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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.

Network148.2.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
148.2.0.0
Broadcast address
148.2.255.255
First usable
148.2.0.1
Last usable
148.2.255.254
Usable hosts
65,534 (65,536 less the network and broadcast addresses)
Subnet mask
255.255.0.0
Wildcard mask
0.0.255.255 (Cisco ACLs, OSPF)
Prefix length
/16
Type
Public public
Old class
B (default /16)
As numbers
Hex 94020000 · Integer 2483159040 to 2483224575
Reverse DNS zone
2.148.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10010100.00000010..00000000.00000000148.2.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network10010100.00000010..00000000.00000000148.2.0.0
Broadcast10010100.00000010..11111111.11111111148.2.255.255
Split into smaller subnets/24
/17 (2)/18 (4)/19 (8)/20 (16)/21 (32)/22 (64)/23 (128)/24 (256)/25 (512)/26 (1,024)/27 (2,048)/28 (4,096)

148.2.0.0/16 makes 256 subnets of /24.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1148.2.0.0/24148.2.0.1 to 148.2.0.254148.2.0.255254
2148.2.1.0/24148.2.1.1 to 148.2.1.254148.2.1.255254
3148.2.2.0/24148.2.2.1 to 148.2.2.254148.2.2.255254
4148.2.3.0/24148.2.3.1 to 148.2.3.254148.2.3.255254
5148.2.4.0/24148.2.4.1 to 148.2.4.254148.2.4.255254
6148.2.5.0/24148.2.5.1 to 148.2.5.254148.2.5.255254
7148.2.6.0/24148.2.6.1 to 148.2.6.254148.2.6.255254
8148.2.7.0/24148.2.7.1 to 148.2.7.254148.2.7.255254
9148.2.8.0/24148.2.8.1 to 148.2.8.254148.2.8.255254
10148.2.9.0/24148.2.9.1 to 148.2.9.254148.2.9.255254
11148.2.10.0/24148.2.10.1 to 148.2.10.254148.2.10.255254
12148.2.11.0/24148.2.11.1 to 148.2.11.254148.2.11.255254
13148.2.12.0/24148.2.12.1 to 148.2.12.254148.2.12.255254
14148.2.13.0/24148.2.13.1 to 148.2.13.254148.2.13.255254
15148.2.14.0/24148.2.14.1 to 148.2.14.254148.2.14.255254
16148.2.15.0/24148.2.15.1 to 148.2.15.254148.2.15.255254
17148.2.16.0/24148.2.16.1 to 148.2.16.254148.2.16.255254
18148.2.17.0/24148.2.17.1 to 148.2.17.254148.2.17.255254
19148.2.18.0/24148.2.18.1 to 148.2.18.254148.2.18.255254
20148.2.19.0/24148.2.19.1 to 148.2.19.254148.2.19.255254
21148.2.20.0/24148.2.20.1 to 148.2.20.254148.2.20.255254
22148.2.21.0/24148.2.21.1 to 148.2.21.254148.2.21.255254
23148.2.22.0/24148.2.22.1 to 148.2.22.254148.2.22.255254
24148.2.23.0/24148.2.23.1 to 148.2.23.254148.2.23.255254
25148.2.24.0/24148.2.24.1 to 148.2.24.254148.2.24.255254
26148.2.25.0/24148.2.25.1 to 148.2.25.254148.2.25.255254
27148.2.26.0/24148.2.26.1 to 148.2.26.254148.2.26.255254
28148.2.27.0/24148.2.27.1 to 148.2.27.254148.2.27.255254
29148.2.28.0/24148.2.28.1 to 148.2.28.254148.2.28.255254
30148.2.29.0/24148.2.29.1 to 148.2.29.254148.2.29.255254
31148.2.30.0/24148.2.30.1 to 148.2.30.254148.2.30.255254
