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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.

Network144.0.0.0/5
Usable hosts134,217,726
Subnet mask248.0.0.0
Addresses134,217,728
Network address
144.0.0.0
Broadcast address
151.255.255.255
First usable
144.0.0.1
Last usable
151.255.255.254
Usable hosts
134,217,726 (134,217,728 less the network and broadcast addresses)
Subnet mask
248.0.0.0
Wildcard mask
7.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/5
Type
Public public
Old class
B (default /16)
As numbers
Hex 90000000 · Integer 2415919104 to 2550136831
Reverse DNS zones
144.in-addr.arpa
145.in-addr.arpa
146.in-addr.arpa
147.in-addr.arpa
148.in-addr.arpa
149.in-addr.arpa
150.in-addr.arpa
151.in-addr.arpa
/5 is not on a 8-bit boundary, so it takes 8 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10010000.00000000.00000000.00000000144.0.0.0
Subnet mask11111000.00000000.00000000.00000000248.0.0.0
Network10010000.00000000.00000000.00000000144.0.0.0
Broadcast10010111.11111111.11111111.11111111151.255.255.255
Split into smaller subnets/14
/6 (2)/7 (4)/8 (8)/9 (16)/10 (32)/11 (64)/12 (128)/13 (256)/14 (512)/15 (1,024)/16 (2,048)/17 (4,096)

144.0.0.0/5 makes 512 subnets of /14; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1144.0.0.0/14144.0.0.1 to 144.3.255.254144.3.255.255262,142
2144.4.0.0/14144.4.0.1 to 144.7.255.254144.7.255.255262,142
3144.8.0.0/14144.8.0.1 to 144.11.255.254144.11.255.255262,142
4144.12.0.0/14144.12.0.1 to 144.15.255.254144.15.255.255262,142
5144.16.0.0/14144.16.0.1 to 144.19.255.254144.19.255.255262,142
6144.20.0.0/14144.20.0.1 to 144.23.255.254144.23.255.255262,142
7144.24.0.0/14144.24.0.1 to 144.27.255.254144.27.255.255262,142
8144.28.0.0/14144.28.0.1 to 144.31.255.254144.31.255.255262,142
9144.32.0.0/14144.32.0.1 to 144.35.255.254144.35.255.255262,142
10144.36.0.0/14144.36.0.1 to 144.39.255.254144.39.255.255262,142
11144.40.0.0/14144.40.0.1 to 144.43.255.254144.43.255.255262,142
12144.44.0.0/14144.44.0.1 to 144.47.255.254144.47.255.255262,142
13144.48.0.0/14144.48.0.1 to 144.51.255.254144.51.255.255262,142
14144.52.0.0/14144.52.0.1 to 144.55.255.254144.55.255.255262,142
15144.56.0.0/14144.56.0.1 to 144.59.255.254144.59.255.255262,142
16144.60.0.0/14144.60.0.1 to 144.63.255.254144.63.255.255262,142
17144.64.0.0/14144.64.0.1 to 144.67.255.254144.67.255.255262,142
18144.68.0.0/14144.68.0.1 to 144.71.255.254144.71.255.255262,142
19144.72.0.0/14144.72.0.1 to 144.75.255.254144.75.255.255262,142
20144.76.0.0/14144.76.0.1 to 144.79.255.254144.79.255.255262,142
21144.80.0.0/14144.80.0.1 to 144.83.255.254144.83.255.255262,142
22144.84.0.0/14144.84.0.1 to 144.87.255.254144.87.255.255262,142
23144.88.0.0/14144.88.0.1 to 144.91.255.254144.91.255.255262,142
24144.92.0.0/14144.92.0.1 to 144.95.255.254144.95.255.255262,142
25144.96.0.0/14144.96.0.1 to 144.99.255.254144.99.255.255262,142
26144.100.0.0/14144.100.0.1 to 144.103.255.254144.103.255.255262,142
27144.104.0.0/14144.104.0.1 to 144.107.255.254144.107.255.255262,142
28144.108.0.0/14144.108.0.1 to 144.111.255.254144.111.255.255262,142
