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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.

Network236.0.0.0/6
Usable hosts67,108,862
Subnet mask252.0.0.0
Addresses67,108,864
Network address
236.0.0.0
Broadcast address
239.255.255.255
First usable
236.0.0.1
Last usable
239.255.255.254
Usable hosts
67,108,862 (67,108,864 less the network and broadcast addresses)
Subnet mask
252.0.0.0
Wildcard mask
3.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/6
Type
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex EC000000 · Integer 3959422976 to 4026531839
Reverse DNS zones
236.in-addr.arpa
237.in-addr.arpa
238.in-addr.arpa
239.in-addr.arpa
/6 is not on a 8-bit boundary, so it takes 4 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11101100.00000000.00000000.00000000236.0.0.0
Subnet mask11111100.00000000.00000000.00000000252.0.0.0
Network11101100.00000000.00000000.00000000236.0.0.0
Broadcast11101111.11111111.11111111.11111111239.255.255.255
Split into smaller subnets/14
/7 (2)/8 (4)/9 (8)/10 (16)/11 (32)/12 (64)/13 (128)/14 (256)/15 (512)/16 (1,024)/17 (2,048)/18 (4,096)

236.0.0.0/6 makes 256 subnets of /14.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1236.0.0.0/14236.0.0.1 to 236.3.255.254236.3.255.255262,142
2236.4.0.0/14236.4.0.1 to 236.7.255.254236.7.255.255262,142
3236.8.0.0/14236.8.0.1 to 236.11.255.254236.11.255.255262,142
4236.12.0.0/14236.12.0.1 to 236.15.255.254236.15.255.255262,142
5236.16.0.0/14236.16.0.1 to 236.19.255.254236.19.255.255262,142
6236.20.0.0/14236.20.0.1 to 236.23.255.254236.23.255.255262,142
7236.24.0.0/14236.24.0.1 to 236.27.255.254236.27.255.255262,142
8236.28.0.0/14236.28.0.1 to 236.31.255.254236.31.255.255262,142
9236.32.0.0/14236.32.0.1 to 236.35.255.254236.35.255.255262,142
10236.36.0.0/14236.36.0.1 to 236.39.255.254236.39.255.255262,142
11236.40.0.0/14236.40.0.1 to 236.43.255.254236.43.255.255262,142
12236.44.0.0/14236.44.0.1 to 236.47.255.254236.47.255.255262,142
13236.48.0.0/14236.48.0.1 to 236.51.255.254236.51.255.255262,142
14236.52.0.0/14236.52.0.1 to 236.55.255.254236.55.255.255262,142
15236.56.0.0/14236.56.0.1 to 236.59.255.254236.59.255.255262,142
16236.60.0.0/14236.60.0.1 to 236.63.255.254236.63.255.255262,142
17236.64.0.0/14236.64.0.1 to 236.67.255.254236.67.255.255262,142
18236.68.0.0/14236.68.0.1 to 236.71.255.254236.71.255.255262,142
19236.72.0.0/14236.72.0.1 to 236.75.255.254236.75.255.255262,142
20236.76.0.0/14236.76.0.1 to 236.79.255.254236.79.255.255262,142
21236.80.0.0/14236.80.0.1 to 236.83.255.254236.83.255.255262,142
22236.84.0.0/14236.84.0.1 to 236.87.255.254236.87.255.255262,142
23236.88.0.0/14236.88.0.1 to 236.91.255.254236.91.255.255262,142
24236.92.0.0/14236.92.0.1 to 236.95.255.254236.95.255.255262,142
25236.96.0.0/14236.96.0.1 to 236.99.255.254236.99.255.255262,142
26236.100.0.0/14236.100.0.1 to 236.103.255.254236.103.255.255262,142
27236.104.0.0/14236.104.0.1 to 236.107.255.254236.107.255.255262,142
28236.108.0.0/14236.108.0.1 to 236.111.255.254236.111.255.255262,142
29236.112.0.0/14236.112.0.1 to 236.115.255.254236.115.255.255262,142
