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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.

Network147.128.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
147.128.0.0
Broadcast address
147.255.255.255
First usable
147.128.0.1
Last usable
147.255.255.254
Usable hosts
8,388,606 (8,388,608 less the network and broadcast addresses)
Subnet mask
255.128.0.0
Wildcard mask
0.127.255.255 (Cisco ACLs, OSPF)
Prefix length
/9
Type
Public public
Old class
B (default /16)
As numbers
Hex 93800000 · Integer 2474639360 to 2483027967
Reverse DNS zones
128.147.in-addr.arpa
129.147.in-addr.arpa
130.147.in-addr.arpa
131.147.in-addr.arpa
132.147.in-addr.arpa
133.147.in-addr.arpa
134.147.in-addr.arpa
135.147.in-addr.arpa
136.147.in-addr.arpa
137.147.in-addr.arpa
138.147.in-addr.arpa
139.147.in-addr.arpa
140.147.in-addr.arpa
141.147.in-addr.arpa
142.147.in-addr.arpa
143.147.in-addr.arpa
and 112 more
/9 is not on a 8-bit boundary, so it takes 128 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10010011.10000000.00000000.00000000147.128.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network10010011.10000000.00000000.00000000147.128.0.0
Broadcast10010011.11111111.11111111.11111111147.255.255.255
Split into smaller subnets/18
/10 (2)/11 (4)/12 (8)/13 (16)/14 (32)/15 (64)/16 (128)/17 (256)/18 (512)/19 (1,024)/20 (2,048)/21 (4,096)

147.128.0.0/9 makes 512 subnets of /18; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1147.128.0.0/18147.128.0.1 to 147.128.63.254147.128.63.25516,382
2147.128.64.0/18147.128.64.1 to 147.128.127.254147.128.127.25516,382
3147.128.128.0/18147.128.128.1 to 147.128.191.254147.128.191.25516,382
4147.128.192.0/18147.128.192.1 to 147.128.255.254147.128.255.25516,382
5147.129.0.0/18147.129.0.1 to 147.129.63.254147.129.63.25516,382
6147.129.64.0/18147.129.64.1 to 147.129.127.254147.129.127.25516,382
7147.129.128.0/18147.129.128.1 to 147.129.191.254147.129.191.25516,382
8147.129.192.0/18147.129.192.1 to 147.129.255.254147.129.255.25516,382
9147.130.0.0/18147.130.0.1 to 147.130.63.254147.130.63.25516,382
10147.130.64.0/18147.130.64.1 to 147.130.127.254147.130.127.25516,382
11147.130.128.0/18147.130.128.1 to 147.130.191.254147.130.191.25516,382
12147.130.192.0/18147.130.192.1 to 147.130.255.254147.130.255.25516,382
13147.131.0.0/18147.131.0.1 to 147.131.63.254147.131.63.25516,382
14147.131.64.0/18147.131.64.1 to 147.131.127.254147.131.127.25516,382
15147.131.128.0/18147.131.128.1 to 147.131.191.254147.131.191.25516,382
16147.131.192.0/18147.131.192.1 to 147.131.255.254147.131.255.25516,382
17147.132.0.0/18147.132.0.1 to 147.132.63.254147.132.63.25516,382
18147.132.64.0/18147.132.64.1 to 147.132.127.254147.132.127.25516,382
19147.132.128.0/18147.132.128.1 to 147.132.191.254147.132.191.25516,382
20147.132.192.0/18147.132.192.1 to 147.132.255.254147.132.255.25516,382
21147.133.0.0/18147.133.0.1 to 147.133.63.254147.133.63.25516,382
22147.133.64.0/18147.133.64.1 to 147.133.127.254147.133.127.25516,382
23147.133.128.0/18147.133.128.1 to 147.133.191.254147.133.191.25516,382
24147.133.192.0/18147.133.192.1 to 147.133.255.254147.133.255.25516,382
25147.134.0.0/18147.134.0.1 to 147.134.63.254147.134.63.25516,382
26147.134.64.0/18147.134.64.1 to 147.134.127.254147.134.127.25516,382
