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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.

Network254.80.0.0/12
Usable hosts1,048,574
Subnet mask255.240.0.0
Addresses1,048,576
Network address
254.80.0.0
Broadcast address
254.95.255.255
First usable
254.80.0.1
Last usable
254.95.255.254
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 FE500000 · Integer 4266655744 to 4267704319
Reverse DNS zones
80.254.in-addr.arpa
81.254.in-addr.arpa
82.254.in-addr.arpa
83.254.in-addr.arpa
84.254.in-addr.arpa
85.254.in-addr.arpa
86.254.in-addr.arpa
87.254.in-addr.arpa
88.254.in-addr.arpa
89.254.in-addr.arpa
90.254.in-addr.arpa
91.254.in-addr.arpa
92.254.in-addr.arpa
93.254.in-addr.arpa
94.254.in-addr.arpa
95.254.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
Address11111110.01010000.00000000.00000000254.80.0.0
Subnet mask11111111.11110000.00000000.00000000255.240.0.0
Network11111110.01010000.00000000.00000000254.80.0.0
Broadcast11111110.01011111.11111111.11111111254.95.255.255
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)

254.80.0.0/12 makes 4,096 subnets of /24; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1254.80.0.0/24254.80.0.1 to 254.80.0.254254.80.0.255254
2254.80.1.0/24254.80.1.1 to 254.80.1.254254.80.1.255254
3254.80.2.0/24254.80.2.1 to 254.80.2.254254.80.2.255254
4254.80.3.0/24254.80.3.1 to 254.80.3.254254.80.3.255254
5254.80.4.0/24254.80.4.1 to 254.80.4.254254.80.4.255254
6254.80.5.0/24254.80.5.1 to 254.80.5.254254.80.5.255254
7254.80.6.0/24254.80.6.1 to 254.80.6.254254.80.6.255254
8254.80.7.0/24254.80.7.1 to 254.80.7.254254.80.7.255254
9254.80.8.0/24254.80.8.1 to 254.80.8.254254.80.8.255254
10254.80.9.0/24254.80.9.1 to 254.80.9.254254.80.9.255254
11254.80.10.0/24254.80.10.1 to 254.80.10.254254.80.10.255254
12254.80.11.0/24254.80.11.1 to 254.80.11.254254.80.11.255254
13254.80.12.0/24254.80.12.1 to 254.80.12.254254.80.12.255254
14254.80.13.0/24254.80.13.1 to 254.80.13.254254.80.13.255254
15254.80.14.0/24254.80.14.1 to 254.80.14.254254.80.14.255254
16254.80.15.0/24254.80.15.1 to 254.80.15.254254.80.15.255254
17254.80.16.0/24254.80.16.1 to 254.80.16.254254.80.16.255254
18254.80.17.0/24254.80.17.1 to 254.80.17.254254.80.17.255254
19254.80.18.0/24254.80.18.1 to 254.80.18.254254.80.18.255254
20254.80.19.0/24254.80.19.1 to 254.80.19.254254.80.19.255254
21254.80.20.0/24254.80.20.1 to 254.80.20.254254.80.20.255254
22254.80.21.0/24254.80.21.1 to 254.80.21.254254.80.21.255254
23254.80.22.0/24254.80.22.1 to 254.80.22.254254.80.22.255254
24254.80.23.0/24254.80.23.1 to 254.80.23.254254.80.23.255254
25254.80.24.0/24254.80.24.1 to 254.80.24.254254.80.24.255254
26254.80.25.0/24254.80.25.1 to 254.80.25.254254.80.25.255254
27254.80.26.0/24254.80.26.1 to 254.80.26.254254.80.26.255254
28254.80.27.0/24254.80.27.1 to 254.80.27.254254.80.27.255254
29254.80.28.0/24254.80.28.1 to 254.80.28.254254.80.28.255254
30254.80.29.0/24254.80.29.1 to 254.80.29.254254.80.29.255254
