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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.

Network192.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
192.0.0.0
Broadcast address
193.255.255.255
First usable
192.0.0.1
Last usable
193.255.255.254
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 C0000000 · Integer 3221225472 to 3254779903
Reverse DNS zones
192.in-addr.arpa
193.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
Address11000000.00000000.00000000.00000000192.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network11000000.00000000.00000000.00000000192.0.0.0
Broadcast11000001.11111111.11111111.11111111193.255.255.255
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)

192.0.0.0/7 makes 512 subnets of /16; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1192.0.0.0/16192.0.0.1 to 192.0.255.254192.0.255.25565,534
2192.1.0.0/16192.1.0.1 to 192.1.255.254192.1.255.25565,534
3192.2.0.0/16192.2.0.1 to 192.2.255.254192.2.255.25565,534
4192.3.0.0/16192.3.0.1 to 192.3.255.254192.3.255.25565,534
5192.4.0.0/16192.4.0.1 to 192.4.255.254192.4.255.25565,534
6192.5.0.0/16192.5.0.1 to 192.5.255.254192.5.255.25565,534
7192.6.0.0/16192.6.0.1 to 192.6.255.254192.6.255.25565,534
8192.7.0.0/16192.7.0.1 to 192.7.255.254192.7.255.25565,534
9192.8.0.0/16192.8.0.1 to 192.8.255.254192.8.255.25565,534
10192.9.0.0/16192.9.0.1 to 192.9.255.254192.9.255.25565,534
11192.10.0.0/16192.10.0.1 to 192.10.255.254192.10.255.25565,534
12192.11.0.0/16192.11.0.1 to 192.11.255.254192.11.255.25565,534
13192.12.0.0/16192.12.0.1 to 192.12.255.254192.12.255.25565,534
14192.13.0.0/16192.13.0.1 to 192.13.255.254192.13.255.25565,534
15192.14.0.0/16192.14.0.1 to 192.14.255.254192.14.255.25565,534
16192.15.0.0/16192.15.0.1 to 192.15.255.254192.15.255.25565,534
17192.16.0.0/16192.16.0.1 to 192.16.255.254192.16.255.25565,534
18192.17.0.0/16192.17.0.1 to 192.17.255.254192.17.255.25565,534
19192.18.0.0/16192.18.0.1 to 192.18.255.254192.18.255.25565,534
20192.19.0.0/16192.19.0.1 to 192.19.255.254192.19.255.25565,534
21192.20.0.0/16192.20.0.1 to 192.20.255.254192.20.255.25565,534
22192.21.0.0/16192.21.0.1 to 192.21.255.254192.21.255.25565,534
23192.22.0.0/16192.22.0.1 to 192.22.255.254192.22.255.25565,534
24192.23.0.0/16192.23.0.1 to 192.23.255.254192.23.255.25565,534
25192.24.0.0/16192.24.0.1 to 192.24.255.254192.24.255.25565,534
26192.25.0.0/16192.25.0.1 to 192.25.255.254192.25.255.25565,534
27192.26.0.0/16192.26.0.1 to 192.26.255.254192.26.255.25565,534
28192.27.0.0/16192.27.0.1 to 192.27.255.254192.27.255.25565,534
29192.28.0.0/16192.28.0.1 to 192.28.255.254192.28.255.25565,534
30192.29.0.0/16192.29.0.1 to 192.29.255.254192.29.255.25565,534
31192.30.0.0/16192.30.0.1 to 192.30.255.254192.30.255.25565,534
32192.31.0.0/16192.31.0.1 to 192.31.255.254192.31.255.25565,534
33192.32.0.0/16192.32.0.1 to 192.32.255.254192.32.255.25565,534
34192.33.0.0/16192.33.0.1 to 192.33.255.254192.33.255.25565,534
35192.34.0.0/16192.34.0.1 to 192.34.255.254192.34.255.25565,534