27147.134.128.0/18147.134.128.1 to 147.134.191.254147.134.191.25516,382
28147.134.192.0/18147.134.192.1 to 147.134.255.254147.134.255.25516,382
29147.135.0.0/18147.135.0.1 to 147.135.63.254147.135.63.25516,382
30147.135.64.0/18147.135.64.1 to 147.135.127.254147.135.127.25516,382
31147.135.128.0/18147.135.128.1 to 147.135.191.254147.135.191.25516,382
32147.135.192.0/18147.135.192.1 to 147.135.255.254147.135.255.25516,382
33147.136.0.0/18147.136.0.1 to 147.136.63.254147.136.63.25516,382
34147.136.64.0/18147.136.64.1 to 147.136.127.254147.136.127.25516,382
35147.136.128.0/18147.136.128.1 to 147.136.191.254147.136.191.25516,382
36147.136.192.0/18147.136.192.1 to 147.136.255.254147.136.255.25516,382
37147.137.0.0/18147.137.0.1 to 147.137.63.254147.137.63.25516,382
38147.137.64.0/18147.137.64.1 to 147.137.127.254147.137.127.25516,382
39147.137.128.0/18147.137.128.1 to 147.137.191.254147.137.191.25516,382
40147.137.192.0/18147.137.192.1 to 147.137.255.254147.137.255.25516,382
41147.138.0.0/18147.138.0.1 to 147.138.63.254147.138.63.25516,382
42147.138.64.0/18147.138.64.1 to 147.138.127.254147.138.127.25516,382
43147.138.128.0/18147.138.128.1 to 147.138.191.254147.138.191.25516,382
44147.138.192.0/18147.138.192.1 to 147.138.255.254147.138.255.25516,382
45147.139.0.0/18147.139.0.1 to 147.139.63.254147.139.63.25516,382
46147.139.64.0/18147.139.64.1 to 147.139.127.254147.139.127.25516,382
47147.139.128.0/18147.139.128.1 to 147.139.191.254147.139.191.25516,382
48147.139.192.0/18147.139.192.1 to 147.139.255.254147.139.255.25516,382
49147.140.0.0/18147.140.0.1 to 147.140.63.254147.140.63.25516,382
50147.140.64.0/18147.140.64.1 to 147.140.127.254147.140.127.25516,382
51147.140.128.0/18147.140.128.1 to 147.140.191.254147.140.191.25516,382
52147.140.192.0/18147.140.192.1 to 147.140.255.254147.140.255.25516,382
53147.141.0.0/18147.141.0.1 to 147.141.63.254147.141.63.25516,382
54147.141.64.0/18147.141.64.1 to 147.141.127.254147.141.127.25516,382
55147.141.128.0/18147.141.128.1 to 147.141.191.254147.141.191.25516,382
56147.141.192.0/18147.141.192.1 to 147.141.255.254147.141.255.25516,382
57147.142.0.0/18147.142.0.1 to 147.142.63.254147.142.63.25516,382
58147.142.64.0/18147.142.64.1 to 147.142.127.254147.142.127.25516,382
59147.142.128.0/18147.142.128.1 to 147.142.191.254147.142.191.25516,382
60147.142.192.0/18147.142.192.1 to 147.142.255.254147.142.255.25516,382
61147.143.0.0/18147.143.0.1 to 147.143.63.254147.143.63.25516,382
62147.143.64.0/18147.143.64.1 to 147.143.127.254147.143.127.25516,382
63147.143.128.0/18147.143.128.1 to 147.143.191.254147.143.191.25516,382
64147.143.192.0/18147.143.192.1 to 147.143.255.254147.143.255.25516,382
65147.144.0.0/18147.144.0.1 to 147.144.63.254147.144.63.25516,382
66147.144.64.0/18147.144.64.1 to 147.144.127.254147.144.127.25516,382
67147.144.128.0/18147.144.128.1 to 147.144.191.254147.144.191.25516,382
68147.144.192.0/18147.144.192.1 to 147.144.255.254147.144.255.25516,382
69147.145.0.0/18147.145.0.1 to 147.145.63.254147.145.63.25516,382
70147.145.64.0/18147.145.64.1 to 147.145.127.254147.145.127.25516,382
71147.145.128.0/18147.145.128.1 to 147.145.191.254147.145.191.25516,382
72147.145.192.0/18147.145.192.1 to 147.145.255.254147.145.255.25516,382
73147.146.0.0/18147.146.0.1 to 147.146.63.254147.146.63.25516,382
