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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.

Network148.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
148.0.0.0
Broadcast address
149.255.255.255
First usable
148.0.0.1
Last usable
149.255.255.254
Usable hosts
33,554,430 (33,554,432 less the network and broadcast addresses)
Subnet mask
254.0.0.0
Wildcard mask
1.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/7
Type
Public public
Old class
B (default /16)
As numbers
Hex 94000000 · Integer 2483027968 to 2516582399
Reverse DNS zones
148.in-addr.arpa
149.in-addr.arpa
/7 is not on a 8-bit boundary, so it takes 2 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10010100.00000000.00000000.00000000148.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network10010100.00000000.00000000.00000000148.0.0.0
Broadcast10010101.11111111.11111111.11111111149.255.255.255
Split into smaller subnets/16
/8 (2)/9 (4)/10 (8)/11 (16)/12 (32)/13 (64)/14 (128)/15 (256)/16 (512)/17 (1,024)/18 (2,048)/19 (4,096)

148.0.0.0/7 makes 512 subnets of /16; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1148.0.0.0/16148.0.0.1 to 148.0.255.254148.0.255.25565,534
2148.1.0.0/16148.1.0.1 to 148.1.255.254148.1.255.25565,534
3148.2.0.0/16148.2.0.1 to 148.2.255.254148.2.255.25565,534
4148.3.0.0/16148.3.0.1 to 148.3.255.254148.3.255.25565,534
5148.4.0.0/16148.4.0.1 to 148.4.255.254148.4.255.25565,534
6148.5.0.0/16148.5.0.1 to 148.5.255.254148.5.255.25565,534
7148.6.0.0/16148.6.0.1 to 148.6.255.254148.6.255.25565,534
8148.7.0.0/16148.7.0.1 to 148.7.255.254148.7.255.25565,534
9148.8.0.0/16148.8.0.1 to 148.8.255.254148.8.255.25565,534
10148.9.0.0/16148.9.0.1 to 148.9.255.254148.9.255.25565,534
11148.10.0.0/16148.10.0.1 to 148.10.255.254148.10.255.25565,534
12148.11.0.0/16148.11.0.1 to 148.11.255.254148.11.255.25565,534
13148.12.0.0/16148.12.0.1 to 148.12.255.254148.12.255.25565,534
14148.13.0.0/16148.13.0.1 to 148.13.255.254148.13.255.25565,534
15148.14.0.0/16148.14.0.1 to 148.14.255.254148.14.255.25565,534
16148.15.0.0/16148.15.0.1 to 148.15.255.254148.15.255.25565,534
17148.16.0.0/16148.16.0.1 to 148.16.255.254148.16.255.25565,534
18148.17.0.0/16148.17.0.1 to 148.17.255.254148.17.255.25565,534
19148.18.0.0/16148.18.0.1 to 148.18.255.254148.18.255.25565,534
20148.19.0.0/16148.19.0.1 to 148.19.255.254148.19.255.25565,534
21148.20.0.0/16148.20.0.1 to 148.20.255.254148.20.255.25565,534
22148.21.0.0/16148.21.0.1 to 148.21.255.254148.21.255.25565,534
23148.22.0.0/16148.22.0.1 to 148.22.255.254148.22.255.25565,534
24148.23.0.0/16148.23.0.1 to 148.23.255.254148.23.255.25565,534
25148.24.0.0/16148.24.0.1 to 148.24.255.254148.24.255.25565,534
26148.25.0.0/16148.25.0.1 to 148.25.255.254148.25.255.25565,534
27148.26.0.0/16148.26.0.1 to 148.26.255.254148.26.255.25565,534
28148.27.0.0/16148.27.0.1 to 148.27.255.254148.27.255.25565,534
29148.28.0.0/16148.28.0.1 to 148.28.255.254148.28.255.25565,534
30148.29.0.0/16148.29.0.1 to 148.29.255.254148.29.255.25565,534
31148.30.0.0/16148.30.0.1 to 148.30.255.254148.30.255.25565,534