32148.2.31.0/24148.2.31.1 to 148.2.31.254148.2.31.255254
33148.2.32.0/24148.2.32.1 to 148.2.32.254148.2.32.255254
34148.2.33.0/24148.2.33.1 to 148.2.33.254148.2.33.255254
35148.2.34.0/24148.2.34.1 to 148.2.34.254148.2.34.255254
36148.2.35.0/24148.2.35.1 to 148.2.35.254148.2.35.255254
37148.2.36.0/24148.2.36.1 to 148.2.36.254148.2.36.255254
38148.2.37.0/24148.2.37.1 to 148.2.37.254148.2.37.255254
39148.2.38.0/24148.2.38.1 to 148.2.38.254148.2.38.255254
40148.2.39.0/24148.2.39.1 to 148.2.39.254148.2.39.255254
41148.2.40.0/24148.2.40.1 to 148.2.40.254148.2.40.255254
42148.2.41.0/24148.2.41.1 to 148.2.41.254148.2.41.255254
43148.2.42.0/24148.2.42.1 to 148.2.42.254148.2.42.255254
44148.2.43.0/24148.2.43.1 to 148.2.43.254148.2.43.255254
45148.2.44.0/24148.2.44.1 to 148.2.44.254148.2.44.255254
46148.2.45.0/24148.2.45.1 to 148.2.45.254148.2.45.255254
47148.2.46.0/24148.2.46.1 to 148.2.46.254148.2.46.255254
48148.2.47.0/24148.2.47.1 to 148.2.47.254148.2.47.255254
49148.2.48.0/24148.2.48.1 to 148.2.48.254148.2.48.255254
50148.2.49.0/24148.2.49.1 to 148.2.49.254148.2.49.255254
51148.2.50.0/24148.2.50.1 to 148.2.50.254148.2.50.255254
52148.2.51.0/24148.2.51.1 to 148.2.51.254148.2.51.255254
53148.2.52.0/24148.2.52.1 to 148.2.52.254148.2.52.255254
54148.2.53.0/24148.2.53.1 to 148.2.53.254148.2.53.255254
55148.2.54.0/24148.2.54.1 to 148.2.54.254148.2.54.255254
56148.2.55.0/24148.2.55.1 to 148.2.55.254148.2.55.255254
57148.2.56.0/24148.2.56.1 to 148.2.56.254148.2.56.255254
58148.2.57.0/24148.2.57.1 to 148.2.57.254148.2.57.255254
59148.2.58.0/24148.2.58.1 to 148.2.58.254148.2.58.255254
60148.2.59.0/24148.2.59.1 to 148.2.59.254148.2.59.255254
61148.2.60.0/24148.2.60.1 to 148.2.60.254148.2.60.255254
62148.2.61.0/24148.2.61.1 to 148.2.61.254148.2.61.255254
63148.2.62.0/24148.2.62.1 to 148.2.62.254148.2.62.255254
64148.2.63.0/24148.2.63.1 to 148.2.63.254148.2.63.255254
65148.2.64.0/24148.2.64.1 to 148.2.64.254148.2.64.255254
66148.2.65.0/24148.2.65.1 to 148.2.65.254148.2.65.255254
67148.2.66.0/24148.2.66.1 to 148.2.66.254148.2.66.255254
68148.2.67.0/24148.2.67.1 to 148.2.67.254148.2.67.255254
69148.2.68.0/24148.2.68.1 to 148.2.68.254148.2.68.255254
70148.2.69.0/24148.2.69.1 to 148.2.69.254148.2.69.255254
71148.2.70.0/24148.2.70.1 to 148.2.70.254148.2.70.255254
72148.2.71.0/24148.2.71.1 to 148.2.71.254148.2.71.255254
73148.2.72.0/24148.2.72.1 to 148.2.72.254148.2.72.255254
74148.2.73.0/24148.2.73.1 to 148.2.73.254148.2.73.255254
75148.2.74.0/24148.2.74.1 to 148.2.74.254148.2.74.255254
76148.2.75.0/24148.2.75.1 to 148.2.75.254148.2.75.255254
77148.2.76.0/24148.2.76.1 to 148.2.76.254148.2.76.255254
78148.2.77.0/24148.2.77.1 to 148.2.77.254148.2.77.255254
79148.2.78.0/24148.2.78.1 to 148.2.78.254148.2.78.255254