31254.80.30.0/24254.80.30.1 to 254.80.30.254254.80.30.255254
32254.80.31.0/24254.80.31.1 to 254.80.31.254254.80.31.255254
33254.80.32.0/24254.80.32.1 to 254.80.32.254254.80.32.255254
34254.80.33.0/24254.80.33.1 to 254.80.33.254254.80.33.255254
35254.80.34.0/24254.80.34.1 to 254.80.34.254254.80.34.255254
36254.80.35.0/24254.80.35.1 to 254.80.35.254254.80.35.255254
37254.80.36.0/24254.80.36.1 to 254.80.36.254254.80.36.255254
38254.80.37.0/24254.80.37.1 to 254.80.37.254254.80.37.255254
39254.80.38.0/24254.80.38.1 to 254.80.38.254254.80.38.255254
40254.80.39.0/24254.80.39.1 to 254.80.39.254254.80.39.255254
41254.80.40.0/24254.80.40.1 to 254.80.40.254254.80.40.255254
42254.80.41.0/24254.80.41.1 to 254.80.41.254254.80.41.255254
43254.80.42.0/24254.80.42.1 to 254.80.42.254254.80.42.255254
44254.80.43.0/24254.80.43.1 to 254.80.43.254254.80.43.255254
45254.80.44.0/24254.80.44.1 to 254.80.44.254254.80.44.255254
46254.80.45.0/24254.80.45.1 to 254.80.45.254254.80.45.255254
47254.80.46.0/24254.80.46.1 to 254.80.46.254254.80.46.255254
48254.80.47.0/24254.80.47.1 to 254.80.47.254254.80.47.255254
49254.80.48.0/24254.80.48.1 to 254.80.48.254254.80.48.255254
50254.80.49.0/24254.80.49.1 to 254.80.49.254254.80.49.255254
51254.80.50.0/24254.80.50.1 to 254.80.50.254254.80.50.255254
52254.80.51.0/24254.80.51.1 to 254.80.51.254254.80.51.255254
53254.80.52.0/24254.80.52.1 to 254.80.52.254254.80.52.255254
54254.80.53.0/24254.80.53.1 to 254.80.53.254254.80.53.255254
55254.80.54.0/24254.80.54.1 to 254.80.54.254254.80.54.255254
56254.80.55.0/24254.80.55.1 to 254.80.55.254254.80.55.255254
57254.80.56.0/24254.80.56.1 to 254.80.56.254254.80.56.255254
58254.80.57.0/24254.80.57.1 to 254.80.57.254254.80.57.255254
59254.80.58.0/24254.80.58.1 to 254.80.58.254254.80.58.255254
60254.80.59.0/24254.80.59.1 to 254.80.59.254254.80.59.255254
61254.80.60.0/24254.80.60.1 to 254.80.60.254254.80.60.255254
62254.80.61.0/24254.80.61.1 to 254.80.61.254254.80.61.255254
63254.80.62.0/24254.80.62.1 to 254.80.62.254254.80.62.255254
64254.80.63.0/24254.80.63.1 to 254.80.63.254254.80.63.255254
65254.80.64.0/24254.80.64.1 to 254.80.64.254254.80.64.255254
66254.80.65.0/24254.80.65.1 to 254.80.65.254254.80.65.255254
67254.80.66.0/24254.80.66.1 to 254.80.66.254254.80.66.255254
68254.80.67.0/24254.80.67.1 to 254.80.67.254254.80.67.255254
69254.80.68.0/24254.80.68.1 to 254.80.68.254254.80.68.255254
70254.80.69.0/24254.80.69.1 to 254.80.69.254254.80.69.255254
71254.80.70.0/24254.80.70.1 to 254.80.70.254254.80.70.255254
72254.80.71.0/24254.80.71.1 to 254.80.71.254254.80.71.255254
73254.80.72.0/24254.80.72.1 to 254.80.72.254254.80.72.255254
74254.80.73.0/24254.80.73.1 to 254.80.73.254254.80.73.255254
75254.80.74.0/24254.80.74.1 to 254.80.74.254254.80.74.255254
76254.80.75.0/24254.80.75.1 to 254.80.75.254254.80.75.255254
77254.80.76.0/24254.80.76.1 to 254.80.76.254254.80.76.255254
78254.80.77.0/24254.80.77.1 to 254.80.77.254254.80.77.255254