32148.31.0.0/16148.31.0.1 to 148.31.255.254148.31.255.25565,534
33148.32.0.0/16148.32.0.1 to 148.32.255.254148.32.255.25565,534
34148.33.0.0/16148.33.0.1 to 148.33.255.254148.33.255.25565,534
35148.34.0.0/16148.34.0.1 to 148.34.255.254148.34.255.25565,534
36148.35.0.0/16148.35.0.1 to 148.35.255.254148.35.255.25565,534
37148.36.0.0/16148.36.0.1 to 148.36.255.254148.36.255.25565,534
38148.37.0.0/16148.37.0.1 to 148.37.255.254148.37.255.25565,534
39148.38.0.0/16148.38.0.1 to 148.38.255.254148.38.255.25565,534
40148.39.0.0/16148.39.0.1 to 148.39.255.254148.39.255.25565,534
41148.40.0.0/16148.40.0.1 to 148.40.255.254148.40.255.25565,534
42148.41.0.0/16148.41.0.1 to 148.41.255.254148.41.255.25565,534
43148.42.0.0/16148.42.0.1 to 148.42.255.254148.42.255.25565,534
44148.43.0.0/16148.43.0.1 to 148.43.255.254148.43.255.25565,534
45148.44.0.0/16148.44.0.1 to 148.44.255.254148.44.255.25565,534
46148.45.0.0/16148.45.0.1 to 148.45.255.254148.45.255.25565,534
47148.46.0.0/16148.46.0.1 to 148.46.255.254148.46.255.25565,534
48148.47.0.0/16148.47.0.1 to 148.47.255.254148.47.255.25565,534
49148.48.0.0/16148.48.0.1 to 148.48.255.254148.48.255.25565,534
50148.49.0.0/16148.49.0.1 to 148.49.255.254148.49.255.25565,534
51148.50.0.0/16148.50.0.1 to 148.50.255.254148.50.255.25565,534
52148.51.0.0/16148.51.0.1 to 148.51.255.254148.51.255.25565,534
53148.52.0.0/16148.52.0.1 to 148.52.255.254148.52.255.25565,534
54148.53.0.0/16148.53.0.1 to 148.53.255.254148.53.255.25565,534
55148.54.0.0/16148.54.0.1 to 148.54.255.254148.54.255.25565,534
56148.55.0.0/16148.55.0.1 to 148.55.255.254148.55.255.25565,534
57148.56.0.0/16148.56.0.1 to 148.56.255.254148.56.255.25565,534
58148.57.0.0/16148.57.0.1 to 148.57.255.254148.57.255.25565,534
59148.58.0.0/16148.58.0.1 to 148.58.255.254148.58.255.25565,534
60148.59.0.0/16148.59.0.1 to 148.59.255.254148.59.255.25565,534
61148.60.0.0/16148.60.0.1 to 148.60.255.254148.60.255.25565,534
62148.61.0.0/16148.61.0.1 to 148.61.255.254148.61.255.25565,534
63148.62.0.0/16148.62.0.1 to 148.62.255.254148.62.255.25565,534
64148.63.0.0/16148.63.0.1 to 148.63.255.254148.63.255.25565,534
65148.64.0.0/16148.64.0.1 to 148.64.255.254148.64.255.25565,534
66148.65.0.0/16148.65.0.1 to 148.65.255.254148.65.255.25565,534
67148.66.0.0/16148.66.0.1 to 148.66.255.254148.66.255.25565,534
68148.67.0.0/16148.67.0.1 to 148.67.255.254148.67.255.25565,534
69148.68.0.0/16148.68.0.1 to 148.68.255.254148.68.255.25565,534
70148.69.0.0/16148.69.0.1 to 148.69.255.254148.69.255.25565,534
71148.70.0.0/16148.70.0.1 to 148.70.255.254148.70.255.25565,534
72148.71.0.0/16148.71.0.1 to 148.71.255.254148.71.255.25565,534
73148.72.0.0/16148.72.0.1 to 148.72.255.254148.72.255.25565,534
74148.73.0.0/16148.73.0.1 to 148.73.255.254148.73.255.25565,534
75148.74.0.0/16148.74.0.1 to 148.74.255.254148.74.255.25565,534
76148.75.0.0/16148.75.0.1 to 148.75.255.254148.75.255.25565,534
77148.76.0.0/16148.76.0.1 to 148.76.255.254148.76.255.25565,534
78148.77.0.0/16148.77.0.1 to 148.77.255.254148.77.255.25565,534