80148.2.79.0/24148.2.79.1 to 148.2.79.254148.2.79.255254
81148.2.80.0/24148.2.80.1 to 148.2.80.254148.2.80.255254
82148.2.81.0/24148.2.81.1 to 148.2.81.254148.2.81.255254
83148.2.82.0/24148.2.82.1 to 148.2.82.254148.2.82.255254
84148.2.83.0/24148.2.83.1 to 148.2.83.254148.2.83.255254
85148.2.84.0/24148.2.84.1 to 148.2.84.254148.2.84.255254
86148.2.85.0/24148.2.85.1 to 148.2.85.254148.2.85.255254
87148.2.86.0/24148.2.86.1 to 148.2.86.254148.2.86.255254
88148.2.87.0/24148.2.87.1 to 148.2.87.254148.2.87.255254
89148.2.88.0/24148.2.88.1 to 148.2.88.254148.2.88.255254
90148.2.89.0/24148.2.89.1 to 148.2.89.254148.2.89.255254
91148.2.90.0/24148.2.90.1 to 148.2.90.254148.2.90.255254
92148.2.91.0/24148.2.91.1 to 148.2.91.254148.2.91.255254
93148.2.92.0/24148.2.92.1 to 148.2.92.254148.2.92.255254
94148.2.93.0/24148.2.93.1 to 148.2.93.254148.2.93.255254
95148.2.94.0/24148.2.94.1 to 148.2.94.254148.2.94.255254
96148.2.95.0/24148.2.95.1 to 148.2.95.254148.2.95.255254
97148.2.96.0/24148.2.96.1 to 148.2.96.254148.2.96.255254
98148.2.97.0/24148.2.97.1 to 148.2.97.254148.2.97.255254
99148.2.98.0/24148.2.98.1 to 148.2.98.254148.2.98.255254
100148.2.99.0/24148.2.99.1 to 148.2.99.254148.2.99.255254
101148.2.100.0/24148.2.100.1 to 148.2.100.254148.2.100.255254
102148.2.101.0/24148.2.101.1 to 148.2.101.254148.2.101.255254
103148.2.102.0/24148.2.102.1 to 148.2.102.254148.2.102.255254
104148.2.103.0/24148.2.103.1 to 148.2.103.254148.2.103.255254
105148.2.104.0/24148.2.104.1 to 148.2.104.254148.2.104.255254
106148.2.105.0/24148.2.105.1 to 148.2.105.254148.2.105.255254
107148.2.106.0/24148.2.106.1 to 148.2.106.254148.2.106.255254
108148.2.107.0/24148.2.107.1 to 148.2.107.254148.2.107.255254
109148.2.108.0/24148.2.108.1 to 148.2.108.254148.2.108.255254
110148.2.109.0/24148.2.109.1 to 148.2.109.254148.2.109.255254
111148.2.110.0/24148.2.110.1 to 148.2.110.254148.2.110.255254
112148.2.111.0/24148.2.111.1 to 148.2.111.254148.2.111.255254
113148.2.112.0/24148.2.112.1 to 148.2.112.254148.2.112.255254
114148.2.113.0/24148.2.113.1 to 148.2.113.254148.2.113.255254
115148.2.114.0/24148.2.114.1 to 148.2.114.254148.2.114.255254
116148.2.115.0/24148.2.115.1 to 148.2.115.254148.2.115.255254
117148.2.116.0/24148.2.116.1 to 148.2.116.254148.2.116.255254
118148.2.117.0/24148.2.117.1 to 148.2.117.254148.2.117.255254
119148.2.118.0/24148.2.118.1 to 148.2.118.254148.2.118.255254
120148.2.119.0/24148.2.119.1 to 148.2.119.254148.2.119.255254
121148.2.120.0/24148.2.120.1 to 148.2.120.254148.2.120.255254
122148.2.121.0/24148.2.121.1 to 148.2.121.254148.2.121.255254
123148.2.122.0/24148.2.122.1 to 148.2.122.254148.2.122.255254
124148.2.123.0/24148.2.123.1 to 148.2.123.254148.2.123.255254
