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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.

Network244.176.0.0/12
Usable hosts1,048,574
Subnet mask255.240.0.0
Addresses1,048,576
Network address
244.176.0.0
Broadcast address
244.191.255.255
First usable
244.176.0.1
Last usable
244.191.255.254
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 F4B00000 · Integer 4105175040 to 4106223615
Reverse DNS zones
176.244.in-addr.arpa
177.244.in-addr.arpa
178.244.in-addr.arpa
179.244.in-addr.arpa
180.244.in-addr.arpa
181.244.in-addr.arpa
182.244.in-addr.arpa
183.244.in-addr.arpa
184.244.in-addr.arpa
185.244.in-addr.arpa
186.244.in-addr.arpa
187.244.in-addr.arpa
188.244.in-addr.arpa
189.244.in-addr.arpa
190.244.in-addr.arpa
191.244.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
Address11110100.10110000.00000000.00000000244.176.0.0
Subnet mask11111111.11110000.00000000.00000000255.240.0.0
Network11110100.10110000.00000000.00000000244.176.0.0
Broadcast11110100.10111111.11111111.11111111244.191.255.255
Split into smaller subnets/24
/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)

244.176.0.0/12 makes 4,096 subnets of /24; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1244.176.0.0/24244.176.0.1 to 244.176.0.254244.176.0.255254
2244.176.1.0/24244.176.1.1 to 244.176.1.254244.176.1.255254
3244.176.2.0/24244.176.2.1 to 244.176.2.254244.176.2.255254
4244.176.3.0/24244.176.3.1 to 244.176.3.254244.176.3.255254
5244.176.4.0/24244.176.4.1 to 244.176.4.254244.176.4.255254
6244.176.5.0/24244.176.5.1 to 244.176.5.254244.176.5.255254
7244.176.6.0/24244.176.6.1 to 244.176.6.254244.176.6.255254
8244.176.7.0/24244.176.7.1 to 244.176.7.254244.176.7.255254
9244.176.8.0/24244.176.8.1 to 244.176.8.254244.176.8.255254
10244.176.9.0/24244.176.9.1 to 244.176.9.254244.176.9.255254
11244.176.10.0/24244.176.10.1 to 244.176.10.254244.176.10.255254
12244.176.11.0/24244.176.11.1 to 244.176.11.254244.176.11.255254
13244.176.12.0/24244.176.12.1 to 244.176.12.254244.176.12.255254
14244.176.13.0/24244.176.13.1 to 244.176.13.254244.176.13.255254
15244.176.14.0/24244.176.14.1 to 244.176.14.254244.176.14.255254
16244.176.15.0/24244.176.15.1 to 244.176.15.254244.176.15.255254
17244.176.16.0/24244.176.16.1 to 244.176.16.254244.176.16.255254
18244.176.17.0/24244.176.17.1 to 244.176.17.254244.176.17.255254
19244.176.18.0/24244.176.18.1 to 244.176.18.254244.176.18.255254
20244.176.19.0/24244.176.19.1 to 244.176.19.254244.176.19.255254
21244.176.20.0/24244.176.20.1 to 244.176.20.254244.176.20.255254
22244.176.21.0/24244.176.21.1 to 244.176.21.254244.176.21.255254
23244.176.22.0/24244.176.22.1 to 244.176.22.254244.176.22.255254
24244.176.23.0/24244.176.23.1 to 244.176.23.254244.176.23.255254
25244.176.24.0/24244.176.24.1 to 244.176.24.254244.176.24.255254
26244.176.25.0/24244.176.25.1 to 244.176.25.254244.176.25.255254
27244.176.26.0/24244.176.26.1 to 244.176.26.254244.176.26.255254
28244.176.27.0/24244.176.27.1 to 244.176.27.254244.176.27.255254
29244.176.28.0/24244.176.28.1 to 244.176.28.254244.176.28.255254
30244.176.29.0/24244.176.29.1 to 244.176.29.254244.176.29.255254
