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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.

Network110.72.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
110.72.0.0
Broadcast address
110.73.255.255
First usable
110.72.0.1
Last usable
110.73.255.254
Usable hosts
131,070 (131,072 less the network and broadcast addresses)
Subnet mask
255.254.0.0
Wildcard mask
0.1.255.255 (Cisco ACLs, OSPF)
Prefix length
/15
Type
Public public
Old class
A (default /8)
As numbers
Hex 6E480000 · Integer 1850212352 to 1850343423
Reverse DNS zones
72.110.in-addr.arpa
73.110.in-addr.arpa
/15 is not on a 8-bit boundary, so it takes 2 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01101110.01001000.00000000.00000000110.72.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network01101110.01001000.00000000.00000000110.72.0.0
Broadcast01101110.01001001.11111111.11111111110.73.255.255
Split into smaller subnets/23
/16 (2)/17 (4)/18 (8)/19 (16)/20 (32)/21 (64)/22 (128)/23 (256)/24 (512)/25 (1,024)/26 (2,048)/27 (4,096)

110.72.0.0/15 makes 256 subnets of /23.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1110.72.0.0/23110.72.0.1 to 110.72.1.254110.72.1.255510
2110.72.2.0/23110.72.2.1 to 110.72.3.254110.72.3.255510
3110.72.4.0/23110.72.4.1 to 110.72.5.254110.72.5.255510
4110.72.6.0/23110.72.6.1 to 110.72.7.254110.72.7.255510
5110.72.8.0/23110.72.8.1 to 110.72.9.254110.72.9.255510
6110.72.10.0/23110.72.10.1 to 110.72.11.254110.72.11.255510
7110.72.12.0/23110.72.12.1 to 110.72.13.254110.72.13.255510
8110.72.14.0/23110.72.14.1 to 110.72.15.254110.72.15.255510
9110.72.16.0/23110.72.16.1 to 110.72.17.254110.72.17.255510
10110.72.18.0/23110.72.18.1 to 110.72.19.254110.72.19.255510
11110.72.20.0/23110.72.20.1 to 110.72.21.254110.72.21.255510
12110.72.22.0/23110.72.22.1 to 110.72.23.254110.72.23.255510
13110.72.24.0/23110.72.24.1 to 110.72.25.254110.72.25.255510
14110.72.26.0/23110.72.26.1 to 110.72.27.254110.72.27.255510
15110.72.28.0/23110.72.28.1 to 110.72.29.254110.72.29.255510
16110.72.30.0/23110.72.30.1 to 110.72.31.254110.72.31.255510
17110.72.32.0/23110.72.32.1 to 110.72.33.254110.72.33.255510
18110.72.34.0/23110.72.34.1 to 110.72.35.254110.72.35.255510
19110.72.36.0/23110.72.36.1 to 110.72.37.254110.72.37.255510
20110.72.38.0/23110.72.38.1 to 110.72.39.254110.72.39.255510
21110.72.40.0/23110.72.40.1 to 110.72.41.254110.72.41.255510
22110.72.42.0/23110.72.42.1 to 110.72.43.254110.72.43.255510
23110.72.44.0/23110.72.44.1 to 110.72.45.254110.72.45.255510
24110.72.46.0/23110.72.46.1 to 110.72.47.254110.72.47.255510
25110.72.48.0/23110.72.48.1 to 110.72.49.254110.72.49.255510
26110.72.50.0/23110.72.50.1 to 110.72.51.254110.72.51.255510
27110.72.52.0/23110.72.52.1 to 110.72.53.254110.72.53.255510
28110.72.54.0/23110.72.54.1 to 110.72.55.254110.72.55.255510
29110.72.56.0/23110.72.56.1 to 110.72.57.254110.72.57.255510
30110.72.58.0/23110.72.58.1 to 110.72.59.254110.72.59.255510
