.254152.70.255.25565,534
72152.71.0.0/16152.71.0.1 to 152.71.255.254152.71.255.25565,534
73152.72.0.0/16152.72.0.1 to 152.72.255.254152.72.255.25565,534
74152.73.0.0/16152.73.0.1 to 152.73.255.254152.73.255.25565,534
75152.74.0.0/16152.74.0.1 to 152.74.255.254152.74.255.25565,534
76152.75.0.0/16152.75.0.1 to 152.75.255.254152.75.255.25565,534
77152.76.0.0/16152.76.0.1 to 152.76.255.254152.76.255.25565,534
78152.77.0.0/16152.77.0.1 to 152.77.255.254152.77.255.25565,534
79152.78.0.0/16152.78.0.1 to 152.78.255.254152.78.255.25565,534
80152.79.0.0/16152.79.0.1 to 152.79.255.254152.79.255.25565,534
81152.80.0.0/16152.80.0.1 to 152.80.255.254152.80.255.25565,534
82152.81.0.0/16152.81.0.1 to 152.81.255.254152.81.255.25565,534
83152.82.0.0/16152.82.0.1 to 152.82.255.254152.82.255.25565,534
84152.83.0.0/16152.83.0.1 to 152.83.255.254152.83.255.25565,534
85152.84.0.0/16152.84.0.1 to 152.84.255.254152.84.255.25565,534
86152.85.0.0/16152.85.0.1 to 152.85.255.254152.85.255.25565,534
87152.86.0.0/16152.86.0.1 to 152.86.255.254152.86.255.25565,534
88152.87.0.0/16152.87.0.1 to 152.87.255.254152.87.255.25565,534
89152.88.0.0/16152.88.0.1 to 152.88.255.254152.88.255.25565,534
90152.89.0.0/16152.89.0.1 to 152.89.255.254152.89.255.25565,534
91152.90.0.0/16152.90.0.1 to 152.90.255.254152.90.255.25565,534
92152.91.0.0/16152.91.0.1 to 152.91.255.254152.91.255.25565,534
93152.92.0.0/16152.92.0.1 to 152.92.255.254152.92.255.25565,534
94152.93.0.0/16152.93.0.1 to 152.93.255.254152.93.255.25565,534
95152.94.0.0/16152.94.0.1 to 152.94.255.254152.94.255.25565,534
96152.95.0.0/16152.95.0.1 to 152.95.255.254152.95.255.25565,534
97152.96.0.0/16152.96.0.1 to 152.96.255.254152.96.255.25565,534
98152.97.0.0/16152.97.0.1 to 152.97.255.254152.97.255.25565,534
99152.98.0.0/16152.98.0.1 to 152.98.255.254152.98.255.25565,534
100152.99.0.0/16152.99.0.1 to 152.99.255.254152.99.255.25565,534
101152.100.0.0/16152.100.0.1 to 152.100.255.254152.100.255.25565,534
102152.101.0.0/16152.101.0.1 to 152.101.255.254152.101.255.25565,534
103152.102.0.0/16152.102.0.1 to 152.102.255.254152.102.255.25565,534
104152.103.0.0/16152.103.0.1 to 152.103.255.254152.103.255.25565,534
105152.104.0.0/16152.104.0.1 to 152.104.255.254152.104.255.25565,534
106152.105.0.0/16152.105.0.1 to 152.105.255.254152.105.255.25565,534
107152.106.0.0/16152.106.0.1 to 152.106.255.254152.106.255.25565,534
108152.107.0.0/16152.107.0.1 to 152.107.255.254152.107.255.25565,534
109152.108.0.0/16152.108.0.1 to 152.108.255.254152.108.255.25565,534
110152.109.0.0/16152.109.0.1 to 152.109.255.254152.109.255.25565,534
111152.110.0.0/16152.110.0.1 to 152.110.255.254152.110.255.25565,534
112152.111.0.0/16152.111.0.1 to 152.111.255.254152.111.255.25565,534
113152.112.0.0/16152.112.0.1 to 152.112.255.254152.112.255.25565,534
114152.113.0.0/16152.113.0.1 to 152.113.255.254152.113.255.25565,534
115152.114.0.0/16152.114.0.1 to 152.114.255.254152.114.255.25565,534
116152.115.0.0/16152.115.0.1 to 152.115.255.254152.115.255.25565,534
117152.116.0.0/16152.116.0.1 to 152.116.255.254152.116.255.25565,534
118152.117.0.0/16152.117.0.1 to 152.117.255.254152.117.255.25565,534
119152.118.0.0/16152.118.0.1 to 152.118.255.254152.118.255.25565,534