36192.35.0.0/16192.35.0.1 to 192.35.255.254192.35.255.25565,534
37192.36.0.0/16192.36.0.1 to 192.36.255.254192.36.255.25565,534
38192.37.0.0/16192.37.0.1 to 192.37.255.254192.37.255.25565,534
39192.38.0.0/16192.38.0.1 to 192.38.255.254192.38.255.25565,534
40192.39.0.0/16192.39.0.1 to 192.39.255.254192.39.255.25565,534
41192.40.0.0/16192.40.0.1 to 192.40.255.254192.40.255.25565,534
42192.41.0.0/16192.41.0.1 to 192.41.255.254192.41.255.25565,534
43192.42.0.0/16192.42.0.1 to 192.42.255.254192.42.255.25565,534
44192.43.0.0/16192.43.0.1 to 192.43.255.254192.43.255.25565,534
45192.44.0.0/16192.44.0.1 to 192.44.255.254192.44.255.25565,534
46192.45.0.0/16192.45.0.1 to 192.45.255.254192.45.255.25565,534
47192.46.0.0/16192.46.0.1 to 192.46.255.254192.46.255.25565,534
48192.47.0.0/16192.47.0.1 to 192.47.255.254192.47.255.25565,534
49192.48.0.0/16192.48.0.1 to 192.48.255.254192.48.255.25565,534
50192.49.0.0/16192.49.0.1 to 192.49.255.254192.49.255.25565,534
51192.50.0.0/16192.50.0.1 to 192.50.255.254192.50.255.25565,534
52192.51.0.0/16192.51.0.1 to 192.51.255.254192.51.255.25565,534
53192.52.0.0/16192.52.0.1 to 192.52.255.254192.52.255.25565,534
54192.53.0.0/16192.53.0.1 to 192.53.255.254192.53.255.25565,534
55192.54.0.0/16192.54.0.1 to 192.54.255.254192.54.255.25565,534
56192.55.0.0/16192.55.0.1 to 192.55.255.254192.55.255.25565,534
57192.56.0.0/16192.56.0.1 to 192.56.255.254192.56.255.25565,534
58192.57.0.0/16192.57.0.1 to 192.57.255.254192.57.255.25565,534
59192.58.0.0/16192.58.0.1 to 192.58.255.254192.58.255.25565,534
60192.59.0.0/16192.59.0.1 to 192.59.255.254192.59.255.25565,534
61192.60.0.0/16192.60.0.1 to 192.60.255.254192.60.255.25565,534
62192.61.0.0/16192.61.0.1 to 192.61.255.254192.61.255.25565,534
63192.62.0.0/16192.62.0.1 to 192.62.255.254192.62.255.25565,534
64192.63.0.0/16192.63.0.1 to 192.63.255.254192.63.255.25565,534
65192.64.0.0/16192.64.0.1 to 192.64.255.254192.64.255.25565,534
66192.65.0.0/16192.65.0.1 to 192.65.255.254192.65.255.25565,534
67192.66.0.0/16192.66.0.1 to 192.66.255.254192.66.255.25565,534
68192.67.0.0/16192.67.0.1 to 192.67.255.254192.67.255.25565,534
69192.68.0.0/16192.68.0.1 to 192.68.255.254192.68.255.25565,534
70192.69.0.0/16192.69.0.1 to 192.69.255.254192.69.255.25565,534
71192.70.0.0/16192.70.0.1 to 192.70.255.254192.70.255.25565,534
72192.71.0.0/16192.71.0.1 to 192.71.255.254192.71.255.25565,534
73192.72.0.0/16192.72.0.1 to 192.72.255.254192.72.255.25565,534
74192.73.0.0/16192.73.0.1 to 192.73.255.254192.73.255.25565,534
75192.74.0.0/16192.74.0.1 to 192.74.255.254192.74.255.25565,534
76192.75.0.0/16192.75.0.1 to 192.75.255.254192.75.255.25565,534
77192.76.0.0/16192.76.0.1 to 192.76.255.254192.76.255.25565,534
78192.77.0.0/16192.77.0.1 to 192.77.255.254192.77.255.25565,534
79192.78.0.0/16192.78.0.1 to 192.78.255.254192.78.255.25565,534
80192.79.0.0/16192.79.0.1 to 192.79.255.254192.79.255.25565,534
81192.80.0.0/16192.80.0.1 to 192.80.255.254192.80.255.25565,534
82192.81.0.0/16192.81.0.1 to 192.81.255.254192.81.255.25565,534
