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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.

Network186.167.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
186.167.0.0
Broadcast address
186.167.255.255
First usable
186.167.0.1
Last usable
186.167.255.254
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 BAA70000 · Integer 3131506688 to 3131572223
Reverse DNS zone
167.186.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10111010.10100111..00000000.00000000186.167.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network10111010.10100111..00000000.00000000186.167.0.0
Broadcast10111010.10100111..11111111.11111111186.167.255.255
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)

186.167.0.0/16 makes 256 subnets of /24.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1186.167.0.0/24186.167.0.1 to 186.167.0.254186.167.0.255254
2186.167.1.0/24186.167.1.1 to 186.167.1.254186.167.1.255254
3186.167.2.0/24186.167.2.1 to 186.167.2.254186.167.2.255254
4186.167.3.0/24186.167.3.1 to 186.167.3.254186.167.3.255254
5186.167.4.0/24186.167.4.1 to 186.167.4.254186.167.4.255254
6186.167.5.0/24186.167.5.1 to 186.167.5.254186.167.5.255254
7186.167.6.0/24186.167.6.1 to 186.167.6.254186.167.6.255254
8186.167.7.0/24186.167.7.1 to 186.167.7.254186.167.7.255254
9186.167.8.0/24186.167.8.1 to 186.167.8.254186.167.8.255254
10186.167.9.0/24186.167.9.1 to 186.167.9.254186.167.9.255254
11186.167.10.0/24186.167.10.1 to 186.167.10.254186.167.10.255254
12186.167.11.0/24186.167.11.1 to 186.167.11.254186.167.11.255254
13186.167.12.0/24186.167.12.1 to 186.167.12.254186.167.12.255254
14186.167.13.0/24186.167.13.1 to 186.167.13.254186.167.13.255254
15186.167.14.0/24186.167.14.1 to 186.167.14.254186.167.14.255254
16186.167.15.0/24186.167.15.1 to 186.167.15.254186.167.15.255254
17186.167.16.0/24186.167.16.1 to 186.167.16.254186.167.16.255254
18186.167.17.0/24186.167.17.1 to 186.167.17.254186.167.17.255254
19186.167.18.0/24186.167.18.1 to 186.167.18.254186.167.18.255254
20186.167.19.0/24186.167.19.1 to 186.167.19.254186.167.19.255254
21186.167.20.0/24186.167.20.1 to 186.167.20.254186.167.20.255254
22186.167.21.0/24186.167.21.1 to 186.167.21.254186.167.21.255254
23186.167.22.0/24186.167.22.1 to 186.167.22.254186.167.22.255254
24186.167.23.0/24186.167.23.1 to 186.167.23.254186.167.23.255254
25186.167.24.0/24186.167.24.1 to 186.167.24.254186.167.24.255254
26186.167.25.0/24186.167.25.1 to 186.167.25.254186.167.25.255254
27186.167.26.0/24186.167.26.1 to 186.167.26.254186.167.26.255254
28186.167.27.0/24186.167.27.1 to 186.167.27.254186.167.27.255254
29186.167.28.0/24186.167.28.1 to 186.167.28.254186.167.28.255254
30186.167.29.0/24186.167.29.1 to 186.167.29.254186.167.29.255254
31186.167.30.0/24186.167.30.1 to 186.167.30.254186.167.30.255254
32186.167.31.0/24186.167.31.1 to 186.167.31.254186.167.31.255254
33186.167.32.0/24186.167.32.1 to 186.167.32.254186.167.32.255254
34186.167.33.0/24186.167.33.1 to 186.167.33.254186.167.33.255254
35186.167.34.0/24186.167.34.1 to 186.167.34.254186.167.34.255254