125148.2.124.0/24148.2.124.1 to 148.2.124.254148.2.124.255254
126148.2.125.0/24148.2.125.1 to 148.2.125.254148.2.125.255254
127148.2.126.0/24148.2.126.1 to 148.2.126.254148.2.126.255254
128148.2.127.0/24148.2.127.1 to 148.2.127.254148.2.127.255254
129148.2.128.0/24148.2.128.1 to 148.2.128.254148.2.128.255254
130148.2.129.0/24148.2.129.1 to 148.2.129.254148.2.129.255254
131148.2.130.0/24148.2.130.1 to 148.2.130.254148.2.130.255254
132148.2.131.0/24148.2.131.1 to 148.2.131.254148.2.131.255254
133148.2.132.0/24148.2.132.1 to 148.2.132.254148.2.132.255254
134148.2.133.0/24148.2.133.1 to 148.2.133.254148.2.133.255254
135148.2.134.0/24148.2.134.1 to 148.2.134.254148.2.134.255254
136148.2.135.0/24148.2.135.1 to 148.2.135.254148.2.135.255254
137148.2.136.0/24148.2.136.1 to 148.2.136.254148.2.136.255254
138148.2.137.0/24148.2.137.1 to 148.2.137.254148.2.137.255254
139148.2.138.0/24148.2.138.1 to 148.2.138.254148.2.138.255254
140148.2.139.0/24148.2.139.1 to 148.2.139.254148.2.139.255254
141148.2.140.0/24148.2.140.1 to 148.2.140.254148.2.140.255254
142148.2.141.0/24148.2.141.1 to 148.2.141.254148.2.141.255254
143148.2.142.0/24148.2.142.1 to 148.2.142.254148.2.142.255254
144148.2.143.0/24148.2.143.1 to 148.2.143.254148.2.143.255254
145148.2.144.0/24148.2.144.1 to 148.2.144.254148.2.144.255254
146148.2.145.0/24148.2.145.1 to 148.2.145.254148.2.145.255254
147148.2.146.0/24148.2.146.1 to 148.2.146.254148.2.146.255254
148148.2.147.0/24148.2.147.1 to 148.2.147.254148.2.147.255254
149148.2.148.0/24148.2.148.1 to 148.2.148.254148.2.148.255254
150148.2.149.0/24148.2.149.1 to 148.2.149.254148.2.149.255254
151148.2.150.0/24148.2.150.1 to 148.2.150.254148.2.150.255254
152148.2.151.0/24148.2.151.1 to 148.2.151.254148.2.151.255254
153148.2.152.0/24148.2.152.1 to 148.2.152.254148.2.152.255254
154148.2.153.0/24148.2.153.1 to 148.2.153.254148.2.153.255254
155148.2.154.0/24148.2.154.1 to 148.2.154.254148.2.154.255254
156148.2.155.0/24148.2.155.1 to 148.2.155.254148.2.155.255254
157148.2.156.0/24148.2.156.1 to 148.2.156.254148.2.156.255254
158148.2.157.0/24148.2.157.1 to 148.2.157.254148.2.157.255254
159148.2.158.0/24148.2.158.1 to 148.2.158.254148.2.158.255254
160148.2.159.0/24148.2.159.1 to 148.2.159.254148.2.159.255254
161148.2.160.0/24148.2.160.1 to 148.2.160.254148.2.160.255254
162148.2.161.0/24148.2.161.1 to 148.2.161.254148.2.161.255254
163148.2.162.0/24148.2.162.1 to 148.2.162.254148.2.162.255254
164148.2.163.0/24148.2.163.1 to 148.2.163.254148.2.163.255254
165148.2.164.0/24148.2.164.1 to 148.2.164.254148.2.164.255254
166148.2.165.0/24148.2.165.1 to 148.2.165.254148.2.165.255254
167148.2.166.0/24148.2.166.1 to 148.2.166.254148.2.166.255254
168148.2.167.0/24148.2.167.1 to 148.2.167.254148.2.167.255254
169148.2.168.0/24148.2.168.1 to 148.2.168.254148.2.168.255254
