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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.

Network202.239.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
202.239.0.0
Broadcast address
202.239.255.255
First usable
202.239.0.1
Last usable
202.239.255.254
Usable hosts
65,534 (65,536 less the network and broadcast addresses)
Subnet mask
255.255.0.0
Wildcard mask
0.0.255.255 (Cisco ACLs, OSPF)
Prefix length
/16
Type
Public public
Old class
C (default /24)
As numbers
Hex CAEF0000 · Integer 3404660736 to 3404726271
Reverse DNS zone
239.202.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11001010.11101111..00000000.00000000202.239.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network11001010.11101111..00000000.00000000202.239.0.0
Broadcast11001010.11101111..11111111.11111111202.239.255.255
Split into smaller subnets/24
/17 (2)/18 (4)/19 (8)/20 (16)/21 (32)/22 (64)/23 (128)/24 (256)/25 (512)/26 (1,024)/27 (2,048)/28 (4,096)

202.239.0.0/16 makes 256 subnets of /24.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1202.239.0.0/24202.239.0.1 to 202.239.0.254202.239.0.255254
2202.239.1.0/24202.239.1.1 to 202.239.1.254202.239.1.255254
3202.239.2.0/24202.239.2.1 to 202.239.2.254202.239.2.255254
4202.239.3.0/24202.239.3.1 to 202.239.3.254202.239.3.255254
5202.239.4.0/24202.239.4.1 to 202.239.4.254202.239.4.255254
6202.239.5.0/24202.239.5.1 to 202.239.5.254202.239.5.255254
7202.239.6.0/24202.239.6.1 to 202.239.6.254202.239.6.255254
8202.239.7.0/24202.239.7.1 to 202.239.7.254202.239.7.255254
9202.239.8.0/24202.239.8.1 to 202.239.8.254202.239.8.255254
10202.239.9.0/24202.239.9.1 to 202.239.9.254202.239.9.255254
11202.239.10.0/24202.239.10.1 to 202.239.10.254202.239.10.255254
12202.239.11.0/24202.239.11.1 to 202.239.11.254202.239.11.255254
13202.239.12.0/24202.239.12.1 to 202.239.12.254202.239.12.255254
14202.239.13.0/24202.239.13.1 to 202.239.13.254202.239.13.255254
15202.239.14.0/24202.239.14.1 to 202.239.14.254202.239.14.255254
16202.239.15.0/24202.239.15.1 to 202.239.15.254202.239.15.255254
17202.239.16.0/24202.239.16.1 to 202.239.16.254202.239.16.255254
18202.239.17.0/24202.239.17.1 to 202.239.17.254202.239.17.255254
19202.239.18.0/24202.239.18.1 to 202.239.18.254202.239.18.255254
20202.239.19.0/24202.239.19.1 to 202.239.19.254202.239.19.255254
21202.239.20.0/24202.239.20.1 to 202.239.20.254202.239.20.255254
22202.239.21.0/24202.239.21.1 to 202.239.21.254202.239.21.255254
23202.239.22.0/24202.239.22.1 to 202.239.22.254202.239.22.255254
24202.239.23.0/24202.239.23.1 to 202.239.23.254202.239.23.255254
25202.239.24.0/24202.239.24.1 to 202.239.24.254202.239.24.255254
26202.239.25.0/24202.239.25.1 to 202.239.25.254202.239.25.255254
27202.239.26.0/24202.239.26.1 to 202.239.26.254202.239.26.255254
28202.239.27.0/24202.239.27.1 to 202.239.27.254202.239.27.255254
29202.239.28.0/24202.239.28.1 to 202.239.28.254202.239.28.255254
30202.239.29.0/24202.239.29.1 to 202.239.29.254202.239.29.255254
31202.239.30.0/24202.239.30.1 to 202.239.30.254202.239.30.255254
32202.239.31.0/24202.239.31.1 to 202.239.31.254202.239.31.255254