31110.72.60.0/23110.72.60.1 to 110.72.61.254110.72.61.255510
32110.72.62.0/23110.72.62.1 to 110.72.63.254110.72.63.255510
33110.72.64.0/23110.72.64.1 to 110.72.65.254110.72.65.255510
34110.72.66.0/23110.72.66.1 to 110.72.67.254110.72.67.255510
35110.72.68.0/23110.72.68.1 to 110.72.69.254110.72.69.255510
36110.72.70.0/23110.72.70.1 to 110.72.71.254110.72.71.255510
37110.72.72.0/23110.72.72.1 to 110.72.73.254110.72.73.255510
38110.72.74.0/23110.72.74.1 to 110.72.75.254110.72.75.255510
39110.72.76.0/23110.72.76.1 to 110.72.77.254110.72.77.255510
40110.72.78.0/23110.72.78.1 to 110.72.79.254110.72.79.255510
41110.72.80.0/23110.72.80.1 to 110.72.81.254110.72.81.255510
42110.72.82.0/23110.72.82.1 to 110.72.83.254110.72.83.255510
43110.72.84.0/23110.72.84.1 to 110.72.85.254110.72.85.255510
44110.72.86.0/23110.72.86.1 to 110.72.87.254110.72.87.255510
45110.72.88.0/23110.72.88.1 to 110.72.89.254110.72.89.255510
46110.72.90.0/23110.72.90.1 to 110.72.91.254110.72.91.255510
47110.72.92.0/23110.72.92.1 to 110.72.93.254110.72.93.255510
48110.72.94.0/23110.72.94.1 to 110.72.95.254110.72.95.255510
49110.72.96.0/23110.72.96.1 to 110.72.97.254110.72.97.255510
50110.72.98.0/23110.72.98.1 to 110.72.99.254110.72.99.255510
51110.72.100.0/23110.72.100.1 to 110.72.101.254110.72.101.255510
52110.72.102.0/23110.72.102.1 to 110.72.103.254110.72.103.255510
53110.72.104.0/23110.72.104.1 to 110.72.105.254110.72.105.255510
54110.72.106.0/23110.72.106.1 to 110.72.107.254110.72.107.255510
55110.72.108.0/23110.72.108.1 to 110.72.109.254110.72.109.255510
56110.72.110.0/23110.72.110.1 to 110.72.111.254110.72.111.255510
57110.72.112.0/23110.72.112.1 to 110.72.113.254110.72.113.255510
58110.72.114.0/23110.72.114.1 to 110.72.115.254110.72.115.255510
59110.72.116.0/23110.72.116.1 to 110.72.117.254110.72.117.255510
60110.72.118.0/23110.72.118.1 to 110.72.119.254110.72.119.255510
61110.72.120.0/23110.72.120.1 to 110.72.121.254110.72.121.255510
62110.72.122.0/23110.72.122.1 to 110.72.123.254110.72.123.255510
63110.72.124.0/23110.72.124.1 to 110.72.125.254110.72.125.255510
64110.72.126.0/23110.72.126.1 to 110.72.127.254110.72.127.255510
65110.72.128.0/23110.72.128.1 to 110.72.129.254110.72.129.255510
66110.72.130.0/23110.72.130.1 to 110.72.131.254110.72.131.255510
67110.72.132.0/23110.72.132.1 to 110.72.133.254110.72.133.255510
68110.72.134.0/23110.72.134.1 to 110.72.135.254110.72.135.255510
69110.72.136.0/23110.72.136.1 to 110.72.137.254110.72.137.255510
70110.72.138.0/23110.72.138.1 to 110.72.139.254110.72.139.255510
71110.72.140.0/23110.72.140.1 to 110.72.141.254110.72.141.255510
72110.72.142.0/23110.72.142.1 to 110.72.143.254110.72.143.255510
73110.72.144.0/23110.72.144.1 to 110.72.145.254110.72.145.255510
74110.72.146.0/23110.72.146.1 to 110.72.147.254110.72.147.255510
75110.72.148.0/23110.72.148.1 to 110.72.149.254110.72.149.255510
76110.72.150.0/23110.72.150.1 to 110.72.151.254110.72.151.255510
