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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.

Network213.0.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
213.0.0.0
Broadcast address
213.7.255.255
First usable
213.0.0.1
Last usable
213.7.255.254
Usable hosts
524,286 (524,288 less the network and broadcast addresses)
Subnet mask
255.248.0.0
Wildcard mask
0.7.255.255 (Cisco ACLs, OSPF)
Prefix length
/13
Type
Public public
Old class
C (default /24)
As numbers
Hex D5000000 · Integer 3573547008 to 3574071295
Reverse DNS zones
0.213.in-addr.arpa
1.213.in-addr.arpa
2.213.in-addr.arpa
3.213.in-addr.arpa
4.213.in-addr.arpa
5.213.in-addr.arpa
6.213.in-addr.arpa
7.213.in-addr.arpa
/13 is not on a 8-bit boundary, so it takes 8 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11010101.00000000.00000000.00000000213.0.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network11010101.00000000.00000000.00000000213.0.0.0
Broadcast11010101.00000111.11111111.11111111213.7.255.255
Split into smaller subnets/24
/14 (2)/15 (4)/16 (8)/17 (16)/18 (32)/19 (64)/20 (128)/21 (256)/22 (512)/23 (1,024)/24 (2,048)/25 (4,096)

213.0.0.0/13 makes 2,048 subnets of /24; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1213.0.0.0/24213.0.0.1 to 213.0.0.254213.0.0.255254
2213.0.1.0/24213.0.1.1 to 213.0.1.254213.0.1.255254
3213.0.2.0/24213.0.2.1 to 213.0.2.254213.0.2.255254
4213.0.3.0/24213.0.3.1 to 213.0.3.254213.0.3.255254
5213.0.4.0/24213.0.4.1 to 213.0.4.254213.0.4.255254
6213.0.5.0/24213.0.5.1 to 213.0.5.254213.0.5.255254
7213.0.6.0/24213.0.6.1 to 213.0.6.254213.0.6.255254
8213.0.7.0/24213.0.7.1 to 213.0.7.254213.0.7.255254
9213.0.8.0/24213.0.8.1 to 213.0.8.254213.0.8.255254
10213.0.9.0/24213.0.9.1 to 213.0.9.254213.0.9.255254
11213.0.10.0/24213.0.10.1 to 213.0.10.254213.0.10.255254
12213.0.11.0/24213.0.11.1 to 213.0.11.254213.0.11.255254
13213.0.12.0/24213.0.12.1 to 213.0.12.254213.0.12.255254
14213.0.13.0/24213.0.13.1 to 213.0.13.254213.0.13.255254
15213.0.14.0/24213.0.14.1 to 213.0.14.254213.0.14.255254
16213.0.15.0/24213.0.15.1 to 213.0.15.254213.0.15.255254
17213.0.16.0/24213.0.16.1 to 213.0.16.254213.0.16.255254
18213.0.17.0/24213.0.17.1 to 213.0.17.254213.0.17.255254
19213.0.18.0/24213.0.18.1 to 213.0.18.254213.0.18.255254
20213.0.19.0/24213.0.19.1 to 213.0.19.254213.0.19.255254
21213.0.20.0/24213.0.20.1 to 213.0.20.254213.0.20.255254
22213.0.21.0/24213.0.21.1 to 213.0.21.254213.0.21.255254
23213.0.22.0/24213.0.22.1 to 213.0.22.254213.0.22.255254
24213.0.23.0/24213.0.23.1 to 213.0.23.254213.0.23.255254
25213.0.24.0/24213.0.24.1 to 213.0.24.254213.0.24.255254
26213.0.25.0/24213.0.25.1 to 213.0.25.254213.0.25.255254
27213.0.26.0/24213.0.26.1 to 213.0.26.254213.0.26.255254
28213.0.27.0/24213.0.27.1 to 213.0.27.254213.0.27.255254