83192.82.0.0/16192.82.0.1 to 192.82.255.254192.82.255.25565,534
84192.83.0.0/16192.83.0.1 to 192.83.255.254192.83.255.25565,534
85192.84.0.0/16192.84.0.1 to 192.84.255.254192.84.255.25565,534
86192.85.0.0/16192.85.0.1 to 192.85.255.254192.85.255.25565,534
87192.86.0.0/16192.86.0.1 to 192.86.255.254192.86.255.25565,534
88192.87.0.0/16192.87.0.1 to 192.87.255.254192.87.255.25565,534
89192.88.0.0/16192.88.0.1 to 192.88.255.254192.88.255.25565,534
90192.89.0.0/16192.89.0.1 to 192.89.255.254192.89.255.25565,534
91192.90.0.0/16192.90.0.1 to 192.90.255.254192.90.255.25565,534
92192.91.0.0/16192.91.0.1 to 192.91.255.254192.91.255.25565,534
93192.92.0.0/16192.92.0.1 to 192.92.255.254192.92.255.25565,534
94192.93.0.0/16192.93.0.1 to 192.93.255.254192.93.255.25565,534
95192.94.0.0/16192.94.0.1 to 192.94.255.254192.94.255.25565,534
96192.95.0.0/16192.95.0.1 to 192.95.255.254192.95.255.25565,534
97192.96.0.0/16192.96.0.1 to 192.96.255.254192.96.255.25565,534
98192.97.0.0/16192.97.0.1 to 192.97.255.254192.97.255.25565,534
99192.98.0.0/16192.98.0.1 to 192.98.255.254192.98.255.25565,534
100192.99.0.0/16192.99.0.1 to 192.99.255.254192.99.255.25565,534
101192.100.0.0/16192.100.0.1 to 192.100.255.254192.100.255.25565,534
102192.101.0.0/16192.101.0.1 to 192.101.255.254192.101.255.25565,534
103192.102.0.0/16192.102.0.1 to 192.102.255.254192.102.255.25565,534
104192.103.0.0/16192.103.0.1 to 192.103.255.254192.103.255.25565,534
105192.104.0.0/16192.104.0.1 to 192.104.255.254192.104.255.25565,534
106192.105.0.0/16192.105.0.1 to 192.105.255.254192.105.255.25565,534
107192.106.0.0/16192.106.0.1 to 192.106.255.254192.106.255.25565,534
108192.107.0.0/16192.107.0.1 to 192.107.255.254192.107.255.25565,534
109192.108.0.0/16192.108.0.1 to 192.108.255.254192.108.255.25565,534
110192.109.0.0/16192.109.0.1 to 192.109.255.254192.109.255.25565,534
111192.110.0.0/16192.110.0.1 to 192.110.255.254192.110.255.25565,534
112192.111.0.0/16192.111.0.1 to 192.111.255.254192.111.255.25565,534
113192.112.0.0/16192.112.0.1 to 192.112.255.254192.112.255.25565,534
114192.113.0.0/16192.113.0.1 to 192.113.255.254192.113.255.25565,534
115192.114.0.0/16192.114.0.1 to 192.114.255.254192.114.255.25565,534
116192.115.0.0/16192.115.0.1 to 192.115.255.254192.115.255.25565,534
117192.116.0.0/16192.116.0.1 to 192.116.255.254192.116.255.25565,534
118192.117.0.0/16192.117.0.1 to 192.117.255.254192.117.255.25565,534
119192.118.0.0/16192.118.0.1 to 192.118.255.254192.118.255.25565,534
120192.119.0.0/16192.119.0.1 to 192.119.255.254192.119.255.25565,534
121192.120.0.0/16192.120.0.1 to 192.120.255.254192.120.255.25565,534
122192.121.0.0/16192.121.0.1 to 192.121.255.254192.121.255.25565,534
123192.122.0.0/16192.122.0.1 to 192.122.255.254192.122.255.25565,534
124192.123.0.0/16192.123.0.1 to 192.123.255.254192.123.255.25565,534
125192.124.0.0/16192.124.0.1 to 192.124.255.254192.124.255.25565,534
126192.125.0.0/16192.125.0.1 to 192.125.255.254192.125.255.25565,534