77110.72.152.0/23110.72.152.1 to 110.72.153.254110.72.153.255510
78110.72.154.0/23110.72.154.1 to 110.72.155.254110.72.155.255510
79110.72.156.0/23110.72.156.1 to 110.72.157.254110.72.157.255510
80110.72.158.0/23110.72.158.1 to 110.72.159.254110.72.159.255510
81110.72.160.0/23110.72.160.1 to 110.72.161.254110.72.161.255510
82110.72.162.0/23110.72.162.1 to 110.72.163.254110.72.163.255510
83110.72.164.0/23110.72.164.1 to 110.72.165.254110.72.165.255510
84110.72.166.0/23110.72.166.1 to 110.72.167.254110.72.167.255510
85110.72.168.0/23110.72.168.1 to 110.72.169.254110.72.169.255510
86110.72.170.0/23110.72.170.1 to 110.72.171.254110.72.171.255510
87110.72.172.0/23110.72.172.1 to 110.72.173.254110.72.173.255510
88110.72.174.0/23110.72.174.1 to 110.72.175.254110.72.175.255510
89110.72.176.0/23110.72.176.1 to 110.72.177.254110.72.177.255510
90110.72.178.0/23110.72.178.1 to 110.72.179.254110.72.179.255510
91110.72.180.0/23110.72.180.1 to 110.72.181.254110.72.181.255510
92110.72.182.0/23110.72.182.1 to 110.72.183.254110.72.183.255510
93110.72.184.0/23110.72.184.1 to 110.72.185.254110.72.185.255510
94110.72.186.0/23110.72.186.1 to 110.72.187.254110.72.187.255510
95110.72.188.0/23110.72.188.1 to 110.72.189.254110.72.189.255510
96110.72.190.0/23110.72.190.1 to 110.72.191.254110.72.191.255510
97110.72.192.0/23110.72.192.1 to 110.72.193.254110.72.193.255510
98110.72.194.0/23110.72.194.1 to 110.72.195.254110.72.195.255510
99110.72.196.0/23110.72.196.1 to 110.72.197.254110.72.197.255510
100110.72.198.0/23110.72.198.1 to 110.72.199.254110.72.199.255510
101110.72.200.0/23110.72.200.1 to 110.72.201.254110.72.201.255510
102110.72.202.0/23110.72.202.1 to 110.72.203.254110.72.203.255510
103110.72.204.0/23110.72.204.1 to 110.72.205.254110.72.205.255510
104110.72.206.0/23110.72.206.1 to 110.72.207.254110.72.207.255510
105110.72.208.0/23110.72.208.1 to 110.72.209.254110.72.209.255510
106110.72.210.0/23110.72.210.1 to 110.72.211.254110.72.211.255510
107110.72.212.0/23110.72.212.1 to 110.72.213.254110.72.213.255510
108110.72.214.0/23110.72.214.1 to 110.72.215.254110.72.215.255510
109110.72.216.0/23110.72.216.1 to 110.72.217.254110.72.217.255510
110110.72.218.0/23110.72.218.1 to 110.72.219.254110.72.219.255510
111110.72.220.0/23110.72.220.1 to 110.72.221.254110.72.221.255510
112110.72.222.0/23110.72.222.1 to 110.72.223.254110.72.223.255510
113110.72.224.0/23110.72.224.1 to 110.72.225.254110.72.225.255510
114110.72.226.0/23110.72.226.1 to 110.72.227.254110.72.227.255510
115110.72.228.0/23110.72.228.1 to 110.72.229.254110.72.229.255510
116110.72.230.0/23110.72.230.1 to 110.72.231.254110.72.231.255510
117110.72.232.0/23110.72.232.1 to 110.72.233.254110.72.233.255510
118110.72.234.0/23110.72.234.1 to 110.72.235.254110.72.235.255510
119110.72.236.0/23110.72.236.1 to 110.72.237.254110.72.237.255510
120110.72.238.0/23110.72.238.1 to 110.72.239.254110.72.239.255510
121110.72.240.0/23110.72.240.1 to 110.72.241.254110.72.241.255510