29213.0.28.0/24213.0.28.1 to 213.0.28.254213.0.28.255254
30213.0.29.0/24213.0.29.1 to 213.0.29.254213.0.29.255254
31213.0.30.0/24213.0.30.1 to 213.0.30.254213.0.30.255254
32213.0.31.0/24213.0.31.1 to 213.0.31.254213.0.31.255254
33213.0.32.0/24213.0.32.1 to 213.0.32.254213.0.32.255254
34213.0.33.0/24213.0.33.1 to 213.0.33.254213.0.33.255254
35213.0.34.0/24213.0.34.1 to 213.0.34.254213.0.34.255254
36213.0.35.0/24213.0.35.1 to 213.0.35.254213.0.35.255254
37213.0.36.0/24213.0.36.1 to 213.0.36.254213.0.36.255254
38213.0.37.0/24213.0.37.1 to 213.0.37.254213.0.37.255254
39213.0.38.0/24213.0.38.1 to 213.0.38.254213.0.38.255254
40213.0.39.0/24213.0.39.1 to 213.0.39.254213.0.39.255254
41213.0.40.0/24213.0.40.1 to 213.0.40.254213.0.40.255254
42213.0.41.0/24213.0.41.1 to 213.0.41.254213.0.41.255254
43213.0.42.0/24213.0.42.1 to 213.0.42.254213.0.42.255254
44213.0.43.0/24213.0.43.1 to 213.0.43.254213.0.43.255254
45213.0.44.0/24213.0.44.1 to 213.0.44.254213.0.44.255254
46213.0.45.0/24213.0.45.1 to 213.0.45.254213.0.45.255254
47213.0.46.0/24213.0.46.1 to 213.0.46.254213.0.46.255254
48213.0.47.0/24213.0.47.1 to 213.0.47.254213.0.47.255254
49213.0.48.0/24213.0.48.1 to 213.0.48.254213.0.48.255254
50213.0.49.0/24213.0.49.1 to 213.0.49.254213.0.49.255254
51213.0.50.0/24213.0.50.1 to 213.0.50.254213.0.50.255254
52213.0.51.0/24213.0.51.1 to 213.0.51.254213.0.51.255254
53213.0.52.0/24213.0.52.1 to 213.0.52.254213.0.52.255254
54213.0.53.0/24213.0.53.1 to 213.0.53.254213.0.53.255254
55213.0.54.0/24213.0.54.1 to 213.0.54.254213.0.54.255254
56213.0.55.0/24213.0.55.1 to 213.0.55.254213.0.55.255254
57213.0.56.0/24213.0.56.1 to 213.0.56.254213.0.56.255254
58213.0.57.0/24213.0.57.1 to 213.0.57.254213.0.57.255254
59213.0.58.0/24213.0.58.1 to 213.0.58.254213.0.58.255254
60213.0.59.0/24213.0.59.1 to 213.0.59.254213.0.59.255254
61213.0.60.0/24213.0.60.1 to 213.0.60.254213.0.60.255254
62213.0.61.0/24213.0.61.1 to 213.0.61.254213.0.61.255254
63213.0.62.0/24213.0.62.1 to 213.0.62.254213.0.62.255254
64213.0.63.0/24213.0.63.1 to 213.0.63.254213.0.63.255254
65213.0.64.0/24213.0.64.1 to 213.0.64.254213.0.64.255254
66213.0.65.0/24213.0.65.1 to 213.0.65.254213.0.65.255254
67213.0.66.0/24213.0.66.1 to 213.0.66.254213.0.66.255254
68213.0.67.0/24213.0.67.1 to 213.0.67.254213.0.67.255254
69213.0.68.0/24213.0.68.1 to 213.0.68.254213.0.68.255254
70213.0.69.0/24213.0.69.1 to 213.0.69.254213.0.69.255254
71213.0.70.0/24213.0.70.1 to 213.0.70.254213.0.70.255254
72213.0.71.0/24213.0.71.1 to 213.0.71.254213.0.71.255254
73213.0.72.0/24213.0.72.1 to 213.0.72.254213.0.72.255254
74213.0.73.0/24213.0.73.1 to 213.0.73.254213.0.73.255254
75213.0.74.0/24213.0.74.1 to 213.0.74.254213.0.74.255254
76213.0.75.0/24213.0.75.1 to 213.0.75.254213.0.75.255254