31244.176.30.0/24244.176.30.1 to 244.176.30.254244.176.30.255254
32244.176.31.0/24244.176.31.1 to 244.176.31.254244.176.31.255254
33244.176.32.0/24244.176.32.1 to 244.176.32.254244.176.32.255254
34244.176.33.0/24244.176.33.1 to 244.176.33.254244.176.33.255254
35244.176.34.0/24244.176.34.1 to 244.176.34.254244.176.34.255254
36244.176.35.0/24244.176.35.1 to 244.176.35.254244.176.35.255254
37244.176.36.0/24244.176.36.1 to 244.176.36.254244.176.36.255254
38244.176.37.0/24244.176.37.1 to 244.176.37.254244.176.37.255254
39244.176.38.0/24244.176.38.1 to 244.176.38.254244.176.38.255254
40244.176.39.0/24244.176.39.1 to 244.176.39.254244.176.39.255254
41244.176.40.0/24244.176.40.1 to 244.176.40.254244.176.40.255254
42244.176.41.0/24244.176.41.1 to 244.176.41.254244.176.41.255254
43244.176.42.0/24244.176.42.1 to 244.176.42.254244.176.42.255254
44244.176.43.0/24244.176.43.1 to 244.176.43.254244.176.43.255254
45244.176.44.0/24244.176.44.1 to 244.176.44.254244.176.44.255254
46244.176.45.0/24244.176.45.1 to 244.176.45.254244.176.45.255254
47244.176.46.0/24244.176.46.1 to 244.176.46.254244.176.46.255254
48244.176.47.0/24244.176.47.1 to 244.176.47.254244.176.47.255254
49244.176.48.0/24244.176.48.1 to 244.176.48.254244.176.48.255254
50244.176.49.0/24244.176.49.1 to 244.176.49.254244.176.49.255254
51244.176.50.0/24244.176.50.1 to 244.176.50.254244.176.50.255254
52244.176.51.0/24244.176.51.1 to 244.176.51.254244.176.51.255254
53244.176.52.0/24244.176.52.1 to 244.176.52.254244.176.52.255254
54244.176.53.0/24244.176.53.1 to 244.176.53.254244.176.53.255254
55244.176.54.0/24244.176.54.1 to 244.176.54.254244.176.54.255254
56244.176.55.0/24244.176.55.1 to 244.176.55.254244.176.55.255254
57244.176.56.0/24244.176.56.1 to 244.176.56.254244.176.56.255254
58244.176.57.0/24244.176.57.1 to 244.176.57.254244.176.57.255254
59244.176.58.0/24244.176.58.1 to 244.176.58.254244.176.58.255254
60244.176.59.0/24244.176.59.1 to 244.176.59.254244.176.59.255254
61244.176.60.0/24244.176.60.1 to 244.176.60.254244.176.60.255254
62244.176.61.0/24244.176.61.1 to 244.176.61.254244.176.61.255254
63244.176.62.0/24244.176.62.1 to 244.176.62.254244.176.62.255254
64244.176.63.0/24244.176.63.1 to 244.176.63.254244.176.63.255254
65244.176.64.0/24244.176.64.1 to 244.176.64.254244.176.64.255254
66244.176.65.0/24244.176.65.1 to 244.176.65.254244.176.65.255254
67244.176.66.0/24244.176.66.1 to 244.176.66.254244.176.66.255254
68244.176.67.0/24244.176.67.1 to 244.176.67.254244.176.67.255254
69244.176.68.0/24244.176.68.1 to 244.176.68.254244.176.68.255254
70244.176.69.0/24244.176.69.1 to 244.176.69.254244.176.69.255254
71244.176.70.0/24244.176.70.1 to 244.176.70.254244.176.70.255254
72244.176.71.0/24244.176.71.1 to 244.176.71.254244.176.71.255254
73244.176.72.0/24244.176.72.1 to 244.176.72.254244.176.72.255254
74244.176.73.0/24244.176.73.1 to 244.176.73.254244.176.73.255254
75244.176.74.0/24244.176.74.1 to 244.176.74.254244.176.74.255254
76244.176.75.0/24244.176.75.1 to 244.176.75.254244.176.75.255254
77244.176.76.0/24244.176.76.1 to 244.176.76.254244.176.76.255254
78244.176.77.0/24244.176.77.1 to 244.176.77.254244.176.77.255254