79148.78.0.0/16148.78.0.1 to 148.78.255.254148.78.255.25565,534
80148.79.0.0/16148.79.0.1 to 148.79.255.254148.79.255.25565,534
81148.80.0.0/16148.80.0.1 to 148.80.255.254148.80.255.25565,534
82148.81.0.0/16148.81.0.1 to 148.81.255.254148.81.255.25565,534
83148.82.0.0/16148.82.0.1 to 148.82.255.254148.82.255.25565,534
84148.83.0.0/16148.83.0.1 to 148.83.255.254148.83.255.25565,534
85148.84.0.0/16148.84.0.1 to 148.84.255.254148.84.255.25565,534
86148.85.0.0/16148.85.0.1 to 148.85.255.254148.85.255.25565,534
87148.86.0.0/16148.86.0.1 to 148.86.255.254148.86.255.25565,534
88148.87.0.0/16148.87.0.1 to 148.87.255.254148.87.255.25565,534
89148.88.0.0/16148.88.0.1 to 148.88.255.254148.88.255.25565,534
90148.89.0.0/16148.89.0.1 to 148.89.255.254148.89.255.25565,534
91148.90.0.0/16148.90.0.1 to 148.90.255.254148.90.255.25565,534
92148.91.0.0/16148.91.0.1 to 148.91.255.254148.91.255.25565,534
93148.92.0.0/16148.92.0.1 to 148.92.255.254148.92.255.25565,534
94148.93.0.0/16148.93.0.1 to 148.93.255.254148.93.255.25565,534
95148.94.0.0/16148.94.0.1 to 148.94.255.254148.94.255.25565,534
96148.95.0.0/16148.95.0.1 to 148.95.255.254148.95.255.25565,534
97148.96.0.0/16148.96.0.1 to 148.96.255.254148.96.255.25565,534
98148.97.0.0/16148.97.0.1 to 148.97.255.254148.97.255.25565,534
99148.98.0.0/16148.98.0.1 to 148.98.255.254148.98.255.25565,534
100148.99.0.0/16148.99.0.1 to 148.99.255.254148.99.255.25565,534
101148.100.0.0/16148.100.0.1 to 148.100.255.254148.100.255.25565,534
102148.101.0.0/16148.101.0.1 to 148.101.255.254148.101.255.25565,534
103148.102.0.0/16148.102.0.1 to 148.102.255.254148.102.255.25565,534
104148.103.0.0/16148.103.0.1 to 148.103.255.254148.103.255.25565,534
105148.104.0.0/16148.104.0.1 to 148.104.255.254148.104.255.25565,534
106148.105.0.0/16148.105.0.1 to 148.105.255.254148.105.255.25565,534
107148.106.0.0/16148.106.0.1 to 148.106.255.254148.106.255.25565,534
108148.107.0.0/16148.107.0.1 to 148.107.255.254148.107.255.25565,534
109148.108.0.0/16148.108.0.1 to 148.108.255.254148.108.255.25565,534
110148.109.0.0/16148.109.0.1 to 148.109.255.254148.109.255.25565,534
111148.110.0.0/16148.110.0.1 to 148.110.255.254148.110.255.25565,534
112148.111.0.0/16148.111.0.1 to 148.111.255.254148.111.255.25565,534
113148.112.0.0/16148.112.0.1 to 148.112.255.254148.112.255.25565,534
114148.113.0.0/16148.113.0.1 to 148.113.255.254148.113.255.25565,534
115148.114.0.0/16148.114.0.1 to 148.114.255.254148.114.255.25565,534
116148.115.0.0/16148.115.0.1 to 148.115.255.254148.115.255.25565,534
117148.116.0.0/16148.116.0.1 to 148.116.255.254148.116.255.25565,534
118148.117.0.0/16148.117.0.1 to 148.117.255.254148.117.255.25565,534
119148.118.0.0/16148.118.0.1 to 148.118.255.254148.118.255.25565,534
120148.119.0.0/16148.119.0.1 to 148.119.255.254148.119.255.25565,534
121148.120.0.0/16148.120.0.1 to 148.120.255.254148.120.255.25565,534
122148.121.0.0/16148.121.0.1 to 148.121.255.254148.121.255.25565,534
123148.122.0.0/16148.122.0.1 to 148.122.255.254148.122.255.25565,534
124148.123.0.0/16148.123.0.1 to 148.123.255.254148.123.255.25565,534
