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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.

Network253.0.0.0/11
Usable hosts2,097,150
Subnet mask255.224.0.0
Addresses2,097,152
Network address
253.0.0.0
Broadcast address
253.31.255.255
First usable
253.0.0.1
Last usable
253.31.255.254
Usable hosts
2,097,150 (2,097,152 less the network and broadcast addresses)
Subnet mask
255.224.0.0
Wildcard mask
0.31.255.255 (Cisco ACLs, OSPF)
Prefix length
/11
Type
Reserved 240.0.0.0/4
Future use; not usable on most systems
Old class
E (reserved)
As numbers
Hex FD000000 · Integer 4244635648 to 4246732799
Reverse DNS zones
0.253.in-addr.arpa
1.253.in-addr.arpa
2.253.in-addr.arpa
3.253.in-addr.arpa
4.253.in-addr.arpa
5.253.in-addr.arpa
6.253.in-addr.arpa
7.253.in-addr.arpa
8.253.in-addr.arpa
9.253.in-addr.arpa
10.253.in-addr.arpa
11.253.in-addr.arpa
12.253.in-addr.arpa
13.253.in-addr.arpa
14.253.in-addr.arpa
15.253.in-addr.arpa
and 16 more
/11 is not on a 8-bit boundary, so it takes 32 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11111101.00000000.00000000.00000000253.0.0.0
Subnet mask11111111.11100000.00000000.00000000255.224.0.0
Network11111101.00000000.00000000.00000000253.0.0.0
Broadcast11111101.00011111.11111111.11111111253.31.255.255
Split into smaller subnets/23
/12 (2)/13 (4)/14 (8)/15 (16)/16 (32)/17 (64)/18 (128)/19 (256)/20 (512)/21 (1,024)/22 (2,048)/23 (4,096)

253.0.0.0/11 makes 4,096 subnets of /23; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1253.0.0.0/23253.0.0.1 to 253.0.1.254253.0.1.255510
2253.0.2.0/23253.0.2.1 to 253.0.3.254253.0.3.255510
3253.0.4.0/23253.0.4.1 to 253.0.5.254253.0.5.255510
4253.0.6.0/23253.0.6.1 to 253.0.7.254253.0.7.255510
5253.0.8.0/23253.0.8.1 to 253.0.9.254253.0.9.255510
6253.0.10.0/23253.0.10.1 to 253.0.11.254253.0.11.255510
7253.0.12.0/23253.0.12.1 to 253.0.13.254253.0.13.255510
8253.0.14.0/23253.0.14.1 to 253.0.15.254253.0.15.255510
9253.0.16.0/23253.0.16.1 to 253.0.17.254253.0.17.255510
10253.0.18.0/23253.0.18.1 to 253.0.19.254253.0.19.255510
11253.0.20.0/23253.0.20.1 to 253.0.21.254253.0.21.255510
12253.0.22.0/23253.0.22.1 to 253.0.23.254253.0.23.255510
13253.0.24.0/23253.0.24.1 to 253.0.25.254253.0.25.255510
14253.0.26.0/23253.0.26.1 to 253.0.27.254253.0.27.255510
15253.0.28.0/23253.0.28.1 to 253.0.29.254253.0.29.255510
16253.0.30.0/23253.0.30.1 to 253.0.31.254253.0.31.255510
17253.0.32.0/23253.0.32.1 to 253.0.33.254253.0.33.255510
18253.0.34.0/23253.0.34.1 to 253.0.35.254253.0.35.255510
19253.0.36.0/23253.0.36.1 to 253.0.37.254253.0.37.255510
20253.0.38.0/23253.0.38.1 to 253.0.39.254253.0.39.255510
21253.0.40.0/23253.0.40.1 to 253.0.41.254253.0.41.255510
22253.0.42.0/23253.0.42.1 to 253.0.43.254253.0.43.255510
23253.0.44.0/23253.0.44.1 to 253.0.45.254253.0.45.255510
24253.0.46.0/23253.0.46.1 to 253.0.47.254253.0.47.255510
