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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.

Network202.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
202.0.0.0
Broadcast address
203.255.255.255
First usable
202.0.0.1
Last usable
203.255.255.254
Usable hosts
33,554,430 (33,554,432 less the network and broadcast addresses)
Subnet mask
254.0.0.0
Wildcard mask
1.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/7
Type
Public public
Old class
C (default /24)
As numbers
Hex CA000000 · Integer 3388997632 to 3422552063
Reverse DNS zones
202.in-addr.arpa
203.in-addr.arpa
/7 is not on a 8-bit boundary, so it takes 2 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11001010.00000000.00000000.00000000202.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network11001010.00000000.00000000.00000000202.0.0.0
Broadcast11001011.11111111.11111111.11111111203.255.255.255
Split into smaller subnets/16
/8 (2)/9 (4)/10 (8)/11 (16)/12 (32)/13 (64)/14 (128)/15 (256)/16 (512)/17 (1,024)/18 (2,048)/19 (4,096)

202.0.0.0/7 makes 512 subnets of /16; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1202.0.0.0/16202.0.0.1 to 202.0.255.254202.0.255.25565,534
2202.1.0.0/16202.1.0.1 to 202.1.255.254202.1.255.25565,534
3202.2.0.0/16202.2.0.1 to 202.2.255.254202.2.255.25565,534
4202.3.0.0/16202.3.0.1 to 202.3.255.254202.3.255.25565,534
5202.4.0.0/16202.4.0.1 to 202.4.255.254202.4.255.25565,534
6202.5.0.0/16202.5.0.1 to 202.5.255.254202.5.255.25565,534
7202.6.0.0/16202.6.0.1 to 202.6.255.254202.6.255.25565,534
8202.7.0.0/16202.7.0.1 to 202.7.255.254202.7.255.25565,534
9202.8.0.0/16202.8.0.1 to 202.8.255.254202.8.255.25565,534
10202.9.0.0/16202.9.0.1 to 202.9.255.254202.9.255.25565,534
11202.10.0.0/16202.10.0.1 to 202.10.255.254202.10.255.25565,534
12202.11.0.0/16202.11.0.1 to 202.11.255.254202.11.255.25565,534
13202.12.0.0/16202.12.0.1 to 202.12.255.254202.12.255.25565,534
14202.13.0.0/16202.13.0.1 to 202.13.255.254202.13.255.25565,534
15202.14.0.0/16202.14.0.1 to 202.14.255.254202.14.255.25565,534
16202.15.0.0/16202.15.0.1 to 202.15.255.254202.15.255.25565,534
17202.16.0.0/16202.16.0.1 to 202.16.255.254202.16.255.25565,534
18202.17.0.0/16202.17.0.1 to 202.17.255.254202.17.255.25565,534
19202.18.0.0/16202.18.0.1 to 202.18.255.254202.18.255.25565,534
20202.19.0.0/16202.19.0.1 to 202.19.255.254202.19.255.25565,534
21202.20.0.0/16202.20.0.1 to 202.20.255.254202.20.255.25565,534
22202.21.0.0/16202.21.0.1 to 202.21.255.254202.21.255.25565,534
23202.22.0.0/16202.22.0.1 to 202.22.255.254202.22.255.25565,534
24202.23.0.0/16202.23.0.1 to 202.23.255.254202.23.255.25565,534
25202.24.0.0/16202.24.0.1 to 202.24.255.254202.24.255.25565,534
26202.25.0.0/16202.25.0.1 to 202.25.255.254202.25.255.25565,534
27202.26.0.0/16202.26.0.1 to 202.26.255.254202.26.255.25565,534
28202.27.0.0/16202.27.0.1 to 202.27.255.254202.27.255.25565,534
29202.28.0.0/16202.28.0.1 to 202.28.255.254202.28.255.25565,534
30202.29.0.0/16202.29.0.1 to 202.29.255.254202.29.255.25565,534
31202.30.0.0/16202.30.0.1 to 202.30.255.254202.30.255.25565,534