125148.124.0.0/16148.124.0.1 to 148.124.255.254148.124.255.25565,534
126148.125.0.0/16148.125.0.1 to 148.125.255.254148.125.255.25565,534
127148.126.0.0/16148.126.0.1 to 148.126.255.254148.126.255.25565,534
128148.127.0.0/16148.127.0.1 to 148.127.255.254148.127.255.25565,534
129148.128.0.0/16148.128.0.1 to 148.128.255.254148.128.255.25565,534
130148.129.0.0/16148.129.0.1 to 148.129.255.254148.129.255.25565,534
131148.130.0.0/16148.130.0.1 to 148.130.255.254148.130.255.25565,534
132148.131.0.0/16148.131.0.1 to 148.131.255.254148.131.255.25565,534
133148.132.0.0/16148.132.0.1 to 148.132.255.254148.132.255.25565,534
134148.133.0.0/16148.133.0.1 to 148.133.255.254148.133.255.25565,534
135148.134.0.0/16148.134.0.1 to 148.134.255.254148.134.255.25565,534
136148.135.0.0/16148.135.0.1 to 148.135.255.254148.135.255.25565,534
137148.136.0.0/16148.136.0.1 to 148.136.255.254148.136.255.25565,534
138148.137.0.0/16148.137.0.1 to 148.137.255.254148.137.255.25565,534
139148.138.0.0/16148.138.0.1 to 148.138.255.254148.138.255.25565,534
140148.139.0.0/16148.139.0.1 to 148.139.255.254148.139.255.25565,534
141148.140.0.0/16148.140.0.1 to 148.140.255.254148.140.255.25565,534
142148.141.0.0/16148.141.0.1 to 148.141.255.254148.141.255.25565,534
143148.142.0.0/16148.142.0.1 to 148.142.255.254148.142.255.25565,534
144148.143.0.0/16148.143.0.1 to 148.143.255.254148.143.255.25565,534
145148.144.0.0/16148.144.0.1 to 148.144.255.254148.144.255.25565,534
146148.145.0.0/16148.145.0.1 to 148.145.255.254148.145.255.25565,534
147148.146.0.0/16148.146.0.1 to 148.146.255.254148.146.255.25565,534
148148.147.0.0/16148.147.0.1 to 148.147.255.254148.147.255.25565,534
149148.148.0.0/16148.148.0.1 to 148.148.255.254148.148.255.25565,534
150148.149.0.0/16148.149.0.1 to 148.149.255.254148.149.255.25565,534
151148.150.0.0/16148.150.0.1 to 148.150.255.254148.150.255.25565,534
152148.151.0.0/16148.151.0.1 to 148.151.255.254148.151.255.25565,534
153148.152.0.0/16148.152.0.1 to 148.152.255.254148.152.255.25565,534
154148.153.0.0/16148.153.0.1 to 148.153.255.254148.153.255.25565,534
155148.154.0.0/16148.154.0.1 to 148.154.255.254148.154.255.25565,534
156148.155.0.0/16148.155.0.1 to 148.155.255.254148.155.255.25565,534
157148.156.0.0/16148.156.0.1 to 148.156.255.254148.156.255.25565,534
158148.157.0.0/16148.157.0.1 to 148.157.255.254148.157.255.25565,534
159148.158.0.0/16148.158.0.1 to 148.158.255.254148.158.255.25565,534
160148.159.0.0/16148.159.0.1 to 148.159.255.254148.159.255.25565,534
161148.160.0.0/16148.160.0.1 to 148.160.255.254148.160.255.25565,534
162148.161.0.0/16148.161.0.1 to 148.161.255.254148.161.255.25565,534
163148.162.0.0/16148.162.0.1 to 148.162.255.254148.162.255.25565,534
164148.163.0.0/16148.163.0.1 to 148.163.255.254148.163.255.25565,534
165148.164.0.0/16148.164.0.1 to 148.164.255.254148.164.255.25565,534
166148.165.0.0/16148.165.0.1 to 148.165.255.254148.165.255.25565,534
167148.166.0.0/16148.166.0.1 to 148.166.255.254148.166.255.25565,534
168148.167.0.0/16148.167.0.1 to 148.167.255.254148.167.255.25565,534