79254.80.78.0/24254.80.78.1 to 254.80.78.254254.80.78.255254
80254.80.79.0/24254.80.79.1 to 254.80.79.254254.80.79.255254
81254.80.80.0/24254.80.80.1 to 254.80.80.254254.80.80.255254
82254.80.81.0/24254.80.81.1 to 254.80.81.254254.80.81.255254
83254.80.82.0/24254.80.82.1 to 254.80.82.254254.80.82.255254
84254.80.83.0/24254.80.83.1 to 254.80.83.254254.80.83.255254
85254.80.84.0/24254.80.84.1 to 254.80.84.254254.80.84.255254
86254.80.85.0/24254.80.85.1 to 254.80.85.254254.80.85.255254
87254.80.86.0/24254.80.86.1 to 254.80.86.254254.80.86.255254
88254.80.87.0/24254.80.87.1 to 254.80.87.254254.80.87.255254
89254.80.88.0/24254.80.88.1 to 254.80.88.254254.80.88.255254
90254.80.89.0/24254.80.89.1 to 254.80.89.254254.80.89.255254
91254.80.90.0/24254.80.90.1 to 254.80.90.254254.80.90.255254
92254.80.91.0/24254.80.91.1 to 254.80.91.254254.80.91.255254
93254.80.92.0/24254.80.92.1 to 254.80.92.254254.80.92.255254
94254.80.93.0/24254.80.93.1 to 254.80.93.254254.80.93.255254
95254.80.94.0/24254.80.94.1 to 254.80.94.254254.80.94.255254
96254.80.95.0/24254.80.95.1 to 254.80.95.254254.80.95.255254
97254.80.96.0/24254.80.96.1 to 254.80.96.254254.80.96.255254
98254.80.97.0/24254.80.97.1 to 254.80.97.254254.80.97.255254
99254.80.98.0/24254.80.98.1 to 254.80.98.254254.80.98.255254
100254.80.99.0/24254.80.99.1 to 254.80.99.254254.80.99.255254
101254.80.100.0/24254.80.100.1 to 254.80.100.254254.80.100.255254
102254.80.101.0/24254.80.101.1 to 254.80.101.254254.80.101.255254
103254.80.102.0/24254.80.102.1 to 254.80.102.254254.80.102.255254
104254.80.103.0/24254.80.103.1 to 254.80.103.254254.80.103.255254
105254.80.104.0/24254.80.104.1 to 254.80.104.254254.80.104.255254
106254.80.105.0/24254.80.105.1 to 254.80.105.254254.80.105.255254
107254.80.106.0/24254.80.106.1 to 254.80.106.254254.80.106.255254
108254.80.107.0/24254.80.107.1 to 254.80.107.254254.80.107.255254
109254.80.108.0/24254.80.108.1 to 254.80.108.254254.80.108.255254
110254.80.109.0/24254.80.109.1 to 254.80.109.254254.80.109.255254
111254.80.110.0/24254.80.110.1 to 254.80.110.254254.80.110.255254
112254.80.111.0/24254.80.111.1 to 254.80.111.254254.80.111.255254
113254.80.112.0/24254.80.112.1 to 254.80.112.254254.80.112.255254
114254.80.113.0/24254.80.113.1 to 254.80.113.254254.80.113.255254
115254.80.114.0/24254.80.114.1 to 254.80.114.254254.80.114.255254
116254.80.115.0/24254.80.115.1 to 254.80.115.254254.80.115.255254
117254.80.116.0/24254.80.116.1 to 254.80.116.254254.80.116.255254
118254.80.117.0/24254.80.117.1 to 254.80.117.254254.80.117.255254
119254.80.118.0/24254.80.118.1 to 254.80.118.254254.80.118.255254
120254.80.119.0/24254.80.119.1 to 254.80.119.254254.80.119.255254
121254.80.120.0/24254.80.120.1 to 254.80.120.254254.80.120.255254
122254.80.121.0/24254.80.121.1 to 254.80.121.254254.80.121.255254
123254.80.122.0/24254.80.122.1 to 254.80.122.254254.80.122.255254
124254.80.123.0/24254.80.123.1 to 254.80.123.254254.80.123.255254