29144.112.0.0/14144.112.0.1 to 144.115.255.254144.115.255.255262,142
30144.116.0.0/14144.116.0.1 to 144.119.255.254144.119.255.255262,142
31144.120.0.0/14144.120.0.1 to 144.123.255.254144.123.255.255262,142
32144.124.0.0/14144.124.0.1 to 144.127.255.254144.127.255.255262,142
33144.128.0.0/14144.128.0.1 to 144.131.255.254144.131.255.255262,142
34144.132.0.0/14144.132.0.1 to 144.135.255.254144.135.255.255262,142
35144.136.0.0/14144.136.0.1 to 144.139.255.254144.139.255.255262,142
36144.140.0.0/14144.140.0.1 to 144.143.255.254144.143.255.255262,142
37144.144.0.0/14144.144.0.1 to 144.147.255.254144.147.255.255262,142
38144.148.0.0/14144.148.0.1 to 144.151.255.254144.151.255.255262,142
39144.152.0.0/14144.152.0.1 to 144.155.255.254144.155.255.255262,142
40144.156.0.0/14144.156.0.1 to 144.159.255.254144.159.255.255262,142
41144.160.0.0/14144.160.0.1 to 144.163.255.254144.163.255.255262,142
42144.164.0.0/14144.164.0.1 to 144.167.255.254144.167.255.255262,142
43144.168.0.0/14144.168.0.1 to 144.171.255.254144.171.255.255262,142
44144.172.0.0/14144.172.0.1 to 144.175.255.254144.175.255.255262,142
45144.176.0.0/14144.176.0.1 to 144.179.255.254144.179.255.255262,142
46144.180.0.0/14144.180.0.1 to 144.183.255.254144.183.255.255262,142
47144.184.0.0/14144.184.0.1 to 144.187.255.254144.187.255.255262,142
48144.188.0.0/14144.188.0.1 to 144.191.255.254144.191.255.255262,142
49144.192.0.0/14144.192.0.1 to 144.195.255.254144.195.255.255262,142
50144.196.0.0/14144.196.0.1 to 144.199.255.254144.199.255.255262,142
51144.200.0.0/14144.200.0.1 to 144.203.255.254144.203.255.255262,142
52144.204.0.0/14144.204.0.1 to 144.207.255.254144.207.255.255262,142
53144.208.0.0/14144.208.0.1 to 144.211.255.254144.211.255.255262,142
54144.212.0.0/14144.212.0.1 to 144.215.255.254144.215.255.255262,142
55144.216.0.0/14144.216.0.1 to 144.219.255.254144.219.255.255262,142
56144.220.0.0/14144.220.0.1 to 144.223.255.254144.223.255.255262,142
57144.224.0.0/14144.224.0.1 to 144.227.255.254144.227.255.255262,142
58144.228.0.0/14144.228.0.1 to 144.231.255.254144.231.255.255262,142
59144.232.0.0/14144.232.0.1 to 144.235.255.254144.235.255.255262,142
60144.236.0.0/14144.236.0.1 to 144.239.255.254144.239.255.255262,142
61144.240.0.0/14144.240.0.1 to 144.243.255.254144.243.255.255262,142
62144.244.0.0/14144.244.0.1 to 144.247.255.254144.247.255.255262,142
63144.248.0.0/14144.248.0.1 to 144.251.255.254144.251.255.255262,142
64144.252.0.0/14144.252.0.1 to 144.255.255.254144.255.255.255262,142
65145.0.0.0/14145.0.0.1 to 145.3.255.254145.3.255.255262,142
66145.4.0.0/14145.4.0.1 to 145.7.255.254145.7.255.255262,142
67145.8.0.0/14145.8.0.1 to 145.11.255.254145.11.255.255262,142
68145.12.0.0/14145.12.0.1 to 145.15.255.254145.15.255.255262,142
69145.16.0.0/14145.16.0.1 to 145.19.255.254145.19.255.255262,142
70145.20.0.0/14145.20.0.1 to 145.23.255.254145.23.255.255262,142
71145.24.0.0/14145.24.0.1 to 145.27.255.254145.27.255.255262,142
72145.28.0.0/14145.28.0.1 to 145.31.255.254145.31.255.255262,142
73145.32.0.0/14145.32.0.1 to 145.35.255.254145.35.255.255262,142
74145.36.0.0/14145.36.0.1 to 145.39.255.254145.39.255.255262,142
