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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.

Network194.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
194.0.0.0
Broadcast address
195.255.255.255
First usable
194.0.0.1
Last usable
195.255.255.254
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 C2000000 · Integer 3254779904 to 3288334335
Reverse DNS zones
194.in-addr.arpa
195.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
Address11000010.00000000.00000000.00000000194.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network11000010.00000000.00000000.00000000194.0.0.0
Broadcast11000011.11111111.11111111.11111111195.255.255.255
Split into smaller subnets/15
/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)

194.0.0.0/7 makes 256 subnets of /15.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1194.0.0.0/15194.0.0.1 to 194.1.255.254194.1.255.255131,070
2194.2.0.0/15194.2.0.1 to 194.3.255.254194.3.255.255131,070
3194.4.0.0/15194.4.0.1 to 194.5.255.254194.5.255.255131,070
4194.6.0.0/15194.6.0.1 to 194.7.255.254194.7.255.255131,070
5194.8.0.0/15194.8.0.1 to 194.9.255.254194.9.255.255131,070
6194.10.0.0/15194.10.0.1 to 194.11.255.254194.11.255.255131,070
7194.12.0.0/15194.12.0.1 to 194.13.255.254194.13.255.255131,070
8194.14.0.0/15194.14.0.1 to 194.15.255.254194.15.255.255131,070
9194.16.0.0/15194.16.0.1 to 194.17.255.254194.17.255.255131,070
10194.18.0.0/15194.18.0.1 to 194.19.255.254194.19.255.255131,070
11194.20.0.0/15194.20.0.1 to 194.21.255.254194.21.255.255131,070
12194.22.0.0/15194.22.0.1 to 194.23.255.254194.23.255.255131,070
13194.24.0.0/15194.24.0.1 to 194.25.255.254194.25.255.255131,070
14194.26.0.0/15194.26.0.1 to 194.27.255.254194.27.255.255131,070
15194.28.0.0/15194.28.0.1 to 194.29.255.254194.29.255.255131,070
16194.30.0.0/15194.30.0.1 to 194.31.255.254194.31.255.255131,070
17194.32.0.0/15194.32.0.1 to 194.33.255.254194.33.255.255131,070
18194.34.0.0/15194.34.0.1 to 194.35.255.254194.35.255.255131,070
19194.36.0.0/15194.36.0.1 to 194.37.255.254194.37.255.255131,070
20194.38.0.0/15194.38.0.1 to 194.39.255.254194.39.255.255131,070
21194.40.0.0/15194.40.0.1 to 194.41.255.254194.41.255.255131,070
22194.42.0.0/15194.42.0.1 to 194.43.255.254194.43.255.255131,070
23194.44.0.0/15194.44.0.1 to 194.45.255.254194.45.255.255131,070
24194.46.0.0/15194.46.0.1 to 194.47.255.254194.47.255.255131,070
25194.48.0.0/15194.48.0.1 to 194.49.255.254194.49.255.255131,070
26194.50.0.0/15194.50.0.1 to 194.51.255.254194.51.255.255131,070
27194.52.0.0/15194.52.0.1 to 194.53.255.254194.53.255.255131,070
28194.54.0.0/15194.54.0.1 to 194.55.255.254194.55.255.255131,070
29194.56.0.0/15194.56.0.1 to 194.57.255.254194.57.255.255131,070
30194.58.0.0/15194.58.0.1 to 194.59.255.254194.59.255.255131,070
31194.60.0.0/15194.60.0.1 to 194.61.255.254194.61.255.255131,070
32194.62.0.0/15194.62.0.1 to 194.63.255.254194.63.255.255131,070
33194.64.0.0/15194.64.0.1 to 194.65.255.254194.65.255.255131,070
34194.66.0.0/15194.66.0.1 to 194.67.255.254194.67.255.255131,070