125254.80.124.0/24254.80.124.1 to 254.80.124.254254.80.124.255254
126254.80.125.0/24254.80.125.1 to 254.80.125.254254.80.125.255254
127254.80.126.0/24254.80.126.1 to 254.80.126.254254.80.126.255254
128254.80.127.0/24254.80.127.1 to 254.80.127.254254.80.127.255254
129254.80.128.0/24254.80.128.1 to 254.80.128.254254.80.128.255254
130254.80.129.0/24254.80.129.1 to 254.80.129.254254.80.129.255254
131254.80.130.0/24254.80.130.1 to 254.80.130.254254.80.130.255254
132254.80.131.0/24254.80.131.1 to 254.80.131.254254.80.131.255254
133254.80.132.0/24254.80.132.1 to 254.80.132.254254.80.132.255254
134254.80.133.0/24254.80.133.1 to 254.80.133.254254.80.133.255254
135254.80.134.0/24254.80.134.1 to 254.80.134.254254.80.134.255254
136254.80.135.0/24254.80.135.1 to 254.80.135.254254.80.135.255254
137254.80.136.0/24254.80.136.1 to 254.80.136.254254.80.136.255254
138254.80.137.0/24254.80.137.1 to 254.80.137.254254.80.137.255254
139254.80.138.0/24254.80.138.1 to 254.80.138.254254.80.138.255254
140254.80.139.0/24254.80.139.1 to 254.80.139.254254.80.139.255254
141254.80.140.0/24254.80.140.1 to 254.80.140.254254.80.140.255254
142254.80.141.0/24254.80.141.1 to 254.80.141.254254.80.141.255254
143254.80.142.0/24254.80.142.1 to 254.80.142.254254.80.142.255254
144254.80.143.0/24254.80.143.1 to 254.80.143.254254.80.143.255254
145254.80.144.0/24254.80.144.1 to 254.80.144.254254.80.144.255254
146254.80.145.0/24254.80.145.1 to 254.80.145.254254.80.145.255254
147254.80.146.0/24254.80.146.1 to 254.80.146.254254.80.146.255254
148254.80.147.0/24254.80.147.1 to 254.80.147.254254.80.147.255254
149254.80.148.0/24254.80.148.1 to 254.80.148.254254.80.148.255254
150254.80.149.0/24254.80.149.1 to 254.80.149.254254.80.149.255254
151254.80.150.0/24254.80.150.1 to 254.80.150.254254.80.150.255254
152254.80.151.0/24254.80.151.1 to 254.80.151.254254.80.151.255254
153254.80.152.0/24254.80.152.1 to 254.80.152.254254.80.152.255254
154254.80.153.0/24254.80.153.1 to 254.80.153.254254.80.153.255254
155254.80.154.0/24254.80.154.1 to 254.80.154.254254.80.154.255254
156254.80.155.0/24254.80.155.1 to 254.80.155.254254.80.155.255254
157254.80.156.0/24254.80.156.1 to 254.80.156.254254.80.156.255254
158254.80.157.0/24254.80.157.1 to 254.80.157.254254.80.157.255254
159254.80.158.0/24254.80.158.1 to 254.80.158.254254.80.158.255254
160254.80.159.0/24254.80.159.1 to 254.80.159.254254.80.159.255254
161254.80.160.0/24254.80.160.1 to 254.80.160.254254.80.160.255254
162254.80.161.0/24254.80.161.1 to 254.80.161.254254.80.161.255254
163254.80.162.0/24254.80.162.1 to 254.80.162.254254.80.162.255254
164254.80.163.0/24254.80.163.1 to 254.80.163.254254.80.163.255254
165254.80.164.0/24254.80.164.1 to 254.80.164.254254.80.164.255254
166254.80.165.0/24254.80.165.1 to 254.80.165.254254.80.165.255254
167254.80.166.0/24254.80.166.1 to 254.80.166.254254.80.166.255254
168254.80.167.0/24254.80.167.1 to 254.80.167.254254.80.167.255254