33202.239.32.0/24202.239.32.1 to 202.239.32.254202.239.32.255254
34202.239.33.0/24202.239.33.1 to 202.239.33.254202.239.33.255254
35202.239.34.0/24202.239.34.1 to 202.239.34.254202.239.34.255254
36202.239.35.0/24202.239.35.1 to 202.239.35.254202.239.35.255254
37202.239.36.0/24202.239.36.1 to 202.239.36.254202.239.36.255254
38202.239.37.0/24202.239.37.1 to 202.239.37.254202.239.37.255254
39202.239.38.0/24202.239.38.1 to 202.239.38.254202.239.38.255254
40202.239.39.0/24202.239.39.1 to 202.239.39.254202.239.39.255254
41202.239.40.0/24202.239.40.1 to 202.239.40.254202.239.40.255254
42202.239.41.0/24202.239.41.1 to 202.239.41.254202.239.41.255254
43202.239.42.0/24202.239.42.1 to 202.239.42.254202.239.42.255254
44202.239.43.0/24202.239.43.1 to 202.239.43.254202.239.43.255254
45202.239.44.0/24202.239.44.1 to 202.239.44.254202.239.44.255254
46202.239.45.0/24202.239.45.1 to 202.239.45.254202.239.45.255254
47202.239.46.0/24202.239.46.1 to 202.239.46.254202.239.46.255254
48202.239.47.0/24202.239.47.1 to 202.239.47.254202.239.47.255254
49202.239.48.0/24202.239.48.1 to 202.239.48.254202.239.48.255254
50202.239.49.0/24202.239.49.1 to 202.239.49.254202.239.49.255254
51202.239.50.0/24202.239.50.1 to 202.239.50.254202.239.50.255254
52202.239.51.0/24202.239.51.1 to 202.239.51.254202.239.51.255254
53202.239.52.0/24202.239.52.1 to 202.239.52.254202.239.52.255254
54202.239.53.0/24202.239.53.1 to 202.239.53.254202.239.53.255254
55202.239.54.0/24202.239.54.1 to 202.239.54.254202.239.54.255254
56202.239.55.0/24202.239.55.1 to 202.239.55.254202.239.55.255254
57202.239.56.0/24202.239.56.1 to 202.239.56.254202.239.56.255254
58202.239.57.0/24202.239.57.1 to 202.239.57.254202.239.57.255254
59202.239.58.0/24202.239.58.1 to 202.239.58.254202.239.58.255254
60202.239.59.0/24202.239.59.1 to 202.239.59.254202.239.59.255254
61202.239.60.0/24202.239.60.1 to 202.239.60.254202.239.60.255254
62202.239.61.0/24202.239.61.1 to 202.239.61.254202.239.61.255254
63202.239.62.0/24202.239.62.1 to 202.239.62.254202.239.62.255254
64202.239.63.0/24202.239.63.1 to 202.239.63.254202.239.63.255254
65202.239.64.0/24202.239.64.1 to 202.239.64.254202.239.64.255254
66202.239.65.0/24202.239.65.1 to 202.239.65.254202.239.65.255254
67202.239.66.0/24202.239.66.1 to 202.239.66.254202.239.66.255254
68202.239.67.0/24202.239.67.1 to 202.239.67.254202.239.67.255254
69202.239.68.0/24202.239.68.1 to 202.239.68.254202.239.68.255254
70202.239.69.0/24202.239.69.1 to 202.239.69.254202.239.69.255254
71202.239.70.0/24202.239.70.1 to 202.239.70.254202.239.70.255254
72202.239.71.0/24202.239.71.1 to 202.239.71.254202.239.71.255254
73202.239.72.0/24202.239.72.1 to 202.239.72.254202.239.72.255254
74202.239.73.0/24202.239.73.1 to 202.239.73.254202.239.73.255254
75202.239.74.0/24202.239.74.1 to 202.239.74.254202.239.74.255254
76202.239.75.0/24202.239.75.1 to 202.239.75.254202.239.75.255254
77202.239.76.0/24202.239.76.1 to 202.239.76.254202.239.76.255254
78202.239.77.0/24202.239.77.1 to 202.239.77.254202.239.77.255254
79202.239.78.0/24202.239.78.1 to 202.239.78.254202.239.78.255254
