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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.

Network244.96.0.0/12
Usable hosts1,048,574
Subnet mask255.240.0.0
Addresses1,048,576
Network address
244.96.0.0
Broadcast address
244.111.255.255
First usable
244.96.0.1
Last usable
244.111.255.254
Usable hosts
1,048,574 (1,048,576 less the network and broadcast addresses)
Subnet mask
255.240.0.0
Wildcard mask
0.15.255.255 (Cisco ACLs, OSPF)
Prefix length
/12
Type
Reserved 240.0.0.0/4
Future use; not usable on most systems
Old class
E (reserved)
As numbers
Hex F4600000 · Integer 4099932160 to 4100980735
Reverse DNS zones
96.244.in-addr.arpa
97.244.in-addr.arpa
98.244.in-addr.arpa
99.244.in-addr.arpa
100.244.in-addr.arpa
101.244.in-addr.arpa
102.244.in-addr.arpa
103.244.in-addr.arpa
104.244.in-addr.arpa
105.244.in-addr.arpa
106.244.in-addr.arpa
107.244.in-addr.arpa
108.244.in-addr.arpa
109.244.in-addr.arpa
110.244.in-addr.arpa
111.244.in-addr.arpa
/12 is not on a 8-bit boundary, so it takes 16 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11110100.01100000.00000000.00000000244.96.0.0
Subnet mask11111111.11110000.00000000.00000000255.240.0.0
Network11110100.01100000.00000000.00000000244.96.0.0
Broadcast11110100.01101111.11111111.11111111244.111.255.255
Split into smaller subnets/23
/13 (2)/14 (4)/15 (8)/16 (16)/17 (32)/18 (64)/19 (128)/20 (256)/21 (512)/22 (1,024)/23 (2,048)/24 (4,096)

244.96.0.0/12 makes 2,048 subnets of /23; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1244.96.0.0/23244.96.0.1 to 244.96.1.254244.96.1.255510
2244.96.2.0/23244.96.2.1 to 244.96.3.254244.96.3.255510
3244.96.4.0/23244.96.4.1 to 244.96.5.254244.96.5.255510
4244.96.6.0/23244.96.6.1 to 244.96.7.254244.96.7.255510
5244.96.8.0/23244.96.8.1 to 244.96.9.254244.96.9.255510
6244.96.10.0/23244.96.10.1 to 244.96.11.254244.96.11.255510
7244.96.12.0/23244.96.12.1 to 244.96.13.254244.96.13.255510
8244.96.14.0/23244.96.14.1 to 244.96.15.254244.96.15.255510
9244.96.16.0/23244.96.16.1 to 244.96.17.254244.96.17.255510
10244.96.18.0/23244.96.18.1 to 244.96.19.254244.96.19.255510
11244.96.20.0/23244.96.20.1 to 244.96.21.254244.96.21.255510
12244.96.22.0/23244.96.22.1 to 244.96.23.254244.96.23.255510
13244.96.24.0/23244.96.24.1 to 244.96.25.254244.96.25.255510
14244.96.26.0/23244.96.26.1 to 244.96.27.254244.96.27.255510
15244.96.28.0/23244.96.28.1 to 244.96.29.254244.96.29.255510
16244.96.30.0/23244.96.30.1 to 244.96.31.254244.96.31.255510
17244.96.32.0/23244.96.32.1 to 244.96.33.254244.96.33.255510
18244.96.34.0/23244.96.34.1 to 244.96.35.254244.96.35.255510
19244.96.36.0/23244.96.36.1 to 244.96.37.254244.96.37.255510
20244.96.38.0/23244.96.38.1 to 244.96.39.254244.96.39.255510
21244.96.40.0/23244.96.40.1 to 244.96.41.254244.96.41.255510
22244.96.42.0/23244.96.42.1 to 244.96.43.254244.96.43.255510
23244.96.44.0/23244.96.44.1 to 244.96.45.254244.96.45.255510
24244.96.46.0/23244.96.46.1 to 244.96.47.254244.96.47.255510
25244.96.48.0/23244.96.48.1 to 244.96.49.254244.96.49.255510