74147.146.64.0/18147.146.64.1 to 147.146.127.254147.146.127.25516,382
75147.146.128.0/18147.146.128.1 to 147.146.191.254147.146.191.25516,382
76147.146.192.0/18147.146.192.1 to 147.146.255.254147.146.255.25516,382
77147.147.0.0/18147.147.0.1 to 147.147.63.254147.147.63.25516,382
78147.147.64.0/18147.147.64.1 to 147.147.127.254147.147.127.25516,382
79147.147.128.0/18147.147.128.1 to 147.147.191.254147.147.191.25516,382
80147.147.192.0/18147.147.192.1 to 147.147.255.254147.147.255.25516,382
81147.148.0.0/18147.148.0.1 to 147.148.63.254147.148.63.25516,382
82147.148.64.0/18147.148.64.1 to 147.148.127.254147.148.127.25516,382
83147.148.128.0/18147.148.128.1 to 147.148.191.254147.148.191.25516,382
84147.148.192.0/18147.148.192.1 to 147.148.255.254147.148.255.25516,382
85147.149.0.0/18147.149.0.1 to 147.149.63.254147.149.63.25516,382
86147.149.64.0/18147.149.64.1 to 147.149.127.254147.149.127.25516,382
87147.149.128.0/18147.149.128.1 to 147.149.191.254147.149.191.25516,382
88147.149.192.0/18147.149.192.1 to 147.149.255.254147.149.255.25516,382
89147.150.0.0/18147.150.0.1 to 147.150.63.254147.150.63.25516,382
90147.150.64.0/18147.150.64.1 to 147.150.127.254147.150.127.25516,382
91147.150.128.0/18147.150.128.1 to 147.150.191.254147.150.191.25516,382
92147.150.192.0/18147.150.192.1 to 147.150.255.254147.150.255.25516,382
93147.151.0.0/18147.151.0.1 to 147.151.63.254147.151.63.25516,382
94147.151.64.0/18147.151.64.1 to 147.151.127.254147.151.127.25516,382
95147.151.128.0/18147.151.128.1 to 147.151.191.254147.151.191.25516,382
96147.151.192.0/18147.151.192.1 to 147.151.255.254147.151.255.25516,382
97147.152.0.0/18147.152.0.1 to 147.152.63.254147.152.63.25516,382
98147.152.64.0/18147.152.64.1 to 147.152.127.254147.152.127.25516,382
99147.152.128.0/18147.152.128.1 to 147.152.191.254147.152.191.25516,382
100147.152.192.0/18147.152.192.1 to 147.152.255.254147.152.255.25516,382
101147.153.0.0/18147.153.0.1 to 147.153.63.254147.153.63.25516,382
102147.153.64.0/18147.153.64.1 to 147.153.127.254147.153.127.25516,382
103147.153.128.0/18147.153.128.1 to 147.153.191.254147.153.191.25516,382
104147.153.192.0/18147.153.192.1 to 147.153.255.254147.153.255.25516,382
105147.154.0.0/18147.154.0.1 to 147.154.63.254147.154.63.25516,382
106147.154.64.0/18147.154.64.1 to 147.154.127.254147.154.127.25516,382
107147.154.128.0/18147.154.128.1 to 147.154.191.254147.154.191.25516,382
108147.154.192.0/18147.154.192.1 to 147.154.255.254147.154.255.25516,382
109147.155.0.0/18147.155.0.1 to 147.155.63.254147.155.63.25516,382
110147.155.64.0/18147.155.64.1 to 147.155.127.254147.155.127.25516,382
111147.155.128.0/18147.155.128.1 to 147.155.191.254147.155.191.25516,382
112147.155.192.0/18147.155.192.1 to 147.155.255.254147.155.255.25516,382
113147.156.0.0/18147.156.0.1 to 147.156.63.254147.156.63.25516,382
114147.156.64.0/18147.156.64.1 to 147.156.127.254147.156.127.25516,382
115147.156.128.0/18147.156.128.1 to 147.156.191.254147.156.191.25516,382
116147.156.192.0/18147.156.192.1 to 147.156.255.254147.156.255.25516,382
117147.157.0.0/18147.157.0.1 to 147.157.63.254147.157.63.25516,382
118147.157.64.0/18147.157.64.1 to 147.157.127.254147.157.127.25516,382
119147.157.128.0/18147.157.128.1 to 147.157.191.254147.157.191.25516,382