169148.168.0.0/16148.168.0.1 to 148.168.255.254148.168.255.25565,534
170148.169.0.0/16148.169.0.1 to 148.169.255.254148.169.255.25565,534
171148.170.0.0/16148.170.0.1 to 148.170.255.254148.170.255.25565,534
172148.171.0.0/16148.171.0.1 to 148.171.255.254148.171.255.25565,534
173148.172.0.0/16148.172.0.1 to 148.172.255.254148.172.255.25565,534
174148.173.0.0/16148.173.0.1 to 148.173.255.254148.173.255.25565,534
175148.174.0.0/16148.174.0.1 to 148.174.255.254148.174.255.25565,534
176148.175.0.0/16148.175.0.1 to 148.175.255.254148.175.255.25565,534
177148.176.0.0/16148.176.0.1 to 148.176.255.254148.176.255.25565,534
178148.177.0.0/16148.177.0.1 to 148.177.255.254148.177.255.25565,534
179148.178.0.0/16148.178.0.1 to 148.178.255.254148.178.255.25565,534
180148.179.0.0/16148.179.0.1 to 148.179.255.254148.179.255.25565,534
181148.180.0.0/16148.180.0.1 to 148.180.255.254148.180.255.25565,534
182148.181.0.0/16148.181.0.1 to 148.181.255.254148.181.255.25565,534
183148.182.0.0/16148.182.0.1 to 148.182.255.254148.182.255.25565,534
184148.183.0.0/16148.183.0.1 to 148.183.255.254148.183.255.25565,534
185148.184.0.0/16148.184.0.1 to 148.184.255.254148.184.255.25565,534
186148.185.0.0/16148.185.0.1 to 148.185.255.254148.185.255.25565,534
187148.186.0.0/16148.186.0.1 to 148.186.255.254148.186.255.25565,534
188148.187.0.0/16148.187.0.1 to 148.187.255.254148.187.255.25565,534
189148.188.0.0/16148.188.0.1 to 148.188.255.254148.188.255.25565,534
190148.189.0.0/16148.189.0.1 to 148.189.255.254148.189.255.25565,534
191148.190.0.0/16148.190.0.1 to 148.190.255.254148.190.255.25565,534
192148.191.0.0/16148.191.0.1 to 148.191.255.254148.191.255.25565,534
193148.192.0.0/16148.192.0.1 to 148.192.255.254148.192.255.25565,534
194148.193.0.0/16148.193.0.1 to 148.193.255.254148.193.255.25565,534
195148.194.0.0/16148.194.0.1 to 148.194.255.254148.194.255.25565,534
196148.195.0.0/16148.195.0.1 to 148.195.255.254148.195.255.25565,534
197148.196.0.0/16148.196.0.1 to 148.196.255.254148.196.255.25565,534
198148.197.0.0/16148.197.0.1 to 148.197.255.254148.197.255.25565,534
199148.198.0.0/16148.198.0.1 to 148.198.255.254148.198.255.25565,534
200148.199.0.0/16148.199.0.1 to 148.199.255.254148.199.255.25565,534
201148.200.0.0/16148.200.0.1 to 148.200.255.254148.200.255.25565,534
202148.201.0.0/16148.201.0.1 to 148.201.255.254148.201.255.25565,534
203148.202.0.0/16148.202.0.1 to 148.202.255.254148.202.255.25565,534
204148.203.0.0/16148.203.0.1 to 148.203.255.254148.203.255.25565,534
205148.204.0.0/16148.204.0.1 to 148.204.255.254148.204.255.25565,534
206148.205.0.0/16148.205.0.1 to 148.205.255.254148.205.255.25565,534
207148.206.0.0/16148.206.0.1 to 148.206.255.254148.206.255.25565,534
208148.207.0.0/16148.207.0.1 to 148.207.255.254148.207.255.25565,534
209148.208.0.0/16148.208.0.1 to 148.208.255.254148.208.255.25565,534
210148.209.0.0/16148.209.0.1 to 148.209.255.254148.209.255.25565,534
211148.210.0.0/16148.210.0.1 to 148.210.255.254148.210.255.25565,534
212148.211.0.0/16148.211.0.1 to 148.211.255.254148.211.255.25565,534
213148.212.0.0/16148.212.0.1 to 148.212.255.254148.212.255.25565,534