127192.126.0.0/16192.126.0.1 to 192.126.255.254192.126.255.25565,534
128192.127.0.0/16192.127.0.1 to 192.127.255.254192.127.255.25565,534
129192.128.0.0/16192.128.0.1 to 192.128.255.254192.128.255.25565,534
130192.129.0.0/16192.129.0.1 to 192.129.255.254192.129.255.25565,534
131192.130.0.0/16192.130.0.1 to 192.130.255.254192.130.255.25565,534
132192.131.0.0/16192.131.0.1 to 192.131.255.254192.131.255.25565,534
133192.132.0.0/16192.132.0.1 to 192.132.255.254192.132.255.25565,534
134192.133.0.0/16192.133.0.1 to 192.133.255.254192.133.255.25565,534
135192.134.0.0/16192.134.0.1 to 192.134.255.254192.134.255.25565,534
136192.135.0.0/16192.135.0.1 to 192.135.255.254192.135.255.25565,534
137192.136.0.0/16192.136.0.1 to 192.136.255.254192.136.255.25565,534
138192.137.0.0/16192.137.0.1 to 192.137.255.254192.137.255.25565,534
139192.138.0.0/16192.138.0.1 to 192.138.255.254192.138.255.25565,534
140192.139.0.0/16192.139.0.1 to 192.139.255.254192.139.255.25565,534
141192.140.0.0/16192.140.0.1 to 192.140.255.254192.140.255.25565,534
142192.141.0.0/16192.141.0.1 to 192.141.255.254192.141.255.25565,534
143192.142.0.0/16192.142.0.1 to 192.142.255.254192.142.255.25565,534
144192.143.0.0/16192.143.0.1 to 192.143.255.254192.143.255.25565,534
145192.144.0.0/16192.144.0.1 to 192.144.255.254192.144.255.25565,534
146192.145.0.0/16192.145.0.1 to 192.145.255.254192.145.255.25565,534
147192.146.0.0/16192.146.0.1 to 192.146.255.254192.146.255.25565,534
148192.147.0.0/16192.147.0.1 to 192.147.255.254192.147.255.25565,534
149192.148.0.0/16192.148.0.1 to 192.148.255.254192.148.255.25565,534
150192.149.0.0/16192.149.0.1 to 192.149.255.254192.149.255.25565,534
151192.150.0.0/16192.150.0.1 to 192.150.255.254192.150.255.25565,534
152192.151.0.0/16192.151.0.1 to 192.151.255.254192.151.255.25565,534
153192.152.0.0/16192.152.0.1 to 192.152.255.254192.152.255.25565,534
154192.153.0.0/16192.153.0.1 to 192.153.255.254192.153.255.25565,534
155192.154.0.0/16192.154.0.1 to 192.154.255.254192.154.255.25565,534
156192.155.0.0/16192.155.0.1 to 192.155.255.254192.155.255.25565,534
157192.156.0.0/16192.156.0.1 to 192.156.255.254192.156.255.25565,534
158192.157.0.0/16192.157.0.1 to 192.157.255.254192.157.255.25565,534
159192.158.0.0/16192.158.0.1 to 192.158.255.254192.158.255.25565,534
160192.159.0.0/16192.159.0.1 to 192.159.255.254192.159.255.25565,534
161192.160.0.0/16192.160.0.1 to 192.160.255.254192.160.255.25565,534
162192.161.0.0/16192.161.0.1 to 192.161.255.254192.161.255.25565,534
163192.162.0.0/16192.162.0.1 to 192.162.255.254192.162.255.25565,534
164192.163.0.0/16192.163.0.1 to 192.163.255.254192.163.255.25565,534
165192.164.0.0/16192.164.0.1 to 192.164.255.254192.164.255.25565,534
166192.165.0.0/16192.165.0.1 to 192.165.255.254192.165.255.25565,534
167192.166.0.0/16192.166.0.1 to 192.166.255.254192.166.255.25565,534
168192.167.0.0/16192.167.0.1 to 192.167.255.254192.167.255.25565,534
169192.168.0.0/16192.168.0.1 to 192.168.255.254192.168.255.25565,534
170192.169.0.0/16192.169.0.1 to 192.169.255.254192.169.255.25565,534
