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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.

Network227.64.0.0/12
Usable hosts1,048,574
Subnet mask255.240.0.0
Addresses1,048,576
Network address
227.64.0.0
Broadcast address
227.79.255.255
First usable
227.64.0.1
Last usable
227.79.255.254
Usable hosts
1,048,574 (1,048,576 less the network and broadcast addresses)
Subnet mask
255.240.0.0
Wildcard mask
0.15.255.255 (Cisco ACLs, OSPF)
Prefix length
/12
Type
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E3400000 · Integer 3812622336 to 3813670911
Reverse DNS zones
64.227.in-addr.arpa
65.227.in-addr.arpa
66.227.in-addr.arpa
67.227.in-addr.arpa
68.227.in-addr.arpa
69.227.in-addr.arpa
70.227.in-addr.arpa
71.227.in-addr.arpa
72.227.in-addr.arpa
73.227.in-addr.arpa
74.227.in-addr.arpa
75.227.in-addr.arpa
76.227.in-addr.arpa
77.227.in-addr.arpa
78.227.in-addr.arpa
79.227.in-addr.arpa
/12 is not on a 8-bit boundary, so it takes 16 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11100011.01000000.00000000.00000000227.64.0.0
Subnet mask11111111.11110000.00000000.00000000255.240.0.0
Network11100011.01000000.00000000.00000000227.64.0.0
Broadcast11100011.01001111.11111111.11111111227.79.255.255
Split into smaller subnets/22
/13 (2)/14 (4)/15 (8)/16 (16)/17 (32)/18 (64)/19 (128)/20 (256)/21 (512)/22 (1,024)/23 (2,048)/24 (4,096)

227.64.0.0/12 makes 1,024 subnets of /22; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1227.64.0.0/22227.64.0.1 to 227.64.3.254227.64.3.2551,022
2227.64.4.0/22227.64.4.1 to 227.64.7.254227.64.7.2551,022
3227.64.8.0/22227.64.8.1 to 227.64.11.254227.64.11.2551,022
4227.64.12.0/22227.64.12.1 to 227.64.15.254227.64.15.2551,022
5227.64.16.0/22227.64.16.1 to 227.64.19.254227.64.19.2551,022
6227.64.20.0/22227.64.20.1 to 227.64.23.254227.64.23.2551,022
7227.64.24.0/22227.64.24.1 to 227.64.27.254227.64.27.2551,022
8227.64.28.0/22227.64.28.1 to 227.64.31.254227.64.31.2551,022
9227.64.32.0/22227.64.32.1 to 227.64.35.254227.64.35.2551,022
10227.64.36.0/22227.64.36.1 to 227.64.39.254227.64.39.2551,022
11227.64.40.0/22227.64.40.1 to 227.64.43.254227.64.43.2551,022
12227.64.44.0/22227.64.44.1 to 227.64.47.254227.64.47.2551,022
13227.64.48.0/22227.64.48.1 to 227.64.51.254227.64.51.2551,022
14227.64.52.0/22227.64.52.1 to 227.64.55.254227.64.55.2551,022
15227.64.56.0/22227.64.56.1 to 227.64.59.254227.64.59.2551,022
16227.64.60.0/22227.64.60.1 to 227.64.63.254227.64.63.2551,022
17227.64.64.0/22227.64.64.1 to 227.64.67.254227.64.67.2551,022
18227.64.68.0/22227.64.68.1 to 227.64.71.254227.64.71.2551,022
19227.64.72.0/22227.64.72.1 to 227.64.75.254227.64.75.2551,022
20227.64.76.0/22227.64.76.1 to 227.64.79.254227.64.79.2551,022
21227.64.80.0/22227.64.80.1 to 227.64.83.254227.64.83.2551,022
22227.64.84.0/22227.64.84.1 to 227.64.87.254227.64.87.2551,022
23227.64.88.0/22227.64.88.1 to 227.64.91.254227.64.91.2551,022
24227.64.92.0/22227.64.92.1 to 227.64.95.254227.64.95.2551,022
25227.64.96.0/22227.64.96.1 to 227.64.99.254227.64.99.2551,022
26227.64.100.0/22227.64.100.1 to 227.64.103.254227.64.103.2551,022