77213.0.76.0/24213.0.76.1 to 213.0.76.254213.0.76.255254
78213.0.77.0/24213.0.77.1 to 213.0.77.254213.0.77.255254
79213.0.78.0/24213.0.78.1 to 213.0.78.254213.0.78.255254
80213.0.79.0/24213.0.79.1 to 213.0.79.254213.0.79.255254
81213.0.80.0/24213.0.80.1 to 213.0.80.254213.0.80.255254
82213.0.81.0/24213.0.81.1 to 213.0.81.254213.0.81.255254
83213.0.82.0/24213.0.82.1 to 213.0.82.254213.0.82.255254
84213.0.83.0/24213.0.83.1 to 213.0.83.254213.0.83.255254
85213.0.84.0/24213.0.84.1 to 213.0.84.254213.0.84.255254
86213.0.85.0/24213.0.85.1 to 213.0.85.254213.0.85.255254
87213.0.86.0/24213.0.86.1 to 213.0.86.254213.0.86.255254
88213.0.87.0/24213.0.87.1 to 213.0.87.254213.0.87.255254
89213.0.88.0/24213.0.88.1 to 213.0.88.254213.0.88.255254
90213.0.89.0/24213.0.89.1 to 213.0.89.254213.0.89.255254
91213.0.90.0/24213.0.90.1 to 213.0.90.254213.0.90.255254
92213.0.91.0/24213.0.91.1 to 213.0.91.254213.0.91.255254
93213.0.92.0/24213.0.92.1 to 213.0.92.254213.0.92.255254
94213.0.93.0/24213.0.93.1 to 213.0.93.254213.0.93.255254
95213.0.94.0/24213.0.94.1 to 213.0.94.254213.0.94.255254
96213.0.95.0/24213.0.95.1 to 213.0.95.254213.0.95.255254
97213.0.96.0/24213.0.96.1 to 213.0.96.254213.0.96.255254
98213.0.97.0/24213.0.97.1 to 213.0.97.254213.0.97.255254
99213.0.98.0/24213.0.98.1 to 213.0.98.254213.0.98.255254
100213.0.99.0/24213.0.99.1 to 213.0.99.254213.0.99.255254
101213.0.100.0/24213.0.100.1 to 213.0.100.254213.0.100.255254
102213.0.101.0/24213.0.101.1 to 213.0.101.254213.0.101.255254
103213.0.102.0/24213.0.102.1 to 213.0.102.254213.0.102.255254
104213.0.103.0/24213.0.103.1 to 213.0.103.254213.0.103.255254
105213.0.104.0/24213.0.104.1 to 213.0.104.254213.0.104.255254
106213.0.105.0/24213.0.105.1 to 213.0.105.254213.0.105.255254
107213.0.106.0/24213.0.106.1 to 213.0.106.254213.0.106.255254
108213.0.107.0/24213.0.107.1 to 213.0.107.254213.0.107.255254
109213.0.108.0/24213.0.108.1 to 213.0.108.254213.0.108.255254
110213.0.109.0/24213.0.109.1 to 213.0.109.254213.0.109.255254
111213.0.110.0/24213.0.110.1 to 213.0.110.254213.0.110.255254
112213.0.111.0/24213.0.111.1 to 213.0.111.254213.0.111.255254
113213.0.112.0/24213.0.112.1 to 213.0.112.254213.0.112.255254
114213.0.113.0/24213.0.113.1 to 213.0.113.254213.0.113.255254
115213.0.114.0/24213.0.114.1 to 213.0.114.254213.0.114.255254
116213.0.115.0/24213.0.115.1 to 213.0.115.254213.0.115.255254
117213.0.116.0/24213.0.116.1 to 213.0.116.254213.0.116.255254
118213.0.117.0/24213.0.117.1 to 213.0.117.254213.0.117.255254
119213.0.118.0/24213.0.118.1 to 213.0.118.254213.0.118.255254
120213.0.119.0/24213.0.119.1 to 213.0.119.254213.0.119.255254
121213.0.120.0/24213.0.120.1 to 213.0.120.254213.0.120.255254
122213.0.121.0/24213.0.121.1 to 213.0.121.254213.0.121.255254
123213.0.122.0/24213.0.122.1 to 213.0.122.254213.0.122.255254