26244.96.50.0/23244.96.50.1 to 244.96.51.254244.96.51.255510
27244.96.52.0/23244.96.52.1 to 244.96.53.254244.96.53.255510
28244.96.54.0/23244.96.54.1 to 244.96.55.254244.96.55.255510
29244.96.56.0/23244.96.56.1 to 244.96.57.254244.96.57.255510
30244.96.58.0/23244.96.58.1 to 244.96.59.254244.96.59.255510
31244.96.60.0/23244.96.60.1 to 244.96.61.254244.96.61.255510
32244.96.62.0/23244.96.62.1 to 244.96.63.254244.96.63.255510
33244.96.64.0/23244.96.64.1 to 244.96.65.254244.96.65.255510
34244.96.66.0/23244.96.66.1 to 244.96.67.254244.96.67.255510
35244.96.68.0/23244.96.68.1 to 244.96.69.254244.96.69.255510
36244.96.70.0/23244.96.70.1 to 244.96.71.254244.96.71.255510
37244.96.72.0/23244.96.72.1 to 244.96.73.254244.96.73.255510
38244.96.74.0/23244.96.74.1 to 244.96.75.254244.96.75.255510
39244.96.76.0/23244.96.76.1 to 244.96.77.254244.96.77.255510
40244.96.78.0/23244.96.78.1 to 244.96.79.254244.96.79.255510
41244.96.80.0/23244.96.80.1 to 244.96.81.254244.96.81.255510
42244.96.82.0/23244.96.82.1 to 244.96.83.254244.96.83.255510
43244.96.84.0/23244.96.84.1 to 244.96.85.254244.96.85.255510
44244.96.86.0/23244.96.86.1 to 244.96.87.254244.96.87.255510
45244.96.88.0/23244.96.88.1 to 244.96.89.254244.96.89.255510
46244.96.90.0/23244.96.90.1 to 244.96.91.254244.96.91.255510
47244.96.92.0/23244.96.92.1 to 244.96.93.254244.96.93.255510
48244.96.94.0/23244.96.94.1 to 244.96.95.254244.96.95.255510
49244.96.96.0/23244.96.96.1 to 244.96.97.254244.96.97.255510
50244.96.98.0/23244.96.98.1 to 244.96.99.254244.96.99.255510
51244.96.100.0/23244.96.100.1 to 244.96.101.254244.96.101.255510
52244.96.102.0/23244.96.102.1 to 244.96.103.254244.96.103.255510
53244.96.104.0/23244.96.104.1 to 244.96.105.254244.96.105.255510
54244.96.106.0/23244.96.106.1 to 244.96.107.254244.96.107.255510
55244.96.108.0/23244.96.108.1 to 244.96.109.254244.96.109.255510
56244.96.110.0/23244.96.110.1 to 244.96.111.254244.96.111.255510
57244.96.112.0/23244.96.112.1 to 244.96.113.254244.96.113.255510
58244.96.114.0/23244.96.114.1 to 244.96.115.254244.96.115.255510
59244.96.116.0/23244.96.116.1 to 244.96.117.254244.96.117.255510
60244.96.118.0/23244.96.118.1 to 244.96.119.254244.96.119.255510
61244.96.120.0/23244.96.120.1 to 244.96.121.254244.96.121.255510
62244.96.122.0/23244.96.122.1 to 244.96.123.254244.96.123.255510
63244.96.124.0/23244.96.124.1 to 244.96.125.254244.96.125.255510
64244.96.126.0/23244.96.126.1 to 244.96.127.254244.96.127.255510
65244.96.128.0/23244.96.128.1 to 244.96.129.254244.96.129.255510
66244.96.130.0/23244.96.130.1 to 244.96.131.254244.96.131.255510
67244.96.132.0/23244.96.132.1 to 244.96.133.254244.96.133.255510
68244.96.134.0/23244.96.134.1 to 244.96.135.254244.96.135.255510
69244.96.136.0/23244.96.136.1 to 244.96.137.254244.96.137.255510
70244.96.138.0/23244.96.138.1 to 244.96.139.254244.96.139.255510
71244.96.140.0/23244.96.140.1 to 244.96.141.254244.96.141.255510
72244.96.142.0/23244.96.142.1 to 244.96.143.254244.96.143.255510