75145.40.0.0/14145.40.0.1 to 145.43.255.254145.43.255.255262,142
76145.44.0.0/14145.44.0.1 to 145.47.255.254145.47.255.255262,142
77145.48.0.0/14145.48.0.1 to 145.51.255.254145.51.255.255262,142
78145.52.0.0/14145.52.0.1 to 145.55.255.254145.55.255.255262,142
79145.56.0.0/14145.56.0.1 to 145.59.255.254145.59.255.255262,142
80145.60.0.0/14145.60.0.1 to 145.63.255.254145.63.255.255262,142
81145.64.0.0/14145.64.0.1 to 145.67.255.254145.67.255.255262,142
82145.68.0.0/14145.68.0.1 to 145.71.255.254145.71.255.255262,142
83145.72.0.0/14145.72.0.1 to 145.75.255.254145.75.255.255262,142
84145.76.0.0/14145.76.0.1 to 145.79.255.254145.79.255.255262,142
85145.80.0.0/14145.80.0.1 to 145.83.255.254145.83.255.255262,142
86145.84.0.0/14145.84.0.1 to 145.87.255.254145.87.255.255262,142
87145.88.0.0/14145.88.0.1 to 145.91.255.254145.91.255.255262,142
88145.92.0.0/14145.92.0.1 to 145.95.255.254145.95.255.255262,142
89145.96.0.0/14145.96.0.1 to 145.99.255.254145.99.255.255262,142
90145.100.0.0/14145.100.0.1 to 145.103.255.254145.103.255.255262,142
91145.104.0.0/14145.104.0.1 to 145.107.255.254145.107.255.255262,142
92145.108.0.0/14145.108.0.1 to 145.111.255.254145.111.255.255262,142
93145.112.0.0/14145.112.0.1 to 145.115.255.254145.115.255.255262,142
94145.116.0.0/14145.116.0.1 to 145.119.255.254145.119.255.255262,142
95145.120.0.0/14145.120.0.1 to 145.123.255.254145.123.255.255262,142
96145.124.0.0/14145.124.0.1 to 145.127.255.254145.127.255.255262,142
97145.128.0.0/14145.128.0.1 to 145.131.255.254145.131.255.255262,142
98145.132.0.0/14145.132.0.1 to 145.135.255.254145.135.255.255262,142
99145.136.0.0/14145.136.0.1 to 145.139.255.254145.139.255.255262,142
100145.140.0.0/14145.140.0.1 to 145.143.255.254145.143.255.255262,142
101145.144.0.0/14145.144.0.1 to 145.147.255.254145.147.255.255262,142
102145.148.0.0/14145.148.0.1 to 145.151.255.254145.151.255.255262,142
103145.152.0.0/14145.152.0.1 to 145.155.255.254145.155.255.255262,142
104145.156.0.0/14145.156.0.1 to 145.159.255.254145.159.255.255262,142
105145.160.0.0/14145.160.0.1 to 145.163.255.254145.163.255.255262,142
106145.164.0.0/14145.164.0.1 to 145.167.255.254145.167.255.255262,142
107145.168.0.0/14145.168.0.1 to 145.171.255.254145.171.255.255262,142
108145.172.0.0/14145.172.0.1 to 145.175.255.254145.175.255.255262,142
109145.176.0.0/14145.176.0.1 to 145.179.255.254145.179.255.255262,142
110145.180.0.0/14145.180.0.1 to 145.183.255.254145.183.255.255262,142
111145.184.0.0/14145.184.0.1 to 145.187.255.254145.187.255.255262,142
112145.188.0.0/14145.188.0.1 to 145.191.255.254145.191.255.255262,142
113145.192.0.0/14145.192.0.1 to 145.195.255.254145.195.255.255262,142
114145.196.0.0/14145.196.0.1 to 145.199.255.254145.199.255.255262,142
115145.200.0.0/14145.200.0.1 to 145.203.255.254145.203.255.255262,142
116145.204.0.0/14145.204.0.1 to 145.207.255.254145.207.255.255262,142
117145.208.0.0/14145.208.0.1 to 145.211.255.254145.211.255.255262,142
118145.212.0.0/14145.212.0.1 to 145.215.255.254145.215.255.255262,142
119145.216.0.0/14145.216.0.1 to 145.219.255.254145.219.255.255262,142
120145.220.0.0/14145.220.0.1 to 145.223.255.254145.223.255.255262,142