30236.116.0.0/14236.116.0.1 to 236.119.255.254236.119.255.255262,142
31236.120.0.0/14236.120.0.1 to 236.123.255.254236.123.255.255262,142
32236.124.0.0/14236.124.0.1 to 236.127.255.254236.127.255.255262,142
33236.128.0.0/14236.128.0.1 to 236.131.255.254236.131.255.255262,142
34236.132.0.0/14236.132.0.1 to 236.135.255.254236.135.255.255262,142
35236.136.0.0/14236.136.0.1 to 236.139.255.254236.139.255.255262,142
36236.140.0.0/14236.140.0.1 to 236.143.255.254236.143.255.255262,142
37236.144.0.0/14236.144.0.1 to 236.147.255.254236.147.255.255262,142
38236.148.0.0/14236.148.0.1 to 236.151.255.254236.151.255.255262,142
39236.152.0.0/14236.152.0.1 to 236.155.255.254236.155.255.255262,142
40236.156.0.0/14236.156.0.1 to 236.159.255.254236.159.255.255262,142
41236.160.0.0/14236.160.0.1 to 236.163.255.254236.163.255.255262,142
42236.164.0.0/14236.164.0.1 to 236.167.255.254236.167.255.255262,142
43236.168.0.0/14236.168.0.1 to 236.171.255.254236.171.255.255262,142
44236.172.0.0/14236.172.0.1 to 236.175.255.254236.175.255.255262,142
45236.176.0.0/14236.176.0.1 to 236.179.255.254236.179.255.255262,142
46236.180.0.0/14236.180.0.1 to 236.183.255.254236.183.255.255262,142
47236.184.0.0/14236.184.0.1 to 236.187.255.254236.187.255.255262,142
48236.188.0.0/14236.188.0.1 to 236.191.255.254236.191.255.255262,142
49236.192.0.0/14236.192.0.1 to 236.195.255.254236.195.255.255262,142
50236.196.0.0/14236.196.0.1 to 236.199.255.254236.199.255.255262,142
51236.200.0.0/14236.200.0.1 to 236.203.255.254236.203.255.255262,142
52236.204.0.0/14236.204.0.1 to 236.207.255.254236.207.255.255262,142
53236.208.0.0/14236.208.0.1 to 236.211.255.254236.211.255.255262,142
54236.212.0.0/14236.212.0.1 to 236.215.255.254236.215.255.255262,142
55236.216.0.0/14236.216.0.1 to 236.219.255.254236.219.255.255262,142
56236.220.0.0/14236.220.0.1 to 236.223.255.254236.223.255.255262,142
57236.224.0.0/14236.224.0.1 to 236.227.255.254236.227.255.255262,142
58236.228.0.0/14236.228.0.1 to 236.231.255.254236.231.255.255262,142
59236.232.0.0/14236.232.0.1 to 236.235.255.254236.235.255.255262,142
60236.236.0.0/14236.236.0.1 to 236.239.255.254236.239.255.255262,142
61236.240.0.0/14236.240.0.1 to 236.243.255.254236.243.255.255262,142
62236.244.0.0/14236.244.0.1 to 236.247.255.254236.247.255.255262,142
63236.248.0.0/14236.248.0.1 to 236.251.255.254236.251.255.255262,142
64236.252.0.0/14236.252.0.1 to 236.255.255.254236.255.255.255262,142
65237.0.0.0/14237.0.0.1 to 237.3.255.254237.3.255.255262,142
66237.4.0.0/14237.4.0.1 to 237.7.255.254237.7.255.255262,142
67237.8.0.0/14237.8.0.1 to 237.11.255.254237.11.255.255262,142
68237.12.0.0/14237.12.0.1 to 237.15.255.254237.15.255.255262,142
69237.16.0.0/14237.16.0.1 to 237.19.255.254237.19.255.255262,142
70237.20.0.0/14237.20.0.1 to 237.23.255.254237.23.255.255262,142
71237.24.0.0/14237.24.0.1 to 237.27.255.254237.27.255.255262,142
72237.28.0.0/14237.28.0.1 to 237.31.255.254237.31.255.255262,142
73237.32.0.0/14237.32.0.1 to 237.35.255.254237.35.255.255262,142
74237.36.0.0/14237.36.0.1 to 237.39.255.254237.39.255.255262,142
75237.40.0.0/14237.40.0.1 to 237.43.255.254237.43.255.255262,142