25253.0.48.0/23253.0.48.1 to 253.0.49.254253.0.49.255510
26253.0.50.0/23253.0.50.1 to 253.0.51.254253.0.51.255510
27253.0.52.0/23253.0.52.1 to 253.0.53.254253.0.53.255510
28253.0.54.0/23253.0.54.1 to 253.0.55.254253.0.55.255510
29253.0.56.0/23253.0.56.1 to 253.0.57.254253.0.57.255510
30253.0.58.0/23253.0.58.1 to 253.0.59.254253.0.59.255510
31253.0.60.0/23253.0.60.1 to 253.0.61.254253.0.61.255510
32253.0.62.0/23253.0.62.1 to 253.0.63.254253.0.63.255510
33253.0.64.0/23253.0.64.1 to 253.0.65.254253.0.65.255510
34253.0.66.0/23253.0.66.1 to 253.0.67.254253.0.67.255510
35253.0.68.0/23253.0.68.1 to 253.0.69.254253.0.69.255510
36253.0.70.0/23253.0.70.1 to 253.0.71.254253.0.71.255510
37253.0.72.0/23253.0.72.1 to 253.0.73.254253.0.73.255510
38253.0.74.0/23253.0.74.1 to 253.0.75.254253.0.75.255510
39253.0.76.0/23253.0.76.1 to 253.0.77.254253.0.77.255510
40253.0.78.0/23253.0.78.1 to 253.0.79.254253.0.79.255510
41253.0.80.0/23253.0.80.1 to 253.0.81.254253.0.81.255510
42253.0.82.0/23253.0.82.1 to 253.0.83.254253.0.83.255510
43253.0.84.0/23253.0.84.1 to 253.0.85.254253.0.85.255510
44253.0.86.0/23253.0.86.1 to 253.0.87.254253.0.87.255510
45253.0.88.0/23253.0.88.1 to 253.0.89.254253.0.89.255510
46253.0.90.0/23253.0.90.1 to 253.0.91.254253.0.91.255510
47253.0.92.0/23253.0.92.1 to 253.0.93.254253.0.93.255510
48253.0.94.0/23253.0.94.1 to 253.0.95.254253.0.95.255510
49253.0.96.0/23253.0.96.1 to 253.0.97.254253.0.97.255510
50253.0.98.0/23253.0.98.1 to 253.0.99.254253.0.99.255510
51253.0.100.0/23253.0.100.1 to 253.0.101.254253.0.101.255510
52253.0.102.0/23253.0.102.1 to 253.0.103.254253.0.103.255510
53253.0.104.0/23253.0.104.1 to 253.0.105.254253.0.105.255510
54253.0.106.0/23253.0.106.1 to 253.0.107.254253.0.107.255510
55253.0.108.0/23253.0.108.1 to 253.0.109.254253.0.109.255510
56253.0.110.0/23253.0.110.1 to 253.0.111.254253.0.111.255510
57253.0.112.0/23253.0.112.1 to 253.0.113.254253.0.113.255510
58253.0.114.0/23253.0.114.1 to 253.0.115.254253.0.115.255510
59253.0.116.0/23253.0.116.1 to 253.0.117.254253.0.117.255510
60253.0.118.0/23253.0.118.1 to 253.0.119.254253.0.119.255510
61253.0.120.0/23253.0.120.1 to 253.0.121.254253.0.121.255510
62253.0.122.0/23253.0.122.1 to 253.0.123.254253.0.123.255510
63253.0.124.0/23253.0.124.1 to 253.0.125.254253.0.125.255510
64253.0.126.0/23253.0.126.1 to 253.0.127.254253.0.127.255510
65253.0.128.0/23253.0.128.1 to 253.0.129.254253.0.129.255510
66253.0.130.0/23253.0.130.1 to 253.0.131.254253.0.131.255510
67253.0.132.0/23253.0.132.1 to 253.0.133.254253.0.133.255510
68253.0.134.0/23253.0.134.1 to 253.0.135.254253.0.135.255510
69253.0.136.0/23253.0.136.1 to 253.0.137.254253.0.137.255510
70253.0.138.0/23253.0.138.1 to 253.0.139.254253.0.139.255510
71253.0.140.0/23253.0.140.1 to 253.0.141.254253.0.141.255510