35194.68.0.0/15194.68.0.1 to 194.69.255.254194.69.255.255131,070
36194.70.0.0/15194.70.0.1 to 194.71.255.254194.71.255.255131,070
37194.72.0.0/15194.72.0.1 to 194.73.255.254194.73.255.255131,070
38194.74.0.0/15194.74.0.1 to 194.75.255.254194.75.255.255131,070
39194.76.0.0/15194.76.0.1 to 194.77.255.254194.77.255.255131,070
40194.78.0.0/15194.78.0.1 to 194.79.255.254194.79.255.255131,070
41194.80.0.0/15194.80.0.1 to 194.81.255.254194.81.255.255131,070
42194.82.0.0/15194.82.0.1 to 194.83.255.254194.83.255.255131,070
43194.84.0.0/15194.84.0.1 to 194.85.255.254194.85.255.255131,070
44194.86.0.0/15194.86.0.1 to 194.87.255.254194.87.255.255131,070
45194.88.0.0/15194.88.0.1 to 194.89.255.254194.89.255.255131,070
46194.90.0.0/15194.90.0.1 to 194.91.255.254194.91.255.255131,070
47194.92.0.0/15194.92.0.1 to 194.93.255.254194.93.255.255131,070
48194.94.0.0/15194.94.0.1 to 194.95.255.254194.95.255.255131,070
49194.96.0.0/15194.96.0.1 to 194.97.255.254194.97.255.255131,070
50194.98.0.0/15194.98.0.1 to 194.99.255.254194.99.255.255131,070
51194.100.0.0/15194.100.0.1 to 194.101.255.254194.101.255.255131,070
52194.102.0.0/15194.102.0.1 to 194.103.255.254194.103.255.255131,070
53194.104.0.0/15194.104.0.1 to 194.105.255.254194.105.255.255131,070
54194.106.0.0/15194.106.0.1 to 194.107.255.254194.107.255.255131,070
55194.108.0.0/15194.108.0.1 to 194.109.255.254194.109.255.255131,070
56194.110.0.0/15194.110.0.1 to 194.111.255.254194.111.255.255131,070
57194.112.0.0/15194.112.0.1 to 194.113.255.254194.113.255.255131,070
58194.114.0.0/15194.114.0.1 to 194.115.255.254194.115.255.255131,070
59194.116.0.0/15194.116.0.1 to 194.117.255.254194.117.255.255131,070
60194.118.0.0/15194.118.0.1 to 194.119.255.254194.119.255.255131,070
61194.120.0.0/15194.120.0.1 to 194.121.255.254194.121.255.255131,070
62194.122.0.0/15194.122.0.1 to 194.123.255.254194.123.255.255131,070
63194.124.0.0/15194.124.0.1 to 194.125.255.254194.125.255.255131,070
64194.126.0.0/15194.126.0.1 to 194.127.255.254194.127.255.255131,070
65194.128.0.0/15194.128.0.1 to 194.129.255.254194.129.255.255131,070
66194.130.0.0/15194.130.0.1 to 194.131.255.254194.131.255.255131,070
67194.132.0.0/15194.132.0.1 to 194.133.255.254194.133.255.255131,070
68194.134.0.0/15194.134.0.1 to 194.135.255.254194.135.255.255131,070
69194.136.0.0/15194.136.0.1 to 194.137.255.254194.137.255.255131,070
70194.138.0.0/15194.138.0.1 to 194.139.255.254194.139.255.255131,070
71194.140.0.0/15194.140.0.1 to 194.141.255.254194.141.255.255131,070
72194.142.0.0/15194.142.0.1 to 194.143.255.254194.143.255.255131,070
73194.144.0.0/15194.144.0.1 to 194.145.255.254194.145.255.255131,070
74194.146.0.0/15194.146.0.1 to 194.147.255.254194.147.255.255131,070
75194.148.0.0/15194.148.0.1 to 194.149.255.254194.149.255.255131,070
76194.150.0.0/15194.150.0.1 to 194.151.255.254194.151.255.255131,070
77194.152.0.0/15194.152.0.1 to 194.153.255.254194.153.255.255131,070
78194.154.0.0/15194.154.0.1 to 194.155.255.254194.155.255.255131,070
79194.156.0.0/15194.156.0.1 to 194.157.255.254194.157.255.255131,070