76237.44.0.0/14237.44.0.1 to 237.47.255.254237.47.255.255262,142
77237.48.0.0/14237.48.0.1 to 237.51.255.254237.51.255.255262,142
78237.52.0.0/14237.52.0.1 to 237.55.255.254237.55.255.255262,142
79237.56.0.0/14237.56.0.1 to 237.59.255.254237.59.255.255262,142
80237.60.0.0/14237.60.0.1 to 237.63.255.254237.63.255.255262,142
81237.64.0.0/14237.64.0.1 to 237.67.255.254237.67.255.255262,142
82237.68.0.0/14237.68.0.1 to 237.71.255.254237.71.255.255262,142
83237.72.0.0/14237.72.0.1 to 237.75.255.254237.75.255.255262,142
84237.76.0.0/14237.76.0.1 to 237.79.255.254237.79.255.255262,142
85237.80.0.0/14237.80.0.1 to 237.83.255.254237.83.255.255262,142
86237.84.0.0/14237.84.0.1 to 237.87.255.254237.87.255.255262,142
87237.88.0.0/14237.88.0.1 to 237.91.255.254237.91.255.255262,142
88237.92.0.0/14237.92.0.1 to 237.95.255.254237.95.255.255262,142
89237.96.0.0/14237.96.0.1 to 237.99.255.254237.99.255.255262,142
90237.100.0.0/14237.100.0.1 to 237.103.255.254237.103.255.255262,142
91237.104.0.0/14237.104.0.1 to 237.107.255.254237.107.255.255262,142
92237.108.0.0/14237.108.0.1 to 237.111.255.254237.111.255.255262,142
93237.112.0.0/14237.112.0.1 to 237.115.255.254237.115.255.255262,142
94237.116.0.0/14237.116.0.1 to 237.119.255.254237.119.255.255262,142
95237.120.0.0/14237.120.0.1 to 237.123.255.254237.123.255.255262,142
96237.124.0.0/14237.124.0.1 to 237.127.255.254237.127.255.255262,142
97237.128.0.0/14237.128.0.1 to 237.131.255.254237.131.255.255262,142
98237.132.0.0/14237.132.0.1 to 237.135.255.254237.135.255.255262,142
99237.136.0.0/14237.136.0.1 to 237.139.255.254237.139.255.255262,142
100237.140.0.0/14237.140.0.1 to 237.143.255.254237.143.255.255262,142
101237.144.0.0/14237.144.0.1 to 237.147.255.254237.147.255.255262,142
102237.148.0.0/14237.148.0.1 to 237.151.255.254237.151.255.255262,142
103237.152.0.0/14237.152.0.1 to 237.155.255.254237.155.255.255262,142
104237.156.0.0/14237.156.0.1 to 237.159.255.254237.159.255.255262,142
105237.160.0.0/14237.160.0.1 to 237.163.255.254237.163.255.255262,142
106237.164.0.0/14237.164.0.1 to 237.167.255.254237.167.255.255262,142
107237.168.0.0/14237.168.0.1 to 237.171.255.254237.171.255.255262,142
108237.172.0.0/14237.172.0.1 to 237.175.255.254237.175.255.255262,142
109237.176.0.0/14237.176.0.1 to 237.179.255.254237.179.255.255262,142
110237.180.0.0/14237.180.0.1 to 237.183.255.254237.183.255.255262,142
111237.184.0.0/14237.184.0.1 to 237.187.255.254237.187.255.255262,142
112237.188.0.0/14237.188.0.1 to 237.191.255.254237.191.255.255262,142
113237.192.0.0/14237.192.0.1 to 237.195.255.254237.195.255.255262,142
114237.196.0.0/14237.196.0.1 to 237.199.255.254237.199.255.255262,142
115237.200.0.0/14237.200.0.1 to 237.203.255.254237.203.255.255262,142
116237.204.0.0/14237.204.0.1 to 237.207.255.254237.207.255.255262,142
117237.208.0.0/14237.208.0.1 to 237.211.255.254237.211.255.255262,142
118237.212.0.0/14237.212.0.1 to 237.215.255.254237.215.255.255262,142
119237.216.0.0/14237.216.0.1 to 237.219.255.254237.219.255.255262,142
120237.220.0.0/14237.220.0.1 to 237.223.255.254237.223.255.255262,142
121237.224.0.0/14237.224.0.1 to 237.227.255.254237.227.255.255262,142