72253.0.142.0/23253.0.142.1 to 253.0.143.254253.0.143.255510
73253.0.144.0/23253.0.144.1 to 253.0.145.254253.0.145.255510
74253.0.146.0/23253.0.146.1 to 253.0.147.254253.0.147.255510
75253.0.148.0/23253.0.148.1 to 253.0.149.254253.0.149.255510
76253.0.150.0/23253.0.150.1 to 253.0.151.254253.0.151.255510
77253.0.152.0/23253.0.152.1 to 253.0.153.254253.0.153.255510
78253.0.154.0/23253.0.154.1 to 253.0.155.254253.0.155.255510
79253.0.156.0/23253.0.156.1 to 253.0.157.254253.0.157.255510
80253.0.158.0/23253.0.158.1 to 253.0.159.254253.0.159.255510
81253.0.160.0/23253.0.160.1 to 253.0.161.254253.0.161.255510
82253.0.162.0/23253.0.162.1 to 253.0.163.254253.0.163.255510
83253.0.164.0/23253.0.164.1 to 253.0.165.254253.0.165.255510
84253.0.166.0/23253.0.166.1 to 253.0.167.254253.0.167.255510
85253.0.168.0/23253.0.168.1 to 253.0.169.254253.0.169.255510
86253.0.170.0/23253.0.170.1 to 253.0.171.254253.0.171.255510
87253.0.172.0/23253.0.172.1 to 253.0.173.254253.0.173.255510
88253.0.174.0/23253.0.174.1 to 253.0.175.254253.0.175.255510
89253.0.176.0/23253.0.176.1 to 253.0.177.254253.0.177.255510
90253.0.178.0/23253.0.178.1 to 253.0.179.254253.0.179.255510
91253.0.180.0/23253.0.180.1 to 253.0.181.254253.0.181.255510
92253.0.182.0/23253.0.182.1 to 253.0.183.254253.0.183.255510
93253.0.184.0/23253.0.184.1 to 253.0.185.254253.0.185.255510
94253.0.186.0/23253.0.186.1 to 253.0.187.254253.0.187.255510
95253.0.188.0/23253.0.188.1 to 253.0.189.254253.0.189.255510
96253.0.190.0/23253.0.190.1 to 253.0.191.254253.0.191.255510
97253.0.192.0/23253.0.192.1 to 253.0.193.254253.0.193.255510
98253.0.194.0/23253.0.194.1 to 253.0.195.254253.0.195.255510
99253.0.196.0/23253.0.196.1 to 253.0.197.254253.0.197.255510
100253.0.198.0/23253.0.198.1 to 253.0.199.254253.0.199.255510
101253.0.200.0/23253.0.200.1 to 253.0.201.254253.0.201.255510
102253.0.202.0/23253.0.202.1 to 253.0.203.254253.0.203.255510
103253.0.204.0/23253.0.204.1 to 253.0.205.254253.0.205.255510
104253.0.206.0/23253.0.206.1 to 253.0.207.254253.0.207.255510
105253.0.208.0/23253.0.208.1 to 253.0.209.254253.0.209.255510
106253.0.210.0/23253.0.210.1 to 253.0.211.254253.0.211.255510
107253.0.212.0/23253.0.212.1 to 253.0.213.254253.0.213.255510
108253.0.214.0/23253.0.214.1 to 253.0.215.254253.0.215.255510
109253.0.216.0/23253.0.216.1 to 253.0.217.254253.0.217.255510
110253.0.218.0/23253.0.218.1 to 253.0.219.254253.0.219.255510
111253.0.220.0/23253.0.220.1 to 253.0.221.254253.0.221.255510
112253.0.222.0/23253.0.222.1 to 253.0.223.254253.0.223.255510
113253.0.224.0/23253.0.224.1 to 253.0.225.254253.0.225.255510
114253.0.226.0/23253.0.226.1 to 253.0.227.254253.0.227.255510
115253.0.228.0/23253.0.228.1 to 253.0.229.254253.0.229.255510
116253.0.230.0/23253.0.230.1 to 253.0.231.254253.0.231.255510
117253.0.232.0/23253.0.232.1 to 253.0.233.254253.0.233.255510