80202.239.79.0/24202.239.79.1 to 202.239.79.254202.239.79.255254
81202.239.80.0/24202.239.80.1 to 202.239.80.254202.239.80.255254
82202.239.81.0/24202.239.81.1 to 202.239.81.254202.239.81.255254
83202.239.82.0/24202.239.82.1 to 202.239.82.254202.239.82.255254
84202.239.83.0/24202.239.83.1 to 202.239.83.254202.239.83.255254
85202.239.84.0/24202.239.84.1 to 202.239.84.254202.239.84.255254
86202.239.85.0/24202.239.85.1 to 202.239.85.254202.239.85.255254
87202.239.86.0/24202.239.86.1 to 202.239.86.254202.239.86.255254
88202.239.87.0/24202.239.87.1 to 202.239.87.254202.239.87.255254
89202.239.88.0/24202.239.88.1 to 202.239.88.254202.239.88.255254
90202.239.89.0/24202.239.89.1 to 202.239.89.254202.239.89.255254
91202.239.90.0/24202.239.90.1 to 202.239.90.254202.239.90.255254
92202.239.91.0/24202.239.91.1 to 202.239.91.254202.239.91.255254
93202.239.92.0/24202.239.92.1 to 202.239.92.254202.239.92.255254
94202.239.93.0/24202.239.93.1 to 202.239.93.254202.239.93.255254
95202.239.94.0/24202.239.94.1 to 202.239.94.254202.239.94.255254
96202.239.95.0/24202.239.95.1 to 202.239.95.254202.239.95.255254
97202.239.96.0/24202.239.96.1 to 202.239.96.254202.239.96.255254
98202.239.97.0/24202.239.97.1 to 202.239.97.254202.239.97.255254
99202.239.98.0/24202.239.98.1 to 202.239.98.254202.239.98.255254
100202.239.99.0/24202.239.99.1 to 202.239.99.254202.239.99.255254
101202.239.100.0/24202.239.100.1 to 202.239.100.254202.239.100.255254
102202.239.101.0/24202.239.101.1 to 202.239.101.254202.239.101.255254
103202.239.102.0/24202.239.102.1 to 202.239.102.254202.239.102.255254
104202.239.103.0/24202.239.103.1 to 202.239.103.254202.239.103.255254
105202.239.104.0/24202.239.104.1 to 202.239.104.254202.239.104.255254
106202.239.105.0/24202.239.105.1 to 202.239.105.254202.239.105.255254
107202.239.106.0/24202.239.106.1 to 202.239.106.254202.239.106.255254
108202.239.107.0/24202.239.107.1 to 202.239.107.254202.239.107.255254
109202.239.108.0/24202.239.108.1 to 202.239.108.254202.239.108.255254
110202.239.109.0/24202.239.109.1 to 202.239.109.254202.239.109.255254
111202.239.110.0/24202.239.110.1 to 202.239.110.254202.239.110.255254
112202.239.111.0/24202.239.111.1 to 202.239.111.254202.239.111.255254
113202.239.112.0/24202.239.112.1 to 202.239.112.254202.239.112.255254
114202.239.113.0/24202.239.113.1 to 202.239.113.254202.239.113.255254
115202.239.114.0/24202.239.114.1 to 202.239.114.254202.239.114.255254
116202.239.115.0/24202.239.115.1 to 202.239.115.254202.239.115.255254
117202.239.116.0/24202.239.116.1 to 202.239.116.254202.239.116.255254
118202.239.117.0/24202.239.117.1 to 202.239.117.254202.239.117.255254
119202.239.118.0/24202.239.118.1 to 202.239.118.254202.239.118.255254
120202.239.119.0/24202.239.119.1 to 202.239.119.254202.239.119.255254
121202.239.120.0/24202.239.120.1 to 202.239.120.254202.239.120.255254
122202.239.121.0/24202.239.121.1 to 202.239.121.254202.239.121.255254
123202.239.122.0/24202.239.122.1 to 202.239.122.254202.239.122.255254
124202.239.123.0/24202.239.123.1 to 202.239.123.254202.239.123.255254
125202.239.124.0/24202.239.124.1 to 202.239.124.254202.239.124.255254