80194.158.0.0/15194.158.0.1 to 194.159.255.254194.159.255.255131,070
81194.160.0.0/15194.160.0.1 to 194.161.255.254194.161.255.255131,070
82194.162.0.0/15194.162.0.1 to 194.163.255.254194.163.255.255131,070
83194.164.0.0/15194.164.0.1 to 194.165.255.254194.165.255.255131,070
84194.166.0.0/15194.166.0.1 to 194.167.255.254194.167.255.255131,070
85194.168.0.0/15194.168.0.1 to 194.169.255.254194.169.255.255131,070
86194.170.0.0/15194.170.0.1 to 194.171.255.254194.171.255.255131,070
87194.172.0.0/15194.172.0.1 to 194.173.255.254194.173.255.255131,070
88194.174.0.0/15194.174.0.1 to 194.175.255.254194.175.255.255131,070
89194.176.0.0/15194.176.0.1 to 194.177.255.254194.177.255.255131,070
90194.178.0.0/15194.178.0.1 to 194.179.255.254194.179.255.255131,070
91194.180.0.0/15194.180.0.1 to 194.181.255.254194.181.255.255131,070
92194.182.0.0/15194.182.0.1 to 194.183.255.254194.183.255.255131,070
93194.184.0.0/15194.184.0.1 to 194.185.255.254194.185.255.255131,070
94194.186.0.0/15194.186.0.1 to 194.187.255.254194.187.255.255131,070
95194.188.0.0/15194.188.0.1 to 194.189.255.254194.189.255.255131,070
96194.190.0.0/15194.190.0.1 to 194.191.255.254194.191.255.255131,070
97194.192.0.0/15194.192.0.1 to 194.193.255.254194.193.255.255131,070
98194.194.0.0/15194.194.0.1 to 194.195.255.254194.195.255.255131,070
99194.196.0.0/15194.196.0.1 to 194.197.255.254194.197.255.255131,070
100194.198.0.0/15194.198.0.1 to 194.199.255.254194.199.255.255131,070
101194.200.0.0/15194.200.0.1 to 194.201.255.254194.201.255.255131,070
102194.202.0.0/15194.202.0.1 to 194.203.255.254194.203.255.255131,070
103194.204.0.0/15194.204.0.1 to 194.205.255.254194.205.255.255131,070
104194.206.0.0/15194.206.0.1 to 194.207.255.254194.207.255.255131,070
105194.208.0.0/15194.208.0.1 to 194.209.255.254194.209.255.255131,070
106194.210.0.0/15194.210.0.1 to 194.211.255.254194.211.255.255131,070
107194.212.0.0/15194.212.0.1 to 194.213.255.254194.213.255.255131,070
108194.214.0.0/15194.214.0.1 to 194.215.255.254194.215.255.255131,070
109194.216.0.0/15194.216.0.1 to 194.217.255.254194.217.255.255131,070
110194.218.0.0/15194.218.0.1 to 194.219.255.254194.219.255.255131,070
111194.220.0.0/15194.220.0.1 to 194.221.255.254194.221.255.255131,070
112194.222.0.0/15194.222.0.1 to 194.223.255.254194.223.255.255131,070
113194.224.0.0/15194.224.0.1 to 194.225.255.254194.225.255.255131,070
114194.226.0.0/15194.226.0.1 to 194.227.255.254194.227.255.255131,070
115194.228.0.0/15194.228.0.1 to 194.229.255.254194.229.255.255131,070
116194.230.0.0/15194.230.0.1 to 194.231.255.254194.231.255.255131,070
117194.232.0.0/15194.232.0.1 to 194.233.255.254194.233.255.255131,070
118194.234.0.0/15194.234.0.1 to 194.235.255.254194.235.255.255131,070
119194.236.0.0/15194.236.0.1 to 194.237.255.254194.237.255.255131,070
120194.238.0.0/15194.238.0.1 to 194.239.255.254194.239.255.255131,070
121194.240.0.0/15194.240.0.1 to 194.241.255.254194.241.255.255131,070
122194.242.0.0/15194.242.0.1 to 194.243.255.254194.243.255.255131,070
123194.244.0.0/15194.244.0.1 to 194.245.255.254194.245.255.255131,070