121145.224.0.0/14145.224.0.1 to 145.227.255.254145.227.255.255262,142
122145.228.0.0/14145.228.0.1 to 145.231.255.254145.231.255.255262,142
123145.232.0.0/14145.232.0.1 to 145.235.255.254145.235.255.255262,142
124145.236.0.0/14145.236.0.1 to 145.239.255.254145.239.255.255262,142
125145.240.0.0/14145.240.0.1 to 145.243.255.254145.243.255.255262,142
126145.244.0.0/14145.244.0.1 to 145.247.255.254145.247.255.255262,142
127145.248.0.0/14145.248.0.1 to 145.251.255.254145.251.255.255262,142
128145.252.0.0/14145.252.0.1 to 145.255.255.254145.255.255.255262,142
129146.0.0.0/14146.0.0.1 to 146.3.255.254146.3.255.255262,142
130146.4.0.0/14146.4.0.1 to 146.7.255.254146.7.255.255262,142
131146.8.0.0/14146.8.0.1 to 146.11.255.254146.11.255.255262,142
132146.12.0.0/14146.12.0.1 to 146.15.255.254146.15.255.255262,142
133146.16.0.0/14146.16.0.1 to 146.19.255.254146.19.255.255262,142
134146.20.0.0/14146.20.0.1 to 146.23.255.254146.23.255.255262,142
135146.24.0.0/14146.24.0.1 to 146.27.255.254146.27.255.255262,142
136146.28.0.0/14146.28.0.1 to 146.31.255.254146.31.255.255262,142
137146.32.0.0/14146.32.0.1 to 146.35.255.254146.35.255.255262,142
138146.36.0.0/14146.36.0.1 to 146.39.255.254146.39.255.255262,142
139146.40.0.0/14146.40.0.1 to 146.43.255.254146.43.255.255262,142
140146.44.0.0/14146.44.0.1 to 146.47.255.254146.47.255.255262,142
141146.48.0.0/14146.48.0.1 to 146.51.255.254146.51.255.255262,142
142146.52.0.0/14146.52.0.1 to 146.55.255.254146.55.255.255262,142
143146.56.0.0/14146.56.0.1 to 146.59.255.254146.59.255.255262,142
144146.60.0.0/14146.60.0.1 to 146.63.255.254146.63.255.255262,142
145146.64.0.0/14146.64.0.1 to 146.67.255.254146.67.255.255262,142
146146.68.0.0/14146.68.0.1 to 146.71.255.254146.71.255.255262,142
147146.72.0.0/14146.72.0.1 to 146.75.255.254146.75.255.255262,142
148146.76.0.0/14146.76.0.1 to 146.79.255.254146.79.255.255262,142
149146.80.0.0/14146.80.0.1 to 146.83.255.254146.83.255.255262,142
150146.84.0.0/14146.84.0.1 to 146.87.255.254146.87.255.255262,142
151146.88.0.0/14146.88.0.1 to 146.91.255.254146.91.255.255262,142
152146.92.0.0/14146.92.0.1 to 146.95.255.254146.95.255.255262,142
153146.96.0.0/14146.96.0.1 to 146.99.255.254146.99.255.255262,142
154146.100.0.0/14146.100.0.1 to 146.103.255.254146.103.255.255262,142
155146.104.0.0/14146.104.0.1 to 146.107.255.254146.107.255.255262,142
156146.108.0.0/14146.108.0.1 to 146.111.255.254146.111.255.255262,142
157146.112.0.0/14146.112.0.1 to 146.115.255.254146.115.255.255262,142
158146.116.0.0/14146.116.0.1 to 146.119.255.254146.119.255.255262,142
159146.120.0.0/14146.120.0.1 to 146.123.255.254146.123.255.255262,142
160146.124.0.0/14146.124.0.1 to 146.127.255.254146.127.255.255262,142
161146.128.0.0/14146.128.0.1 to 146.131.255.254146.131.255.255262,142
162146.132.0.0/14146.132.0.1 to 146.135.255.254146.135.255.255262,142
163146.136.0.0/14146.136.0.1 to 146.139.255.254146.139.255.255262,142
164146.140.0.0/14146.140.0.1 to 146.143.255.254146.143.255.255262,142
165146.144.0.0/14146.144.0.1 to 146.147.255.254146.147.255.255262,142
166146.148.0.0/14146.148.0.1 to 146.151.255.254146.151.255.255262,142