79244.176.78.0/24244.176.78.1 to 244.176.78.254244.176.78.255254
80244.176.79.0/24244.176.79.1 to 244.176.79.254244.176.79.255254
81244.176.80.0/24244.176.80.1 to 244.176.80.254244.176.80.255254
82244.176.81.0/24244.176.81.1 to 244.176.81.254244.176.81.255254
83244.176.82.0/24244.176.82.1 to 244.176.82.254244.176.82.255254
84244.176.83.0/24244.176.83.1 to 244.176.83.254244.176.83.255254
85244.176.84.0/24244.176.84.1 to 244.176.84.254244.176.84.255254
86244.176.85.0/24244.176.85.1 to 244.176.85.254244.176.85.255254
87244.176.86.0/24244.176.86.1 to 244.176.86.254244.176.86.255254
88244.176.87.0/24244.176.87.1 to 244.176.87.254244.176.87.255254
89244.176.88.0/24244.176.88.1 to 244.176.88.254244.176.88.255254
90244.176.89.0/24244.176.89.1 to 244.176.89.254244.176.89.255254
91244.176.90.0/24244.176.90.1 to 244.176.90.254244.176.90.255254
92244.176.91.0/24244.176.91.1 to 244.176.91.254244.176.91.255254
93244.176.92.0/24244.176.92.1 to 244.176.92.254244.176.92.255254
94244.176.93.0/24244.176.93.1 to 244.176.93.254244.176.93.255254
95244.176.94.0/24244.176.94.1 to 244.176.94.254244.176.94.255254
96244.176.95.0/24244.176.95.1 to 244.176.95.254244.176.95.255254
97244.176.96.0/24244.176.96.1 to 244.176.96.254244.176.96.255254
98244.176.97.0/24244.176.97.1 to 244.176.97.254244.176.97.255254
99244.176.98.0/24244.176.98.1 to 244.176.98.254244.176.98.255254
100244.176.99.0/24244.176.99.1 to 244.176.99.254244.176.99.255254
101244.176.100.0/24244.176.100.1 to 244.176.100.254244.176.100.255254
102244.176.101.0/24244.176.101.1 to 244.176.101.254244.176.101.255254
103244.176.102.0/24244.176.102.1 to 244.176.102.254244.176.102.255254
104244.176.103.0/24244.176.103.1 to 244.176.103.254244.176.103.255254
105244.176.104.0/24244.176.104.1 to 244.176.104.254244.176.104.255254
106244.176.105.0/24244.176.105.1 to 244.176.105.254244.176.105.255254
107244.176.106.0/24244.176.106.1 to 244.176.106.254244.176.106.255254
108244.176.107.0/24244.176.107.1 to 244.176.107.254244.176.107.255254
109244.176.108.0/24244.176.108.1 to 244.176.108.254244.176.108.255254
110244.176.109.0/24244.176.109.1 to 244.176.109.254244.176.109.255254
111244.176.110.0/24244.176.110.1 to 244.176.110.254244.176.110.255254
112244.176.111.0/24244.176.111.1 to 244.176.111.254244.176.111.255254
113244.176.112.0/24244.176.112.1 to 244.176.112.254244.176.112.255254
114244.176.113.0/24244.176.113.1 to 244.176.113.254244.176.113.255254
115244.176.114.0/24244.176.114.1 to 244.176.114.254244.176.114.255254
116244.176.115.0/24244.176.115.1 to 244.176.115.254244.176.115.255254
117244.176.116.0/24244.176.116.1 to 244.176.116.254244.176.116.255254
118244.176.117.0/24244.176.117.1 to 244.176.117.254244.176.117.255254
119244.176.118.0/24244.176.118.1 to 244.176.118.254244.176.118.255254
120244.176.119.0/24244.176.119.1 to 244.176.119.254244.176.119.255254
121244.176.120.0/24244.176.120.1 to 244.176.120.254244.176.120.255254
122244.176.121.0/24244.176.121.1 to 244.176.121.254244.176.121.255254
123244.176.122.0/24244.176.122.1 to 244.176.122.254244.176.122.255254
124244.176.123.0/24244.176.123.1 to 244.176.123.254244.176.123.255254