27227.64.104.0/22227.64.104.1 to 227.64.107.254227.64.107.2551,022
28227.64.108.0/22227.64.108.1 to 227.64.111.254227.64.111.2551,022
29227.64.112.0/22227.64.112.1 to 227.64.115.254227.64.115.2551,022
30227.64.116.0/22227.64.116.1 to 227.64.119.254227.64.119.2551,022
31227.64.120.0/22227.64.120.1 to 227.64.123.254227.64.123.2551,022
32227.64.124.0/22227.64.124.1 to 227.64.127.254227.64.127.2551,022
33227.64.128.0/22227.64.128.1 to 227.64.131.254227.64.131.2551,022
34227.64.132.0/22227.64.132.1 to 227.64.135.254227.64.135.2551,022
35227.64.136.0/22227.64.136.1 to 227.64.139.254227.64.139.2551,022
36227.64.140.0/22227.64.140.1 to 227.64.143.254227.64.143.2551,022
37227.64.144.0/22227.64.144.1 to 227.64.147.254227.64.147.2551,022
38227.64.148.0/22227.64.148.1 to 227.64.151.254227.64.151.2551,022
39227.64.152.0/22227.64.152.1 to 227.64.155.254227.64.155.2551,022
40227.64.156.0/22227.64.156.1 to 227.64.159.254227.64.159.2551,022
41227.64.160.0/22227.64.160.1 to 227.64.163.254227.64.163.2551,022
42227.64.164.0/22227.64.164.1 to 227.64.167.254227.64.167.2551,022
43227.64.168.0/22227.64.168.1 to 227.64.171.254227.64.171.2551,022
44227.64.172.0/22227.64.172.1 to 227.64.175.254227.64.175.2551,022
45227.64.176.0/22227.64.176.1 to 227.64.179.254227.64.179.2551,022
46227.64.180.0/22227.64.180.1 to 227.64.183.254227.64.183.2551,022
47227.64.184.0/22227.64.184.1 to 227.64.187.254227.64.187.2551,022
48227.64.188.0/22227.64.188.1 to 227.64.191.254227.64.191.2551,022
49227.64.192.0/22227.64.192.1 to 227.64.195.254227.64.195.2551,022
50227.64.196.0/22227.64.196.1 to 227.64.199.254227.64.199.2551,022
51227.64.200.0/22227.64.200.1 to 227.64.203.254227.64.203.2551,022
52227.64.204.0/22227.64.204.1 to 227.64.207.254227.64.207.2551,022
53227.64.208.0/22227.64.208.1 to 227.64.211.254227.64.211.2551,022
54227.64.212.0/22227.64.212.1 to 227.64.215.254227.64.215.2551,022
55227.64.216.0/22227.64.216.1 to 227.64.219.254227.64.219.2551,022
56227.64.220.0/22227.64.220.1 to 227.64.223.254227.64.223.2551,022
57227.64.224.0/22227.64.224.1 to 227.64.227.254227.64.227.2551,022
58227.64.228.0/22227.64.228.1 to 227.64.231.254227.64.231.2551,022
59227.64.232.0/22227.64.232.1 to 227.64.235.254227.64.235.2551,022
60227.64.236.0/22227.64.236.1 to 227.64.239.254227.64.239.2551,022
61227.64.240.0/22227.64.240.1 to 227.64.243.254227.64.243.2551,022
62227.64.244.0/22227.64.244.1 to 227.64.247.254227.64.247.2551,022
63227.64.248.0/22227.64.248.1 to 227.64.251.254227.64.251.2551,022
64227.64.252.0/22227.64.252.1 to 227.64.255.254227.64.255.2551,022
65227.65.0.0/22227.65.0.1 to 227.65.3.254227.65.3.2551,022
66227.65.4.0/22227.65.4.1 to 227.65.7.254227.65.7.2551,022
67227.65.8.0/22227.65.8.1 to 227.65.11.254227.65.11.2551,022
68227.65.12.0/22227.65.12.1 to 227.65.15.254227.65.15.2551,022
69227.65.16.0/22227.65.16.1 to 227.65.19.254227.65.19.2551,022
70227.65.20.0/22227.65.20.1 to 227.65.23.254227.65.23.2551,022
71227.65.24.0/22227.65.24.1 to 227.65.27.254227.65.27.2551,022
72227.65.28.0/22227.65.28.1 to 227.65.31.254227.65.31.2551,022