122110.72.242.0/23110.72.242.1 to 110.72.243.254110.72.243.255510
123110.72.244.0/23110.72.244.1 to 110.72.245.254110.72.245.255510
124110.72.246.0/23110.72.246.1 to 110.72.247.254110.72.247.255510
125110.72.248.0/23110.72.248.1 to 110.72.249.254110.72.249.255510
126110.72.250.0/23110.72.250.1 to 110.72.251.254110.72.251.255510
127110.72.252.0/23110.72.252.1 to 110.72.253.254110.72.253.255510
128110.72.254.0/23110.72.254.1 to 110.72.255.254110.72.255.255510
129110.73.0.0/23110.73.0.1 to 110.73.1.254110.73.1.255510
130110.73.2.0/23110.73.2.1 to 110.73.3.254110.73.3.255510
131110.73.4.0/23110.73.4.1 to 110.73.5.254110.73.5.255510
132110.73.6.0/23110.73.6.1 to 110.73.7.254110.73.7.255510
133110.73.8.0/23110.73.8.1 to 110.73.9.254110.73.9.255510
134110.73.10.0/23110.73.10.1 to 110.73.11.254110.73.11.255510
135110.73.12.0/23110.73.12.1 to 110.73.13.254110.73.13.255510
136110.73.14.0/23110.73.14.1 to 110.73.15.254110.73.15.255510
137110.73.16.0/23110.73.16.1 to 110.73.17.254110.73.17.255510
138110.73.18.0/23110.73.18.1 to 110.73.19.254110.73.19.255510
139110.73.20.0/23110.73.20.1 to 110.73.21.254110.73.21.255510
140110.73.22.0/23110.73.22.1 to 110.73.23.254110.73.23.255510
141110.73.24.0/23110.73.24.1 to 110.73.25.254110.73.25.255510
142110.73.26.0/23110.73.26.1 to 110.73.27.254110.73.27.255510
143110.73.28.0/23110.73.28.1 to 110.73.29.254110.73.29.255510
144110.73.30.0/23110.73.30.1 to 110.73.31.254110.73.31.255510
145110.73.32.0/23110.73.32.1 to 110.73.33.254110.73.33.255510
146110.73.34.0/23110.73.34.1 to 110.73.35.254110.73.35.255510
147110.73.36.0/23110.73.36.1 to 110.73.37.254110.73.37.255510
148110.73.38.0/23110.73.38.1 to 110.73.39.254110.73.39.255510
149110.73.40.0/23110.73.40.1 to 110.73.41.254110.73.41.255510
150110.73.42.0/23110.73.42.1 to 110.73.43.254110.73.43.255510
151110.73.44.0/23110.73.44.1 to 110.73.45.254110.73.45.255510
152110.73.46.0/23110.73.46.1 to 110.73.47.254110.73.47.255510
153110.73.48.0/23110.73.48.1 to 110.73.49.254110.73.49.255510
154110.73.50.0/23110.73.50.1 to 110.73.51.254110.73.51.255510
155110.73.52.0/23110.73.52.1 to 110.73.53.254110.73.53.255510
156110.73.54.0/23110.73.54.1 to 110.73.55.254110.73.55.255510
157110.73.56.0/23110.73.56.1 to 110.73.57.254110.73.57.255510
158110.73.58.0/23110.73.58.1 to 110.73.59.254110.73.59.255510
159110.73.60.0/23110.73.60.1 to 110.73.61.254110.73.61.255510
160110.73.62.0/23110.73.62.1 to 110.73.63.254110.73.63.255510
161110.73.64.0/23110.73.64.1 to 110.73.65.254110.73.65.255510
162110.73.66.0/23110.73.66.1 to 110.73.67.254110.73.67.255510
163110.73.68.0/23110.73.68.1 to 110.73.69.254110.73.69.255510
164110.73.70.0/23110.73.70.1 to 110.73.71.254110.73.71.255510
165110.73.72.0/23110.73.72.1 to 110.73.73.254110.73.73.255510
166110.73.74.0/23110.73.74.1 to 110.73.75.254110.73.75.255510
167110.73.76.0/23110.73.76.1 to 110.73.77.254110.73.77.255510
168110.73.78.0/23110.73.78.1 to 110.73.79.254110.73.79.255510