32202.31.0.0/16202.31.0.1 to 202.31.255.254202.31.255.25565,534
33202.32.0.0/16202.32.0.1 to 202.32.255.254202.32.255.25565,534
34202.33.0.0/16202.33.0.1 to 202.33.255.254202.33.255.25565,534
35202.34.0.0/16202.34.0.1 to 202.34.255.254202.34.255.25565,534
36202.35.0.0/16202.35.0.1 to 202.35.255.254202.35.255.25565,534
37202.36.0.0/16202.36.0.1 to 202.36.255.254202.36.255.25565,534
38202.37.0.0/16202.37.0.1 to 202.37.255.254202.37.255.25565,534
39202.38.0.0/16202.38.0.1 to 202.38.255.254202.38.255.25565,534
40202.39.0.0/16202.39.0.1 to 202.39.255.254202.39.255.25565,534
41202.40.0.0/16202.40.0.1 to 202.40.255.254202.40.255.25565,534
42202.41.0.0/16202.41.0.1 to 202.41.255.254202.41.255.25565,534
43202.42.0.0/16202.42.0.1 to 202.42.255.254202.42.255.25565,534
44202.43.0.0/16202.43.0.1 to 202.43.255.254202.43.255.25565,534
45202.44.0.0/16202.44.0.1 to 202.44.255.254202.44.255.25565,534
46202.45.0.0/16202.45.0.1 to 202.45.255.254202.45.255.25565,534
47202.46.0.0/16202.46.0.1 to 202.46.255.254202.46.255.25565,534
48202.47.0.0/16202.47.0.1 to 202.47.255.254202.47.255.25565,534
49202.48.0.0/16202.48.0.1 to 202.48.255.254202.48.255.25565,534
50202.49.0.0/16202.49.0.1 to 202.49.255.254202.49.255.25565,534
51202.50.0.0/16202.50.0.1 to 202.50.255.254202.50.255.25565,534
52202.51.0.0/16202.51.0.1 to 202.51.255.254202.51.255.25565,534
53202.52.0.0/16202.52.0.1 to 202.52.255.254202.52.255.25565,534
54202.53.0.0/16202.53.0.1 to 202.53.255.254202.53.255.25565,534
55202.54.0.0/16202.54.0.1 to 202.54.255.254202.54.255.25565,534
56202.55.0.0/16202.55.0.1 to 202.55.255.254202.55.255.25565,534
57202.56.0.0/16202.56.0.1 to 202.56.255.254202.56.255.25565,534
58202.57.0.0/16202.57.0.1 to 202.57.255.254202.57.255.25565,534
59202.58.0.0/16202.58.0.1 to 202.58.255.254202.58.255.25565,534
60202.59.0.0/16202.59.0.1 to 202.59.255.254202.59.255.25565,534
61202.60.0.0/16202.60.0.1 to 202.60.255.254202.60.255.25565,534
62202.61.0.0/16202.61.0.1 to 202.61.255.254202.61.255.25565,534
63202.62.0.0/16202.62.0.1 to 202.62.255.254202.62.255.25565,534
64202.63.0.0/16202.63.0.1 to 202.63.255.254202.63.255.25565,534
65202.64.0.0/16202.64.0.1 to 202.64.255.254202.64.255.25565,534
66202.65.0.0/16202.65.0.1 to 202.65.255.254202.65.255.25565,534
67202.66.0.0/16202.66.0.1 to 202.66.255.254202.66.255.25565,534
68202.67.0.0/16202.67.0.1 to 202.67.255.254202.67.255.25565,534
69202.68.0.0/16202.68.0.1 to 202.68.255.254202.68.255.25565,534
70202.69.0.0/16202.69.0.1 to 202.69.255.254202.69.255.25565,534
71202.70.0.0/16202.70.0.1 to 202.70.255.254202.70.255.25565,534
72202.71.0.0/16202.71.0.1 to 202.71.255.254202.71.255.25565,534
73202.72.0.0/16202.72.0.1 to 202.72.255.254202.72.255.25565,534
74202.73.0.0/16202.73.0.1 to 202.73.255.254202.73.255.25565,534
75202.74.0.0/16202.74.0.1 to 202.74.255.254202.74.255.25565,534
76202.75.0.0/16202.75.0.1 to 202.75.255.254202.75.255.25565,534
77202.76.0.0/16202.76.0.1 to 202.76.255.254202.76.255.25565,534
78202.77.0.0/16202.77.0.1 to 202.77.255.254202.77.255.25565,534
