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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.

Network227.128.0.0/11
Usable hosts2,097,150
Subnet mask255.224.0.0
Addresses2,097,152
Network address
227.128.0.0
Broadcast address
227.159.255.255
First usable
227.128.0.1
Last usable
227.159.255.254
Usable hosts
2,097,150 (2,097,152 less the network and broadcast addresses)
Subnet mask
255.224.0.0
Wildcard mask
0.31.255.255 (Cisco ACLs, OSPF)
Prefix length
/11
Type
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E3800000 · Integer 3816816640 to 3818913791
Reverse DNS zones
128.227.in-addr.arpa
129.227.in-addr.arpa
130.227.in-addr.arpa
131.227.in-addr.arpa
132.227.in-addr.arpa
133.227.in-addr.arpa
134.227.in-addr.arpa
135.227.in-addr.arpa
136.227.in-addr.arpa
137.227.in-addr.arpa
138.227.in-addr.arpa
139.227.in-addr.arpa
140.227.in-addr.arpa
141.227.in-addr.arpa
142.227.in-addr.arpa
143.227.in-addr.arpa
and 16 more
/11 is not on a 8-bit boundary, so it takes 32 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11100011.10000000.00000000.00000000227.128.0.0
Subnet mask11111111.11100000.00000000.00000000255.224.0.0
Network11100011.10000000.00000000.00000000227.128.0.0
Broadcast11100011.10011111.11111111.11111111227.159.255.255
Split into smaller subnets/19
/12 (2)/13 (4)/14 (8)/15 (16)/16 (32)/17 (64)/18 (128)/19 (256)/20 (512)/21 (1,024)/22 (2,048)/23 (4,096)

227.128.0.0/11 makes 256 subnets of /19.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1227.128.0.0/19227.128.0.1 to 227.128.31.254227.128.31.2558,190
2227.128.32.0/19227.128.32.1 to 227.128.63.254227.128.63.2558,190
3227.128.64.0/19227.128.64.1 to 227.128.95.254227.128.95.2558,190
4227.128.96.0/19227.128.96.1 to 227.128.127.254227.128.127.2558,190
5227.128.128.0/19227.128.128.1 to 227.128.159.254227.128.159.2558,190
6227.128.160.0/19227.128.160.1 to 227.128.191.254227.128.191.2558,190
7227.128.192.0/19227.128.192.1 to 227.128.223.254227.128.223.2558,190
8227.128.224.0/19227.128.224.1 to 227.128.255.254227.128.255.2558,190
9227.129.0.0/19227.129.0.1 to 227.129.31.254227.129.31.2558,190
10227.129.32.0/19227.129.32.1 to 227.129.63.254227.129.63.2558,190
11227.129.64.0/19227.129.64.1 to 227.129.95.254227.129.95.2558,190
12227.129.96.0/19227.129.96.1 to 227.129.127.254227.129.127.2558,190
13227.129.128.0/19227.129.128.1 to 227.129.159.254227.129.159.2558,190
14227.129.160.0/19227.129.160.1 to 227.129.191.254227.129.191.2558,190
15227.129.192.0/19227.129.192.1 to 227.129.223.254227.129.223.2558,190
16227.129.224.0/19227.129.224.1 to 227.129.255.254227.129.255.2558,190
17227.130.0.0/19227.130.0.1 to 227.130.31.254227.130.31.2558,190
18227.130.32.0/19227.130.32.1 to 227.130.63.254227.130.63.2558,190
19227.130.64.0/19227.130.64.1 to 227.130.95.254227.130.95.2558,190
20227.130.96.0/19227.130.96.1 to 227.130.127.254227.130.127.2558,190
21227.130.128.0/19227.130.128.1 to 227.130.159.254227.130.159.2558,190
22227.130.160.0/19227.130.160.1 to 227.130.191.254227.130.191.2558,190
23227.130.192.0/19227.130.192.1 to 227.130.223.254227.130.223.2558,190
24227.130.224.0/19227.130.224.1 to 227.130.255.254227.130.255.2558,190
25227.131.0.0/19227.131.0.1 to 227.131.31.254227.131.31.2558,190