73227.65.32.0/22227.65.32.1 to 227.65.35.254227.65.35.2551,022
74227.65.36.0/22227.65.36.1 to 227.65.39.254227.65.39.2551,022
75227.65.40.0/22227.65.40.1 to 227.65.43.254227.65.43.2551,022
76227.65.44.0/22227.65.44.1 to 227.65.47.254227.65.47.2551,022
77227.65.48.0/22227.65.48.1 to 227.65.51.254227.65.51.2551,022
78227.65.52.0/22227.65.52.1 to 227.65.55.254227.65.55.2551,022
79227.65.56.0/22227.65.56.1 to 227.65.59.254227.65.59.2551,022
80227.65.60.0/22227.65.60.1 to 227.65.63.254227.65.63.2551,022
81227.65.64.0/22227.65.64.1 to 227.65.67.254227.65.67.2551,022
82227.65.68.0/22227.65.68.1 to 227.65.71.254227.65.71.2551,022
83227.65.72.0/22227.65.72.1 to 227.65.75.254227.65.75.2551,022
84227.65.76.0/22227.65.76.1 to 227.65.79.254227.65.79.2551,022
85227.65.80.0/22227.65.80.1 to 227.65.83.254227.65.83.2551,022
86227.65.84.0/22227.65.84.1 to 227.65.87.254227.65.87.2551,022
87227.65.88.0/22227.65.88.1 to 227.65.91.254227.65.91.2551,022
88227.65.92.0/22227.65.92.1 to 227.65.95.254227.65.95.2551,022
89227.65.96.0/22227.65.96.1 to 227.65.99.254227.65.99.2551,022
90227.65.100.0/22227.65.100.1 to 227.65.103.254227.65.103.2551,022
91227.65.104.0/22227.65.104.1 to 227.65.107.254227.65.107.2551,022
92227.65.108.0/22227.65.108.1 to 227.65.111.254227.65.111.2551,022
93227.65.112.0/22227.65.112.1 to 227.65.115.254227.65.115.2551,022
94227.65.116.0/22227.65.116.1 to 227.65.119.254227.65.119.2551,022
95227.65.120.0/22227.65.120.1 to 227.65.123.254227.65.123.2551,022
96227.65.124.0/22227.65.124.1 to 227.65.127.254227.65.127.2551,022
97227.65.128.0/22227.65.128.1 to 227.65.131.254227.65.131.2551,022
98227.65.132.0/22227.65.132.1 to 227.65.135.254227.65.135.2551,022
99227.65.136.0/22227.65.136.1 to 227.65.139.254227.65.139.2551,022
100227.65.140.0/22227.65.140.1 to 227.65.143.254227.65.143.2551,022
101227.65.144.0/22227.65.144.1 to 227.65.147.254227.65.147.2551,022
102227.65.148.0/22227.65.148.1 to 227.65.151.254227.65.151.2551,022
103227.65.152.0/22227.65.152.1 to 227.65.155.254227.65.155.2551,022
104227.65.156.0/22227.65.156.1 to 227.65.159.254227.65.159.2551,022
105227.65.160.0/22227.65.160.1 to 227.65.163.254227.65.163.2551,022
106227.65.164.0/22227.65.164.1 to 227.65.167.254227.65.167.2551,022
107227.65.168.0/22227.65.168.1 to 227.65.171.254227.65.171.2551,022
108227.65.172.0/22227.65.172.1 to 227.65.175.254227.65.175.2551,022
109227.65.176.0/22227.65.176.1 to 227.65.179.254227.65.179.2551,022
110227.65.180.0/22227.65.180.1 to 227.65.183.254227.65.183.2551,022
111227.65.184.0/22227.65.184.1 to 227.65.187.254227.65.187.2551,022
112227.65.188.0/22227.65.188.1 to 227.65.191.254227.65.191.2551,022
113227.65.192.0/22227.65.192.1 to 227.65.195.254227.65.195.2551,022
114227.65.196.0/22227.65.196.1 to 227.65.199.254227.65.199.2551,022
115227.65.200.0/22227.65.200.1 to 227.65.203.254227.65.203.2551,022
116227.65.204.0/22227.65.204.1 to 227.65.207.254227.65.207.2551,022
117227.65.208.0/22227.65.208.1 to 227.65.211.254227.65.211.2551,022
118227.65.212.0/22227.65.212.1 to 227.65.215.254227.65.215.2551,022