73244.96.144.0/23244.96.144.1 to 244.96.145.254244.96.145.255510
74244.96.146.0/23244.96.146.1 to 244.96.147.254244.96.147.255510
75244.96.148.0/23244.96.148.1 to 244.96.149.254244.96.149.255510
76244.96.150.0/23244.96.150.1 to 244.96.151.254244.96.151.255510
77244.96.152.0/23244.96.152.1 to 244.96.153.254244.96.153.255510
78244.96.154.0/23244.96.154.1 to 244.96.155.254244.96.155.255510
79244.96.156.0/23244.96.156.1 to 244.96.157.254244.96.157.255510
80244.96.158.0/23244.96.158.1 to 244.96.159.254244.96.159.255510
81244.96.160.0/23244.96.160.1 to 244.96.161.254244.96.161.255510
82244.96.162.0/23244.96.162.1 to 244.96.163.254244.96.163.255510
83244.96.164.0/23244.96.164.1 to 244.96.165.254244.96.165.255510
84244.96.166.0/23244.96.166.1 to 244.96.167.254244.96.167.255510
85244.96.168.0/23244.96.168.1 to 244.96.169.254244.96.169.255510
86244.96.170.0/23244.96.170.1 to 244.96.171.254244.96.171.255510
87244.96.172.0/23244.96.172.1 to 244.96.173.254244.96.173.255510
88244.96.174.0/23244.96.174.1 to 244.96.175.254244.96.175.255510
89244.96.176.0/23244.96.176.1 to 244.96.177.254244.96.177.255510
90244.96.178.0/23244.96.178.1 to 244.96.179.254244.96.179.255510
91244.96.180.0/23244.96.180.1 to 244.96.181.254244.96.181.255510
92244.96.182.0/23244.96.182.1 to 244.96.183.254244.96.183.255510
93244.96.184.0/23244.96.184.1 to 244.96.185.254244.96.185.255510
94244.96.186.0/23244.96.186.1 to 244.96.187.254244.96.187.255510
95244.96.188.0/23244.96.188.1 to 244.96.189.254244.96.189.255510
96244.96.190.0/23244.96.190.1 to 244.96.191.254244.96.191.255510
97244.96.192.0/23244.96.192.1 to 244.96.193.254244.96.193.255510
98244.96.194.0/23244.96.194.1 to 244.96.195.254244.96.195.255510
99244.96.196.0/23244.96.196.1 to 244.96.197.254244.96.197.255510
100244.96.198.0/23244.96.198.1 to 244.96.199.254244.96.199.255510
101244.96.200.0/23244.96.200.1 to 244.96.201.254244.96.201.255510
102244.96.202.0/23244.96.202.1 to 244.96.203.254244.96.203.255510
103244.96.204.0/23244.96.204.1 to 244.96.205.254244.96.205.255510
104244.96.206.0/23244.96.206.1 to 244.96.207.254244.96.207.255510
105244.96.208.0/23244.96.208.1 to 244.96.209.254244.96.209.255510
106244.96.210.0/23244.96.210.1 to 244.96.211.254244.96.211.255510
107244.96.212.0/23244.96.212.1 to 244.96.213.254244.96.213.255510
108244.96.214.0/23244.96.214.1 to 244.96.215.254244.96.215.255510
109244.96.216.0/23244.96.216.1 to 244.96.217.254244.96.217.255510
110244.96.218.0/23244.96.218.1 to 244.96.219.254244.96.219.255510
111244.96.220.0/23244.96.220.1 to 244.96.221.254244.96.221.255510
112244.96.222.0/23244.96.222.1 to 244.96.223.254244.96.223.255510
113244.96.224.0/23244.96.224.1 to 244.96.225.254244.96.225.255510
114244.96.226.0/23244.96.226.1 to 244.96.227.254244.96.227.255510
115244.96.228.0/23244.96.228.1 to 244.96.229.254244.96.229.255510
116244.96.230.0/23244.96.230.1 to 244.96.231.254244.96.231.255510
117244.96.232.0/23244.96.232.1 to 244.96.233.254244.96.233.255510
118244.96.234.0/23244.96.234.1 to 244.96.235.254244.96.235.255510