122237.228.0.0/14237.228.0.1 to 237.231.255.254237.231.255.255262,142
123237.232.0.0/14237.232.0.1 to 237.235.255.254237.235.255.255262,142
124237.236.0.0/14237.236.0.1 to 237.239.255.254237.239.255.255262,142
125237.240.0.0/14237.240.0.1 to 237.243.255.254237.243.255.255262,142
126237.244.0.0/14237.244.0.1 to 237.247.255.254237.247.255.255262,142
127237.248.0.0/14237.248.0.1 to 237.251.255.254237.251.255.255262,142
128237.252.0.0/14237.252.0.1 to 237.255.255.254237.255.255.255262,142
129238.0.0.0/14238.0.0.1 to 238.3.255.254238.3.255.255262,142
130238.4.0.0/14238.4.0.1 to 238.7.255.254238.7.255.255262,142
131238.8.0.0/14238.8.0.1 to 238.11.255.254238.11.255.255262,142
132238.12.0.0/14238.12.0.1 to 238.15.255.254238.15.255.255262,142
133238.16.0.0/14238.16.0.1 to 238.19.255.254238.19.255.255262,142
134238.20.0.0/14238.20.0.1 to 238.23.255.254238.23.255.255262,142
135238.24.0.0/14238.24.0.1 to 238.27.255.254238.27.255.255262,142
136238.28.0.0/14238.28.0.1 to 238.31.255.254238.31.255.255262,142
137238.32.0.0/14238.32.0.1 to 238.35.255.254238.35.255.255262,142
138238.36.0.0/14238.36.0.1 to 238.39.255.254238.39.255.255262,142
139238.40.0.0/14238.40.0.1 to 238.43.255.254238.43.255.255262,142
140238.44.0.0/14238.44.0.1 to 238.47.255.254238.47.255.255262,142
141238.48.0.0/14238.48.0.1 to 238.51.255.254238.51.255.255262,142
142238.52.0.0/14238.52.0.1 to 238.55.255.254238.55.255.255262,142
143238.56.0.0/14238.56.0.1 to 238.59.255.254238.59.255.255262,142
144238.60.0.0/14238.60.0.1 to 238.63.255.254238.63.255.255262,142
145238.64.0.0/14238.64.0.1 to 238.67.255.254238.67.255.255262,142
146238.68.0.0/14238.68.0.1 to 238.71.255.254238.71.255.255262,142
147238.72.0.0/14238.72.0.1 to 238.75.255.254238.75.255.255262,142
148238.76.0.0/14238.76.0.1 to 238.79.255.254238.79.255.255262,142
149238.80.0.0/14238.80.0.1 to 238.83.255.254238.83.255.255262,142
150238.84.0.0/14238.84.0.1 to 238.87.255.254238.87.255.255262,142
151238.88.0.0/14238.88.0.1 to 238.91.255.254238.91.255.255262,142
152238.92.0.0/14238.92.0.1 to 238.95.255.254238.95.255.255262,142
153238.96.0.0/14238.96.0.1 to 238.99.255.254238.99.255.255262,142
154238.100.0.0/14238.100.0.1 to 238.103.255.254238.103.255.255262,142
155238.104.0.0/14238.104.0.1 to 238.107.255.254238.107.255.255262,142
156238.108.0.0/14238.108.0.1 to 238.111.255.254238.111.255.255262,142
157238.112.0.0/14238.112.0.1 to 238.115.255.254238.115.255.255262,142
158238.116.0.0/14238.116.0.1 to 238.119.255.254238.119.255.255262,142
159238.120.0.0/14238.120.0.1 to 238.123.255.254238.123.255.255262,142
160238.124.0.0/14238.124.0.1 to 238.127.255.254238.127.255.255262,142
161238.128.0.0/14238.128.0.1 to 238.131.255.254238.131.255.255262,142
162238.132.0.0/14238.132.0.1 to 238.135.255.254238.135.255.255262,142
163238.136.0.0/14238.136.0.1 to 238.139.255.254238.139.255.255262,142
164238.140.0.0/14238.140.0.1 to 238.143.255.254238.143.255.255262,142
165238.144.0.0/14238.144.0.1 to 238.147.255.254238.147.255.255262,142
166238.148.0.0/14238.148.0.1 to 238.151.255.254238.151.255.255262,142
167238.152.0.0/14238.152.0.1 to 238.155.255.254238.155.255.255262,142