171192.170.0.0/16192.170.0.1 to 192.170.255.254192.170.255.25565,534
172192.171.0.0/16192.171.0.1 to 192.171.255.254192.171.255.25565,534
173192.172.0.0/16192.172.0.1 to 192.172.255.254192.172.255.25565,534
174192.173.0.0/16192.173.0.1 to 192.173.255.254192.173.255.25565,534
175192.174.0.0/16192.174.0.1 to 192.174.255.254192.174.255.25565,534
176192.175.0.0/16192.175.0.1 to 192.175.255.254192.175.255.25565,534
177192.176.0.0/16192.176.0.1 to 192.176.255.254192.176.255.25565,534
178192.177.0.0/16192.177.0.1 to 192.177.255.254192.177.255.25565,534
179192.178.0.0/16192.178.0.1 to 192.178.255.254192.178.255.25565,534
180192.179.0.0/16192.179.0.1 to 192.179.255.254192.179.255.25565,534
181192.180.0.0/16192.180.0.1 to 192.180.255.254192.180.255.25565,534
182192.181.0.0/16192.181.0.1 to 192.181.255.254192.181.255.25565,534
183192.182.0.0/16192.182.0.1 to 192.182.255.254192.182.255.25565,534
184192.183.0.0/16192.183.0.1 to 192.183.255.254192.183.255.25565,534
185192.184.0.0/16192.184.0.1 to 192.184.255.254192.184.255.25565,534
186192.185.0.0/16192.185.0.1 to 192.185.255.254192.185.255.25565,534
187192.186.0.0/16192.186.0.1 to 192.186.255.254192.186.255.25565,534
188192.187.0.0/16192.187.0.1 to 192.187.255.254192.187.255.25565,534
189192.188.0.0/16192.188.0.1 to 192.188.255.254192.188.255.25565,534
190192.189.0.0/16192.189.0.1 to 192.189.255.254192.189.255.25565,534
191192.190.0.0/16192.190.0.1 to 192.190.255.254192.190.255.25565,534
192192.191.0.0/16192.191.0.1 to 192.191.255.254192.191.255.25565,534
193192.192.0.0/16192.192.0.1 to 192.192.255.254192.192.255.25565,534
194192.193.0.0/16192.193.0.1 to 192.193.255.254192.193.255.25565,534
195192.194.0.0/16192.194.0.1 to 192.194.255.254192.194.255.25565,534
196192.195.0.0/16192.195.0.1 to 192.195.255.254192.195.255.25565,534
197192.196.0.0/16192.196.0.1 to 192.196.255.254192.196.255.25565,534
198192.197.0.0/16192.197.0.1 to 192.197.255.254192.197.255.25565,534
199192.198.0.0/16192.198.0.1 to 192.198.255.254192.198.255.25565,534
200192.199.0.0/16192.199.0.1 to 192.199.255.254192.199.255.25565,534
201192.200.0.0/16192.200.0.1 to 192.200.255.254192.200.255.25565,534
202192.201.0.0/16192.201.0.1 to 192.201.255.254192.201.255.25565,534
203192.202.0.0/16192.202.0.1 to 192.202.255.254192.202.255.25565,534
204192.203.0.0/16192.203.0.1 to 192.203.255.254192.203.255.25565,534
205192.204.0.0/16192.204.0.1 to 192.204.255.254192.204.255.25565,534
206192.205.0.0/16192.205.0.1 to 192.205.255.254192.205.255.25565,534
207192.206.0.0/16192.206.0.1 to 192.206.255.254192.206.255.25565,534
208192.207.0.0/16192.207.0.1 to 192.207.255.254192.207.255.25565,534
209192.208.0.0/16192.208.0.1 to 192.208.255.254192.208.255.25565,534
210192.209.0.0/16192.209.0.1 to 192.209.255.254192.209.255.25565,534
211192.210.0.0/16192.210.0.1 to 192.210.255.254192.210.255.25565,534
212192.211.0.0/16192.211.0.1 to 192.211.255.254192.211.255.25565,534
213192.212.0.0/16192.212.0.1 to 192.212.255.254192.212.255.25565,534