79202.78.0.0/16202.78.0.1 to 202.78.255.254202.78.255.25565,534
80202.79.0.0/16202.79.0.1 to 202.79.255.254202.79.255.25565,534
81202.80.0.0/16202.80.0.1 to 202.80.255.254202.80.255.25565,534
82202.81.0.0/16202.81.0.1 to 202.81.255.254202.81.255.25565,534
83202.82.0.0/16202.82.0.1 to 202.82.255.254202.82.255.25565,534
84202.83.0.0/16202.83.0.1 to 202.83.255.254202.83.255.25565,534
85202.84.0.0/16202.84.0.1 to 202.84.255.254202.84.255.25565,534
86202.85.0.0/16202.85.0.1 to 202.85.255.254202.85.255.25565,534
87202.86.0.0/16202.86.0.1 to 202.86.255.254202.86.255.25565,534
88202.87.0.0/16202.87.0.1 to 202.87.255.254202.87.255.25565,534
89202.88.0.0/16202.88.0.1 to 202.88.255.254202.88.255.25565,534
90202.89.0.0/16202.89.0.1 to 202.89.255.254202.89.255.25565,534
91202.90.0.0/16202.90.0.1 to 202.90.255.254202.90.255.25565,534
92202.91.0.0/16202.91.0.1 to 202.91.255.254202.91.255.25565,534
93202.92.0.0/16202.92.0.1 to 202.92.255.254202.92.255.25565,534
94202.93.0.0/16202.93.0.1 to 202.93.255.254202.93.255.25565,534
95202.94.0.0/16202.94.0.1 to 202.94.255.254202.94.255.25565,534
96202.95.0.0/16202.95.0.1 to 202.95.255.254202.95.255.25565,534
97202.96.0.0/16202.96.0.1 to 202.96.255.254202.96.255.25565,534
98202.97.0.0/16202.97.0.1 to 202.97.255.254202.97.255.25565,534
99202.98.0.0/16202.98.0.1 to 202.98.255.254202.98.255.25565,534
100202.99.0.0/16202.99.0.1 to 202.99.255.254202.99.255.25565,534
101202.100.0.0/16202.100.0.1 to 202.100.255.254202.100.255.25565,534
102202.101.0.0/16202.101.0.1 to 202.101.255.254202.101.255.25565,534
103202.102.0.0/16202.102.0.1 to 202.102.255.254202.102.255.25565,534
104202.103.0.0/16202.103.0.1 to 202.103.255.254202.103.255.25565,534
105202.104.0.0/16202.104.0.1 to 202.104.255.254202.104.255.25565,534
106202.105.0.0/16202.105.0.1 to 202.105.255.254202.105.255.25565,534
107202.106.0.0/16202.106.0.1 to 202.106.255.254202.106.255.25565,534
108202.107.0.0/16202.107.0.1 to 202.107.255.254202.107.255.25565,534
109202.108.0.0/16202.108.0.1 to 202.108.255.254202.108.255.25565,534
110202.109.0.0/16202.109.0.1 to 202.109.255.254202.109.255.25565,534
111202.110.0.0/16202.110.0.1 to 202.110.255.254202.110.255.25565,534
112202.111.0.0/16202.111.0.1 to 202.111.255.254202.111.255.25565,534
113202.112.0.0/16202.112.0.1 to 202.112.255.254202.112.255.25565,534
114202.113.0.0/16202.113.0.1 to 202.113.255.254202.113.255.25565,534
115202.114.0.0/16202.114.0.1 to 202.114.255.254202.114.255.25565,534
116202.115.0.0/16202.115.0.1 to 202.115.255.254202.115.255.25565,534
117202.116.0.0/16202.116.0.1 to 202.116.255.254202.116.255.25565,534
118202.117.0.0/16202.117.0.1 to 202.117.255.254202.117.255.25565,534
119202.118.0.0/16202.118.0.1 to 202.118.255.254202.118.255.25565,534
120202.119.0.0/16202.119.0.1 to 202.119.255.254202.119.255.25565,534
121202.120.0.0/16202.120.0.1 to 202.120.255.254202.120.255.25565,534
122202.121.0.0/16202.121.0.1 to 202.121.255.254202.121.255.25565,534
123202.122.0.0/16202.122.0.1 to 202.122.255.254202.122.255.25565,534
124202.123.0.0/16202.123.0.1 to 202.123.255.254202.123.255.25565,534