125244.176.124.0/24244.176.124.1 to 244.176.124.254244.176.124.255254
126244.176.125.0/24244.176.125.1 to 244.176.125.254244.176.125.255254
127244.176.126.0/24244.176.126.1 to 244.176.126.254244.176.126.255254
128244.176.127.0/24244.176.127.1 to 244.176.127.254244.176.127.255254
129244.176.128.0/24244.176.128.1 to 244.176.128.254244.176.128.255254
130244.176.129.0/24244.176.129.1 to 244.176.129.254244.176.129.255254
131244.176.130.0/24244.176.130.1 to 244.176.130.254244.176.130.255254
132244.176.131.0/24244.176.131.1 to 244.176.131.254244.176.131.255254
133244.176.132.0/24244.176.132.1 to 244.176.132.254244.176.132.255254
134244.176.133.0/24244.176.133.1 to 244.176.133.254244.176.133.255254
135244.176.134.0/24244.176.134.1 to 244.176.134.254244.176.134.255254
136244.176.135.0/24244.176.135.1 to 244.176.135.254244.176.135.255254
137244.176.136.0/24244.176.136.1 to 244.176.136.254244.176.136.255254
138244.176.137.0/24244.176.137.1 to 244.176.137.254244.176.137.255254
139244.176.138.0/24244.176.138.1 to 244.176.138.254244.176.138.255254
140244.176.139.0/24244.176.139.1 to 244.176.139.254244.176.139.255254
141244.176.140.0/24244.176.140.1 to 244.176.140.254244.176.140.255254
142244.176.141.0/24244.176.141.1 to 244.176.141.254244.176.141.255254
143244.176.142.0/24244.176.142.1 to 244.176.142.254244.176.142.255254
144244.176.143.0/24244.176.143.1 to 244.176.143.254244.176.143.255254
145244.176.144.0/24244.176.144.1 to 244.176.144.254244.176.144.255254
146244.176.145.0/24244.176.145.1 to 244.176.145.254244.176.145.255254
147244.176.146.0/24244.176.146.1 to 244.176.146.254244.176.146.255254
148244.176.147.0/24244.176.147.1 to 244.176.147.254244.176.147.255254
149244.176.148.0/24244.176.148.1 to 244.176.148.254244.176.148.255254
150244.176.149.0/24244.176.149.1 to 244.176.149.254244.176.149.255254
151244.176.150.0/24244.176.150.1 to 244.176.150.254244.176.150.255254
152244.176.151.0/24244.176.151.1 to 244.176.151.254244.176.151.255254
153244.176.152.0/24244.176.152.1 to 244.176.152.254244.176.152.255254
154244.176.153.0/24244.176.153.1 to 244.176.153.254244.176.153.255254
155244.176.154.0/24244.176.154.1 to 244.176.154.254244.176.154.255254
156244.176.155.0/24244.176.155.1 to 244.176.155.254244.176.155.255254
157244.176.156.0/24244.176.156.1 to 244.176.156.254244.176.156.255254
158244.176.157.0/24244.176.157.1 to 244.176.157.254244.176.157.255254
159244.176.158.0/24244.176.158.1 to 244.176.158.254244.176.158.255254
160244.176.159.0/24244.176.159.1 to 244.176.159.254244.176.159.255254
161244.176.160.0/24244.176.160.1 to 244.176.160.254244.176.160.255254
162244.176.161.0/24244.176.161.1 to 244.176.161.254244.176.161.255254
163244.176.162.0/24244.176.162.1 to 244.176.162.254244.176.162.255254
164244.176.163.0/24244.176.163.1 to 244.176.163.254244.176.163.255254
165244.176.164.0/24244.176.164.1 to 244.176.164.254244.176.164.255254
166244.176.165.0/24244.176.165.1 to 244.176.165.254244.176.165.255254
167244.176.166.0/24244.176.166.1 to 244.176.166.254244.176.166.255254
168244.176.167.0/24244.176.167.1 to 244.176.167.254244.176.167.255254