167146.152.0.0/14146.152.0.1 to 146.155.255.254146.155.255.255262,142
168146.156.0.0/14146.156.0.1 to 146.159.255.254146.159.255.255262,142
169146.160.0.0/14146.160.0.1 to 146.163.255.254146.163.255.255262,142
170146.164.0.0/14146.164.0.1 to 146.167.255.254146.167.255.255262,142
171146.168.0.0/14146.168.0.1 to 146.171.255.254146.171.255.255262,142
172146.172.0.0/14146.172.0.1 to 146.175.255.254146.175.255.255262,142
173146.176.0.0/14146.176.0.1 to 146.179.255.254146.179.255.255262,142
174146.180.0.0/14146.180.0.1 to 146.183.255.254146.183.255.255262,142
175146.184.0.0/14146.184.0.1 to 146.187.255.254146.187.255.255262,142
176146.188.0.0/14146.188.0.1 to 146.191.255.254146.191.255.255262,142
177146.192.0.0/14146.192.0.1 to 146.195.255.254146.195.255.255262,142
178146.196.0.0/14146.196.0.1 to 146.199.255.254146.199.255.255262,142
179146.200.0.0/14146.200.0.1 to 146.203.255.254146.203.255.255262,142
180146.204.0.0/14146.204.0.1 to 146.207.255.254146.207.255.255262,142
181146.208.0.0/14146.208.0.1 to 146.211.255.254146.211.255.255262,142
182146.212.0.0/14146.212.0.1 to 146.215.255.254146.215.255.255262,142
183146.216.0.0/14146.216.0.1 to 146.219.255.254146.219.255.255262,142
184146.220.0.0/14146.220.0.1 to 146.223.255.254146.223.255.255262,142
185146.224.0.0/14146.224.0.1 to 146.227.255.254146.227.255.255262,142
186146.228.0.0/14146.228.0.1 to 146.231.255.254146.231.255.255262,142
187146.232.0.0/14146.232.0.1 to 146.235.255.254146.235.255.255262,142
188146.236.0.0/14146.236.0.1 to 146.239.255.254146.239.255.255262,142
189146.240.0.0/14146.240.0.1 to 146.243.255.254146.243.255.255262,142
190146.244.0.0/14146.244.0.1 to 146.247.255.254146.247.255.255262,142
191146.248.0.0/14146.248.0.1 to 146.251.255.254146.251.255.255262,142
192146.252.0.0/14146.252.0.1 to 146.255.255.254146.255.255.255262,142
193147.0.0.0/14147.0.0.1 to 147.3.255.254147.3.255.255262,142
194147.4.0.0/14147.4.0.1 to 147.7.255.254147.7.255.255262,142
195147.8.0.0/14147.8.0.1 to 147.11.255.254147.11.255.255262,142
196147.12.0.0/14147.12.0.1 to 147.15.255.254147.15.255.255262,142
197147.16.0.0/14147.16.0.1 to 147.19.255.254147.19.255.255262,142
198147.20.0.0/14147.20.0.1 to 147.23.255.254147.23.255.255262,142
199147.24.0.0/14147.24.0.1 to 147.27.255.254147.27.255.255262,142
200147.28.0.0/14147.28.0.1 to 147.31.255.254147.31.255.255262,142
201147.32.0.0/14147.32.0.1 to 147.35.255.254147.35.255.255262,142
202147.36.0.0/14147.36.0.1 to 147.39.255.254147.39.255.255262,142
203147.40.0.0/14147.40.0.1 to 147.43.255.254147.43.255.255262,142
204147.44.0.0/14147.44.0.1 to 147.47.255.254147.47.255.255262,142
205147.48.0.0/14147.48.0.1 to 147.51.255.254147.51.255.255262,142
206147.52.0.0/14147.52.0.1 to 147.55.255.254147.55.255.255262,142
207147.56.0.0/14147.56.0.1 to 147.59.255.254147.59.255.255262,142
208147.60.0.0/14147.60.0.1 to 147.63.255.254147.63.255.255262,142
209147.64.0.0/14147.64.0.1 to 147.67.255.254147.67.255.255262,142
210147.68.0.0/14147.68.0.1 to 147.71.255.254147.71.255.255262,142
211147.72.0.0/14147.72.0.1 to 147.75.255.254147.75.255.255262,142
212147.76.0.0/14147.76.0.1 to 147.79.255.254147.79.255.255262,142