36186.167.35.0/24186.167.35.1 to 186.167.35.254186.167.35.255254
37186.167.36.0/24186.167.36.1 to 186.167.36.254186.167.36.255254
38186.167.37.0/24186.167.37.1 to 186.167.37.254186.167.37.255254
39186.167.38.0/24186.167.38.1 to 186.167.38.254186.167.38.255254
40186.167.39.0/24186.167.39.1 to 186.167.39.254186.167.39.255254
41186.167.40.0/24186.167.40.1 to 186.167.40.254186.167.40.255254
42186.167.41.0/24186.167.41.1 to 186.167.41.254186.167.41.255254
43186.167.42.0/24186.167.42.1 to 186.167.42.254186.167.42.255254
44186.167.43.0/24186.167.43.1 to 186.167.43.254186.167.43.255254
45186.167.44.0/24186.167.44.1 to 186.167.44.254186.167.44.255254
46186.167.45.0/24186.167.45.1 to 186.167.45.254186.167.45.255254
47186.167.46.0/24186.167.46.1 to 186.167.46.254186.167.46.255254
48186.167.47.0/24186.167.47.1 to 186.167.47.254186.167.47.255254
49186.167.48.0/24186.167.48.1 to 186.167.48.254186.167.48.255254
50186.167.49.0/24186.167.49.1 to 186.167.49.254186.167.49.255254
51186.167.50.0/24186.167.50.1 to 186.167.50.254186.167.50.255254
52186.167.51.0/24186.167.51.1 to 186.167.51.254186.167.51.255254
53186.167.52.0/24186.167.52.1 to 186.167.52.254186.167.52.255254
54186.167.53.0/24186.167.53.1 to 186.167.53.254186.167.53.255254
55186.167.54.0/24186.167.54.1 to 186.167.54.254186.167.54.255254
56186.167.55.0/24186.167.55.1 to 186.167.55.254186.167.55.255254
57186.167.56.0/24186.167.56.1 to 186.167.56.254186.167.56.255254
58186.167.57.0/24186.167.57.1 to 186.167.57.254186.167.57.255254
59186.167.58.0/24186.167.58.1 to 186.167.58.254186.167.58.255254
60186.167.59.0/24186.167.59.1 to 186.167.59.254186.167.59.255254
61186.167.60.0/24186.167.60.1 to 186.167.60.254186.167.60.255254
62186.167.61.0/24186.167.61.1 to 186.167.61.254186.167.61.255254
63186.167.62.0/24186.167.62.1 to 186.167.62.254186.167.62.255254
64186.167.63.0/24186.167.63.1 to 186.167.63.254186.167.63.255254
65186.167.64.0/24186.167.64.1 to 186.167.64.254186.167.64.255254
66186.167.65.0/24186.167.65.1 to 186.167.65.254186.167.65.255254
67186.167.66.0/24186.167.66.1 to 186.167.66.254186.167.66.255254
68186.167.67.0/24186.167.67.1 to 186.167.67.254186.167.67.255254
69186.167.68.0/24186.167.68.1 to 186.167.68.254186.167.68.255254
70186.167.69.0/24186.167.69.1 to 186.167.69.254186.167.69.255254
71186.167.70.0/24186.167.70.1 to 186.167.70.254186.167.70.255254
72186.167.71.0/24186.167.71.1 to 186.167.71.254186.167.71.255254
73186.167.72.0/24186.167.72.1 to 186.167.72.254186.167.72.255254
74186.167.73.0/24186.167.73.1 to 186.167.73.254186.167.73.255254
75186.167.74.0/24186.167.74.1 to 186.167.74.254186.167.74.255254
76186.167.75.0/24186.167.75.1 to 186.167.75.254186.167.75.255254
77186.167.76.0/24186.167.76.1 to 186.167.76.254186.167.76.255254
78186.167.77.0/24186.167.77.1 to 186.167.77.254186.167.77.255254
79186.167.78.0/24186.167.78.1 to 186.167.78.254186.167.78.255254
80186.167.79.0/24186.167.79.1 to 186.167.79.254186.167.79.255254
81186.167.80.0/24186.167.80.1 to 186.167.80.254186.167.80.255254