169244.176.168.0/24244.176.168.1 to 244.176.168.254244.176.168.255254
170244.176.169.0/24244.176.169.1 to 244.176.169.254244.176.169.255254
171244.176.170.0/24244.176.170.1 to 244.176.170.254244.176.170.255254
172244.176.171.0/24244.176.171.1 to 244.176.171.254244.176.171.255254
173244.176.172.0/24244.176.172.1 to 244.176.172.254244.176.172.255254
174244.176.173.0/24244.176.173.1 to 244.176.173.254244.176.173.255254
175244.176.174.0/24244.176.174.1 to 244.176.174.254244.176.174.255254
176244.176.175.0/24244.176.175.1 to 244.176.175.254244.176.175.255254
177244.176.176.0/24244.176.176.1 to 244.176.176.254244.176.176.255254
178244.176.177.0/24244.176.177.1 to 244.176.177.254244.176.177.255254
179244.176.178.0/24244.176.178.1 to 244.176.178.254244.176.178.255254
180244.176.179.0/24244.176.179.1 to 244.176.179.254244.176.179.255254
181244.176.180.0/24244.176.180.1 to 244.176.180.254244.176.180.255254
182244.176.181.0/24244.176.181.1 to 244.176.181.254244.176.181.255254
183244.176.182.0/24244.176.182.1 to 244.176.182.254244.176.182.255254
184244.176.183.0/24244.176.183.1 to 244.176.183.254244.176.183.255254
185244.176.184.0/24244.176.184.1 to 244.176.184.254244.176.184.255254
186244.176.185.0/24244.176.185.1 to 244.176.185.254244.176.185.255254
187244.176.186.0/24244.176.186.1 to 244.176.186.254244.176.186.255254
188244.176.187.0/24244.176.187.1 to 244.176.187.254244.176.187.255254
189244.176.188.0/24244.176.188.1 to 244.176.188.254244.176.188.255254
190244.176.189.0/24244.176.189.1 to 244.176.189.254244.176.189.255254
191244.176.190.0/24244.176.190.1 to 244.176.190.254244.176.190.255254
192244.176.191.0/24244.176.191.1 to 244.176.191.254244.176.191.255254
193244.176.192.0/24244.176.192.1 to 244.176.192.254244.176.192.255254
194244.176.193.0/24244.176.193.1 to 244.176.193.254244.176.193.255254
195244.176.194.0/24244.176.194.1 to 244.176.194.254244.176.194.255254
196244.176.195.0/24244.176.195.1 to 244.176.195.254244.176.195.255254
197244.176.196.0/24244.176.196.1 to 244.176.196.254244.176.196.255254
198244.176.197.0/24244.176.197.1 to 244.176.197.254244.176.197.255254
199244.176.198.0/24244.176.198.1 to 244.176.198.254244.176.198.255254
200244.176.199.0/24244.176.199.1 to 244.176.199.254244.176.199.255254
201244.176.200.0/24244.176.200.1 to 244.176.200.254244.176.200.255254
202244.176.201.0/24244.176.201.1 to 244.176.201.254244.176.201.255254
203244.176.202.0/24244.176.202.1 to 244.176.202.254244.176.202.255254
204244.176.203.0/24244.176.203.1 to 244.176.203.254244.176.203.255254
205244.176.204.0/24244.176.204.1 to 244.176.204.254244.176.204.255254
206244.176.205.0/24244.176.205.1 to 244.176.205.254244.176.205.255254
207244.176.206.0/24244.176.206.1 to 244.176.206.254244.176.206.255254
208244.176.207.0/24244.176.207.1 to 244.176.207.254244.176.207.255254
209244.176.208.0/24244.176.208.1 to 244.176.208.254244.176.208.255254
210244.176.209.0/24244.176.209.1 to 244.176.209.254244.176.209.255254
211244.176.210.0/24244.176.210.1 to 244.176.210.254244.176.210.255254
212244.176.211.0/24244.176.211.1 to 244.176.211.254244.176.211.255254