126202.239.125.0/24202.239.125.1 to 202.239.125.254202.239.125.255254
127202.239.126.0/24202.239.126.1 to 202.239.126.254202.239.126.255254
128202.239.127.0/24202.239.127.1 to 202.239.127.254202.239.127.255254
129202.239.128.0/24202.239.128.1 to 202.239.128.254202.239.128.255254
130202.239.129.0/24202.239.129.1 to 202.239.129.254202.239.129.255254
131202.239.130.0/24202.239.130.1 to 202.239.130.254202.239.130.255254
132202.239.131.0/24202.239.131.1 to 202.239.131.254202.239.131.255254
133202.239.132.0/24202.239.132.1 to 202.239.132.254202.239.132.255254
134202.239.133.0/24202.239.133.1 to 202.239.133.254202.239.133.255254
135202.239.134.0/24202.239.134.1 to 202.239.134.254202.239.134.255254
136202.239.135.0/24202.239.135.1 to 202.239.135.254202.239.135.255254
137202.239.136.0/24202.239.136.1 to 202.239.136.254202.239.136.255254
138202.239.137.0/24202.239.137.1 to 202.239.137.254202.239.137.255254
139202.239.138.0/24202.239.138.1 to 202.239.138.254202.239.138.255254
140202.239.139.0/24202.239.139.1 to 202.239.139.254202.239.139.255254
141202.239.140.0/24202.239.140.1 to 202.239.140.254202.239.140.255254
142202.239.141.0/24202.239.141.1 to 202.239.141.254202.239.141.255254
143202.239.142.0/24202.239.142.1 to 202.239.142.254202.239.142.255254
144202.239.143.0/24202.239.143.1 to 202.239.143.254202.239.143.255254
145202.239.144.0/24202.239.144.1 to 202.239.144.254202.239.144.255254
146202.239.145.0/24202.239.145.1 to 202.239.145.254202.239.145.255254
147202.239.146.0/24202.239.146.1 to 202.239.146.254202.239.146.255254
148202.239.147.0/24202.239.147.1 to 202.239.147.254202.239.147.255254
149202.239.148.0/24202.239.148.1 to 202.239.148.254202.239.148.255254
150202.239.149.0/24202.239.149.1 to 202.239.149.254202.239.149.255254
151202.239.150.0/24202.239.150.1 to 202.239.150.254202.239.150.255254
152202.239.151.0/24202.239.151.1 to 202.239.151.254202.239.151.255254
153202.239.152.0/24202.239.152.1 to 202.239.152.254202.239.152.255254
154202.239.153.0/24202.239.153.1 to 202.239.153.254202.239.153.255254
155202.239.154.0/24202.239.154.1 to 202.239.154.254202.239.154.255254
156202.239.155.0/24202.239.155.1 to 202.239.155.254202.239.155.255254
157202.239.156.0/24202.239.156.1 to 202.239.156.254202.239.156.255254
158202.239.157.0/24202.239.157.1 to 202.239.157.254202.239.157.255254
159202.239.158.0/24202.239.158.1 to 202.239.158.254202.239.158.255254
160202.239.159.0/24202.239.159.1 to 202.239.159.254202.239.159.255254
161202.239.160.0/24202.239.160.1 to 202.239.160.254202.239.160.255254
162202.239.161.0/24202.239.161.1 to 202.239.161.254202.239.161.255254
163202.239.162.0/24202.239.162.1 to 202.239.162.254202.239.162.255254
164202.239.163.0/24202.239.163.1 to 202.239.163.254202.239.163.255254
165202.239.164.0/24202.239.164.1 to 202.239.164.254202.239.164.255254
166202.239.165.0/24202.239.165.1 to 202.239.165.254202.239.165.255254
167202.239.166.0/24202.239.166.1 to 202.239.166.254202.239.166.255254
168202.239.167.0/24202.239.167.1 to 202.239.167.254202.239.167.255254
169202.239.168.0/24202.239.168.1 to 202.239.168.254202.239.168.255254