82186.167.81.0/24186.167.81.1 to 186.167.81.254186.167.81.255254
83186.167.82.0/24186.167.82.1 to 186.167.82.254186.167.82.255254
84186.167.83.0/24186.167.83.1 to 186.167.83.254186.167.83.255254
85186.167.84.0/24186.167.84.1 to 186.167.84.254186.167.84.255254
86186.167.85.0/24186.167.85.1 to 186.167.85.254186.167.85.255254
87186.167.86.0/24186.167.86.1 to 186.167.86.254186.167.86.255254
88186.167.87.0/24186.167.87.1 to 186.167.87.254186.167.87.255254
89186.167.88.0/24186.167.88.1 to 186.167.88.254186.167.88.255254
90186.167.89.0/24186.167.89.1 to 186.167.89.254186.167.89.255254
91186.167.90.0/24186.167.90.1 to 186.167.90.254186.167.90.255254
92186.167.91.0/24186.167.91.1 to 186.167.91.254186.167.91.255254
93186.167.92.0/24186.167.92.1 to 186.167.92.254186.167.92.255254
94186.167.93.0/24186.167.93.1 to 186.167.93.254186.167.93.255254
95186.167.94.0/24186.167.94.1 to 186.167.94.254186.167.94.255254
96186.167.95.0/24186.167.95.1 to 186.167.95.254186.167.95.255254
97186.167.96.0/24186.167.96.1 to 186.167.96.254186.167.96.255254
98186.167.97.0/24186.167.97.1 to 186.167.97.254186.167.97.255254
99186.167.98.0/24186.167.98.1 to 186.167.98.254186.167.98.255254
100186.167.99.0/24186.167.99.1 to 186.167.99.254186.167.99.255254
101186.167.100.0/24186.167.100.1 to 186.167.100.254186.167.100.255254
102186.167.101.0/24186.167.101.1 to 186.167.101.254186.167.101.255254
103186.167.102.0/24186.167.102.1 to 186.167.102.254186.167.102.255254
104186.167.103.0/24186.167.103.1 to 186.167.103.254186.167.103.255254
105186.167.104.0/24186.167.104.1 to 186.167.104.254186.167.104.255254
106186.167.105.0/24186.167.105.1 to 186.167.105.254186.167.105.255254
107186.167.106.0/24186.167.106.1 to 186.167.106.254186.167.106.255254
108186.167.107.0/24186.167.107.1 to 186.167.107.254186.167.107.255254
109186.167.108.0/24186.167.108.1 to 186.167.108.254186.167.108.255254
110186.167.109.0/24186.167.109.1 to 186.167.109.254186.167.109.255254
111186.167.110.0/24186.167.110.1 to 186.167.110.254186.167.110.255254
112186.167.111.0/24186.167.111.1 to 186.167.111.254186.167.111.255254
113186.167.112.0/24186.167.112.1 to 186.167.112.254186.167.112.255254
114186.167.113.0/24186.167.113.1 to 186.167.113.254186.167.113.255254
115186.167.114.0/24186.167.114.1 to 186.167.114.254186.167.114.255254
116186.167.115.0/24186.167.115.1 to 186.167.115.254186.167.115.255254
117186.167.116.0/24186.167.116.1 to 186.167.116.254186.167.116.255254
118186.167.117.0/24186.167.117.1 to 186.167.117.254186.167.117.255254
119186.167.118.0/24186.167.118.1 to 186.167.118.254186.167.118.255254
120186.167.119.0/24186.167.119.1 to 186.167.119.254186.167.119.255254
121186.167.120.0/24186.167.120.1 to 186.167.120.254186.167.120.255254
122186.167.121.0/24186.167.121.1 to 186.167.121.254186.167.121.255254
123186.167.122.0/24186.167.122.1 to 186.167.122.254186.167.122.255254
124186.167.123.0/24186.167.123.1 to 186.167.123.254186.167.123.255254
125186.167.124.0/24186.167.124.1 to 186.167.124.254186.167.124.255254