120147.157.192.0/18147.157.192.1 to 147.157.255.254147.157.255.25516,382
121147.158.0.0/18147.158.0.1 to 147.158.63.254147.158.63.25516,382
122147.158.64.0/18147.158.64.1 to 147.158.127.254147.158.127.25516,382
123147.158.128.0/18147.158.128.1 to 147.158.191.254147.158.191.25516,382
124147.158.192.0/18147.158.192.1 to 147.158.255.254147.158.255.25516,382
125147.159.0.0/18147.159.0.1 to 147.159.63.254147.159.63.25516,382
126147.159.64.0/18147.159.64.1 to 147.159.127.254147.159.127.25516,382
127147.159.128.0/18147.159.128.1 to 147.159.191.254147.159.191.25516,382
128147.159.192.0/18147.159.192.1 to 147.159.255.254147.159.255.25516,382
129147.160.0.0/18147.160.0.1 to 147.160.63.254147.160.63.25516,382
130147.160.64.0/18147.160.64.1 to 147.160.127.254147.160.127.25516,382
131147.160.128.0/18147.160.128.1 to 147.160.191.254147.160.191.25516,382
132147.160.192.0/18147.160.192.1 to 147.160.255.254147.160.255.25516,382
133147.161.0.0/18147.161.0.1 to 147.161.63.254147.161.63.25516,382
134147.161.64.0/18147.161.64.1 to 147.161.127.254147.161.127.25516,382
135147.161.128.0/18147.161.128.1 to 147.161.191.254147.161.191.25516,382
136147.161.192.0/18147.161.192.1 to 147.161.255.254147.161.255.25516,382
137147.162.0.0/18147.162.0.1 to 147.162.63.254147.162.63.25516,382
138147.162.64.0/18147.162.64.1 to 147.162.127.254147.162.127.25516,382
139147.162.128.0/18147.162.128.1 to 147.162.191.254147.162.191.25516,382
140147.162.192.0/18147.162.192.1 to 147.162.255.254147.162.255.25516,382
141147.163.0.0/18147.163.0.1 to 147.163.63.254147.163.63.25516,382
142147.163.64.0/18147.163.64.1 to 147.163.127.254147.163.127.25516,382
143147.163.128.0/18147.163.128.1 to 147.163.191.254147.163.191.25516,382
144147.163.192.0/18147.163.192.1 to 147.163.255.254147.163.255.25516,382
145147.164.0.0/18147.164.0.1 to 147.164.63.254147.164.63.25516,382
146147.164.64.0/18147.164.64.1 to 147.164.127.254147.164.127.25516,382
147147.164.128.0/18147.164.128.1 to 147.164.191.254147.164.191.25516,382
148147.164.192.0/18147.164.192.1 to 147.164.255.254147.164.255.25516,382
149147.165.0.0/18147.165.0.1 to 147.165.63.254147.165.63.25516,382
150147.165.64.0/18147.165.64.1 to 147.165.127.254147.165.127.25516,382
151147.165.128.0/18147.165.128.1 to 147.165.191.254147.165.191.25516,382
152147.165.192.0/18147.165.192.1 to 147.165.255.254147.165.255.25516,382
153147.166.0.0/18147.166.0.1 to 147.166.63.254147.166.63.25516,382
154147.166.64.0/18147.166.64.1 to 147.166.127.254147.166.127.25516,382
155147.166.128.0/18147.166.128.1 to 147.166.191.254147.166.191.25516,382
156147.166.192.0/18147.166.192.1 to 147.166.255.254147.166.255.25516,382
157147.167.0.0/18147.167.0.1 to 147.167.63.254147.167.63.25516,382
158147.167.64.0/18147.167.64.1 to 147.167.127.254147.167.127.25516,382
159147.167.128.0/18147.167.128.1 to 147.167.191.254147.167.191.25516,382
160147.167.192.0/18147.167.192.1 to 147.167.255.254147.167.255.25516,382
161147.168.0.0/18147.168.0.1 to 147.168.63.254147.168.63.25516,382
162147.168.64.0/18147.168.64.1 to 147.168.127.254147.168.127.25516,382
163147.168.128.0/18147.168.128.1 to 147.168.191.254147.168.191.25516,382
164147.168.192.0/18147.168.192.1 to 147.168.255.254147.168.255.25516,382
165147.169.0.0/18147.169.0.1 to 147.169.63.254147.169.63.25516,382