124213.0.123.0/24213.0.123.1 to 213.0.123.254213.0.123.255254
125213.0.124.0/24213.0.124.1 to 213.0.124.254213.0.124.255254
126213.0.125.0/24213.0.125.1 to 213.0.125.254213.0.125.255254
127213.0.126.0/24213.0.126.1 to 213.0.126.254213.0.126.255254
128213.0.127.0/24213.0.127.1 to 213.0.127.254213.0.127.255254
129213.0.128.0/24213.0.128.1 to 213.0.128.254213.0.128.255254
130213.0.129.0/24213.0.129.1 to 213.0.129.254213.0.129.255254
131213.0.130.0/24213.0.130.1 to 213.0.130.254213.0.130.255254
132213.0.131.0/24213.0.131.1 to 213.0.131.254213.0.131.255254
133213.0.132.0/24213.0.132.1 to 213.0.132.254213.0.132.255254
134213.0.133.0/24213.0.133.1 to 213.0.133.254213.0.133.255254
135213.0.134.0/24213.0.134.1 to 213.0.134.254213.0.134.255254
136213.0.135.0/24213.0.135.1 to 213.0.135.254213.0.135.255254
137213.0.136.0/24213.0.136.1 to 213.0.136.254213.0.136.255254
138213.0.137.0/24213.0.137.1 to 213.0.137.254213.0.137.255254
139213.0.138.0/24213.0.138.1 to 213.0.138.254213.0.138.255254
140213.0.139.0/24213.0.139.1 to 213.0.139.254213.0.139.255254
141213.0.140.0/24213.0.140.1 to 213.0.140.254213.0.140.255254
142213.0.141.0/24213.0.141.1 to 213.0.141.254213.0.141.255254
143213.0.142.0/24213.0.142.1 to 213.0.142.254213.0.142.255254
144213.0.143.0/24213.0.143.1 to 213.0.143.254213.0.143.255254
145213.0.144.0/24213.0.144.1 to 213.0.144.254213.0.144.255254
146213.0.145.0/24213.0.145.1 to 213.0.145.254213.0.145.255254
147213.0.146.0/24213.0.146.1 to 213.0.146.254213.0.146.255254
148213.0.147.0/24213.0.147.1 to 213.0.147.254213.0.147.255254
149213.0.148.0/24213.0.148.1 to 213.0.148.254213.0.148.255254
150213.0.149.0/24213.0.149.1 to 213.0.149.254213.0.149.255254
151213.0.150.0/24213.0.150.1 to 213.0.150.254213.0.150.255254
152213.0.151.0/24213.0.151.1 to 213.0.151.254213.0.151.255254
153213.0.152.0/24213.0.152.1 to 213.0.152.254213.0.152.255254
154213.0.153.0/24213.0.153.1 to 213.0.153.254213.0.153.255254
155213.0.154.0/24213.0.154.1 to 213.0.154.254213.0.154.255254
156213.0.155.0/24213.0.155.1 to 213.0.155.254213.0.155.255254
157213.0.156.0/24213.0.156.1 to 213.0.156.254213.0.156.255254
158213.0.157.0/24213.0.157.1 to 213.0.157.254213.0.157.255254
159213.0.158.0/24213.0.158.1 to 213.0.158.254213.0.158.255254
160213.0.159.0/24213.0.159.1 to 213.0.159.254213.0.159.255254
161213.0.160.0/24213.0.160.1 to 213.0.160.254213.0.160.255254
162213.0.161.0/24213.0.161.1 to 213.0.161.254213.0.161.255254
163213.0.162.0/24213.0.162.1 to 213.0.162.254213.0.162.255254
164213.0.163.0/24213.0.163.1 to 213.0.163.254213.0.163.255254
165213.0.164.0/24213.0.164.1 to 213.0.164.254213.0.164.255254
166213.0.165.0/24213.0.165.1 to 213.0.165.254213.0.165.255254
167213.0.166.0/24213.0.166.1 to 213.0.166.254213.0.166.255254
168213.0.167.0/24213.0.167.1 to 213.0.167.254213.0.167.255254