213147.80.0.0/14147.80.0.1 to 147.83.255.254147.83.255.255262,142
214147.84.0.0/14147.84.0.1 to 147.87.255.254147.87.255.255262,142
215147.88.0.0/14147.88.0.1 to 147.91.255.254147.91.255.255262,142
216147.92.0.0/14147.92.0.1 to 147.95.255.254147.95.255.255262,142
217147.96.0.0/14147.96.0.1 to 147.99.255.254147.99.255.255262,142
218147.100.0.0/14147.100.0.1 to 147.103.255.254147.103.255.255262,142
219147.104.0.0/14147.104.0.1 to 147.107.255.254147.107.255.255262,142
220147.108.0.0/14147.108.0.1 to 147.111.255.254147.111.255.255262,142
221147.112.0.0/14147.112.0.1 to 147.115.255.254147.115.255.255262,142
222147.116.0.0/14147.116.0.1 to 147.119.255.254147.119.255.255262,142
223147.120.0.0/14147.120.0.1 to 147.123.255.254147.123.255.255262,142
224147.124.0.0/14147.124.0.1 to 147.127.255.254147.127.255.255262,142
225147.128.0.0/14147.128.0.1 to 147.131.255.254147.131.255.255262,142
226147.132.0.0/14147.132.0.1 to 147.135.255.254147.135.255.255262,142
227147.136.0.0/14147.136.0.1 to 147.139.255.254147.139.255.255262,142
228147.140.0.0/14147.140.0.1 to 147.143.255.254147.143.255.255262,142
229147.144.0.0/14147.144.0.1 to 147.147.255.254147.147.255.255262,142
230147.148.0.0/14147.148.0.1 to 147.151.255.254147.151.255.255262,142
231147.152.0.0/14147.152.0.1 to 147.155.255.254147.155.255.255262,142
232147.156.0.0/14147.156.0.1 to 147.159.255.254147.159.255.255262,142
233147.160.0.0/14147.160.0.1 to 147.163.255.254147.163.255.255262,142
234147.164.0.0/14147.164.0.1 to 147.167.255.254147.167.255.255262,142
235147.168.0.0/14147.168.0.1 to 147.171.255.254147.171.255.255262,142
236147.172.0.0/14147.172.0.1 to 147.175.255.254147.175.255.255262,142
237147.176.0.0/14147.176.0.1 to 147.179.255.254147.179.255.255262,142
238147.180.0.0/14147.180.0.1 to 147.183.255.254147.183.255.255262,142
239147.184.0.0/14147.184.0.1 to 147.187.255.254147.187.255.255262,142
240147.188.0.0/14147.188.0.1 to 147.191.255.254147.191.255.255262,142
241147.192.0.0/14147.192.0.1 to 147.195.255.254147.195.255.255262,142
242147.196.0.0/14147.196.0.1 to 147.199.255.254147.199.255.255262,142
243147.200.0.0/14147.200.0.1 to 147.203.255.254147.203.255.255262,142
244147.204.0.0/14147.204.0.1 to 147.207.255.254147.207.255.255262,142
245147.208.0.0/14147.208.0.1 to 147.211.255.254147.211.255.255262,142
246147.212.0.0/14147.212.0.1 to 147.215.255.254147.215.255.255262,142
247147.216.0.0/14147.216.0.1 to 147.219.255.254147.219.255.255262,142
248147.220.0.0/14147.220.0.1 to 147.223.255.254147.223.255.255262,142
249147.224.0.0/14147.224.0.1 to 147.227.255.254147.227.255.255262,142
250147.228.0.0/14147.228.0.1 to 147.231.255.254147.231.255.255262,142
251147.232.0.0/14147.232.0.1 to 147.235.255.254147.235.255.255262,142
252147.236.0.0/14147.236.0.1 to 147.239.255.254147.239.255.255262,142
253147.240.0.0/14147.240.0.1 to 147.243.255.254147.243.255.255262,142
254147.244.0.0/14147.244.0.1 to 147.247.255.254147.247.255.255262,142
255147.248.0.0/14147.248.0.1 to 147.251.255.254147.251.255.255262,142
256147.252.0.0/14147.252.0.1 to 147.255.255.254147.255.255.255262,142

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.