124194.246.0.0/15194.246.0.1 to 194.247.255.254194.247.255.255131,070
125194.248.0.0/15194.248.0.1 to 194.249.255.254194.249.255.255131,070
126194.250.0.0/15194.250.0.1 to 194.251.255.254194.251.255.255131,070
127194.252.0.0/15194.252.0.1 to 194.253.255.254194.253.255.255131,070
128194.254.0.0/15194.254.0.1 to 194.255.255.254194.255.255.255131,070
129195.0.0.0/15195.0.0.1 to 195.1.255.254195.1.255.255131,070
130195.2.0.0/15195.2.0.1 to 195.3.255.254195.3.255.255131,070
131195.4.0.0/15195.4.0.1 to 195.5.255.254195.5.255.255131,070
132195.6.0.0/15195.6.0.1 to 195.7.255.254195.7.255.255131,070
133195.8.0.0/15195.8.0.1 to 195.9.255.254195.9.255.255131,070
134195.10.0.0/15195.10.0.1 to 195.11.255.254195.11.255.255131,070
135195.12.0.0/15195.12.0.1 to 195.13.255.254195.13.255.255131,070
136195.14.0.0/15195.14.0.1 to 195.15.255.254195.15.255.255131,070
137195.16.0.0/15195.16.0.1 to 195.17.255.254195.17.255.255131,070
138195.18.0.0/15195.18.0.1 to 195.19.255.254195.19.255.255131,070
139195.20.0.0/15195.20.0.1 to 195.21.255.254195.21.255.255131,070
140195.22.0.0/15195.22.0.1 to 195.23.255.254195.23.255.255131,070
141195.24.0.0/15195.24.0.1 to 195.25.255.254195.25.255.255131,070
142195.26.0.0/15195.26.0.1 to 195.27.255.254195.27.255.255131,070
143195.28.0.0/15195.28.0.1 to 195.29.255.254195.29.255.255131,070
144195.30.0.0/15195.30.0.1 to 195.31.255.254195.31.255.255131,070
145195.32.0.0/15195.32.0.1 to 195.33.255.254195.33.255.255131,070
146195.34.0.0/15195.34.0.1 to 195.35.255.254195.35.255.255131,070
147195.36.0.0/15195.36.0.1 to 195.37.255.254195.37.255.255131,070
148195.38.0.0/15195.38.0.1 to 195.39.255.254195.39.255.255131,070
149195.40.0.0/15195.40.0.1 to 195.41.255.254195.41.255.255131,070
150195.42.0.0/15195.42.0.1 to 195.43.255.254195.43.255.255131,070
151195.44.0.0/15195.44.0.1 to 195.45.255.254195.45.255.255131,070
152195.46.0.0/15195.46.0.1 to 195.47.255.254195.47.255.255131,070
153195.48.0.0/15195.48.0.1 to 195.49.255.254195.49.255.255131,070
154195.50.0.0/15195.50.0.1 to 195.51.255.254195.51.255.255131,070
155195.52.0.0/15195.52.0.1 to 195.53.255.254195.53.255.255131,070
156195.54.0.0/15195.54.0.1 to 195.55.255.254195.55.255.255131,070
157195.56.0.0/15195.56.0.1 to 195.57.255.254195.57.255.255131,070
158195.58.0.0/15195.58.0.1 to 195.59.255.254195.59.255.255131,070
159195.60.0.0/15195.60.0.1 to 195.61.255.254195.61.255.255131,070
160195.62.0.0/15195.62.0.1 to 195.63.255.254195.63.255.255131,070
161195.64.0.0/15195.64.0.1 to 195.65.255.254195.65.255.255131,070
162195.66.0.0/15195.66.0.1 to 195.67.255.254195.67.255.255131,070
163195.68.0.0/15195.68.0.1 to 195.69.255.254195.69.255.255131,070
164195.70.0.0/15195.70.0.1 to 195.71.255.254195.71.255.255131,070
165195.72.0.0/15195.72.0.1 to 195.73.255.254195.73.255.255131,070
166195.74.0.0/15195.74.0.1 to 195.75.255.254195.75.255.255131,070
167195.76.0.0/15195.76.0.1 to 195.77.255.254195.77.255.255131,070
168195.78.0.0/15195.78.0.1 to 195.79.255.254195.79.255.255131,070
169195.80.0.0/15195.80.0.1 to 195.81.255.254195.81.255.255131,070