118253.0.234.0/23253.0.234.1 to 253.0.235.254253.0.235.255510
119253.0.236.0/23253.0.236.1 to 253.0.237.254253.0.237.255510
120253.0.238.0/23253.0.238.1 to 253.0.239.254253.0.239.255510
121253.0.240.0/23253.0.240.1 to 253.0.241.254253.0.241.255510
122253.0.242.0/23253.0.242.1 to 253.0.243.254253.0.243.255510
123253.0.244.0/23253.0.244.1 to 253.0.245.254253.0.245.255510
124253.0.246.0/23253.0.246.1 to 253.0.247.254253.0.247.255510
125253.0.248.0/23253.0.248.1 to 253.0.249.254253.0.249.255510
126253.0.250.0/23253.0.250.1 to 253.0.251.254253.0.251.255510
127253.0.252.0/23253.0.252.1 to 253.0.253.254253.0.253.255510
128253.0.254.0/23253.0.254.1 to 253.0.255.254253.0.255.255510
129253.1.0.0/23253.1.0.1 to 253.1.1.254253.1.1.255510
130253.1.2.0/23253.1.2.1 to 253.1.3.254253.1.3.255510
131253.1.4.0/23253.1.4.1 to 253.1.5.254253.1.5.255510
132253.1.6.0/23253.1.6.1 to 253.1.7.254253.1.7.255510
133253.1.8.0/23253.1.8.1 to 253.1.9.254253.1.9.255510
134253.1.10.0/23253.1.10.1 to 253.1.11.254253.1.11.255510
135253.1.12.0/23253.1.12.1 to 253.1.13.254253.1.13.255510
136253.1.14.0/23253.1.14.1 to 253.1.15.254253.1.15.255510
137253.1.16.0/23253.1.16.1 to 253.1.17.254253.1.17.255510
138253.1.18.0/23253.1.18.1 to 253.1.19.254253.1.19.255510
139253.1.20.0/23253.1.20.1 to 253.1.21.254253.1.21.255510
140253.1.22.0/23253.1.22.1 to 253.1.23.254253.1.23.255510
141253.1.24.0/23253.1.24.1 to 253.1.25.254253.1.25.255510
142253.1.26.0/23253.1.26.1 to 253.1.27.254253.1.27.255510
143253.1.28.0/23253.1.28.1 to 253.1.29.254253.1.29.255510
144253.1.30.0/23253.1.30.1 to 253.1.31.254253.1.31.255510
145253.1.32.0/23253.1.32.1 to 253.1.33.254253.1.33.255510
146253.1.34.0/23253.1.34.1 to 253.1.35.254253.1.35.255510
147253.1.36.0/23253.1.36.1 to 253.1.37.254253.1.37.255510
148253.1.38.0/23253.1.38.1 to 253.1.39.254253.1.39.255510
149253.1.40.0/23253.1.40.1 to 253.1.41.254253.1.41.255510
150253.1.42.0/23253.1.42.1 to 253.1.43.254253.1.43.255510
151253.1.44.0/23253.1.44.1 to 253.1.45.254253.1.45.255510
152253.1.46.0/23253.1.46.1 to 253.1.47.254253.1.47.255510
153253.1.48.0/23253.1.48.1 to 253.1.49.254253.1.49.255510
154253.1.50.0/23253.1.50.1 to 253.1.51.254253.1.51.255510
155253.1.52.0/23253.1.52.1 to 253.1.53.254253.1.53.255510
156253.1.54.0/23253.1.54.1 to 253.1.55.254253.1.55.255510
157253.1.56.0/23253.1.56.1 to 253.1.57.254253.1.57.255510
158253.1.58.0/23253.1.58.1 to 253.1.59.254253.1.59.255510
159253.1.60.0/23253.1.60.1 to 253.1.61.254253.1.61.255510
160253.1.62.0/23253.1.62.1 to 253.1.63.254253.1.63.255510
161253.1.64.0/23253.1.64.1 to 253.1.65.254253.1.65.255510
162253.1.66.0/23253.1.66.1 to 253.1.67.254253.1.67.255510
163253.1.68.0/23253.1.68.1 to 253.1.69.254253.1.69.255510
164253.1.70.0/23253.1.70.1 to 253.1.71.254253.1.71.255510
165253.1.72.0/23253.1.72.1 to 253.1.73.254253.1.73.255510