119244.96.236.0/23244.96.236.1 to 244.96.237.254244.96.237.255510
120244.96.238.0/23244.96.238.1 to 244.96.239.254244.96.239.255510
121244.96.240.0/23244.96.240.1 to 244.96.241.254244.96.241.255510
122244.96.242.0/23244.96.242.1 to 244.96.243.254244.96.243.255510
123244.96.244.0/23244.96.244.1 to 244.96.245.254244.96.245.255510
124244.96.246.0/23244.96.246.1 to 244.96.247.254244.96.247.255510
125244.96.248.0/23244.96.248.1 to 244.96.249.254244.96.249.255510
126244.96.250.0/23244.96.250.1 to 244.96.251.254244.96.251.255510
127244.96.252.0/23244.96.252.1 to 244.96.253.254244.96.253.255510
128244.96.254.0/23244.96.254.1 to 244.96.255.254244.96.255.255510
129244.97.0.0/23244.97.0.1 to 244.97.1.254244.97.1.255510
130244.97.2.0/23244.97.2.1 to 244.97.3.254244.97.3.255510
131244.97.4.0/23244.97.4.1 to 244.97.5.254244.97.5.255510
132244.97.6.0/23244.97.6.1 to 244.97.7.254244.97.7.255510
133244.97.8.0/23244.97.8.1 to 244.97.9.254244.97.9.255510
134244.97.10.0/23244.97.10.1 to 244.97.11.254244.97.11.255510
135244.97.12.0/23244.97.12.1 to 244.97.13.254244.97.13.255510
136244.97.14.0/23244.97.14.1 to 244.97.15.254244.97.15.255510
137244.97.16.0/23244.97.16.1 to 244.97.17.254244.97.17.255510
138244.97.18.0/23244.97.18.1 to 244.97.19.254244.97.19.255510
139244.97.20.0/23244.97.20.1 to 244.97.21.254244.97.21.255510
140244.97.22.0/23244.97.22.1 to 244.97.23.254244.97.23.255510
141244.97.24.0/23244.97.24.1 to 244.97.25.254244.97.25.255510
142244.97.26.0/23244.97.26.1 to 244.97.27.254244.97.27.255510
143244.97.28.0/23244.97.28.1 to 244.97.29.254244.97.29.255510
144244.97.30.0/23244.97.30.1 to 244.97.31.254244.97.31.255510
145244.97.32.0/23244.97.32.1 to 244.97.33.254244.97.33.255510
146244.97.34.0/23244.97.34.1 to 244.97.35.254244.97.35.255510
147244.97.36.0/23244.97.36.1 to 244.97.37.254244.97.37.255510
148244.97.38.0/23244.97.38.1 to 244.97.39.254244.97.39.255510
149244.97.40.0/23244.97.40.1 to 244.97.41.254244.97.41.255510
150244.97.42.0/23244.97.42.1 to 244.97.43.254244.97.43.255510
151244.97.44.0/23244.97.44.1 to 244.97.45.254244.97.45.255510
152244.97.46.0/23244.97.46.1 to 244.97.47.254244.97.47.255510
153244.97.48.0/23244.97.48.1 to 244.97.49.254244.97.49.255510
154244.97.50.0/23244.97.50.1 to 244.97.51.254244.97.51.255510
155244.97.52.0/23244.97.52.1 to 244.97.53.254244.97.53.255510
156244.97.54.0/23244.97.54.1 to 244.97.55.254244.97.55.255510
157244.97.56.0/23244.97.56.1 to 244.97.57.254244.97.57.255510
158244.97.58.0/23244.97.58.1 to 244.97.59.254244.97.59.255510
159244.97.60.0/23244.97.60.1 to 244.97.61.254244.97.61.255510
160244.97.62.0/23244.97.62.1 to 244.97.63.254244.97.63.255510
161244.97.64.0/23244.97.64.1 to 244.97.65.254244.97.65.255510
162244.97.66.0/23244.97.66.1 to 244.97.67.254244.97.67.255510
163244.97.68.0/23244.97.68.1 to 244.97.69.254244.97.69.255510
164244.97.70.0/23244.97.70.1 to 244.97.71.254244.97.71.255510
165244.97.72.0/23244.97.72.1 to 244.97.73.254244.97.73.255510
166244.97.74.0/23244.97.74.1 to 244.97.75.254244.97.75.255510