170148.2.169.0/24148.2.169.1 to 148.2.169.254148.2.169.255254
171148.2.170.0/24148.2.170.1 to 148.2.170.254148.2.170.255254
172148.2.171.0/24148.2.171.1 to 148.2.171.254148.2.171.255254
173148.2.172.0/24148.2.172.1 to 148.2.172.254148.2.172.255254
174148.2.173.0/24148.2.173.1 to 148.2.173.254148.2.173.255254
175148.2.174.0/24148.2.174.1 to 148.2.174.254148.2.174.255254
176148.2.175.0/24148.2.175.1 to 148.2.175.254148.2.175.255254
177148.2.176.0/24148.2.176.1 to 148.2.176.254148.2.176.255254
178148.2.177.0/24148.2.177.1 to 148.2.177.254148.2.177.255254
179148.2.178.0/24148.2.178.1 to 148.2.178.254148.2.178.255254
180148.2.179.0/24148.2.179.1 to 148.2.179.254148.2.179.255254
181148.2.180.0/24148.2.180.1 to 148.2.180.254148.2.180.255254
182148.2.181.0/24148.2.181.1 to 148.2.181.254148.2.181.255254
183148.2.182.0/24148.2.182.1 to 148.2.182.254148.2.182.255254
184148.2.183.0/24148.2.183.1 to 148.2.183.254148.2.183.255254
185148.2.184.0/24148.2.184.1 to 148.2.184.254148.2.184.255254
186148.2.185.0/24148.2.185.1 to 148.2.185.254148.2.185.255254
187148.2.186.0/24148.2.186.1 to 148.2.186.254148.2.186.255254
188148.2.187.0/24148.2.187.1 to 148.2.187.254148.2.187.255254
189148.2.188.0/24148.2.188.1 to 148.2.188.254148.2.188.255254
190148.2.189.0/24148.2.189.1 to 148.2.189.254148.2.189.255254
191148.2.190.0/24148.2.190.1 to 148.2.190.254148.2.190.255254
192148.2.191.0/24148.2.191.1 to 148.2.191.254148.2.191.255254
193148.2.192.0/24148.2.192.1 to 148.2.192.254148.2.192.255254
194148.2.193.0/24148.2.193.1 to 148.2.193.254148.2.193.255254
195148.2.194.0/24148.2.194.1 to 148.2.194.254148.2.194.255254
196148.2.195.0/24148.2.195.1 to 148.2.195.254148.2.195.255254
197148.2.196.0/24148.2.196.1 to 148.2.196.254148.2.196.255254
198148.2.197.0/24148.2.197.1 to 148.2.197.254148.2.197.255254
199148.2.198.0/24148.2.198.1 to 148.2.198.254148.2.198.255254
200148.2.199.0/24148.2.199.1 to 148.2.199.254148.2.199.255254
201148.2.200.0/24148.2.200.1 to 148.2.200.254148.2.200.255254
202148.2.201.0/24148.2.201.1 to 148.2.201.254148.2.201.255254
203148.2.202.0/24148.2.202.1 to 148.2.202.254148.2.202.255254
204148.2.203.0/24148.2.203.1 to 148.2.203.254148.2.203.255254
205148.2.204.0/24148.2.204.1 to 148.2.204.254148.2.204.255254
206148.2.205.0/24148.2.205.1 to 148.2.205.254148.2.205.255254
207148.2.206.0/24148.2.206.1 to 148.2.206.254148.2.206.255254
208148.2.207.0/24148.2.207.1 to 148.2.207.254148.2.207.255254
209148.2.208.0/24148.2.208.1 to 148.2.208.254148.2.208.255254
210148.2.209.0/24148.2.209.1 to 148.2.209.254148.2.209.255254
211148.2.210.0/24148.2.210.1 to 148.2.210.254148.2.210.255254
212148.2.211.0/24148.2.211.1 to 148.2.211.254148.2.211.255254
213148.2.212.0/24148.2.212.1 to 148.2.212.254148.2.212.255254