169213.0.168.0/24213.0.168.1 to 213.0.168.254213.0.168.255254
170213.0.169.0/24213.0.169.1 to 213.0.169.254213.0.169.255254
171213.0.170.0/24213.0.170.1 to 213.0.170.254213.0.170.255254
172213.0.171.0/24213.0.171.1 to 213.0.171.254213.0.171.255254
173213.0.172.0/24213.0.172.1 to 213.0.172.254213.0.172.255254
174213.0.173.0/24213.0.173.1 to 213.0.173.254213.0.173.255254
175213.0.174.0/24213.0.174.1 to 213.0.174.254213.0.174.255254
176213.0.175.0/24213.0.175.1 to 213.0.175.254213.0.175.255254
177213.0.176.0/24213.0.176.1 to 213.0.176.254213.0.176.255254
178213.0.177.0/24213.0.177.1 to 213.0.177.254213.0.177.255254
179213.0.178.0/24213.0.178.1 to 213.0.178.254213.0.178.255254
180213.0.179.0/24213.0.179.1 to 213.0.179.254213.0.179.255254
181213.0.180.0/24213.0.180.1 to 213.0.180.254213.0.180.255254
182213.0.181.0/24213.0.181.1 to 213.0.181.254213.0.181.255254
183213.0.182.0/24213.0.182.1 to 213.0.182.254213.0.182.255254
184213.0.183.0/24213.0.183.1 to 213.0.183.254213.0.183.255254
185213.0.184.0/24213.0.184.1 to 213.0.184.254213.0.184.255254
186213.0.185.0/24213.0.185.1 to 213.0.185.254213.0.185.255254
187213.0.186.0/24213.0.186.1 to 213.0.186.254213.0.186.255254
188213.0.187.0/24213.0.187.1 to 213.0.187.254213.0.187.255254
189213.0.188.0/24213.0.188.1 to 213.0.188.254213.0.188.255254
190213.0.189.0/24213.0.189.1 to 213.0.189.254213.0.189.255254
191213.0.190.0/24213.0.190.1 to 213.0.190.254213.0.190.255254
192213.0.191.0/24213.0.191.1 to 213.0.191.254213.0.191.255254
193213.0.192.0/24213.0.192.1 to 213.0.192.254213.0.192.255254
194213.0.193.0/24213.0.193.1 to 213.0.193.254213.0.193.255254
195213.0.194.0/24213.0.194.1 to 213.0.194.254213.0.194.255254
196213.0.195.0/24213.0.195.1 to 213.0.195.254213.0.195.255254
197213.0.196.0/24213.0.196.1 to 213.0.196.254213.0.196.255254
198213.0.197.0/24213.0.197.1 to 213.0.197.254213.0.197.255254
199213.0.198.0/24213.0.198.1 to 213.0.198.254213.0.198.255254
200213.0.199.0/24213.0.199.1 to 213.0.199.254213.0.199.255254
201213.0.200.0/24213.0.200.1 to 213.0.200.254213.0.200.255254
202213.0.201.0/24213.0.201.1 to 213.0.201.254213.0.201.255254
203213.0.202.0/24213.0.202.1 to 213.0.202.254213.0.202.255254
204213.0.203.0/24213.0.203.1 to 213.0.203.254213.0.203.255254
205213.0.204.0/24213.0.204.1 to 213.0.204.254213.0.204.255254
206213.0.205.0/24213.0.205.1 to 213.0.205.254213.0.205.255254
207213.0.206.0/24213.0.206.1 to 213.0.206.254213.0.206.255254
208213.0.207.0/24213.0.207.1 to 213.0.207.254213.0.207.255254
209213.0.208.0/24213.0.208.1 to 213.0.208.254213.0.208.255254
210213.0.209.0/24213.0.209.1 to 213.0.209.254213.0.209.255254
211213.0.210.0/24213.0.210.1 to 213.0.210.254213.0.210.255254
212213.0.211.0/24213.0.211.1 to 213.0.211.254213.0.211.255254