169110.73.80.0/23110.73.80.1 to 110.73.81.254110.73.81.255510
170110.73.82.0/23110.73.82.1 to 110.73.83.254110.73.83.255510
171110.73.84.0/23110.73.84.1 to 110.73.85.254110.73.85.255510
172110.73.86.0/23110.73.86.1 to 110.73.87.254110.73.87.255510
173110.73.88.0/23110.73.88.1 to 110.73.89.254110.73.89.255510
174110.73.90.0/23110.73.90.1 to 110.73.91.254110.73.91.255510
175110.73.92.0/23110.73.92.1 to 110.73.93.254110.73.93.255510
176110.73.94.0/23110.73.94.1 to 110.73.95.254110.73.95.255510
177110.73.96.0/23110.73.96.1 to 110.73.97.254110.73.97.255510
178110.73.98.0/23110.73.98.1 to 110.73.99.254110.73.99.255510
179110.73.100.0/23110.73.100.1 to 110.73.101.254110.73.101.255510
180110.73.102.0/23110.73.102.1 to 110.73.103.254110.73.103.255510
181110.73.104.0/23110.73.104.1 to 110.73.105.254110.73.105.255510
182110.73.106.0/23110.73.106.1 to 110.73.107.254110.73.107.255510
183110.73.108.0/23110.73.108.1 to 110.73.109.254110.73.109.255510
184110.73.110.0/23110.73.110.1 to 110.73.111.254110.73.111.255510
185110.73.112.0/23110.73.112.1 to 110.73.113.254110.73.113.255510
186110.73.114.0/23110.73.114.1 to 110.73.115.254110.73.115.255510
187110.73.116.0/23110.73.116.1 to 110.73.117.254110.73.117.255510
188110.73.118.0/23110.73.118.1 to 110.73.119.254110.73.119.255510
189110.73.120.0/23110.73.120.1 to 110.73.121.254110.73.121.255510
190110.73.122.0/23110.73.122.1 to 110.73.123.254110.73.123.255510
191110.73.124.0/23110.73.124.1 to 110.73.125.254110.73.125.255510
192110.73.126.0/23110.73.126.1 to 110.73.127.254110.73.127.255510
193110.73.128.0/23110.73.128.1 to 110.73.129.254110.73.129.255510
194110.73.130.0/23110.73.130.1 to 110.73.131.254110.73.131.255510
195110.73.132.0/23110.73.132.1 to 110.73.133.254110.73.133.255510
196110.73.134.0/23110.73.134.1 to 110.73.135.254110.73.135.255510
197110.73.136.0/23110.73.136.1 to 110.73.137.254110.73.137.255510
198110.73.138.0/23110.73.138.1 to 110.73.139.254110.73.139.255510
199110.73.140.0/23110.73.140.1 to 110.73.141.254110.73.141.255510
200110.73.142.0/23110.73.142.1 to 110.73.143.254110.73.143.255510
201110.73.144.0/23110.73.144.1 to 110.73.145.254110.73.145.255510
202110.73.146.0/23110.73.146.1 to 110.73.147.254110.73.147.255510
203110.73.148.0/23110.73.148.1 to 110.73.149.254110.73.149.255510
204110.73.150.0/23110.73.150.1 to 110.73.151.254110.73.151.255510
205110.73.152.0/23110.73.152.1 to 110.73.153.254110.73.153.255510
206110.73.154.0/23110.73.154.1 to 110.73.155.254110.73.155.255510
207110.73.156.0/23110.73.156.1 to 110.73.157.254110.73.157.255510
208110.73.158.0/23110.73.158.1 to 110.73.159.254110.73.159.255510
209110.73.160.0/23110.73.160.1 to 110.73.161.254110.73.161.255510
210110.73.162.0/23110.73.162.1 to 110.73.163.254110.73.163.255510
211110.73.164.0/23110.73.164.1 to 110.73.165.254110.73.165.255510
212110.73.166.0/23110.73.166.1 to 110.73.167.254110.73.167.255510
213110.73.168.0/23110.73.168.1 to 110.73.169.254110.73.169.255510