120152.119.0.0/16152.119.0.1 to 152.119.255.254152.119.255.25565,534
121152.120.0.0/16152.120.0.1 to 152.120.255.254152.120.255.25565,534
122152.121.0.0/16152.121.0.1 to 152.121.255.254152.121.255.25565,534
123152.122.0.0/16152.122.0.1 to 152.122.255.254152.122.255.25565,534
124152.123.0.0/16152.123.0.1 to 152.123.255.254152.123.255.25565,534
125152.124.0.0/16152.124.0.1 to 152.124.255.254152.124.255.25565,534
126152.125.0.0/16152.125.0.1 to 152.125.255.254152.125.255.25565,534
127152.126.0.0/16152.126.0.1 to 152.126.255.254152.126.255.25565,534
128152.127.0.0/16152.127.0.1 to 152.127.255.254152.127.255.25565,534
129152.128.0.0/16152.128.0.1 to 152.128.255.254152.128.255.25565,534
130152.129.0.0/16152.129.0.1 to 152.129.255.254152.129.255.25565,534
131152.130.0.0/16152.130.0.1 to 152.130.255.254152.130.255.25565,534
132152.131.0.0/16152.131.0.1 to 152.131.255.254152.131.255.25565,534
133152.132.0.0/16152.132.0.1 to 152.132.255.254152.132.255.25565,534
134152.133.0.0/16152.133.0.1 to 152.133.255.254152.133.255.25565,534
135152.134.0.0/16152.134.0.1 to 152.134.255.254152.134.255.25565,534
136152.135.0.0/16152.135.0.1 to 152.135.255.254152.135.255.25565,534
137152.136.0.0/16152.136.0.1 to 152.136.255.254152.136.255.25565,534
138152.137.0.0/16152.137.0.1 to 152.137.255.254152.137.255.25565,534
139152.138.0.0/16152.138.0.1 to 152.138.255.254152.138.255.25565,534
140152.139.0.0/16152.139.0.1 to 152.139.255.254152.139.255.25565,534
141152.140.0.0/16152.140.0.1 to 152.140.255.254152.140.255.25565,534
142152.141.0.0/16152.141.0.1 to 152.141.255.254152.141.255.25565,534
143152.142.0.0/16152.142.0.1 to 152.142.255.254152.142.255.25565,534
144152.143.0.0/16152.143.0.1 to 152.143.255.254152.143.255.25565,534
145152.144.0.0/16152.144.0.1 to 152.144.255.254152.144.255.25565,534
146152.145.0.0/16152.145.0.1 to 152.145.255.254152.145.255.25565,534
147152.146.0.0/16152.146.0.1 to 152.146.255.254152.146.255.25565,534
148152.147.0.0/16152.147.0.1 to 152.147.255.254152.147.255.25565,534
149152.148.0.0/16152.148.0.1 to 152.148.255.254152.148.255.25565,534
150152.149.0.0/16152.149.0.1 to 152.149.255.254152.149.255.25565,534
151152.150.0.0/16152.150.0.1 to 152.150.255.254152.150.255.25565,534
152152.151.0.0/16152.151.0.1 to 152.151.255.254152.151.255.25565,534
153152.152.0.0/16152.152.0.1 to 152.152.255.254152.152.255.25565,534
154152.153.0.0/16152.153.0.1 to 152.153.255.254152.153.255.25565,534
155152.154.0.0/16152.154.0.1 to 152.154.255.254152.154.255.25565,534
156152.155.0.0/16152.155.0.1 to 152.155.255.254152.155.255.25565,534
157152.156.0.0/16152.156.0.1 to 152.156.255.254152.156.255.25565,534
158152.157.0.0/16152.157.0.1 to 152.157.255.254152.157.255.25565,534
159152.158.0.0/16152.158.0.1 to 152.158.255.254152.158.255.25565,534
160152.159.0.0/16152.159.0.1 to 152.159.255.254152.159.255.25565,534
161152.160.0.0/16152.160.0.1 to 152.160.255.254152.160.255.25565,534
162152.161.0.0/16152.161.0.1 to 152.161.255.254152.161.255.25565,534
163152.162.0.0/16152.162.0.1 to 152.162.255.254152.162.255.25565,534
164152.163.0.0/16152.163.0.1 to 152.163.255.254152.163.255.25565,534
165152.164.0.0/16152.164.0.1 to 152.164.255.254152.164.255.25565,534