170195.82.0.0/15195.82.0.1 to 195.83.255.254195.83.255.255131,070
171195.84.0.0/15195.84.0.1 to 195.85.255.254195.85.255.255131,070
172195.86.0.0/15195.86.0.1 to 195.87.255.254195.87.255.255131,070
173195.88.0.0/15195.88.0.1 to 195.89.255.254195.89.255.255131,070
174195.90.0.0/15195.90.0.1 to 195.91.255.254195.91.255.255131,070
175195.92.0.0/15195.92.0.1 to 195.93.255.254195.93.255.255131,070
176195.94.0.0/15195.94.0.1 to 195.95.255.254195.95.255.255131,070
177195.96.0.0/15195.96.0.1 to 195.97.255.254195.97.255.255131,070
178195.98.0.0/15195.98.0.1 to 195.99.255.254195.99.255.255131,070
179195.100.0.0/15195.100.0.1 to 195.101.255.254195.101.255.255131,070
180195.102.0.0/15195.102.0.1 to 195.103.255.254195.103.255.255131,070
181195.104.0.0/15195.104.0.1 to 195.105.255.254195.105.255.255131,070
182195.106.0.0/15195.106.0.1 to 195.107.255.254195.107.255.255131,070
183195.108.0.0/15195.108.0.1 to 195.109.255.254195.109.255.255131,070
184195.110.0.0/15195.110.0.1 to 195.111.255.254195.111.255.255131,070
185195.112.0.0/15195.112.0.1 to 195.113.255.254195.113.255.255131,070
186195.114.0.0/15195.114.0.1 to 195.115.255.254195.115.255.255131,070
187195.116.0.0/15195.116.0.1 to 195.117.255.254195.117.255.255131,070
188195.118.0.0/15195.118.0.1 to 195.119.255.254195.119.255.255131,070
189195.120.0.0/15195.120.0.1 to 195.121.255.254195.121.255.255131,070
190195.122.0.0/15195.122.0.1 to 195.123.255.254195.123.255.255131,070
191195.124.0.0/15195.124.0.1 to 195.125.255.254195.125.255.255131,070
192195.126.0.0/15195.126.0.1 to 195.127.255.254195.127.255.255131,070
193195.128.0.0/15195.128.0.1 to 195.129.255.254195.129.255.255131,070
194195.130.0.0/15195.130.0.1 to 195.131.255.254195.131.255.255131,070
195195.132.0.0/15195.132.0.1 to 195.133.255.254195.133.255.255131,070
196195.134.0.0/15195.134.0.1 to 195.135.255.254195.135.255.255131,070
197195.136.0.0/15195.136.0.1 to 195.137.255.254195.137.255.255131,070
198195.138.0.0/15195.138.0.1 to 195.139.255.254195.139.255.255131,070
199195.140.0.0/15195.140.0.1 to 195.141.255.254195.141.255.255131,070
200195.142.0.0/15195.142.0.1 to 195.143.255.254195.143.255.255131,070
201195.144.0.0/15195.144.0.1 to 195.145.255.254195.145.255.255131,070
202195.146.0.0/15195.146.0.1 to 195.147.255.254195.147.255.255131,070
203195.148.0.0/15195.148.0.1 to 195.149.255.254195.149.255.255131,070
204195.150.0.0/15195.150.0.1 to 195.151.255.254195.151.255.255131,070
205195.152.0.0/15195.152.0.1 to 195.153.255.254195.153.255.255131,070
206195.154.0.0/15195.154.0.1 to 195.155.255.254195.155.255.255131,070
207195.156.0.0/15195.156.0.1 to 195.157.255.254195.157.255.255131,070
208195.158.0.0/15195.158.0.1 to 195.159.255.254195.159.255.255131,070
209195.160.0.0/15195.160.0.1 to 195.161.255.254195.161.255.255131,070
210195.162.0.0/15195.162.0.1 to 195.163.255.254195.163.255.255131,070
211195.164.0.0/15195.164.0.1 to 195.165.255.254195.165.255.255131,070
212195.166.0.0/15195.166.0.1 to 195.167.255.254195.167.255.255131,070
213195.168.0.0/15195.168.0.1 to 195.169.255.254195.169.255.255131,070