167244.97.76.0/23244.97.76.1 to 244.97.77.254244.97.77.255510
168244.97.78.0/23244.97.78.1 to 244.97.79.254244.97.79.255510
169244.97.80.0/23244.97.80.1 to 244.97.81.254244.97.81.255510
170244.97.82.0/23244.97.82.1 to 244.97.83.254244.97.83.255510
171244.97.84.0/23244.97.84.1 to 244.97.85.254244.97.85.255510
172244.97.86.0/23244.97.86.1 to 244.97.87.254244.97.87.255510
173244.97.88.0/23244.97.88.1 to 244.97.89.254244.97.89.255510
174244.97.90.0/23244.97.90.1 to 244.97.91.254244.97.91.255510
175244.97.92.0/23244.97.92.1 to 244.97.93.254244.97.93.255510
176244.97.94.0/23244.97.94.1 to 244.97.95.254244.97.95.255510
177244.97.96.0/23244.97.96.1 to 244.97.97.254244.97.97.255510
178244.97.98.0/23244.97.98.1 to 244.97.99.254244.97.99.255510
179244.97.100.0/23244.97.100.1 to 244.97.101.254244.97.101.255510
180244.97.102.0/23244.97.102.1 to 244.97.103.254244.97.103.255510
181244.97.104.0/23244.97.104.1 to 244.97.105.254244.97.105.255510
182244.97.106.0/23244.97.106.1 to 244.97.107.254244.97.107.255510
183244.97.108.0/23244.97.108.1 to 244.97.109.254244.97.109.255510
184244.97.110.0/23244.97.110.1 to 244.97.111.254244.97.111.255510
185244.97.112.0/23244.97.112.1 to 244.97.113.254244.97.113.255510
186244.97.114.0/23244.97.114.1 to 244.97.115.254244.97.115.255510
187244.97.116.0/23244.97.116.1 to 244.97.117.254244.97.117.255510
188244.97.118.0/23244.97.118.1 to 244.97.119.254244.97.119.255510
189244.97.120.0/23244.97.120.1 to 244.97.121.254244.97.121.255510
190244.97.122.0/23244.97.122.1 to 244.97.123.254244.97.123.255510
191244.97.124.0/23244.97.124.1 to 244.97.125.254244.97.125.255510
192244.97.126.0/23244.97.126.1 to 244.97.127.254244.97.127.255510
193244.97.128.0/23244.97.128.1 to 244.97.129.254244.97.129.255510
194244.97.130.0/23244.97.130.1 to 244.97.131.254244.97.131.255510
195244.97.132.0/23244.97.132.1 to 244.97.133.254244.97.133.255510
196244.97.134.0/23244.97.134.1 to 244.97.135.254244.97.135.255510
197244.97.136.0/23244.97.136.1 to 244.97.137.254244.97.137.255510
198244.97.138.0/23244.97.138.1 to 244.97.139.254244.97.139.255510
199244.97.140.0/23244.97.140.1 to 244.97.141.254244.97.141.255510
200244.97.142.0/23244.97.142.1 to 244.97.143.254244.97.143.255510
201244.97.144.0/23244.97.144.1 to 244.97.145.254244.97.145.255510
202244.97.146.0/23244.97.146.1 to 244.97.147.254244.97.147.255510
203244.97.148.0/23244.97.148.1 to 244.97.149.254244.97.149.255510
204244.97.150.0/23244.97.150.1 to 244.97.151.254244.97.151.255510
205244.97.152.0/23244.97.152.1 to 244.97.153.254244.97.153.255510
206244.97.154.0/23244.97.154.1 to 244.97.155.254244.97.155.255510
207244.97.156.0/23244.97.156.1 to 244.97.157.254244.97.157.255510
208244.97.158.0/23244.97.158.1 to 244.97.159.254244.97.159.255510
209244.97.160.0/23244.97.160.1 to 244.97.161.254244.97.161.255510
210244.97.162.0/23244.97.162.1 to 244.97.163.254244.97.163.255510
211244.97.164.0/23244.97.164.1 to 244.97.165.254244.97.165.255510
212244.97.166.0/23244.97.166.1 to 244.97.167.254244.97.167.255510