214192.213.0.0/16192.213.0.1 to 192.213.255.254192.213.255.25565,534
215192.214.0.0/16192.214.0.1 to 192.214.255.254192.214.255.25565,534
216192.215.0.0/16192.215.0.1 to 192.215.255.254192.215.255.25565,534
217192.216.0.0/16192.216.0.1 to 192.216.255.254192.216.255.25565,534
218192.217.0.0/16192.217.0.1 to 192.217.255.254192.217.255.25565,534
219192.218.0.0/16192.218.0.1 to 192.218.255.254192.218.255.25565,534
220192.219.0.0/16192.219.0.1 to 192.219.255.254192.219.255.25565,534
221192.220.0.0/16192.220.0.1 to 192.220.255.254192.220.255.25565,534
222192.221.0.0/16192.221.0.1 to 192.221.255.254192.221.255.25565,534
223192.222.0.0/16192.222.0.1 to 192.222.255.254192.222.255.25565,534
224192.223.0.0/16192.223.0.1 to 192.223.255.254192.223.255.25565,534
225192.224.0.0/16192.224.0.1 to 192.224.255.254192.224.255.25565,534
226192.225.0.0/16192.225.0.1 to 192.225.255.254192.225.255.25565,534
227192.226.0.0/16192.226.0.1 to 192.226.255.254192.226.255.25565,534
228192.227.0.0/16192.227.0.1 to 192.227.255.254192.227.255.25565,534
229192.228.0.0/16192.228.0.1 to 192.228.255.254192.228.255.25565,534
230192.229.0.0/16192.229.0.1 to 192.229.255.254192.229.255.25565,534
231192.230.0.0/16192.230.0.1 to 192.230.255.254192.230.255.25565,534
232192.231.0.0/16192.231.0.1 to 192.231.255.254192.231.255.25565,534
233192.232.0.0/16192.232.0.1 to 192.232.255.254192.232.255.25565,534
234192.233.0.0/16192.233.0.1 to 192.233.255.254192.233.255.25565,534
235192.234.0.0/16192.234.0.1 to 192.234.255.254192.234.255.25565,534
236192.235.0.0/16192.235.0.1 to 192.235.255.254192.235.255.25565,534
237192.236.0.0/16192.236.0.1 to 192.236.255.254192.236.255.25565,534
238192.237.0.0/16192.237.0.1 to 192.237.255.254192.237.255.25565,534
239192.238.0.0/16192.238.0.1 to 192.238.255.254192.238.255.25565,534
240192.239.0.0/16192.239.0.1 to 192.239.255.254192.239.255.25565,534
241192.240.0.0/16192.240.0.1 to 192.240.255.254192.240.255.25565,534
242192.241.0.0/16192.241.0.1 to 192.241.255.254192.241.255.25565,534
243192.242.0.0/16192.242.0.1 to 192.242.255.254192.242.255.25565,534
244192.243.0.0/16192.243.0.1 to 192.243.255.254192.243.255.25565,534
245192.244.0.0/16192.244.0.1 to 192.244.255.254192.244.255.25565,534
246192.245.0.0/16192.245.0.1 to 192.245.255.254192.245.255.25565,534
247192.246.0.0/16192.246.0.1 to 192.246.255.254192.246.255.25565,534
248192.247.0.0/16192.247.0.1 to 192.247.255.254192.247.255.25565,534
249192.248.0.0/16192.248.0.1 to 192.248.255.254192.248.255.25565,534
250192.249.0.0/16192.249.0.1 to 192.249.255.254192.249.255.25565,534
251192.250.0.0/16192.250.0.1 to 192.250.255.254192.250.255.25565,534
252192.251.0.0/16192.251.0.1 to 192.251.255.254192.251.255.25565,534
253192.252.0.0/16192.252.0.1 to 192.252.255.254192.252.255.25565,534
254192.253.0.0/16192.253.0.1 to 192.253.255.254192.253.255.25565,534
255192.254.0.0/16192.254.0.1 to 192.254.255.254192.254.255.25565,534
256192.255.0.0/16192.255.0.1 to 192.255.255.254192.255.255.25565,534

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.