119227.65.216.0/22227.65.216.1 to 227.65.219.254227.65.219.2551,022
120227.65.220.0/22227.65.220.1 to 227.65.223.254227.65.223.2551,022
121227.65.224.0/22227.65.224.1 to 227.65.227.254227.65.227.2551,022
122227.65.228.0/22227.65.228.1 to 227.65.231.254227.65.231.2551,022
123227.65.232.0/22227.65.232.1 to 227.65.235.254227.65.235.2551,022
124227.65.236.0/22227.65.236.1 to 227.65.239.254227.65.239.2551,022
125227.65.240.0/22227.65.240.1 to 227.65.243.254227.65.243.2551,022
126227.65.244.0/22227.65.244.1 to 227.65.247.254227.65.247.2551,022
127227.65.248.0/22227.65.248.1 to 227.65.251.254227.65.251.2551,022
128227.65.252.0/22227.65.252.1 to 227.65.255.254227.65.255.2551,022
129227.66.0.0/22227.66.0.1 to 227.66.3.254227.66.3.2551,022
130227.66.4.0/22227.66.4.1 to 227.66.7.254227.66.7.2551,022
131227.66.8.0/22227.66.8.1 to 227.66.11.254227.66.11.2551,022
132227.66.12.0/22227.66.12.1 to 227.66.15.254227.66.15.2551,022
133227.66.16.0/22227.66.16.1 to 227.66.19.254227.66.19.2551,022
134227.66.20.0/22227.66.20.1 to 227.66.23.254227.66.23.2551,022
135227.66.24.0/22227.66.24.1 to 227.66.27.254227.66.27.2551,022
136227.66.28.0/22227.66.28.1 to 227.66.31.254227.66.31.2551,022
137227.66.32.0/22227.66.32.1 to 227.66.35.254227.66.35.2551,022
138227.66.36.0/22227.66.36.1 to 227.66.39.254227.66.39.2551,022
139227.66.40.0/22227.66.40.1 to 227.66.43.254227.66.43.2551,022
140227.66.44.0/22227.66.44.1 to 227.66.47.254227.66.47.2551,022
141227.66.48.0/22227.66.48.1 to 227.66.51.254227.66.51.2551,022
142227.66.52.0/22227.66.52.1 to 227.66.55.254227.66.55.2551,022
143227.66.56.0/22227.66.56.1 to 227.66.59.254227.66.59.2551,022
144227.66.60.0/22227.66.60.1 to 227.66.63.254227.66.63.2551,022
145227.66.64.0/22227.66.64.1 to 227.66.67.254227.66.67.2551,022
146227.66.68.0/22227.66.68.1 to 227.66.71.254227.66.71.2551,022
147227.66.72.0/22227.66.72.1 to 227.66.75.254227.66.75.2551,022
148227.66.76.0/22227.66.76.1 to 227.66.79.254227.66.79.2551,022
149227.66.80.0/22227.66.80.1 to 227.66.83.254227.66.83.2551,022
150227.66.84.0/22227.66.84.1 to 227.66.87.254227.66.87.2551,022
151227.66.88.0/22227.66.88.1 to 227.66.91.254227.66.91.2551,022
152227.66.92.0/22227.66.92.1 to 227.66.95.254227.66.95.2551,022
153227.66.96.0/22227.66.96.1 to 227.66.99.254227.66.99.2551,022
154227.66.100.0/22227.66.100.1 to 227.66.103.254227.66.103.2551,022
155227.66.104.0/22227.66.104.1 to 227.66.107.254227.66.107.2551,022
156227.66.108.0/22227.66.108.1 to 227.66.111.254227.66.111.2551,022
157227.66.112.0/22227.66.112.1 to 227.66.115.254227.66.115.2551,022
158227.66.116.0/22227.66.116.1 to 227.66.119.254227.66.119.2551,022
159227.66.120.0/22227.66.120.1 to 227.66.123.254227.66.123.2551,022
160227.66.124.0/22227.66.124.1 to 227.66.127.254227.66.127.2551,022
161227.66.128.0/22227.66.128.1 to 227.66.131.254227.66.131.2551,022
162227.66.132.0/22227.66.132.1 to 227.66.135.254227.66.135.2551,022
163227.66.136.0/22227.66.136.1 to 227.66.139.254227.66.139.2551,022
164227.66.140.0/22227.66.140.1 to 227.66.143.254227.66.143.2551,022
165227.66.144.0/22227.66.144.1 to 227.66.147.254227.66.147.2551,022