26227.131.32.0/19227.131.32.1 to 227.131.63.254227.131.63.2558,190
27227.131.64.0/19227.131.64.1 to 227.131.95.254227.131.95.2558,190
28227.131.96.0/19227.131.96.1 to 227.131.127.254227.131.127.2558,190
29227.131.128.0/19227.131.128.1 to 227.131.159.254227.131.159.2558,190
30227.131.160.0/19227.131.160.1 to 227.131.191.254227.131.191.2558,190
31227.131.192.0/19227.131.192.1 to 227.131.223.254227.131.223.2558,190
32227.131.224.0/19227.131.224.1 to 227.131.255.254227.131.255.2558,190
33227.132.0.0/19227.132.0.1 to 227.132.31.254227.132.31.2558,190
34227.132.32.0/19227.132.32.1 to 227.132.63.254227.132.63.2558,190
35227.132.64.0/19227.132.64.1 to 227.132.95.254227.132.95.2558,190
36227.132.96.0/19227.132.96.1 to 227.132.127.254227.132.127.2558,190
37227.132.128.0/19227.132.128.1 to 227.132.159.254227.132.159.2558,190
38227.132.160.0/19227.132.160.1 to 227.132.191.254227.132.191.2558,190
39227.132.192.0/19227.132.192.1 to 227.132.223.254227.132.223.2558,190
40227.132.224.0/19227.132.224.1 to 227.132.255.254227.132.255.2558,190
41227.133.0.0/19227.133.0.1 to 227.133.31.254227.133.31.2558,190
42227.133.32.0/19227.133.32.1 to 227.133.63.254227.133.63.2558,190
43227.133.64.0/19227.133.64.1 to 227.133.95.254227.133.95.2558,190
44227.133.96.0/19227.133.96.1 to 227.133.127.254227.133.127.2558,190
45227.133.128.0/19227.133.128.1 to 227.133.159.254227.133.159.2558,190
46227.133.160.0/19227.133.160.1 to 227.133.191.254227.133.191.2558,190
47227.133.192.0/19227.133.192.1 to 227.133.223.254227.133.223.2558,190
48227.133.224.0/19227.133.224.1 to 227.133.255.254227.133.255.2558,190
49227.134.0.0/19227.134.0.1 to 227.134.31.254227.134.31.2558,190
50227.134.32.0/19227.134.32.1 to 227.134.63.254227.134.63.2558,190
51227.134.64.0/19227.134.64.1 to 227.134.95.254227.134.95.2558,190
52227.134.96.0/19227.134.96.1 to 227.134.127.254227.134.127.2558,190
53227.134.128.0/19227.134.128.1 to 227.134.159.254227.134.159.2558,190
54227.134.160.0/19227.134.160.1 to 227.134.191.254227.134.191.2558,190
55227.134.192.0/19227.134.192.1 to 227.134.223.254227.134.223.2558,190
56227.134.224.0/19227.134.224.1 to 227.134.255.254227.134.255.2558,190
57227.135.0.0/19227.135.0.1 to 227.135.31.254227.135.31.2558,190
58227.135.32.0/19227.135.32.1 to 227.135.63.254227.135.63.2558,190
59227.135.64.0/19227.135.64.1 to 227.135.95.254227.135.95.2558,190
60227.135.96.0/19227.135.96.1 to 227.135.127.254227.135.127.2558,190
61227.135.128.0/19227.135.128.1 to 227.135.159.254227.135.159.2558,190
62227.135.160.0/19227.135.160.1 to 227.135.191.254227.135.191.2558,190
63227.135.192.0/19227.135.192.1 to 227.135.223.254227.135.223.2558,190
64227.135.224.0/19227.135.224.1 to 227.135.255.254227.135.255.2558,190
65227.136.0.0/19227.136.0.1 to 227.136.31.254227.136.31.2558,190
66227.136.32.0/19227.136.32.1 to 227.136.63.254227.136.63.2558,190
67227.136.64.0/19227.136.64.1 to 227.136.95.254227.136.95.2558,190
68227.136.96.0/19227.136.96.1 to 227.136.127.254227.136.127.2558,190
69227.136.128.0/19227.136.128.1 to 227.136.159.254227.136.159.2558,190
70227.136.160.0/19227.136.160.1 to 227.136.191.254227.136.191.2558,190
71227.136.192.0/19227.136.192.1 to 227.136.223.254227.136.223.2558,190
72227.136.224.0/19227.136.224.1 to 227.136.255.254227.136.255.2558,190