213213.0.212.0/24213.0.212.1 to 213.0.212.254213.0.212.255254
214213.0.213.0/24213.0.213.1 to 213.0.213.254213.0.213.255254
215213.0.214.0/24213.0.214.1 to 213.0.214.254213.0.214.255254
216213.0.215.0/24213.0.215.1 to 213.0.215.254213.0.215.255254
217213.0.216.0/24213.0.216.1 to 213.0.216.254213.0.216.255254
218213.0.217.0/24213.0.217.1 to 213.0.217.254213.0.217.255254
219213.0.218.0/24213.0.218.1 to 213.0.218.254213.0.218.255254
220213.0.219.0/24213.0.219.1 to 213.0.219.254213.0.219.255254
221213.0.220.0/24213.0.220.1 to 213.0.220.254213.0.220.255254
222213.0.221.0/24213.0.221.1 to 213.0.221.254213.0.221.255254
223213.0.222.0/24213.0.222.1 to 213.0.222.254213.0.222.255254
224213.0.223.0/24213.0.223.1 to 213.0.223.254213.0.223.255254
225213.0.224.0/24213.0.224.1 to 213.0.224.254213.0.224.255254
226213.0.225.0/24213.0.225.1 to 213.0.225.254213.0.225.255254
227213.0.226.0/24213.0.226.1 to 213.0.226.254213.0.226.255254
228213.0.227.0/24213.0.227.1 to 213.0.227.254213.0.227.255254
229213.0.228.0/24213.0.228.1 to 213.0.228.254213.0.228.255254
230213.0.229.0/24213.0.229.1 to 213.0.229.254213.0.229.255254
231213.0.230.0/24213.0.230.1 to 213.0.230.254213.0.230.255254
232213.0.231.0/24213.0.231.1 to 213.0.231.254213.0.231.255254
233213.0.232.0/24213.0.232.1 to 213.0.232.254213.0.232.255254
234213.0.233.0/24213.0.233.1 to 213.0.233.254213.0.233.255254
235213.0.234.0/24213.0.234.1 to 213.0.234.254213.0.234.255254
236213.0.235.0/24213.0.235.1 to 213.0.235.254213.0.235.255254
237213.0.236.0/24213.0.236.1 to 213.0.236.254213.0.236.255254
238213.0.237.0/24213.0.237.1 to 213.0.237.254213.0.237.255254
239213.0.238.0/24213.0.238.1 to 213.0.238.254213.0.238.255254
240213.0.239.0/24213.0.239.1 to 213.0.239.254213.0.239.255254
241213.0.240.0/24213.0.240.1 to 213.0.240.254213.0.240.255254
242213.0.241.0/24213.0.241.1 to 213.0.241.254213.0.241.255254
243213.0.242.0/24213.0.242.1 to 213.0.242.254213.0.242.255254
244213.0.243.0/24213.0.243.1 to 213.0.243.254213.0.243.255254
245213.0.244.0/24213.0.244.1 to 213.0.244.254213.0.244.255254
246213.0.245.0/24213.0.245.1 to 213.0.245.254213.0.245.255254
247213.0.246.0/24213.0.246.1 to 213.0.246.254213.0.246.255254
248213.0.247.0/24213.0.247.1 to 213.0.247.254213.0.247.255254
249213.0.248.0/24213.0.248.1 to 213.0.248.254213.0.248.255254
250213.0.249.0/24213.0.249.1 to 213.0.249.254213.0.249.255254
251213.0.250.0/24213.0.250.1 to 213.0.250.254213.0.250.255254
252213.0.251.0/24213.0.251.1 to 213.0.251.254213.0.251.255254
253213.0.252.0/24213.0.252.1 to 213.0.252.254213.0.252.255254
254213.0.253.0/24213.0.253.1 to 213.0.253.254213.0.253.255254
255213.0.254.0/24213.0.254.1 to 213.0.254.254213.0.254.255254
256213.0.255.0/24213.0.255.1 to 213.0.255.254213.0.255.255254

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.