166227.66.148.0/22227.66.148.1 to 227.66.151.254227.66.151.2551,022
167227.66.152.0/22227.66.152.1 to 227.66.155.254227.66.155.2551,022
168227.66.156.0/22227.66.156.1 to 227.66.159.254227.66.159.2551,022
169227.66.160.0/22227.66.160.1 to 227.66.163.254227.66.163.2551,022
170227.66.164.0/22227.66.164.1 to 227.66.167.254227.66.167.2551,022
171227.66.168.0/22227.66.168.1 to 227.66.171.254227.66.171.2551,022
172227.66.172.0/22227.66.172.1 to 227.66.175.254227.66.175.2551,022
173227.66.176.0/22227.66.176.1 to 227.66.179.254227.66.179.2551,022
174227.66.180.0/22227.66.180.1 to 227.66.183.254227.66.183.2551,022
175227.66.184.0/22227.66.184.1 to 227.66.187.254227.66.187.2551,022
176227.66.188.0/22227.66.188.1 to 227.66.191.254227.66.191.2551,022
177227.66.192.0/22227.66.192.1 to 227.66.195.254227.66.195.2551,022
178227.66.196.0/22227.66.196.1 to 227.66.199.254227.66.199.2551,022
179227.66.200.0/22227.66.200.1 to 227.66.203.254227.66.203.2551,022
180227.66.204.0/22227.66.204.1 to 227.66.207.254227.66.207.2551,022
181227.66.208.0/22227.66.208.1 to 227.66.211.254227.66.211.2551,022
182227.66.212.0/22227.66.212.1 to 227.66.215.254227.66.215.2551,022
183227.66.216.0/22227.66.216.1 to 227.66.219.254227.66.219.2551,022
184227.66.220.0/22227.66.220.1 to 227.66.223.254227.66.223.2551,022
185227.66.224.0/22227.66.224.1 to 227.66.227.254227.66.227.2551,022
186227.66.228.0/22227.66.228.1 to 227.66.231.254227.66.231.2551,022
187227.66.232.0/22227.66.232.1 to 227.66.235.254227.66.235.2551,022
188227.66.236.0/22227.66.236.1 to 227.66.239.254227.66.239.2551,022
189227.66.240.0/22227.66.240.1 to 227.66.243.254227.66.243.2551,022
190227.66.244.0/22227.66.244.1 to 227.66.247.254227.66.247.2551,022
191227.66.248.0/22227.66.248.1 to 227.66.251.254227.66.251.2551,022
192227.66.252.0/22227.66.252.1 to 227.66.255.254227.66.255.2551,022
193227.67.0.0/22227.67.0.1 to 227.67.3.254227.67.3.2551,022
194227.67.4.0/22227.67.4.1 to 227.67.7.254227.67.7.2551,022
195227.67.8.0/22227.67.8.1 to 227.67.11.254227.67.11.2551,022
196227.67.12.0/22227.67.12.1 to 227.67.15.254227.67.15.2551,022
197227.67.16.0/22227.67.16.1 to 227.67.19.254227.67.19.2551,022
198227.67.20.0/22227.67.20.1 to 227.67.23.254227.67.23.2551,022
199227.67.24.0/22227.67.24.1 to 227.67.27.254227.67.27.2551,022
200227.67.28.0/22227.67.28.1 to 227.67.31.254227.67.31.2551,022
201227.67.32.0/22227.67.32.1 to 227.67.35.254227.67.35.2551,022
202227.67.36.0/22227.67.36.1 to 227.67.39.254227.67.39.2551,022
203227.67.40.0/22227.67.40.1 to 227.67.43.254227.67.43.2551,022
204227.67.44.0/22227.67.44.1 to 227.67.47.254227.67.47.2551,022
205227.67.48.0/22227.67.48.1 to 227.67.51.254227.67.51.2551,022
206227.67.52.0/22227.67.52.1 to 227.67.55.254227.67.55.2551,022
207227.67.56.0/22227.67.56.1 to 227.67.59.254227.67.59.2551,022
208227.67.60.0/22227.67.60.1 to 227.67.63.254227.67.63.2551,022
209227.67.64.0/22227.67.64.1 to 227.67.67.254227.67.67.2551,022
210227.67.68.0/22227.67.68.1 to 227.67.71.254227.67.71.2551,022
211227.67.72.0/22227.67.72.1 to 227.67.75.254227.67.75.2551,022