73227.137.0.0/19227.137.0.1 to 227.137.31.254227.137.31.2558,190
74227.137.32.0/19227.137.32.1 to 227.137.63.254227.137.63.2558,190
75227.137.64.0/19227.137.64.1 to 227.137.95.254227.137.95.2558,190
76227.137.96.0/19227.137.96.1 to 227.137.127.254227.137.127.2558,190
77227.137.128.0/19227.137.128.1 to 227.137.159.254227.137.159.2558,190
78227.137.160.0/19227.137.160.1 to 227.137.191.254227.137.191.2558,190
79227.137.192.0/19227.137.192.1 to 227.137.223.254227.137.223.2558,190
80227.137.224.0/19227.137.224.1 to 227.137.255.254227.137.255.2558,190
81227.138.0.0/19227.138.0.1 to 227.138.31.254227.138.31.2558,190
82227.138.32.0/19227.138.32.1 to 227.138.63.254227.138.63.2558,190
83227.138.64.0/19227.138.64.1 to 227.138.95.254227.138.95.2558,190
84227.138.96.0/19227.138.96.1 to 227.138.127.254227.138.127.2558,190
85227.138.128.0/19227.138.128.1 to 227.138.159.254227.138.159.2558,190
86227.138.160.0/19227.138.160.1 to 227.138.191.254227.138.191.2558,190
87227.138.192.0/19227.138.192.1 to 227.138.223.254227.138.223.2558,190
88227.138.224.0/19227.138.224.1 to 227.138.255.254227.138.255.2558,190
89227.139.0.0/19227.139.0.1 to 227.139.31.254227.139.31.2558,190
90227.139.32.0/19227.139.32.1 to 227.139.63.254227.139.63.2558,190
91227.139.64.0/19227.139.64.1 to 227.139.95.254227.139.95.2558,190
92227.139.96.0/19227.139.96.1 to 227.139.127.254227.139.127.2558,190
93227.139.128.0/19227.139.128.1 to 227.139.159.254227.139.159.2558,190
94227.139.160.0/19227.139.160.1 to 227.139.191.254227.139.191.2558,190
95227.139.192.0/19227.139.192.1 to 227.139.223.254227.139.223.2558,190
96227.139.224.0/19227.139.224.1 to 227.139.255.254227.139.255.2558,190
97227.140.0.0/19227.140.0.1 to 227.140.31.254227.140.31.2558,190
98227.140.32.0/19227.140.32.1 to 227.140.63.254227.140.63.2558,190
99227.140.64.0/19227.140.64.1 to 227.140.95.254227.140.95.2558,190
100227.140.96.0/19227.140.96.1 to 227.140.127.254227.140.127.2558,190
101227.140.128.0/19227.140.128.1 to 227.140.159.254227.140.159.2558,190
102227.140.160.0/19227.140.160.1 to 227.140.191.254227.140.191.2558,190
103227.140.192.0/19227.140.192.1 to 227.140.223.254227.140.223.2558,190
104227.140.224.0/19227.140.224.1 to 227.140.255.254227.140.255.2558,190
105227.141.0.0/19227.141.0.1 to 227.141.31.254227.141.31.2558,190
106227.141.32.0/19227.141.32.1 to 227.141.63.254227.141.63.2558,190
107227.141.64.0/19227.141.64.1 to 227.141.95.254227.141.95.2558,190
108227.141.96.0/19227.141.96.1 to 227.141.127.254227.141.127.2558,190
109227.141.128.0/19227.141.128.1 to 227.141.159.254227.141.159.2558,190
110227.141.160.0/19227.141.160.1 to 227.141.191.254227.141.191.2558,190
111227.141.192.0/19227.141.192.1 to 227.141.223.254227.141.223.2558,190
112227.141.224.0/19227.141.224.1 to 227.141.255.254227.141.255.2558,190
113227.142.0.0/19227.142.0.1 to 227.142.31.254227.142.31.2558,190
114227.142.32.0/19227.142.32.1 to 227.142.63.254227.142.63.2558,190
115227.142.64.0/19227.142.64.1 to 227.142.95.254227.142.95.2558,190
116227.142.96.0/19227.142.96.1 to 227.142.127.254227.142.127.2558,190
117227.142.128.0/19227.142.128.1 to 227.142.159.254227.142.159.2558,190
118227.142.160.0/19227.142.160.1 to 227.142.191.254227.142.191.2558,190
119227.142.192.0/19227.142.192.1 to 227.142.223.254227.142.223.2558,190