125202.124.0.0/16202.124.0.1 to 202.124.255.254202.124.255.25565,534
126202.125.0.0/16202.125.0.1 to 202.125.255.254202.125.255.25565,534
127202.126.0.0/16202.126.0.1 to 202.126.255.254202.126.255.25565,534
128202.127.0.0/16202.127.0.1 to 202.127.255.254202.127.255.25565,534
129202.128.0.0/16202.128.0.1 to 202.128.255.254202.128.255.25565,534
130202.129.0.0/16202.129.0.1 to 202.129.255.254202.129.255.25565,534
131202.130.0.0/16202.130.0.1 to 202.130.255.254202.130.255.25565,534
132202.131.0.0/16202.131.0.1 to 202.131.255.254202.131.255.25565,534
133202.132.0.0/16202.132.0.1 to 202.132.255.254202.132.255.25565,534
134202.133.0.0/16202.133.0.1 to 202.133.255.254202.133.255.25565,534
135202.134.0.0/16202.134.0.1 to 202.134.255.254202.134.255.25565,534
136202.135.0.0/16202.135.0.1 to 202.135.255.254202.135.255.25565,534
137202.136.0.0/16202.136.0.1 to 202.136.255.254202.136.255.25565,534
138202.137.0.0/16202.137.0.1 to 202.137.255.254202.137.255.25565,534
139202.138.0.0/16202.138.0.1 to 202.138.255.254202.138.255.25565,534
140202.139.0.0/16202.139.0.1 to 202.139.255.254202.139.255.25565,534
141202.140.0.0/16202.140.0.1 to 202.140.255.254202.140.255.25565,534
142202.141.0.0/16202.141.0.1 to 202.141.255.254202.141.255.25565,534
143202.142.0.0/16202.142.0.1 to 202.142.255.254202.142.255.25565,534
144202.143.0.0/16202.143.0.1 to 202.143.255.254202.143.255.25565,534
145202.144.0.0/16202.144.0.1 to 202.144.255.254202.144.255.25565,534
146202.145.0.0/16202.145.0.1 to 202.145.255.254202.145.255.25565,534
147202.146.0.0/16202.146.0.1 to 202.146.255.254202.146.255.25565,534
148202.147.0.0/16202.147.0.1 to 202.147.255.254202.147.255.25565,534
149202.148.0.0/16202.148.0.1 to 202.148.255.254202.148.255.25565,534
150202.149.0.0/16202.149.0.1 to 202.149.255.254202.149.255.25565,534
151202.150.0.0/16202.150.0.1 to 202.150.255.254202.150.255.25565,534
152202.151.0.0/16202.151.0.1 to 202.151.255.254202.151.255.25565,534
153202.152.0.0/16202.152.0.1 to 202.152.255.254202.152.255.25565,534
154202.153.0.0/16202.153.0.1 to 202.153.255.254202.153.255.25565,534
155202.154.0.0/16202.154.0.1 to 202.154.255.254202.154.255.25565,534
156202.155.0.0/16202.155.0.1 to 202.155.255.254202.155.255.25565,534
157202.156.0.0/16202.156.0.1 to 202.156.255.254202.156.255.25565,534
158202.157.0.0/16202.157.0.1 to 202.157.255.254202.157.255.25565,534
159202.158.0.0/16202.158.0.1 to 202.158.255.254202.158.255.25565,534
160202.159.0.0/16202.159.0.1 to 202.159.255.254202.159.255.25565,534
161202.160.0.0/16202.160.0.1 to 202.160.255.254202.160.255.25565,534
162202.161.0.0/16202.161.0.1 to 202.161.255.254202.161.255.25565,534
163202.162.0.0/16202.162.0.1 to 202.162.255.254202.162.255.25565,534
164202.163.0.0/16202.163.0.1 to 202.163.255.254202.163.255.25565,534
165202.164.0.0/16202.164.0.1 to 202.164.255.254202.164.255.25565,534
166202.165.0.0/16202.165.0.1 to 202.165.255.254202.165.255.25565,534
167202.166.0.0/16202.166.0.1 to 202.166.255.254202.166.255.25565,534
168202.167.0.0/16202.167.0.1 to 202.167.255.254202.167.255.25565,534