169254.80.168.0/24254.80.168.1 to 254.80.168.254254.80.168.255254
170254.80.169.0/24254.80.169.1 to 254.80.169.254254.80.169.255254
171254.80.170.0/24254.80.170.1 to 254.80.170.254254.80.170.255254
172254.80.171.0/24254.80.171.1 to 254.80.171.254254.80.171.255254
173254.80.172.0/24254.80.172.1 to 254.80.172.254254.80.172.255254
174254.80.173.0/24254.80.173.1 to 254.80.173.254254.80.173.255254
175254.80.174.0/24254.80.174.1 to 254.80.174.254254.80.174.255254
176254.80.175.0/24254.80.175.1 to 254.80.175.254254.80.175.255254
177254.80.176.0/24254.80.176.1 to 254.80.176.254254.80.176.255254
178254.80.177.0/24254.80.177.1 to 254.80.177.254254.80.177.255254
179254.80.178.0/24254.80.178.1 to 254.80.178.254254.80.178.255254
180254.80.179.0/24254.80.179.1 to 254.80.179.254254.80.179.255254
181254.80.180.0/24254.80.180.1 to 254.80.180.254254.80.180.255254
182254.80.181.0/24254.80.181.1 to 254.80.181.254254.80.181.255254
183254.80.182.0/24254.80.182.1 to 254.80.182.254254.80.182.255254
184254.80.183.0/24254.80.183.1 to 254.80.183.254254.80.183.255254
185254.80.184.0/24254.80.184.1 to 254.80.184.254254.80.184.255254
186254.80.185.0/24254.80.185.1 to 254.80.185.254254.80.185.255254
187254.80.186.0/24254.80.186.1 to 254.80.186.254254.80.186.255254
188254.80.187.0/24254.80.187.1 to 254.80.187.254254.80.187.255254
189254.80.188.0/24254.80.188.1 to 254.80.188.254254.80.188.255254
190254.80.189.0/24254.80.189.1 to 254.80.189.254254.80.189.255254
191254.80.190.0/24254.80.190.1 to 254.80.190.254254.80.190.255254
192254.80.191.0/24254.80.191.1 to 254.80.191.254254.80.191.255254
193254.80.192.0/24254.80.192.1 to 254.80.192.254254.80.192.255254
194254.80.193.0/24254.80.193.1 to 254.80.193.254254.80.193.255254
195254.80.194.0/24254.80.194.1 to 254.80.194.254254.80.194.255254
196254.80.195.0/24254.80.195.1 to 254.80.195.254254.80.195.255254
197254.80.196.0/24254.80.196.1 to 254.80.196.254254.80.196.255254
198254.80.197.0/24254.80.197.1 to 254.80.197.254254.80.197.255254
199254.80.198.0/24254.80.198.1 to 254.80.198.254254.80.198.255254
200254.80.199.0/24254.80.199.1 to 254.80.199.254254.80.199.255254
201254.80.200.0/24254.80.200.1 to 254.80.200.254254.80.200.255254
202254.80.201.0/24254.80.201.1 to 254.80.201.254254.80.201.255254
203254.80.202.0/24254.80.202.1 to 254.80.202.254254.80.202.255254
204254.80.203.0/24254.80.203.1 to 254.80.203.254254.80.203.255254
205254.80.204.0/24254.80.204.1 to 254.80.204.254254.80.204.255254
206254.80.205.0/24254.80.205.1 to 254.80.205.254254.80.205.255254
207254.80.206.0/24254.80.206.1 to 254.80.206.254254.80.206.255254
208254.80.207.0/24254.80.207.1 to 254.80.207.254254.80.207.255254
209254.80.208.0/24254.80.208.1 to 254.80.208.254254.80.208.255254
210254.80.209.0/24254.80.209.1 to 254.80.209.254254.80.209.255254
211254.80.210.0/24254.80.210.1 to 254.80.210.254254.80.210.255254
212254.80.211.0/24254.80.211.1 to 254.80.211.254254.80.211.255254