120227.142.224.0/19227.142.224.1 to 227.142.255.254227.142.255.2558,190
121227.143.0.0/19227.143.0.1 to 227.143.31.254227.143.31.2558,190
122227.143.32.0/19227.143.32.1 to 227.143.63.254227.143.63.2558,190
123227.143.64.0/19227.143.64.1 to 227.143.95.254227.143.95.2558,190
124227.143.96.0/19227.143.96.1 to 227.143.127.254227.143.127.2558,190
125227.143.128.0/19227.143.128.1 to 227.143.159.254227.143.159.2558,190
126227.143.160.0/19227.143.160.1 to 227.143.191.254227.143.191.2558,190
127227.143.192.0/19227.143.192.1 to 227.143.223.254227.143.223.2558,190
128227.143.224.0/19227.143.224.1 to 227.143.255.254227.143.255.2558,190
129227.144.0.0/19227.144.0.1 to 227.144.31.254227.144.31.2558,190
130227.144.32.0/19227.144.32.1 to 227.144.63.254227.144.63.2558,190
131227.144.64.0/19227.144.64.1 to 227.144.95.254227.144.95.2558,190
132227.144.96.0/19227.144.96.1 to 227.144.127.254227.144.127.2558,190
133227.144.128.0/19227.144.128.1 to 227.144.159.254227.144.159.2558,190
134227.144.160.0/19227.144.160.1 to 227.144.191.254227.144.191.2558,190
135227.144.192.0/19227.144.192.1 to 227.144.223.254227.144.223.2558,190
136227.144.224.0/19227.144.224.1 to 227.144.255.254227.144.255.2558,190
137227.145.0.0/19227.145.0.1 to 227.145.31.254227.145.31.2558,190
138227.145.32.0/19227.145.32.1 to 227.145.63.254227.145.63.2558,190
139227.145.64.0/19227.145.64.1 to 227.145.95.254227.145.95.2558,190
140227.145.96.0/19227.145.96.1 to 227.145.127.254227.145.127.2558,190
141227.145.128.0/19227.145.128.1 to 227.145.159.254227.145.159.2558,190
142227.145.160.0/19227.145.160.1 to 227.145.191.254227.145.191.2558,190
143227.145.192.0/19227.145.192.1 to 227.145.223.254227.145.223.2558,190
144227.145.224.0/19227.145.224.1 to 227.145.255.254227.145.255.2558,190
145227.146.0.0/19227.146.0.1 to 227.146.31.254227.146.31.2558,190
146227.146.32.0/19227.146.32.1 to 227.146.63.254227.146.63.2558,190
147227.146.64.0/19227.146.64.1 to 227.146.95.254227.146.95.2558,190
148227.146.96.0/19227.146.96.1 to 227.146.127.254227.146.127.2558,190
149227.146.128.0/19227.146.128.1 to 227.146.159.254227.146.159.2558,190
150227.146.160.0/19227.146.160.1 to 227.146.191.254227.146.191.2558,190
151227.146.192.0/19227.146.192.1 to 227.146.223.254227.146.223.2558,190
152227.146.224.0/19227.146.224.1 to 227.146.255.254227.146.255.2558,190
153227.147.0.0/19227.147.0.1 to 227.147.31.254227.147.31.2558,190
154227.147.32.0/19227.147.32.1 to 227.147.63.254227.147.63.2558,190
155227.147.64.0/19227.147.64.1 to 227.147.95.254227.147.95.2558,190
156227.147.96.0/19227.147.96.1 to 227.147.127.254227.147.127.2558,190
157227.147.128.0/19227.147.128.1 to 227.147.159.254227.147.159.2558,190
158227.147.160.0/19227.147.160.1 to 227.147.191.254227.147.191.2558,190
159227.147.192.0/19227.147.192.1 to 227.147.223.254227.147.223.2558,190
160227.147.224.0/19227.147.224.1 to 227.147.255.254227.147.255.2558,190
161227.148.0.0/19227.148.0.1 to 227.148.31.254227.148.31.2558,190
162227.148.32.0/19227.148.32.1 to 227.148.63.254227.148.63.2558,190
163227.148.64.0/19227.148.64.1 to 227.148.95.254227.148.95.2558,190
164227.148.96.0/19227.148.96.1 to 227.148.127.254227.148.127.2558,190
165227.148.128.0/19227.148.128.1 to 227.148.159.254227.148.159.2558,190