166152.165.0.0/16152.165.0.1 to 152.165.255.254152.165.255.25565,534
167152.166.0.0/16152.166.0.1 to 152.166.255.254152.166.255.25565,534
168152.167.0.0/16152.167.0.1 to 152.167.255.254152.167.255.25565,534
169152.168.0.0/16152.168.0.1 to 152.168.255.254152.168.255.25565,534
170152.169.0.0/16152.169.0.1 to 152.169.255.254152.169.255.25565,534
171152.170.0.0/16152.170.0.1 to 152.170.255.254152.170.255.25565,534
172152.171.0.0/16152.171.0.1 to 152.171.255.254152.171.255.25565,534
173152.172.0.0/16152.172.0.1 to 152.172.255.254152.172.255.25565,534
174152.173.0.0/16152.173.0.1 to 152.173.255.254152.173.255.25565,534
175152.174.0.0/16152.174.0.1 to 152.174.255.254152.174.255.25565,534
176152.175.0.0/16152.175.0.1 to 152.175.255.254152.175.255.25565,534
177152.176.0.0/16152.176.0.1 to 152.176.255.254152.176.255.25565,534
178152.177.0.0/16152.177.0.1 to 152.177.255.254152.177.255.25565,534
179152.178.0.0/16152.178.0.1 to 152.178.255.254152.178.255.25565,534
180152.179.0.0/16152.179.0.1 to 152.179.255.254152.179.255.25565,534
181152.180.0.0/16152.180.0.1 to 152.180.255.254152.180.255.25565,534
182152.181.0.0/16152.181.0.1 to 152.181.255.254152.181.255.25565,534
183152.182.0.0/16152.182.0.1 to 152.182.255.254152.182.255.25565,534
184152.183.0.0/16152.183.0.1 to 152.183.255.254152.183.255.25565,534
185152.184.0.0/16152.184.0.1 to 152.184.255.254152.184.255.25565,534
186152.185.0.0/16152.185.0.1 to 152.185.255.254152.185.255.25565,534
187152.186.0.0/16152.186.0.1 to 152.186.255.254152.186.255.25565,534
188152.187.0.0/16152.187.0.1 to 152.187.255.254152.187.255.25565,534
189152.188.0.0/16152.188.0.1 to 152.188.255.254152.188.255.25565,534
190152.189.0.0/16152.189.0.1 to 152.189.255.254152.189.255.25565,534
191152.190.0.0/16152.190.0.1 to 152.190.255.254152.190.255.25565,534
192152.191.0.0/16152.191.0.1 to 152.191.255.254152.191.255.25565,534
193152.192.0.0/16152.192.0.1 to 152.192.255.254152.192.255.25565,534
194152.193.0.0/16152.193.0.1 to 152.193.255.254152.193.255.25565,534
195152.194.0.0/16152.194.0.1 to 152.194.255.254152.194.255.25565,534
196152.195.0.0/16152.195.0.1 to 152.195.255.254152.195.255.25565,534
197152.196.0.0/16152.196.0.1 to 152.196.255.254152.196.255.25565,534
198152.197.0.0/16152.197.0.1 to 152.197.255.254152.197.255.25565,534
199152.198.0.0/16152.198.0.1 to 152.198.255.254152.198.255.25565,534
200152.199.0.0/16152.199.0.1 to 152.199.255.254152.199.255.25565,534
201152.200.0.0/16152.200.0.1 to 152.200.255.254152.200.255.25565,534
202152.201.0.0/16152.201.0.1 to 152.201.255.254152.201.255.25565,534
203152.202.0.0/16152.202.0.1 to 152.202.255.254152.202.255.25565,534
204152.203.0.0/16152.203.0.1 to 152.203.255.254152.203.255.25565,534
205152.204.0.0/16152.204.0.1 to 152.204.255.254152.204.255.25565,534
206152.205.0.0/16152.205.0.1 to 152.205.255.254152.205.255.25565,534
207152.206.0.0/16152.206.0.1 to 152.206.255.254152.206.255.25565,534
208152.207.0.0/16152.207.0.1 to 152.207.255.254152.207.255.25565,534
209152.208.0.0/16152.208.0.1 to 152.208.255.254152.208.255.25565,534
210152.209.0.0/16152.209.0.1 to 152.209.255.254152.209.255.25565,534
211152.210.0.0/16152.210.0.1 to 152.210.255.254152.210.255.25565,534