213244.176.212.0/24244.176.212.1 to 244.176.212.254244.176.212.255254
214244.176.213.0/24244.176.213.1 to 244.176.213.254244.176.213.255254
215244.176.214.0/24244.176.214.1 to 244.176.214.254244.176.214.255254
216244.176.215.0/24244.176.215.1 to 244.176.215.254244.176.215.255254
217244.176.216.0/24244.176.216.1 to 244.176.216.254244.176.216.255254
218244.176.217.0/24244.176.217.1 to 244.176.217.254244.176.217.255254
219244.176.218.0/24244.176.218.1 to 244.176.218.254244.176.218.255254
220244.176.219.0/24244.176.219.1 to 244.176.219.254244.176.219.255254
221244.176.220.0/24244.176.220.1 to 244.176.220.254244.176.220.255254
222244.176.221.0/24244.176.221.1 to 244.176.221.254244.176.221.255254
223244.176.222.0/24244.176.222.1 to 244.176.222.254244.176.222.255254
224244.176.223.0/24244.176.223.1 to 244.176.223.254244.176.223.255254
225244.176.224.0/24244.176.224.1 to 244.176.224.254244.176.224.255254
226244.176.225.0/24244.176.225.1 to 244.176.225.254244.176.225.255254
227244.176.226.0/24244.176.226.1 to 244.176.226.254244.176.226.255254
228244.176.227.0/24244.176.227.1 to 244.176.227.254244.176.227.255254
229244.176.228.0/24244.176.228.1 to 244.176.228.254244.176.228.255254
230244.176.229.0/24244.176.229.1 to 244.176.229.254244.176.229.255254
231244.176.230.0/24244.176.230.1 to 244.176.230.254244.176.230.255254
232244.176.231.0/24244.176.231.1 to 244.176.231.254244.176.231.255254
233244.176.232.0/24244.176.232.1 to 244.176.232.254244.176.232.255254
234244.176.233.0/24244.176.233.1 to 244.176.233.254244.176.233.255254
235244.176.234.0/24244.176.234.1 to 244.176.234.254244.176.234.255254
236244.176.235.0/24244.176.235.1 to 244.176.235.254244.176.235.255254
237244.176.236.0/24244.176.236.1 to 244.176.236.254244.176.236.255254
238244.176.237.0/24244.176.237.1 to 244.176.237.254244.176.237.255254
239244.176.238.0/24244.176.238.1 to 244.176.238.254244.176.238.255254
240244.176.239.0/24244.176.239.1 to 244.176.239.254244.176.239.255254
241244.176.240.0/24244.176.240.1 to 244.176.240.254244.176.240.255254
242244.176.241.0/24244.176.241.1 to 244.176.241.254244.176.241.255254
243244.176.242.0/24244.176.242.1 to 244.176.242.254244.176.242.255254
244244.176.243.0/24244.176.243.1 to 244.176.243.254244.176.243.255254
245244.176.244.0/24244.176.244.1 to 244.176.244.254244.176.244.255254
246244.176.245.0/24244.176.245.1 to 244.176.245.254244.176.245.255254
247244.176.246.0/24244.176.246.1 to 244.176.246.254244.176.246.255254
248244.176.247.0/24244.176.247.1 to 244.176.247.254244.176.247.255254
249244.176.248.0/24244.176.248.1 to 244.176.248.254244.176.248.255254
250244.176.249.0/24244.176.249.1 to 244.176.249.254244.176.249.255254
251244.176.250.0/24244.176.250.1 to 244.176.250.254244.176.250.255254
252244.176.251.0/24244.176.251.1 to 244.176.251.254244.176.251.255254
253244.176.252.0/24244.176.252.1 to 244.176.252.254244.176.252.255254
254244.176.253.0/24244.176.253.1 to 244.176.253.254244.176.253.255254
255244.176.254.0/24244.176.254.1 to 244.176.254.254244.176.254.255254
256244.176.255.0/24244.176.255.1 to 244.176.255.254244.176.255.255254

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.