213254.80.212.0/24254.80.212.1 to 254.80.212.254254.80.212.255254
214254.80.213.0/24254.80.213.1 to 254.80.213.254254.80.213.255254
215254.80.214.0/24254.80.214.1 to 254.80.214.254254.80.214.255254
216254.80.215.0/24254.80.215.1 to 254.80.215.254254.80.215.255254
217254.80.216.0/24254.80.216.1 to 254.80.216.254254.80.216.255254
218254.80.217.0/24254.80.217.1 to 254.80.217.254254.80.217.255254
219254.80.218.0/24254.80.218.1 to 254.80.218.254254.80.218.255254
220254.80.219.0/24254.80.219.1 to 254.80.219.254254.80.219.255254
221254.80.220.0/24254.80.220.1 to 254.80.220.254254.80.220.255254
222254.80.221.0/24254.80.221.1 to 254.80.221.254254.80.221.255254
223254.80.222.0/24254.80.222.1 to 254.80.222.254254.80.222.255254
224254.80.223.0/24254.80.223.1 to 254.80.223.254254.80.223.255254
225254.80.224.0/24254.80.224.1 to 254.80.224.254254.80.224.255254
226254.80.225.0/24254.80.225.1 to 254.80.225.254254.80.225.255254
227254.80.226.0/24254.80.226.1 to 254.80.226.254254.80.226.255254
228254.80.227.0/24254.80.227.1 to 254.80.227.254254.80.227.255254
229254.80.228.0/24254.80.228.1 to 254.80.228.254254.80.228.255254
230254.80.229.0/24254.80.229.1 to 254.80.229.254254.80.229.255254
231254.80.230.0/24254.80.230.1 to 254.80.230.254254.80.230.255254
232254.80.231.0/24254.80.231.1 to 254.80.231.254254.80.231.255254
233254.80.232.0/24254.80.232.1 to 254.80.232.254254.80.232.255254
234254.80.233.0/24254.80.233.1 to 254.80.233.254254.80.233.255254
235254.80.234.0/24254.80.234.1 to 254.80.234.254254.80.234.255254
236254.80.235.0/24254.80.235.1 to 254.80.235.254254.80.235.255254
237254.80.236.0/24254.80.236.1 to 254.80.236.254254.80.236.255254
238254.80.237.0/24254.80.237.1 to 254.80.237.254254.80.237.255254
239254.80.238.0/24254.80.238.1 to 254.80.238.254254.80.238.255254
240254.80.239.0/24254.80.239.1 to 254.80.239.254254.80.239.255254
241254.80.240.0/24254.80.240.1 to 254.80.240.254254.80.240.255254
242254.80.241.0/24254.80.241.1 to 254.80.241.254254.80.241.255254
243254.80.242.0/24254.80.242.1 to 254.80.242.254254.80.242.255254
244254.80.243.0/24254.80.243.1 to 254.80.243.254254.80.243.255254
245254.80.244.0/24254.80.244.1 to 254.80.244.254254.80.244.255254
246254.80.245.0/24254.80.245.1 to 254.80.245.254254.80.245.255254
247254.80.246.0/24254.80.246.1 to 254.80.246.254254.80.246.255254
248254.80.247.0/24254.80.247.1 to 254.80.247.254254.80.247.255254
249254.80.248.0/24254.80.248.1 to 254.80.248.254254.80.248.255254
250254.80.249.0/24254.80.249.1 to 254.80.249.254254.80.249.255254
251254.80.250.0/24254.80.250.1 to 254.80.250.254254.80.250.255254
252254.80.251.0/24254.80.251.1 to 254.80.251.254254.80.251.255254
253254.80.252.0/24254.80.252.1 to 254.80.252.254254.80.252.255254
254254.80.253.0/24254.80.253.1 to 254.80.253.254254.80.253.255254
255254.80.254.0/24254.80.254.1 to 254.80.254.254254.80.254.255254
256254.80.255.0/24254.80.255.1 to 254.80.255.254254.80.255.255254

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.