126186.167.125.0/24186.167.125.1 to 186.167.125.254186.167.125.255254
127186.167.126.0/24186.167.126.1 to 186.167.126.254186.167.126.255254
128186.167.127.0/24186.167.127.1 to 186.167.127.254186.167.127.255254
129186.167.128.0/24186.167.128.1 to 186.167.128.254186.167.128.255254
130186.167.129.0/24186.167.129.1 to 186.167.129.254186.167.129.255254
131186.167.130.0/24186.167.130.1 to 186.167.130.254186.167.130.255254
132186.167.131.0/24186.167.131.1 to 186.167.131.254186.167.131.255254
133186.167.132.0/24186.167.132.1 to 186.167.132.254186.167.132.255254
134186.167.133.0/24186.167.133.1 to 186.167.133.254186.167.133.255254
135186.167.134.0/24186.167.134.1 to 186.167.134.254186.167.134.255254
136186.167.135.0/24186.167.135.1 to 186.167.135.254186.167.135.255254
137186.167.136.0/24186.167.136.1 to 186.167.136.254186.167.136.255254
138186.167.137.0/24186.167.137.1 to 186.167.137.254186.167.137.255254
139186.167.138.0/24186.167.138.1 to 186.167.138.254186.167.138.255254
140186.167.139.0/24186.167.139.1 to 186.167.139.254186.167.139.255254
141186.167.140.0/24186.167.140.1 to 186.167.140.254186.167.140.255254
142186.167.141.0/24186.167.141.1 to 186.167.141.254186.167.141.255254
143186.167.142.0/24186.167.142.1 to 186.167.142.254186.167.142.255254
144186.167.143.0/24186.167.143.1 to 186.167.143.254186.167.143.255254
145186.167.144.0/24186.167.144.1 to 186.167.144.254186.167.144.255254
146186.167.145.0/24186.167.145.1 to 186.167.145.254186.167.145.255254
147186.167.146.0/24186.167.146.1 to 186.167.146.254186.167.146.255254
148186.167.147.0/24186.167.147.1 to 186.167.147.254186.167.147.255254
149186.167.148.0/24186.167.148.1 to 186.167.148.254186.167.148.255254
150186.167.149.0/24186.167.149.1 to 186.167.149.254186.167.149.255254
151186.167.150.0/24186.167.150.1 to 186.167.150.254186.167.150.255254
152186.167.151.0/24186.167.151.1 to 186.167.151.254186.167.151.255254
153186.167.152.0/24186.167.152.1 to 186.167.152.254186.167.152.255254
154186.167.153.0/24186.167.153.1 to 186.167.153.254186.167.153.255254
155186.167.154.0/24186.167.154.1 to 186.167.154.254186.167.154.255254
156186.167.155.0/24186.167.155.1 to 186.167.155.254186.167.155.255254
157186.167.156.0/24186.167.156.1 to 186.167.156.254186.167.156.255254
158186.167.157.0/24186.167.157.1 to 186.167.157.254186.167.157.255254
159186.167.158.0/24186.167.158.1 to 186.167.158.254186.167.158.255254
160186.167.159.0/24186.167.159.1 to 186.167.159.254186.167.159.255254
161186.167.160.0/24186.167.160.1 to 186.167.160.254186.167.160.255254
162186.167.161.0/24186.167.161.1 to 186.167.161.254186.167.161.255254
163186.167.162.0/24186.167.162.1 to 186.167.162.254186.167.162.255254
164186.167.163.0/24186.167.163.1 to 186.167.163.254186.167.163.255254
165186.167.164.0/24186.167.164.1 to 186.167.164.254186.167.164.255254
166186.167.165.0/24186.167.165.1 to 186.167.165.254186.167.165.255254
167186.167.166.0/24186.167.166.1 to 186.167.166.254186.167.166.255254
168186.167.167.0/24186.167.167.1 to 186.167.167.254186.167.167.255254
169186.167.168.0/24186.167.168.1 to 186.167.168.254186.167.168.255254