214110.73.170.0/23110.73.170.1 to 110.73.171.254110.73.171.255510
215110.73.172.0/23110.73.172.1 to 110.73.173.254110.73.173.255510
216110.73.174.0/23110.73.174.1 to 110.73.175.254110.73.175.255510
217110.73.176.0/23110.73.176.1 to 110.73.177.254110.73.177.255510
218110.73.178.0/23110.73.178.1 to 110.73.179.254110.73.179.255510
219110.73.180.0/23110.73.180.1 to 110.73.181.254110.73.181.255510
220110.73.182.0/23110.73.182.1 to 110.73.183.254110.73.183.255510
221110.73.184.0/23110.73.184.1 to 110.73.185.254110.73.185.255510
222110.73.186.0/23110.73.186.1 to 110.73.187.254110.73.187.255510
223110.73.188.0/23110.73.188.1 to 110.73.189.254110.73.189.255510
224110.73.190.0/23110.73.190.1 to 110.73.191.254110.73.191.255510
225110.73.192.0/23110.73.192.1 to 110.73.193.254110.73.193.255510
226110.73.194.0/23110.73.194.1 to 110.73.195.254110.73.195.255510
227110.73.196.0/23110.73.196.1 to 110.73.197.254110.73.197.255510
228110.73.198.0/23110.73.198.1 to 110.73.199.254110.73.199.255510
229110.73.200.0/23110.73.200.1 to 110.73.201.254110.73.201.255510
230110.73.202.0/23110.73.202.1 to 110.73.203.254110.73.203.255510
231110.73.204.0/23110.73.204.1 to 110.73.205.254110.73.205.255510
232110.73.206.0/23110.73.206.1 to 110.73.207.254110.73.207.255510
233110.73.208.0/23110.73.208.1 to 110.73.209.254110.73.209.255510
234110.73.210.0/23110.73.210.1 to 110.73.211.254110.73.211.255510
235110.73.212.0/23110.73.212.1 to 110.73.213.254110.73.213.255510
236110.73.214.0/23110.73.214.1 to 110.73.215.254110.73.215.255510
237110.73.216.0/23110.73.216.1 to 110.73.217.254110.73.217.255510
238110.73.218.0/23110.73.218.1 to 110.73.219.254110.73.219.255510
239110.73.220.0/23110.73.220.1 to 110.73.221.254110.73.221.255510
240110.73.222.0/23110.73.222.1 to 110.73.223.254110.73.223.255510
241110.73.224.0/23110.73.224.1 to 110.73.225.254110.73.225.255510
242110.73.226.0/23110.73.226.1 to 110.73.227.254110.73.227.255510
243110.73.228.0/23110.73.228.1 to 110.73.229.254110.73.229.255510
244110.73.230.0/23110.73.230.1 to 110.73.231.254110.73.231.255510
245110.73.232.0/23110.73.232.1 to 110.73.233.254110.73.233.255510
246110.73.234.0/23110.73.234.1 to 110.73.235.254110.73.235.255510
247110.73.236.0/23110.73.236.1 to 110.73.237.254110.73.237.255510
248110.73.238.0/23110.73.238.1 to 110.73.239.254110.73.239.255510
249110.73.240.0/23110.73.240.1 to 110.73.241.254110.73.241.255510
250110.73.242.0/23110.73.242.1 to 110.73.243.254110.73.243.255510
251110.73.244.0/23110.73.244.1 to 110.73.245.254110.73.245.255510
252110.73.246.0/23110.73.246.1 to 110.73.247.254110.73.247.255510
253110.73.248.0/23110.73.248.1 to 110.73.249.254110.73.249.255510
254110.73.250.0/23110.73.250.1 to 110.73.251.254110.73.251.255510
255110.73.252.0/23110.73.252.1 to 110.73.253.254110.73.253.255510
256110.73.254.0/23110.73.254.1 to 110.73.255.254110.73.255.255510

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.