214148.213.0.0/16148.213.0.1 to 148.213.255.254148.213.255.25565,534
215148.214.0.0/16148.214.0.1 to 148.214.255.254148.214.255.25565,534
216148.215.0.0/16148.215.0.1 to 148.215.255.254148.215.255.25565,534
217148.216.0.0/16148.216.0.1 to 148.216.255.254148.216.255.25565,534
218148.217.0.0/16148.217.0.1 to 148.217.255.254148.217.255.25565,534
219148.218.0.0/16148.218.0.1 to 148.218.255.254148.218.255.25565,534
220148.219.0.0/16148.219.0.1 to 148.219.255.254148.219.255.25565,534
221148.220.0.0/16148.220.0.1 to 148.220.255.254148.220.255.25565,534
222148.221.0.0/16148.221.0.1 to 148.221.255.254148.221.255.25565,534
223148.222.0.0/16148.222.0.1 to 148.222.255.254148.222.255.25565,534
224148.223.0.0/16148.223.0.1 to 148.223.255.254148.223.255.25565,534
225148.224.0.0/16148.224.0.1 to 148.224.255.254148.224.255.25565,534
226148.225.0.0/16148.225.0.1 to 148.225.255.254148.225.255.25565,534
227148.226.0.0/16148.226.0.1 to 148.226.255.254148.226.255.25565,534
228148.227.0.0/16148.227.0.1 to 148.227.255.254148.227.255.25565,534
229148.228.0.0/16148.228.0.1 to 148.228.255.254148.228.255.25565,534
230148.229.0.0/16148.229.0.1 to 148.229.255.254148.229.255.25565,534
231148.230.0.0/16148.230.0.1 to 148.230.255.254148.230.255.25565,534
232148.231.0.0/16148.231.0.1 to 148.231.255.254148.231.255.25565,534
233148.232.0.0/16148.232.0.1 to 148.232.255.254148.232.255.25565,534
234148.233.0.0/16148.233.0.1 to 148.233.255.254148.233.255.25565,534
235148.234.0.0/16148.234.0.1 to 148.234.255.254148.234.255.25565,534
236148.235.0.0/16148.235.0.1 to 148.235.255.254148.235.255.25565,534
237148.236.0.0/16148.236.0.1 to 148.236.255.254148.236.255.25565,534
238148.237.0.0/16148.237.0.1 to 148.237.255.254148.237.255.25565,534
239148.238.0.0/16148.238.0.1 to 148.238.255.254148.238.255.25565,534
240148.239.0.0/16148.239.0.1 to 148.239.255.254148.239.255.25565,534
241148.240.0.0/16148.240.0.1 to 148.240.255.254148.240.255.25565,534
242148.241.0.0/16148.241.0.1 to 148.241.255.254148.241.255.25565,534
243148.242.0.0/16148.242.0.1 to 148.242.255.254148.242.255.25565,534
244148.243.0.0/16148.243.0.1 to 148.243.255.254148.243.255.25565,534
245148.244.0.0/16148.244.0.1 to 148.244.255.254148.244.255.25565,534
246148.245.0.0/16148.245.0.1 to 148.245.255.254148.245.255.25565,534
247148.246.0.0/16148.246.0.1 to 148.246.255.254148.246.255.25565,534
248148.247.0.0/16148.247.0.1 to 148.247.255.254148.247.255.25565,534
249148.248.0.0/16148.248.0.1 to 148.248.255.254148.248.255.25565,534
250148.249.0.0/16148.249.0.1 to 148.249.255.254148.249.255.25565,534
251148.250.0.0/16148.250.0.1 to 148.250.255.254148.250.255.25565,534
252148.251.0.0/16148.251.0.1 to 148.251.255.254148.251.255.25565,534
253148.252.0.0/16148.252.0.1 to 148.252.255.254148.252.255.25565,534
254148.253.0.0/16148.253.0.1 to 148.253.255.254148.253.255.25565,534
255148.254.0.0/16148.254.0.1 to 148.254.255.254148.254.255.25565,534
256148.255.0.0/16148.255.0.1 to 148.255.255.254148.255.255.25565,534

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.