169202.168.0.0/16202.168.0.1 to 202.168.255.254202.168.255.25565,534
170202.169.0.0/16202.169.0.1 to 202.169.255.254202.169.255.25565,534
171202.170.0.0/16202.170.0.1 to 202.170.255.254202.170.255.25565,534
172202.171.0.0/16202.171.0.1 to 202.171.255.254202.171.255.25565,534
173202.172.0.0/16202.172.0.1 to 202.172.255.254202.172.255.25565,534
174202.173.0.0/16202.173.0.1 to 202.173.255.254202.173.255.25565,534
175202.174.0.0/16202.174.0.1 to 202.174.255.254202.174.255.25565,534
176202.175.0.0/16202.175.0.1 to 202.175.255.254202.175.255.25565,534
177202.176.0.0/16202.176.0.1 to 202.176.255.254202.176.255.25565,534
178202.177.0.0/16202.177.0.1 to 202.177.255.254202.177.255.25565,534
179202.178.0.0/16202.178.0.1 to 202.178.255.254202.178.255.25565,534
180202.179.0.0/16202.179.0.1 to 202.179.255.254202.179.255.25565,534
181202.180.0.0/16202.180.0.1 to 202.180.255.254202.180.255.25565,534
182202.181.0.0/16202.181.0.1 to 202.181.255.254202.181.255.25565,534
183202.182.0.0/16202.182.0.1 to 202.182.255.254202.182.255.25565,534
184202.183.0.0/16202.183.0.1 to 202.183.255.254202.183.255.25565,534
185202.184.0.0/16202.184.0.1 to 202.184.255.254202.184.255.25565,534
186202.185.0.0/16202.185.0.1 to 202.185.255.254202.185.255.25565,534
187202.186.0.0/16202.186.0.1 to 202.186.255.254202.186.255.25565,534
188202.187.0.0/16202.187.0.1 to 202.187.255.254202.187.255.25565,534
189202.188.0.0/16202.188.0.1 to 202.188.255.254202.188.255.25565,534
190202.189.0.0/16202.189.0.1 to 202.189.255.254202.189.255.25565,534
191202.190.0.0/16202.190.0.1 to 202.190.255.254202.190.255.25565,534
192202.191.0.0/16202.191.0.1 to 202.191.255.254202.191.255.25565,534
193202.192.0.0/16202.192.0.1 to 202.192.255.254202.192.255.25565,534
194202.193.0.0/16202.193.0.1 to 202.193.255.254202.193.255.25565,534
195202.194.0.0/16202.194.0.1 to 202.194.255.254202.194.255.25565,534
196202.195.0.0/16202.195.0.1 to 202.195.255.254202.195.255.25565,534
197202.196.0.0/16202.196.0.1 to 202.196.255.254202.196.255.25565,534
198202.197.0.0/16202.197.0.1 to 202.197.255.254202.197.255.25565,534
199202.198.0.0/16202.198.0.1 to 202.198.255.254202.198.255.25565,534
200202.199.0.0/16202.199.0.1 to 202.199.255.254202.199.255.25565,534
201202.200.0.0/16202.200.0.1 to 202.200.255.254202.200.255.25565,534
202202.201.0.0/16202.201.0.1 to 202.201.255.254202.201.255.25565,534
203202.202.0.0/16202.202.0.1 to 202.202.255.254202.202.255.25565,534
204202.203.0.0/16202.203.0.1 to 202.203.255.254202.203.255.25565,534
205202.204.0.0/16202.204.0.1 to 202.204.255.254202.204.255.25565,534
206202.205.0.0/16202.205.0.1 to 202.205.255.254202.205.255.25565,534
207202.206.0.0/16202.206.0.1 to 202.206.255.254202.206.255.25565,534
208202.207.0.0/16202.207.0.1 to 202.207.255.254202.207.255.25565,534
209202.208.0.0/16202.208.0.1 to 202.208.255.254202.208.255.25565,534
210202.209.0.0/16202.209.0.1 to 202.209.255.254202.209.255.25565,534
211202.210.0.0/16202.210.0.1 to 202.210.255.254202.210.255.25565,534
212202.211.0.0/16202.211.0.1 to 202.211.255.254202.211.255.25565,534
213202.212.0.0/16202.212.0.1 to 202.212.255.254202.212.255.25565,534