166147.169.64.0/18147.169.64.1 to 147.169.127.254147.169.127.25516,382
167147.169.128.0/18147.169.128.1 to 147.169.191.254147.169.191.25516,382
168147.169.192.0/18147.169.192.1 to 147.169.255.254147.169.255.25516,382
169147.170.0.0/18147.170.0.1 to 147.170.63.254147.170.63.25516,382
170147.170.64.0/18147.170.64.1 to 147.170.127.254147.170.127.25516,382
171147.170.128.0/18147.170.128.1 to 147.170.191.254147.170.191.25516,382
172147.170.192.0/18147.170.192.1 to 147.170.255.254147.170.255.25516,382
173147.171.0.0/18147.171.0.1 to 147.171.63.254147.171.63.25516,382
174147.171.64.0/18147.171.64.1 to 147.171.127.254147.171.127.25516,382
175147.171.128.0/18147.171.128.1 to 147.171.191.254147.171.191.25516,382
176147.171.192.0/18147.171.192.1 to 147.171.255.254147.171.255.25516,382
177147.172.0.0/18147.172.0.1 to 147.172.63.254147.172.63.25516,382
178147.172.64.0/18147.172.64.1 to 147.172.127.254147.172.127.25516,382
179147.172.128.0/18147.172.128.1 to 147.172.191.254147.172.191.25516,382
180147.172.192.0/18147.172.192.1 to 147.172.255.254147.172.255.25516,382
181147.173.0.0/18147.173.0.1 to 147.173.63.254147.173.63.25516,382
182147.173.64.0/18147.173.64.1 to 147.173.127.254147.173.127.25516,382
183147.173.128.0/18147.173.128.1 to 147.173.191.254147.173.191.25516,382
184147.173.192.0/18147.173.192.1 to 147.173.255.254147.173.255.25516,382
185147.174.0.0/18147.174.0.1 to 147.174.63.254147.174.63.25516,382
186147.174.64.0/18147.174.64.1 to 147.174.127.254147.174.127.25516,382
187147.174.128.0/18147.174.128.1 to 147.174.191.254147.174.191.25516,382
188147.174.192.0/18147.174.192.1 to 147.174.255.254147.174.255.25516,382
189147.175.0.0/18147.175.0.1 to 147.175.63.254147.175.63.25516,382
190147.175.64.0/18147.175.64.1 to 147.175.127.254147.175.127.25516,382
191147.175.128.0/18147.175.128.1 to 147.175.191.254147.175.191.25516,382
192147.175.192.0/18147.175.192.1 to 147.175.255.254147.175.255.25516,382
193147.176.0.0/18147.176.0.1 to 147.176.63.254147.176.63.25516,382
194147.176.64.0/18147.176.64.1 to 147.176.127.254147.176.127.25516,382
195147.176.128.0/18147.176.128.1 to 147.176.191.254147.176.191.25516,382
196147.176.192.0/18147.176.192.1 to 147.176.255.254147.176.255.25516,382
197147.177.0.0/18147.177.0.1 to 147.177.63.254147.177.63.25516,382
198147.177.64.0/18147.177.64.1 to 147.177.127.254147.177.127.25516,382
199147.177.128.0/18147.177.128.1 to 147.177.191.254147.177.191.25516,382
200147.177.192.0/18147.177.192.1 to 147.177.255.254147.177.255.25516,382
201147.178.0.0/18147.178.0.1 to 147.178.63.254147.178.63.25516,382
202147.178.64.0/18147.178.64.1 to 147.178.127.254147.178.127.25516,382
203147.178.128.0/18147.178.128.1 to 147.178.191.254147.178.191.25516,382
204147.178.192.0/18147.178.192.1 to 147.178.255.254147.178.255.25516,382
205147.179.0.0/18147.179.0.1 to 147.179.63.254147.179.63.25516,382
206147.179.64.0/18147.179.64.1 to 147.179.127.254147.179.127.25516,382
207147.179.128.0/18147.179.128.1 to 147.179.191.254147.179.191.25516,382
208147.179.192.0/18147.179.192.1 to 147.179.255.254147.179.255.25516,382
209147.180.0.0/18147.180.0.1 to 147.180.63.254147.180.63.25516,382
210147.180.64.0/18147.180.64.1 to 147.180.127.254147.180.127.25516,382
211147.180.128.0/18147.180.128.1 to 147.180.191.254147.180.191.25516,382