166227.148.160.0/19227.148.160.1 to 227.148.191.254227.148.191.2558,190
167227.148.192.0/19227.148.192.1 to 227.148.223.254227.148.223.2558,190
168227.148.224.0/19227.148.224.1 to 227.148.255.254227.148.255.2558,190
169227.149.0.0/19227.149.0.1 to 227.149.31.254227.149.31.2558,190
170227.149.32.0/19227.149.32.1 to 227.149.63.254227.149.63.2558,190
171227.149.64.0/19227.149.64.1 to 227.149.95.254227.149.95.2558,190
172227.149.96.0/19227.149.96.1 to 227.149.127.254227.149.127.2558,190
173227.149.128.0/19227.149.128.1 to 227.149.159.254227.149.159.2558,190
174227.149.160.0/19227.149.160.1 to 227.149.191.254227.149.191.2558,190
175227.149.192.0/19227.149.192.1 to 227.149.223.254227.149.223.2558,190
176227.149.224.0/19227.149.224.1 to 227.149.255.254227.149.255.2558,190
177227.150.0.0/19227.150.0.1 to 227.150.31.254227.150.31.2558,190
178227.150.32.0/19227.150.32.1 to 227.150.63.254227.150.63.2558,190
179227.150.64.0/19227.150.64.1 to 227.150.95.254227.150.95.2558,190
180227.150.96.0/19227.150.96.1 to 227.150.127.254227.150.127.2558,190
181227.150.128.0/19227.150.128.1 to 227.150.159.254227.150.159.2558,190
182227.150.160.0/19227.150.160.1 to 227.150.191.254227.150.191.2558,190
183227.150.192.0/19227.150.192.1 to 227.150.223.254227.150.223.2558,190
184227.150.224.0/19227.150.224.1 to 227.150.255.254227.150.255.2558,190
185227.151.0.0/19227.151.0.1 to 227.151.31.254227.151.31.2558,190
186227.151.32.0/19227.151.32.1 to 227.151.63.254227.151.63.2558,190
187227.151.64.0/19227.151.64.1 to 227.151.95.254227.151.95.2558,190
188227.151.96.0/19227.151.96.1 to 227.151.127.254227.151.127.2558,190
189227.151.128.0/19227.151.128.1 to 227.151.159.254227.151.159.2558,190
190227.151.160.0/19227.151.160.1 to 227.151.191.254227.151.191.2558,190
191227.151.192.0/19227.151.192.1 to 227.151.223.254227.151.223.2558,190
192227.151.224.0/19227.151.224.1 to 227.151.255.254227.151.255.2558,190
193227.152.0.0/19227.152.0.1 to 227.152.31.254227.152.31.2558,190
194227.152.32.0/19227.152.32.1 to 227.152.63.254227.152.63.2558,190
195227.152.64.0/19227.152.64.1 to 227.152.95.254227.152.95.2558,190
196227.152.96.0/19227.152.96.1 to 227.152.127.254227.152.127.2558,190
197227.152.128.0/19227.152.128.1 to 227.152.159.254227.152.159.2558,190
198227.152.160.0/19227.152.160.1 to 227.152.191.254227.152.191.2558,190
199227.152.192.0/19227.152.192.1 to 227.152.223.254227.152.223.2558,190
200227.152.224.0/19227.152.224.1 to 227.152.255.254227.152.255.2558,190
201227.153.0.0/19227.153.0.1 to 227.153.31.254227.153.31.2558,190
202227.153.32.0/19227.153.32.1 to 227.153.63.254227.153.63.2558,190
203227.153.64.0/19227.153.64.1 to 227.153.95.254227.153.95.2558,190
204227.153.96.0/19227.153.96.1 to 227.153.127.254227.153.127.2558,190
205227.153.128.0/19227.153.128.1 to 227.153.159.254227.153.159.2558,190
206227.153.160.0/19227.153.160.1 to 227.153.191.254227.153.191.2558,190
207227.153.192.0/19227.153.192.1 to 227.153.223.254227.153.223.2558,190
208227.153.224.0/19227.153.224.1 to 227.153.255.254227.153.255.2558,190
209227.154.0.0/19227.154.0.1 to 227.154.31.254227.154.31.2558,190
210227.154.32.0/19227.154.32.1 to 227.154.63.254227.154.63.2558,190
211227.154.64.0/19227.154.64.1 to 227.154.95.254227.154.95.2558,190