168238.156.0.0/14238.156.0.1 to 238.159.255.254238.159.255.255262,142
169238.160.0.0/14238.160.0.1 to 238.163.255.254238.163.255.255262,142
170238.164.0.0/14238.164.0.1 to 238.167.255.254238.167.255.255262,142
171238.168.0.0/14238.168.0.1 to 238.171.255.254238.171.255.255262,142
172238.172.0.0/14238.172.0.1 to 238.175.255.254238.175.255.255262,142
173238.176.0.0/14238.176.0.1 to 238.179.255.254238.179.255.255262,142
174238.180.0.0/14238.180.0.1 to 238.183.255.254238.183.255.255262,142
175238.184.0.0/14238.184.0.1 to 238.187.255.254238.187.255.255262,142
176238.188.0.0/14238.188.0.1 to 238.191.255.254238.191.255.255262,142
177238.192.0.0/14238.192.0.1 to 238.195.255.254238.195.255.255262,142
178238.196.0.0/14238.196.0.1 to 238.199.255.254238.199.255.255262,142
179238.200.0.0/14238.200.0.1 to 238.203.255.254238.203.255.255262,142
180238.204.0.0/14238.204.0.1 to 238.207.255.254238.207.255.255262,142
181238.208.0.0/14238.208.0.1 to 238.211.255.254238.211.255.255262,142
182238.212.0.0/14238.212.0.1 to 238.215.255.254238.215.255.255262,142
183238.216.0.0/14238.216.0.1 to 238.219.255.254238.219.255.255262,142
184238.220.0.0/14238.220.0.1 to 238.223.255.254238.223.255.255262,142
185238.224.0.0/14238.224.0.1 to 238.227.255.254238.227.255.255262,142
186238.228.0.0/14238.228.0.1 to 238.231.255.254238.231.255.255262,142
187238.232.0.0/14238.232.0.1 to 238.235.255.254238.235.255.255262,142
188238.236.0.0/14238.236.0.1 to 238.239.255.254238.239.255.255262,142
189238.240.0.0/14238.240.0.1 to 238.243.255.254238.243.255.255262,142
190238.244.0.0/14238.244.0.1 to 238.247.255.254238.247.255.255262,142
191238.248.0.0/14238.248.0.1 to 238.251.255.254238.251.255.255262,142
192238.252.0.0/14238.252.0.1 to 238.255.255.254238.255.255.255262,142
193239.0.0.0/14239.0.0.1 to 239.3.255.254239.3.255.255262,142
194239.4.0.0/14239.4.0.1 to 239.7.255.254239.7.255.255262,142
195239.8.0.0/14239.8.0.1 to 239.11.255.254239.11.255.255262,142
196239.12.0.0/14239.12.0.1 to 239.15.255.254239.15.255.255262,142
197239.16.0.0/14239.16.0.1 to 239.19.255.254239.19.255.255262,142
198239.20.0.0/14239.20.0.1 to 239.23.255.254239.23.255.255262,142
199239.24.0.0/14239.24.0.1 to 239.27.255.254239.27.255.255262,142
200239.28.0.0/14239.28.0.1 to 239.31.255.254239.31.255.255262,142
201239.32.0.0/14239.32.0.1 to 239.35.255.254239.35.255.255262,142
202239.36.0.0/14239.36.0.1 to 239.39.255.254239.39.255.255262,142
203239.40.0.0/14239.40.0.1 to 239.43.255.254239.43.255.255262,142
204239.44.0.0/14239.44.0.1 to 239.47.255.254239.47.255.255262,142
205239.48.0.0/14239.48.0.1 to 239.51.255.254239.51.255.255262,142
206239.52.0.0/14239.52.0.1 to 239.55.255.254239.55.255.255262,142
207239.56.0.0/14239.56.0.1 to 239.59.255.254239.59.255.255262,142
208239.60.0.0/14239.60.0.1 to 239.63.255.254239.63.255.255262,142
209239.64.0.0/14239.64.0.1 to 239.67.255.254239.67.255.255262,142
210239.68.0.0/14239.68.0.1 to 239.71.255.254239.71.255.255262,142
211239.72.0.0/14239.72.0.1 to 239.75.255.254239.75.255.255262,142
212239.76.0.0/14239.76.0.1 to 239.79.255.254239.79.255.255262,142