212152.211.0.0/16152.211.0.1 to 152.211.255.254152.211.255.25565,534
213152.212.0.0/16152.212.0.1 to 152.212.255.254152.212.255.25565,534
214152.213.0.0/16152.213.0.1 to 152.213.255.254152.213.255.25565,534
215152.214.0.0/16152.214.0.1 to 152.214.255.254152.214.255.25565,534
216152.215.0.0/16152.215.0.1 to 152.215.255.254152.215.255.25565,534
217152.216.0.0/16152.216.0.1 to 152.216.255.254152.216.255.25565,534
218152.217.0.0/16152.217.0.1 to 152.217.255.254152.217.255.25565,534
219152.218.0.0/16152.218.0.1 to 152.218.255.254152.218.255.25565,534
220152.219.0.0/16152.219.0.1 to 152.219.255.254152.219.255.25565,534
221152.220.0.0/16152.220.0.1 to 152.220.255.254152.220.255.25565,534
222152.221.0.0/16152.221.0.1 to 152.221.255.254152.221.255.25565,534
223152.222.0.0/16152.222.0.1 to 152.222.255.254152.222.255.25565,534
224152.223.0.0/16152.223.0.1 to 152.223.255.254152.223.255.25565,534
225152.224.0.0/16152.224.0.1 to 152.224.255.254152.224.255.25565,534
226152.225.0.0/16152.225.0.1 to 152.225.255.254152.225.255.25565,534
227152.226.0.0/16152.226.0.1 to 152.226.255.254152.226.255.25565,534
228152.227.0.0/16152.227.0.1 to 152.227.255.254152.227.255.25565,534
229152.228.0.0/16152.228.0.1 to 152.228.255.254152.228.255.25565,534
230152.229.0.0/16152.229.0.1 to 152.229.255.254152.229.255.25565,534
231152.230.0.0/16152.230.0.1 to 152.230.255.254152.230.255.25565,534
232152.231.0.0/16152.231.0.1 to 152.231.255.254152.231.255.25565,534
233152.232.0.0/16152.232.0.1 to 152.232.255.254152.232.255.25565,534
234152.233.0.0/16152.233.0.1 to 152.233.255.254152.233.255.25565,534
235152.234.0.0/16152.234.0.1 to 152.234.255.254152.234.255.25565,534
236152.235.0.0/16152.235.0.1 to 152.235.255.254152.235.255.25565,534
237152.236.0.0/16152.236.0.1 to 152.236.255.254152.236.255.25565,534
238152.237.0.0/16152.237.0.1 to 152.237.255.254152.237.255.25565,534
239152.238.0.0/16152.238.0.1 to 152.238.255.254152.238.255.25565,534
240152.239.0.0/16152.239.0.1 to 152.239.255.254152.239.255.25565,534
241152.240.0.0/16152.240.0.1 to 152.240.255.254152.240.255.25565,534
242152.241.0.0/16152.241.0.1 to 152.241.255.254152.241.255.25565,534
243152.242.0.0/16152.242.0.1 to 152.242.255.254152.242.255.25565,534
244152.243.0.0/16152.243.0.1 to 152.243.255.254152.243.255.25565,534
245152.244.0.0/16152.244.0.1 to 152.244.255.254152.244.255.25565,534
246152.245.0.0/16152.245.0.1 to 152.245.255.254152.245.255.25565,534
247152.246.0.0/16152.246.0.1 to 152.246.255.254152.246.255.25565,534
248152.247.0.0/16152.247.0.1 to 152.247.255.254152.247.255.25565,534
249152.248.0.0/16152.248.0.1 to 152.248.255.254152.248.255.25565,534
250152.249.0.0/16152.249.0.1 to 152.249.255.254152.249.255.25565,534
251152.250.0.0/16152.250.0.1 to 152.250.255.254152.250.255.25565,534
252152.251.0.0/16152.251.0.1 to 152.251.255.254152.251.255.25565,534
253152.252.0.0/16152.252.0.1 to 152.252.255.254152.252.255.25565,534
254152.253.0.0/16152.253.0.1 to 152.253.255.254152.253.255.25565,534
255152.254.0.0/16152.254.0.1 to 152.254.255.254152.254.255.25565,534
256152.255.0.0/16152.255.0.1 to 152.255.255.254152.255.255.25565,534

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.