212227.154.96.0/19227.154.96.1 to 227.154.127.254227.154.127.2558,190
213227.154.128.0/19227.154.128.1 to 227.154.159.254227.154.159.2558,190
214227.154.160.0/19227.154.160.1 to 227.154.191.254227.154.191.2558,190
215227.154.192.0/19227.154.192.1 to 227.154.223.254227.154.223.2558,190
216227.154.224.0/19227.154.224.1 to 227.154.255.254227.154.255.2558,190
217227.155.0.0/19227.155.0.1 to 227.155.31.254227.155.31.2558,190
218227.155.32.0/19227.155.32.1 to 227.155.63.254227.155.63.2558,190
219227.155.64.0/19227.155.64.1 to 227.155.95.254227.155.95.2558,190
220227.155.96.0/19227.155.96.1 to 227.155.127.254227.155.127.2558,190
221227.155.128.0/19227.155.128.1 to 227.155.159.254227.155.159.2558,190
222227.155.160.0/19227.155.160.1 to 227.155.191.254227.155.191.2558,190
223227.155.192.0/19227.155.192.1 to 227.155.223.254227.155.223.2558,190
224227.155.224.0/19227.155.224.1 to 227.155.255.254227.155.255.2558,190
225227.156.0.0/19227.156.0.1 to 227.156.31.254227.156.31.2558,190
226227.156.32.0/19227.156.32.1 to 227.156.63.254227.156.63.2558,190
227227.156.64.0/19227.156.64.1 to 227.156.95.254227.156.95.2558,190
228227.156.96.0/19227.156.96.1 to 227.156.127.254227.156.127.2558,190
229227.156.128.0/19227.156.128.1 to 227.156.159.254227.156.159.2558,190
230227.156.160.0/19227.156.160.1 to 227.156.191.254227.156.191.2558,190
231227.156.192.0/19227.156.192.1 to 227.156.223.254227.156.223.2558,190
232227.156.224.0/19227.156.224.1 to 227.156.255.254227.156.255.2558,190
233227.157.0.0/19227.157.0.1 to 227.157.31.254227.157.31.2558,190
234227.157.32.0/19227.157.32.1 to 227.157.63.254227.157.63.2558,190
235227.157.64.0/19227.157.64.1 to 227.157.95.254227.157.95.2558,190
236227.157.96.0/19227.157.96.1 to 227.157.127.254227.157.127.2558,190
237227.157.128.0/19227.157.128.1 to 227.157.159.254227.157.159.2558,190
238227.157.160.0/19227.157.160.1 to 227.157.191.254227.157.191.2558,190
239227.157.192.0/19227.157.192.1 to 227.157.223.254227.157.223.2558,190
240227.157.224.0/19227.157.224.1 to 227.157.255.254227.157.255.2558,190
241227.158.0.0/19227.158.0.1 to 227.158.31.254227.158.31.2558,190
242227.158.32.0/19227.158.32.1 to 227.158.63.254227.158.63.2558,190
243227.158.64.0/19227.158.64.1 to 227.158.95.254227.158.95.2558,190
244227.158.96.0/19227.158.96.1 to 227.158.127.254227.158.127.2558,190
245227.158.128.0/19227.158.128.1 to 227.158.159.254227.158.159.2558,190
246227.158.160.0/19227.158.160.1 to 227.158.191.254227.158.191.2558,190
247227.158.192.0/19227.158.192.1 to 227.158.223.254227.158.223.2558,190
248227.158.224.0/19227.158.224.1 to 227.158.255.254227.158.255.2558,190
249227.159.0.0/19227.159.0.1 to 227.159.31.254227.159.31.2558,190
250227.159.32.0/19227.159.32.1 to 227.159.63.254227.159.63.2558,190
251227.159.64.0/19227.159.64.1 to 227.159.95.254227.159.95.2558,190
252227.159.96.0/19227.159.96.1 to 227.159.127.254227.159.127.2558,190
253227.159.128.0/19227.159.128.1 to 227.159.159.254227.159.159.2558,190
254227.159.160.0/19227.159.160.1 to 227.159.191.254227.159.191.2558,190
255227.159.192.0/19227.159.192.1 to 227.159.223.254227.159.223.2558,190
256227.159.224.0/19227.159.224.1 to 227.159.255.254227.159.255.2558,190

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.