214148.2.213.0/24148.2.213.1 to 148.2.213.254148.2.213.255254
215148.2.214.0/24148.2.214.1 to 148.2.214.254148.2.214.255254
216148.2.215.0/24148.2.215.1 to 148.2.215.254148.2.215.255254
217148.2.216.0/24148.2.216.1 to 148.2.216.254148.2.216.255254
218148.2.217.0/24148.2.217.1 to 148.2.217.254148.2.217.255254
219148.2.218.0/24148.2.218.1 to 148.2.218.254148.2.218.255254
220148.2.219.0/24148.2.219.1 to 148.2.219.254148.2.219.255254
221148.2.220.0/24148.2.220.1 to 148.2.220.254148.2.220.255254
222148.2.221.0/24148.2.221.1 to 148.2.221.254148.2.221.255254
223148.2.222.0/24148.2.222.1 to 148.2.222.254148.2.222.255254
224148.2.223.0/24148.2.223.1 to 148.2.223.254148.2.223.255254
225148.2.224.0/24148.2.224.1 to 148.2.224.254148.2.224.255254
226148.2.225.0/24148.2.225.1 to 148.2.225.254148.2.225.255254
227148.2.226.0/24148.2.226.1 to 148.2.226.254148.2.226.255254
228148.2.227.0/24148.2.227.1 to 148.2.227.254148.2.227.255254
229148.2.228.0/24148.2.228.1 to 148.2.228.254148.2.228.255254
230148.2.229.0/24148.2.229.1 to 148.2.229.254148.2.229.255254
231148.2.230.0/24148.2.230.1 to 148.2.230.254148.2.230.255254
232148.2.231.0/24148.2.231.1 to 148.2.231.254148.2.231.255254
233148.2.232.0/24148.2.232.1 to 148.2.232.254148.2.232.255254
234148.2.233.0/24148.2.233.1 to 148.2.233.254148.2.233.255254
235148.2.234.0/24148.2.234.1 to 148.2.234.254148.2.234.255254
236148.2.235.0/24148.2.235.1 to 148.2.235.254148.2.235.255254
237148.2.236.0/24148.2.236.1 to 148.2.236.254148.2.236.255254
238148.2.237.0/24148.2.237.1 to 148.2.237.254148.2.237.255254
239148.2.238.0/24148.2.238.1 to 148.2.238.254148.2.238.255254
240148.2.239.0/24148.2.239.1 to 148.2.239.254148.2.239.255254
241148.2.240.0/24148.2.240.1 to 148.2.240.254148.2.240.255254
242148.2.241.0/24148.2.241.1 to 148.2.241.254148.2.241.255254
243148.2.242.0/24148.2.242.1 to 148.2.242.254148.2.242.255254
244148.2.243.0/24148.2.243.1 to 148.2.243.254148.2.243.255254
245148.2.244.0/24148.2.244.1 to 148.2.244.254148.2.244.255254
246148.2.245.0/24148.2.245.1 to 148.2.245.254148.2.245.255254
247148.2.246.0/24148.2.246.1 to 148.2.246.254148.2.246.255254
248148.2.247.0/24148.2.247.1 to 148.2.247.254148.2.247.255254
249148.2.248.0/24148.2.248.1 to 148.2.248.254148.2.248.255254
250148.2.249.0/24148.2.249.1 to 148.2.249.254148.2.249.255254
251148.2.250.0/24148.2.250.1 to 148.2.250.254148.2.250.255254
252148.2.251.0/24148.2.251.1 to 148.2.251.254148.2.251.255254
253148.2.252.0/24148.2.252.1 to 148.2.252.254148.2.252.255254
254148.2.253.0/24148.2.253.1 to 148.2.253.254148.2.253.255254
255148.2.254.0/24148.2.254.1 to 148.2.254.254148.2.254.255254
256148.2.255.0/24148.2.255.1 to 148.2.255.254148.2.255.255254

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.