170202.239.169.0/24202.239.169.1 to 202.239.169.254202.239.169.255254
171202.239.170.0/24202.239.170.1 to 202.239.170.254202.239.170.255254
172202.239.171.0/24202.239.171.1 to 202.239.171.254202.239.171.255254
173202.239.172.0/24202.239.172.1 to 202.239.172.254202.239.172.255254
174202.239.173.0/24202.239.173.1 to 202.239.173.254202.239.173.255254
175202.239.174.0/24202.239.174.1 to 202.239.174.254202.239.174.255254
176202.239.175.0/24202.239.175.1 to 202.239.175.254202.239.175.255254
177202.239.176.0/24202.239.176.1 to 202.239.176.254202.239.176.255254
178202.239.177.0/24202.239.177.1 to 202.239.177.254202.239.177.255254
179202.239.178.0/24202.239.178.1 to 202.239.178.254202.239.178.255254
180202.239.179.0/24202.239.179.1 to 202.239.179.254202.239.179.255254
181202.239.180.0/24202.239.180.1 to 202.239.180.254202.239.180.255254
182202.239.181.0/24202.239.181.1 to 202.239.181.254202.239.181.255254
183202.239.182.0/24202.239.182.1 to 202.239.182.254202.239.182.255254
184202.239.183.0/24202.239.183.1 to 202.239.183.254202.239.183.255254
185202.239.184.0/24202.239.184.1 to 202.239.184.254202.239.184.255254
186202.239.185.0/24202.239.185.1 to 202.239.185.254202.239.185.255254
187202.239.186.0/24202.239.186.1 to 202.239.186.254202.239.186.255254
188202.239.187.0/24202.239.187.1 to 202.239.187.254202.239.187.255254
189202.239.188.0/24202.239.188.1 to 202.239.188.254202.239.188.255254
190202.239.189.0/24202.239.189.1 to 202.239.189.254202.239.189.255254
191202.239.190.0/24202.239.190.1 to 202.239.190.254202.239.190.255254
192202.239.191.0/24202.239.191.1 to 202.239.191.254202.239.191.255254
193202.239.192.0/24202.239.192.1 to 202.239.192.254202.239.192.255254
194202.239.193.0/24202.239.193.1 to 202.239.193.254202.239.193.255254
195202.239.194.0/24202.239.194.1 to 202.239.194.254202.239.194.255254
196202.239.195.0/24202.239.195.1 to 202.239.195.254202.239.195.255254
197202.239.196.0/24202.239.196.1 to 202.239.196.254202.239.196.255254
198202.239.197.0/24202.239.197.1 to 202.239.197.254202.239.197.255254
199202.239.198.0/24202.239.198.1 to 202.239.198.254202.239.198.255254
200202.239.199.0/24202.239.199.1 to 202.239.199.254202.239.199.255254
201202.239.200.0/24202.239.200.1 to 202.239.200.254202.239.200.255254
202202.239.201.0/24202.239.201.1 to 202.239.201.254202.239.201.255254
203202.239.202.0/24202.239.202.1 to 202.239.202.254202.239.202.255254
204202.239.203.0/24202.239.203.1 to 202.239.203.254202.239.203.255254
205202.239.204.0/24202.239.204.1 to 202.239.204.254202.239.204.255254
206202.239.205.0/24202.239.205.1 to 202.239.205.254202.239.205.255254
207202.239.206.0/24202.239.206.1 to 202.239.206.254202.239.206.255254
208202.239.207.0/24202.239.207.1 to 202.239.207.254202.239.207.255254
209202.239.208.0/24202.239.208.1 to 202.239.208.254202.239.208.255254
210202.239.209.0/24202.239.209.1 to 202.239.209.254202.239.209.255254
211202.239.210.0/24202.239.210.1 to 202.239.210.254202.239.210.255254
212202.239.211.0/24202.239.211.1 to 202.239.211.254202.239.211.255254
213202.239.212.0/24202.239.212.1 to 202.239.212.254202.239.212.255254