212227.67.76.0/22227.67.76.1 to 227.67.79.254227.67.79.2551,022
213227.67.80.0/22227.67.80.1 to 227.67.83.254227.67.83.2551,022
214227.67.84.0/22227.67.84.1 to 227.67.87.254227.67.87.2551,022
215227.67.88.0/22227.67.88.1 to 227.67.91.254227.67.91.2551,022
216227.67.92.0/22227.67.92.1 to 227.67.95.254227.67.95.2551,022
217227.67.96.0/22227.67.96.1 to 227.67.99.254227.67.99.2551,022
218227.67.100.0/22227.67.100.1 to 227.67.103.254227.67.103.2551,022
219227.67.104.0/22227.67.104.1 to 227.67.107.254227.67.107.2551,022
220227.67.108.0/22227.67.108.1 to 227.67.111.254227.67.111.2551,022
221227.67.112.0/22227.67.112.1 to 227.67.115.254227.67.115.2551,022
222227.67.116.0/22227.67.116.1 to 227.67.119.254227.67.119.2551,022
223227.67.120.0/22227.67.120.1 to 227.67.123.254227.67.123.2551,022
224227.67.124.0/22227.67.124.1 to 227.67.127.254227.67.127.2551,022
225227.67.128.0/22227.67.128.1 to 227.67.131.254227.67.131.2551,022
226227.67.132.0/22227.67.132.1 to 227.67.135.254227.67.135.2551,022
227227.67.136.0/22227.67.136.1 to 227.67.139.254227.67.139.2551,022
228227.67.140.0/22227.67.140.1 to 227.67.143.254227.67.143.2551,022
229227.67.144.0/22227.67.144.1 to 227.67.147.254227.67.147.2551,022
230227.67.148.0/22227.67.148.1 to 227.67.151.254227.67.151.2551,022
231227.67.152.0/22227.67.152.1 to 227.67.155.254227.67.155.2551,022
232227.67.156.0/22227.67.156.1 to 227.67.159.254227.67.159.2551,022
233227.67.160.0/22227.67.160.1 to 227.67.163.254227.67.163.2551,022
234227.67.164.0/22227.67.164.1 to 227.67.167.254227.67.167.2551,022
235227.67.168.0/22227.67.168.1 to 227.67.171.254227.67.171.2551,022
236227.67.172.0/22227.67.172.1 to 227.67.175.254227.67.175.2551,022
237227.67.176.0/22227.67.176.1 to 227.67.179.254227.67.179.2551,022
238227.67.180.0/22227.67.180.1 to 227.67.183.254227.67.183.2551,022
239227.67.184.0/22227.67.184.1 to 227.67.187.254227.67.187.2551,022
240227.67.188.0/22227.67.188.1 to 227.67.191.254227.67.191.2551,022
241227.67.192.0/22227.67.192.1 to 227.67.195.254227.67.195.2551,022
242227.67.196.0/22227.67.196.1 to 227.67.199.254227.67.199.2551,022
243227.67.200.0/22227.67.200.1 to 227.67.203.254227.67.203.2551,022
244227.67.204.0/22227.67.204.1 to 227.67.207.254227.67.207.2551,022
245227.67.208.0/22227.67.208.1 to 227.67.211.254227.67.211.2551,022
246227.67.212.0/22227.67.212.1 to 227.67.215.254227.67.215.2551,022
247227.67.216.0/22227.67.216.1 to 227.67.219.254227.67.219.2551,022
248227.67.220.0/22227.67.220.1 to 227.67.223.254227.67.223.2551,022
249227.67.224.0/22227.67.224.1 to 227.67.227.254227.67.227.2551,022
250227.67.228.0/22227.67.228.1 to 227.67.231.254227.67.231.2551,022
251227.67.232.0/22227.67.232.1 to 227.67.235.254227.67.235.2551,022
252227.67.236.0/22227.67.236.1 to 227.67.239.254227.67.239.2551,022
253227.67.240.0/22227.67.240.1 to 227.67.243.254227.67.243.2551,022
254227.67.244.0/22227.67.244.1 to 227.67.247.254227.67.247.2551,022
255227.67.248.0/22227.67.248.1 to 227.67.251.254227.67.251.2551,022
256227.67.252.0/22227.67.252.1 to 227.67.255.254227.67.255.2551,022

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.