213244.97.168.0/23244.97.168.1 to 244.97.169.254244.97.169.255510
214244.97.170.0/23244.97.170.1 to 244.97.171.254244.97.171.255510
215244.97.172.0/23244.97.172.1 to 244.97.173.254244.97.173.255510
216244.97.174.0/23244.97.174.1 to 244.97.175.254244.97.175.255510
217244.97.176.0/23244.97.176.1 to 244.97.177.254244.97.177.255510
218244.97.178.0/23244.97.178.1 to 244.97.179.254244.97.179.255510
219244.97.180.0/23244.97.180.1 to 244.97.181.254244.97.181.255510
220244.97.182.0/23244.97.182.1 to 244.97.183.254244.97.183.255510
221244.97.184.0/23244.97.184.1 to 244.97.185.254244.97.185.255510
222244.97.186.0/23244.97.186.1 to 244.97.187.254244.97.187.255510
223244.97.188.0/23244.97.188.1 to 244.97.189.254244.97.189.255510
224244.97.190.0/23244.97.190.1 to 244.97.191.254244.97.191.255510
225244.97.192.0/23244.97.192.1 to 244.97.193.254244.97.193.255510
226244.97.194.0/23244.97.194.1 to 244.97.195.254244.97.195.255510
227244.97.196.0/23244.97.196.1 to 244.97.197.254244.97.197.255510
228244.97.198.0/23244.97.198.1 to 244.97.199.254244.97.199.255510
229244.97.200.0/23244.97.200.1 to 244.97.201.254244.97.201.255510
230244.97.202.0/23244.97.202.1 to 244.97.203.254244.97.203.255510
231244.97.204.0/23244.97.204.1 to 244.97.205.254244.97.205.255510
232244.97.206.0/23244.97.206.1 to 244.97.207.254244.97.207.255510
233244.97.208.0/23244.97.208.1 to 244.97.209.254244.97.209.255510
234244.97.210.0/23244.97.210.1 to 244.97.211.254244.97.211.255510
235244.97.212.0/23244.97.212.1 to 244.97.213.254244.97.213.255510
236244.97.214.0/23244.97.214.1 to 244.97.215.254244.97.215.255510
237244.97.216.0/23244.97.216.1 to 244.97.217.254244.97.217.255510
238244.97.218.0/23244.97.218.1 to 244.97.219.254244.97.219.255510
239244.97.220.0/23244.97.220.1 to 244.97.221.254244.97.221.255510
240244.97.222.0/23244.97.222.1 to 244.97.223.254244.97.223.255510
241244.97.224.0/23244.97.224.1 to 244.97.225.254244.97.225.255510
242244.97.226.0/23244.97.226.1 to 244.97.227.254244.97.227.255510
243244.97.228.0/23244.97.228.1 to 244.97.229.254244.97.229.255510
244244.97.230.0/23244.97.230.1 to 244.97.231.254244.97.231.255510
245244.97.232.0/23244.97.232.1 to 244.97.233.254244.97.233.255510
246244.97.234.0/23244.97.234.1 to 244.97.235.254244.97.235.255510
247244.97.236.0/23244.97.236.1 to 244.97.237.254244.97.237.255510
248244.97.238.0/23244.97.238.1 to 244.97.239.254244.97.239.255510
249244.97.240.0/23244.97.240.1 to 244.97.241.254244.97.241.255510
250244.97.242.0/23244.97.242.1 to 244.97.243.254244.97.243.255510
251244.97.244.0/23244.97.244.1 to 244.97.245.254244.97.245.255510
252244.97.246.0/23244.97.246.1 to 244.97.247.254244.97.247.255510
253244.97.248.0/23244.97.248.1 to 244.97.249.254244.97.249.255510
254244.97.250.0/23244.97.250.1 to 244.97.251.254244.97.251.255510
255244.97.252.0/23244.97.252.1 to 244.97.253.254244.97.253.255510
256244.97.254.0/23244.97.254.1 to 244.97.255.254244.97.255.255510

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.