214195.170.0.0/15195.170.0.1 to 195.171.255.254195.171.255.255131,070
215195.172.0.0/15195.172.0.1 to 195.173.255.254195.173.255.255131,070
216195.174.0.0/15195.174.0.1 to 195.175.255.254195.175.255.255131,070
217195.176.0.0/15195.176.0.1 to 195.177.255.254195.177.255.255131,070
218195.178.0.0/15195.178.0.1 to 195.179.255.254195.179.255.255131,070
219195.180.0.0/15195.180.0.1 to 195.181.255.254195.181.255.255131,070
220195.182.0.0/15195.182.0.1 to 195.183.255.254195.183.255.255131,070
221195.184.0.0/15195.184.0.1 to 195.185.255.254195.185.255.255131,070
222195.186.0.0/15195.186.0.1 to 195.187.255.254195.187.255.255131,070
223195.188.0.0/15195.188.0.1 to 195.189.255.254195.189.255.255131,070
224195.190.0.0/15195.190.0.1 to 195.191.255.254195.191.255.255131,070
225195.192.0.0/15195.192.0.1 to 195.193.255.254195.193.255.255131,070
226195.194.0.0/15195.194.0.1 to 195.195.255.254195.195.255.255131,070
227195.196.0.0/15195.196.0.1 to 195.197.255.254195.197.255.255131,070
228195.198.0.0/15195.198.0.1 to 195.199.255.254195.199.255.255131,070
229195.200.0.0/15195.200.0.1 to 195.201.255.254195.201.255.255131,070
230195.202.0.0/15195.202.0.1 to 195.203.255.254195.203.255.255131,070
231195.204.0.0/15195.204.0.1 to 195.205.255.254195.205.255.255131,070
232195.206.0.0/15195.206.0.1 to 195.207.255.254195.207.255.255131,070
233195.208.0.0/15195.208.0.1 to 195.209.255.254195.209.255.255131,070
234195.210.0.0/15195.210.0.1 to 195.211.255.254195.211.255.255131,070
235195.212.0.0/15195.212.0.1 to 195.213.255.254195.213.255.255131,070
236195.214.0.0/15195.214.0.1 to 195.215.255.254195.215.255.255131,070
237195.216.0.0/15195.216.0.1 to 195.217.255.254195.217.255.255131,070
238195.218.0.0/15195.218.0.1 to 195.219.255.254195.219.255.255131,070
239195.220.0.0/15195.220.0.1 to 195.221.255.254195.221.255.255131,070
240195.222.0.0/15195.222.0.1 to 195.223.255.254195.223.255.255131,070
241195.224.0.0/15195.224.0.1 to 195.225.255.254195.225.255.255131,070
242195.226.0.0/15195.226.0.1 to 195.227.255.254195.227.255.255131,070
243195.228.0.0/15195.228.0.1 to 195.229.255.254195.229.255.255131,070
244195.230.0.0/15195.230.0.1 to 195.231.255.254195.231.255.255131,070
245195.232.0.0/15195.232.0.1 to 195.233.255.254195.233.255.255131,070
246195.234.0.0/15195.234.0.1 to 195.235.255.254195.235.255.255131,070
247195.236.0.0/15195.236.0.1 to 195.237.255.254195.237.255.255131,070
248195.238.0.0/15195.238.0.1 to 195.239.255.254195.239.255.255131,070
249195.240.0.0/15195.240.0.1 to 195.241.255.254195.241.255.255131,070
250195.242.0.0/15195.242.0.1 to 195.243.255.254195.243.255.255131,070
251195.244.0.0/15195.244.0.1 to 195.245.255.254195.245.255.255131,070
252195.246.0.0/15195.246.0.1 to 195.247.255.254195.247.255.255131,070
253195.248.0.0/15195.248.0.1 to 195.249.255.254195.249.255.255131,070
254195.250.0.0/15195.250.0.1 to 195.251.255.254195.251.255.255131,070
255195.252.0.0/15195.252.0.1 to 195.253.255.254195.253.255.255131,070
256195.254.0.0/15195.254.0.1 to 195.255.255.254195.255.255.255131,070

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.