214202.239.213.0/24202.239.213.1 to 202.239.213.254202.239.213.255254
215202.239.214.0/24202.239.214.1 to 202.239.214.254202.239.214.255254
216202.239.215.0/24202.239.215.1 to 202.239.215.254202.239.215.255254
217202.239.216.0/24202.239.216.1 to 202.239.216.254202.239.216.255254
218202.239.217.0/24202.239.217.1 to 202.239.217.254202.239.217.255254
219202.239.218.0/24202.239.218.1 to 202.239.218.254202.239.218.255254
220202.239.219.0/24202.239.219.1 to 202.239.219.254202.239.219.255254
221202.239.220.0/24202.239.220.1 to 202.239.220.254202.239.220.255254
222202.239.221.0/24202.239.221.1 to 202.239.221.254202.239.221.255254
223202.239.222.0/24202.239.222.1 to 202.239.222.254202.239.222.255254
224202.239.223.0/24202.239.223.1 to 202.239.223.254202.239.223.255254
225202.239.224.0/24202.239.224.1 to 202.239.224.254202.239.224.255254
226202.239.225.0/24202.239.225.1 to 202.239.225.254202.239.225.255254
227202.239.226.0/24202.239.226.1 to 202.239.226.254202.239.226.255254
228202.239.227.0/24202.239.227.1 to 202.239.227.254202.239.227.255254
229202.239.228.0/24202.239.228.1 to 202.239.228.254202.239.228.255254
230202.239.229.0/24202.239.229.1 to 202.239.229.254202.239.229.255254
231202.239.230.0/24202.239.230.1 to 202.239.230.254202.239.230.255254
232202.239.231.0/24202.239.231.1 to 202.239.231.254202.239.231.255254
233202.239.232.0/24202.239.232.1 to 202.239.232.254202.239.232.255254
234202.239.233.0/24202.239.233.1 to 202.239.233.254202.239.233.255254
235202.239.234.0/24202.239.234.1 to 202.239.234.254202.239.234.255254
236202.239.235.0/24202.239.235.1 to 202.239.235.254202.239.235.255254
237202.239.236.0/24202.239.236.1 to 202.239.236.254202.239.236.255254
238202.239.237.0/24202.239.237.1 to 202.239.237.254202.239.237.255254
239202.239.238.0/24202.239.238.1 to 202.239.238.254202.239.238.255254
240202.239.239.0/24202.239.239.1 to 202.239.239.254202.239.239.255254
241202.239.240.0/24202.239.240.1 to 202.239.240.254202.239.240.255254
242202.239.241.0/24202.239.241.1 to 202.239.241.254202.239.241.255254
243202.239.242.0/24202.239.242.1 to 202.239.242.254202.239.242.255254
244202.239.243.0/24202.239.243.1 to 202.239.243.254202.239.243.255254
245202.239.244.0/24202.239.244.1 to 202.239.244.254202.239.244.255254
246202.239.245.0/24202.239.245.1 to 202.239.245.254202.239.245.255254
247202.239.246.0/24202.239.246.1 to 202.239.246.254202.239.246.255254
248202.239.247.0/24202.239.247.1 to 202.239.247.254202.239.247.255254
249202.239.248.0/24202.239.248.1 to 202.239.248.254202.239.248.255254
250202.239.249.0/24202.239.249.1 to 202.239.249.254202.239.249.255254
251202.239.250.0/24202.239.250.1 to 202.239.250.254202.239.250.255254
252202.239.251.0/24202.239.251.1 to 202.239.251.254202.239.251.255254
253202.239.252.0/24202.239.252.1 to 202.239.252.254202.239.252.255254
254202.239.253.0/24202.239.253.1 to 202.239.253.254202.239.253.255254
255202.239.254.0/24202.239.254.1 to 202.239.254.254202.239.254.255254
256202.239.255.0/24202.239.255.1 to 202.239.255.254202.239.255.255254

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.