166253.1.74.0/23253.1.74.1 to 253.1.75.254253.1.75.255510
167253.1.76.0/23253.1.76.1 to 253.1.77.254253.1.77.255510
168253.1.78.0/23253.1.78.1 to 253.1.79.254253.1.79.255510
169253.1.80.0/23253.1.80.1 to 253.1.81.254253.1.81.255510
170253.1.82.0/23253.1.82.1 to 253.1.83.254253.1.83.255510
171253.1.84.0/23253.1.84.1 to 253.1.85.254253.1.85.255510
172253.1.86.0/23253.1.86.1 to 253.1.87.254253.1.87.255510
173253.1.88.0/23253.1.88.1 to 253.1.89.254253.1.89.255510
174253.1.90.0/23253.1.90.1 to 253.1.91.254253.1.91.255510
175253.1.92.0/23253.1.92.1 to 253.1.93.254253.1.93.255510
176253.1.94.0/23253.1.94.1 to 253.1.95.254253.1.95.255510
177253.1.96.0/23253.1.96.1 to 253.1.97.254253.1.97.255510
178253.1.98.0/23253.1.98.1 to 253.1.99.254253.1.99.255510
179253.1.100.0/23253.1.100.1 to 253.1.101.254253.1.101.255510
180253.1.102.0/23253.1.102.1 to 253.1.103.254253.1.103.255510
181253.1.104.0/23253.1.104.1 to 253.1.105.254253.1.105.255510
182253.1.106.0/23253.1.106.1 to 253.1.107.254253.1.107.255510
183253.1.108.0/23253.1.108.1 to 253.1.109.254253.1.109.255510
184253.1.110.0/23253.1.110.1 to 253.1.111.254253.1.111.255510
185253.1.112.0/23253.1.112.1 to 253.1.113.254253.1.113.255510
186253.1.114.0/23253.1.114.1 to 253.1.115.254253.1.115.255510
187253.1.116.0/23253.1.116.1 to 253.1.117.254253.1.117.255510
188253.1.118.0/23253.1.118.1 to 253.1.119.254253.1.119.255510
189253.1.120.0/23253.1.120.1 to 253.1.121.254253.1.121.255510
190253.1.122.0/23253.1.122.1 to 253.1.123.254253.1.123.255510
191253.1.124.0/23253.1.124.1 to 253.1.125.254253.1.125.255510
192253.1.126.0/23253.1.126.1 to 253.1.127.254253.1.127.255510
193253.1.128.0/23253.1.128.1 to 253.1.129.254253.1.129.255510
194253.1.130.0/23253.1.130.1 to 253.1.131.254253.1.131.255510
195253.1.132.0/23253.1.132.1 to 253.1.133.254253.1.133.255510
196253.1.134.0/23253.1.134.1 to 253.1.135.254253.1.135.255510
197253.1.136.0/23253.1.136.1 to 253.1.137.254253.1.137.255510
198253.1.138.0/23253.1.138.1 to 253.1.139.254253.1.139.255510
199253.1.140.0/23253.1.140.1 to 253.1.141.254253.1.141.255510
200253.1.142.0/23253.1.142.1 to 253.1.143.254253.1.143.255510
201253.1.144.0/23253.1.144.1 to 253.1.145.254253.1.145.255510
202253.1.146.0/23253.1.146.1 to 253.1.147.254253.1.147.255510
203253.1.148.0/23253.1.148.1 to 253.1.149.254253.1.149.255510
204253.1.150.0/23253.1.150.1 to 253.1.151.254253.1.151.255510
205253.1.152.0/23253.1.152.1 to 253.1.153.254253.1.153.255510
206253.1.154.0/23253.1.154.1 to 253.1.155.254253.1.155.255510
207253.1.156.0/23253.1.156.1 to 253.1.157.254253.1.157.255510
208253.1.158.0/23253.1.158.1 to 253.1.159.254253.1.159.255510
209253.1.160.0/23253.1.160.1 to 253.1.161.254253.1.161.255510
210253.1.162.0/23253.1.162.1 to 253.1.163.254253.1.163.255510
211253.1.164.0/23253.1.164.1 to 253.1.165.254253.1.165.255510
212253.1.166.0/23253.1.166.1 to 253.1.167.254253.1.167.255510