212147.180.192.0/18147.180.192.1 to 147.180.255.254147.180.255.25516,382
213147.181.0.0/18147.181.0.1 to 147.181.63.254147.181.63.25516,382
214147.181.64.0/18147.181.64.1 to 147.181.127.254147.181.127.25516,382
215147.181.128.0/18147.181.128.1 to 147.181.191.254147.181.191.25516,382
216147.181.192.0/18147.181.192.1 to 147.181.255.254147.181.255.25516,382
217147.182.0.0/18147.182.0.1 to 147.182.63.254147.182.63.25516,382
218147.182.64.0/18147.182.64.1 to 147.182.127.254147.182.127.25516,382
219147.182.128.0/18147.182.128.1 to 147.182.191.254147.182.191.25516,382
220147.182.192.0/18147.182.192.1 to 147.182.255.254147.182.255.25516,382
221147.183.0.0/18147.183.0.1 to 147.183.63.254147.183.63.25516,382
222147.183.64.0/18147.183.64.1 to 147.183.127.254147.183.127.25516,382
223147.183.128.0/18147.183.128.1 to 147.183.191.254147.183.191.25516,382
224147.183.192.0/18147.183.192.1 to 147.183.255.254147.183.255.25516,382
225147.184.0.0/18147.184.0.1 to 147.184.63.254147.184.63.25516,382
226147.184.64.0/18147.184.64.1 to 147.184.127.254147.184.127.25516,382
227147.184.128.0/18147.184.128.1 to 147.184.191.254147.184.191.25516,382
228147.184.192.0/18147.184.192.1 to 147.184.255.254147.184.255.25516,382
229147.185.0.0/18147.185.0.1 to 147.185.63.254147.185.63.25516,382
230147.185.64.0/18147.185.64.1 to 147.185.127.254147.185.127.25516,382
231147.185.128.0/18147.185.128.1 to 147.185.191.254147.185.191.25516,382
232147.185.192.0/18147.185.192.1 to 147.185.255.254147.185.255.25516,382
233147.186.0.0/18147.186.0.1 to 147.186.63.254147.186.63.25516,382
234147.186.64.0/18147.186.64.1 to 147.186.127.254147.186.127.25516,382
235147.186.128.0/18147.186.128.1 to 147.186.191.254147.186.191.25516,382
236147.186.192.0/18147.186.192.1 to 147.186.255.254147.186.255.25516,382
237147.187.0.0/18147.187.0.1 to 147.187.63.254147.187.63.25516,382
238147.187.64.0/18147.187.64.1 to 147.187.127.254147.187.127.25516,382
239147.187.128.0/18147.187.128.1 to 147.187.191.254147.187.191.25516,382
240147.187.192.0/18147.187.192.1 to 147.187.255.254147.187.255.25516,382
241147.188.0.0/18147.188.0.1 to 147.188.63.254147.188.63.25516,382
242147.188.64.0/18147.188.64.1 to 147.188.127.254147.188.127.25516,382
243147.188.128.0/18147.188.128.1 to 147.188.191.254147.188.191.25516,382
244147.188.192.0/18147.188.192.1 to 147.188.255.254147.188.255.25516,382
245147.189.0.0/18147.189.0.1 to 147.189.63.254147.189.63.25516,382
246147.189.64.0/18147.189.64.1 to 147.189.127.254147.189.127.25516,382
247147.189.128.0/18147.189.128.1 to 147.189.191.254147.189.191.25516,382
248147.189.192.0/18147.189.192.1 to 147.189.255.254147.189.255.25516,382
249147.190.0.0/18147.190.0.1 to 147.190.63.254147.190.63.25516,382
250147.190.64.0/18147.190.64.1 to 147.190.127.254147.190.127.25516,382
251147.190.128.0/18147.190.128.1 to 147.190.191.254147.190.191.25516,382
252147.190.192.0/18147.190.192.1 to 147.190.255.254147.190.255.25516,382
253147.191.0.0/18147.191.0.1 to 147.191.63.254147.191.63.25516,382
254147.191.64.0/18147.191.64.1 to 147.191.127.254147.191.127.25516,382
255147.191.128.0/18147.191.128.1 to 147.191.191.254147.191.191.25516,382
256147.191.192.0/18147.191.192.1 to 147.191.255.254147.191.255.25516,382

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.