213239.80.0.0/14239.80.0.1 to 239.83.255.254239.83.255.255262,142
214239.84.0.0/14239.84.0.1 to 239.87.255.254239.87.255.255262,142
215239.88.0.0/14239.88.0.1 to 239.91.255.254239.91.255.255262,142
216239.92.0.0/14239.92.0.1 to 239.95.255.254239.95.255.255262,142
217239.96.0.0/14239.96.0.1 to 239.99.255.254239.99.255.255262,142
218239.100.0.0/14239.100.0.1 to 239.103.255.254239.103.255.255262,142
219239.104.0.0/14239.104.0.1 to 239.107.255.254239.107.255.255262,142
220239.108.0.0/14239.108.0.1 to 239.111.255.254239.111.255.255262,142
221239.112.0.0/14239.112.0.1 to 239.115.255.254239.115.255.255262,142
222239.116.0.0/14239.116.0.1 to 239.119.255.254239.119.255.255262,142
223239.120.0.0/14239.120.0.1 to 239.123.255.254239.123.255.255262,142
224239.124.0.0/14239.124.0.1 to 239.127.255.254239.127.255.255262,142
225239.128.0.0/14239.128.0.1 to 239.131.255.254239.131.255.255262,142
226239.132.0.0/14239.132.0.1 to 239.135.255.254239.135.255.255262,142
227239.136.0.0/14239.136.0.1 to 239.139.255.254239.139.255.255262,142
228239.140.0.0/14239.140.0.1 to 239.143.255.254239.143.255.255262,142
229239.144.0.0/14239.144.0.1 to 239.147.255.254239.147.255.255262,142
230239.148.0.0/14239.148.0.1 to 239.151.255.254239.151.255.255262,142
231239.152.0.0/14239.152.0.1 to 239.155.255.254239.155.255.255262,142
232239.156.0.0/14239.156.0.1 to 239.159.255.254239.159.255.255262,142
233239.160.0.0/14239.160.0.1 to 239.163.255.254239.163.255.255262,142
234239.164.0.0/14239.164.0.1 to 239.167.255.254239.167.255.255262,142
235239.168.0.0/14239.168.0.1 to 239.171.255.254239.171.255.255262,142
236239.172.0.0/14239.172.0.1 to 239.175.255.254239.175.255.255262,142
237239.176.0.0/14239.176.0.1 to 239.179.255.254239.179.255.255262,142
238239.180.0.0/14239.180.0.1 to 239.183.255.254239.183.255.255262,142
239239.184.0.0/14239.184.0.1 to 239.187.255.254239.187.255.255262,142
240239.188.0.0/14239.188.0.1 to 239.191.255.254239.191.255.255262,142
241239.192.0.0/14239.192.0.1 to 239.195.255.254239.195.255.255262,142
242239.196.0.0/14239.196.0.1 to 239.199.255.254239.199.255.255262,142
243239.200.0.0/14239.200.0.1 to 239.203.255.254239.203.255.255262,142
244239.204.0.0/14239.204.0.1 to 239.207.255.254239.207.255.255262,142
245239.208.0.0/14239.208.0.1 to 239.211.255.254239.211.255.255262,142
246239.212.0.0/14239.212.0.1 to 239.215.255.254239.215.255.255262,142
247239.216.0.0/14239.216.0.1 to 239.219.255.254239.219.255.255262,142
248239.220.0.0/14239.220.0.1 to 239.223.255.254239.223.255.255262,142
249239.224.0.0/14239.224.0.1 to 239.227.255.254239.227.255.255262,142
250239.228.0.0/14239.228.0.1 to 239.231.255.254239.231.255.255262,142
251239.232.0.0/14239.232.0.1 to 239.235.255.254239.235.255.255262,142
252239.236.0.0/14239.236.0.1 to 239.239.255.254239.239.255.255262,142
253239.240.0.0/14239.240.0.1 to 239.243.255.254239.243.255.255262,142
254239.244.0.0/14239.244.0.1 to 239.247.255.254239.247.255.255262,142
255239.248.0.0/14239.248.0.1 to 239.251.255.254239.251.255.255262,142
256239.252.0.0/14239.252.0.1 to 239.255.255.254239.255.255.255262,142

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.