213253.1.168.0/23253.1.168.1 to 253.1.169.254253.1.169.255510
214253.1.170.0/23253.1.170.1 to 253.1.171.254253.1.171.255510
215253.1.172.0/23253.1.172.1 to 253.1.173.254253.1.173.255510
216253.1.174.0/23253.1.174.1 to 253.1.175.254253.1.175.255510
217253.1.176.0/23253.1.176.1 to 253.1.177.254253.1.177.255510
218253.1.178.0/23253.1.178.1 to 253.1.179.254253.1.179.255510
219253.1.180.0/23253.1.180.1 to 253.1.181.254253.1.181.255510
220253.1.182.0/23253.1.182.1 to 253.1.183.254253.1.183.255510
221253.1.184.0/23253.1.184.1 to 253.1.185.254253.1.185.255510
222253.1.186.0/23253.1.186.1 to 253.1.187.254253.1.187.255510
223253.1.188.0/23253.1.188.1 to 253.1.189.254253.1.189.255510
224253.1.190.0/23253.1.190.1 to 253.1.191.254253.1.191.255510
225253.1.192.0/23253.1.192.1 to 253.1.193.254253.1.193.255510
226253.1.194.0/23253.1.194.1 to 253.1.195.254253.1.195.255510
227253.1.196.0/23253.1.196.1 to 253.1.197.254253.1.197.255510
228253.1.198.0/23253.1.198.1 to 253.1.199.254253.1.199.255510
229253.1.200.0/23253.1.200.1 to 253.1.201.254253.1.201.255510
230253.1.202.0/23253.1.202.1 to 253.1.203.254253.1.203.255510
231253.1.204.0/23253.1.204.1 to 253.1.205.254253.1.205.255510
232253.1.206.0/23253.1.206.1 to 253.1.207.254253.1.207.255510
233253.1.208.0/23253.1.208.1 to 253.1.209.254253.1.209.255510
234253.1.210.0/23253.1.210.1 to 253.1.211.254253.1.211.255510
235253.1.212.0/23253.1.212.1 to 253.1.213.254253.1.213.255510
236253.1.214.0/23253.1.214.1 to 253.1.215.254253.1.215.255510
237253.1.216.0/23253.1.216.1 to 253.1.217.254253.1.217.255510
238253.1.218.0/23253.1.218.1 to 253.1.219.254253.1.219.255510
239253.1.220.0/23253.1.220.1 to 253.1.221.254253.1.221.255510
240253.1.222.0/23253.1.222.1 to 253.1.223.254253.1.223.255510
241253.1.224.0/23253.1.224.1 to 253.1.225.254253.1.225.255510
242253.1.226.0/23253.1.226.1 to 253.1.227.254253.1.227.255510
243253.1.228.0/23253.1.228.1 to 253.1.229.254253.1.229.255510
244253.1.230.0/23253.1.230.1 to 253.1.231.254253.1.231.255510
245253.1.232.0/23253.1.232.1 to 253.1.233.254253.1.233.255510
246253.1.234.0/23253.1.234.1 to 253.1.235.254253.1.235.255510
247253.1.236.0/23253.1.236.1 to 253.1.237.254253.1.237.255510
248253.1.238.0/23253.1.238.1 to 253.1.239.254253.1.239.255510
249253.1.240.0/23253.1.240.1 to 253.1.241.254253.1.241.255510
250253.1.242.0/23253.1.242.1 to 253.1.243.254253.1.243.255510
251253.1.244.0/23253.1.244.1 to 253.1.245.254253.1.245.255510
252253.1.246.0/23253.1.246.1 to 253.1.247.254253.1.247.255510
253253.1.248.0/23253.1.248.1 to 253.1.249.254253.1.249.255510
254253.1.250.0/23253.1.250.1 to 253.1.251.254253.1.251.255510
255253.1.252.0/23253.1.252.1 to 253.1.253.254253.1.253.255510
256253.1.254.0/23253.1.254.1 to 253.1.255.254253.1.255.255510

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.