170186.167.169.0/24186.167.169.1 to 186.167.169.254186.167.169.255254
171186.167.170.0/24186.167.170.1 to 186.167.170.254186.167.170.255254
172186.167.171.0/24186.167.171.1 to 186.167.171.254186.167.171.255254
173186.167.172.0/24186.167.172.1 to 186.167.172.254186.167.172.255254
174186.167.173.0/24186.167.173.1 to 186.167.173.254186.167.173.255254
175186.167.174.0/24186.167.174.1 to 186.167.174.254186.167.174.255254
176186.167.175.0/24186.167.175.1 to 186.167.175.254186.167.175.255254
177186.167.176.0/24186.167.176.1 to 186.167.176.254186.167.176.255254
178186.167.177.0/24186.167.177.1 to 186.167.177.254186.167.177.255254
179186.167.178.0/24186.167.178.1 to 186.167.178.254186.167.178.255254
180186.167.179.0/24186.167.179.1 to 186.167.179.254186.167.179.255254
181186.167.180.0/24186.167.180.1 to 186.167.180.254186.167.180.255254
182186.167.181.0/24186.167.181.1 to 186.167.181.254186.167.181.255254
183186.167.182.0/24186.167.182.1 to 186.167.182.254186.167.182.255254
184186.167.183.0/24186.167.183.1 to 186.167.183.254186.167.183.255254
185186.167.184.0/24186.167.184.1 to 186.167.184.254186.167.184.255254
186186.167.185.0/24186.167.185.1 to 186.167.185.254186.167.185.255254
187186.167.186.0/24186.167.186.1 to 186.167.186.254186.167.186.255254
188186.167.187.0/24186.167.187.1 to 186.167.187.254186.167.187.255254
189186.167.188.0/24186.167.188.1 to 186.167.188.254186.167.188.255254
190186.167.189.0/24186.167.189.1 to 186.167.189.254186.167.189.255254
191186.167.190.0/24186.167.190.1 to 186.167.190.254186.167.190.255254
192186.167.191.0/24186.167.191.1 to 186.167.191.254186.167.191.255254
193186.167.192.0/24186.167.192.1 to 186.167.192.254186.167.192.255254
194186.167.193.0/24186.167.193.1 to 186.167.193.254186.167.193.255254
195186.167.194.0/24186.167.194.1 to 186.167.194.254186.167.194.255254
196186.167.195.0/24186.167.195.1 to 186.167.195.254186.167.195.255254
197186.167.196.0/24186.167.196.1 to 186.167.196.254186.167.196.255254
198186.167.197.0/24186.167.197.1 to 186.167.197.254186.167.197.255254
199186.167.198.0/24186.167.198.1 to 186.167.198.254186.167.198.255254
200186.167.199.0/24186.167.199.1 to 186.167.199.254186.167.199.255254
201186.167.200.0/24186.167.200.1 to 186.167.200.254186.167.200.255254
202186.167.201.0/24186.167.201.1 to 186.167.201.254186.167.201.255254
203186.167.202.0/24186.167.202.1 to 186.167.202.254186.167.202.255254
204186.167.203.0/24186.167.203.1 to 186.167.203.254186.167.203.255254
205186.167.204.0/24186.167.204.1 to 186.167.204.254186.167.204.255254
206186.167.205.0/24186.167.205.1 to 186.167.205.254186.167.205.255254
207186.167.206.0/24186.167.206.1 to 186.167.206.254186.167.206.255254
208186.167.207.0/24186.167.207.1 to 186.167.207.254186.167.207.255254
209186.167.208.0/24186.167.208.1 to 186.167.208.254186.167.208.255254
210186.167.209.0/24186.167.209.1 to 186.167.209.254186.167.209.255254
211186.167.210.0/24186.167.210.1 to 186.167.210.254186.167.210.255254
212186.167.211.0/24186.167.211.1 to 186.167.211.254186.167.211.255254