214202.213.0.0/16202.213.0.1 to 202.213.255.254202.213.255.25565,534
215202.214.0.0/16202.214.0.1 to 202.214.255.254202.214.255.25565,534
216202.215.0.0/16202.215.0.1 to 202.215.255.254202.215.255.25565,534
217202.216.0.0/16202.216.0.1 to 202.216.255.254202.216.255.25565,534
218202.217.0.0/16202.217.0.1 to 202.217.255.254202.217.255.25565,534
219202.218.0.0/16202.218.0.1 to 202.218.255.254202.218.255.25565,534
220202.219.0.0/16202.219.0.1 to 202.219.255.254202.219.255.25565,534
221202.220.0.0/16202.220.0.1 to 202.220.255.254202.220.255.25565,534
222202.221.0.0/16202.221.0.1 to 202.221.255.254202.221.255.25565,534
223202.222.0.0/16202.222.0.1 to 202.222.255.254202.222.255.25565,534
224202.223.0.0/16202.223.0.1 to 202.223.255.254202.223.255.25565,534
225202.224.0.0/16202.224.0.1 to 202.224.255.254202.224.255.25565,534
226202.225.0.0/16202.225.0.1 to 202.225.255.254202.225.255.25565,534
227202.226.0.0/16202.226.0.1 to 202.226.255.254202.226.255.25565,534
228202.227.0.0/16202.227.0.1 to 202.227.255.254202.227.255.25565,534
229202.228.0.0/16202.228.0.1 to 202.228.255.254202.228.255.25565,534
230202.229.0.0/16202.229.0.1 to 202.229.255.254202.229.255.25565,534
231202.230.0.0/16202.230.0.1 to 202.230.255.254202.230.255.25565,534
232202.231.0.0/16202.231.0.1 to 202.231.255.254202.231.255.25565,534
233202.232.0.0/16202.232.0.1 to 202.232.255.254202.232.255.25565,534
234202.233.0.0/16202.233.0.1 to 202.233.255.254202.233.255.25565,534
235202.234.0.0/16202.234.0.1 to 202.234.255.254202.234.255.25565,534
236202.235.0.0/16202.235.0.1 to 202.235.255.254202.235.255.25565,534
237202.236.0.0/16202.236.0.1 to 202.236.255.254202.236.255.25565,534
238202.237.0.0/16202.237.0.1 to 202.237.255.254202.237.255.25565,534
239202.238.0.0/16202.238.0.1 to 202.238.255.254202.238.255.25565,534
240202.239.0.0/16202.239.0.1 to 202.239.255.254202.239.255.25565,534
241202.240.0.0/16202.240.0.1 to 202.240.255.254202.240.255.25565,534
242202.241.0.0/16202.241.0.1 to 202.241.255.254202.241.255.25565,534
243202.242.0.0/16202.242.0.1 to 202.242.255.254202.242.255.25565,534
244202.243.0.0/16202.243.0.1 to 202.243.255.254202.243.255.25565,534
245202.244.0.0/16202.244.0.1 to 202.244.255.254202.244.255.25565,534
246202.245.0.0/16202.245.0.1 to 202.245.255.254202.245.255.25565,534
247202.246.0.0/16202.246.0.1 to 202.246.255.254202.246.255.25565,534
248202.247.0.0/16202.247.0.1 to 202.247.255.254202.247.255.25565,534
249202.248.0.0/16202.248.0.1 to 202.248.255.254202.248.255.25565,534
250202.249.0.0/16202.249.0.1 to 202.249.255.254202.249.255.25565,534
251202.250.0.0/16202.250.0.1 to 202.250.255.254202.250.255.25565,534
252202.251.0.0/16202.251.0.1 to 202.251.255.254202.251.255.25565,534
253202.252.0.0/16202.252.0.1 to 202.252.255.254202.252.255.25565,534
254202.253.0.0/16202.253.0.1 to 202.253.255.254202.253.255.25565,534
255202.254.0.0/16202.254.0.1 to 202.254.255.254202.254.255.25565,534
256202.255.0.0/16202.255.0.1 to 202.255.255.254202.255.255.25565,534

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.