213186.167.212.0/24186.167.212.1 to 186.167.212.254186.167.212.255254
214186.167.213.0/24186.167.213.1 to 186.167.213.254186.167.213.255254
215186.167.214.0/24186.167.214.1 to 186.167.214.254186.167.214.255254
216186.167.215.0/24186.167.215.1 to 186.167.215.254186.167.215.255254
217186.167.216.0/24186.167.216.1 to 186.167.216.254186.167.216.255254
218186.167.217.0/24186.167.217.1 to 186.167.217.254186.167.217.255254
219186.167.218.0/24186.167.218.1 to 186.167.218.254186.167.218.255254
220186.167.219.0/24186.167.219.1 to 186.167.219.254186.167.219.255254
221186.167.220.0/24186.167.220.1 to 186.167.220.254186.167.220.255254
222186.167.221.0/24186.167.221.1 to 186.167.221.254186.167.221.255254
223186.167.222.0/24186.167.222.1 to 186.167.222.254186.167.222.255254
224186.167.223.0/24186.167.223.1 to 186.167.223.254186.167.223.255254
225186.167.224.0/24186.167.224.1 to 186.167.224.254186.167.224.255254
226186.167.225.0/24186.167.225.1 to 186.167.225.254186.167.225.255254
227186.167.226.0/24186.167.226.1 to 186.167.226.254186.167.226.255254
228186.167.227.0/24186.167.227.1 to 186.167.227.254186.167.227.255254
229186.167.228.0/24186.167.228.1 to 186.167.228.254186.167.228.255254
230186.167.229.0/24186.167.229.1 to 186.167.229.254186.167.229.255254
231186.167.230.0/24186.167.230.1 to 186.167.230.254186.167.230.255254
232186.167.231.0/24186.167.231.1 to 186.167.231.254186.167.231.255254
233186.167.232.0/24186.167.232.1 to 186.167.232.254186.167.232.255254
234186.167.233.0/24186.167.233.1 to 186.167.233.254186.167.233.255254
235186.167.234.0/24186.167.234.1 to 186.167.234.254186.167.234.255254
236186.167.235.0/24186.167.235.1 to 186.167.235.254186.167.235.255254
237186.167.236.0/24186.167.236.1 to 186.167.236.254186.167.236.255254
238186.167.237.0/24186.167.237.1 to 186.167.237.254186.167.237.255254
239186.167.238.0/24186.167.238.1 to 186.167.238.254186.167.238.255254
240186.167.239.0/24186.167.239.1 to 186.167.239.254186.167.239.255254
241186.167.240.0/24186.167.240.1 to 186.167.240.254186.167.240.255254
242186.167.241.0/24186.167.241.1 to 186.167.241.254186.167.241.255254
243186.167.242.0/24186.167.242.1 to 186.167.242.254186.167.242.255254
244186.167.243.0/24186.167.243.1 to 186.167.243.254186.167.243.255254
245186.167.244.0/24186.167.244.1 to 186.167.244.254186.167.244.255254
246186.167.245.0/24186.167.245.1 to 186.167.245.254186.167.245.255254
247186.167.246.0/24186.167.246.1 to 186.167.246.254186.167.246.255254
248186.167.247.0/24186.167.247.1 to 186.167.247.254186.167.247.255254
249186.167.248.0/24186.167.248.1 to 186.167.248.254186.167.248.255254
250186.167.249.0/24186.167.249.1 to 186.167.249.254186.167.249.255254
251186.167.250.0/24186.167.250.1 to 186.167.250.254186.167.250.255254
252186.167.251.0/24186.167.251.1 to 186.167.251.254186.167.251.255254
253186.167.252.0/24186.167.252.1 to 186.167.252.254186.167.252.255254
254186.167.253.0/24186.167.253.1 to 186.167.253.254186.167.253.255254
255186.167.254.0/24186.167.254.1 to 186.167.254.254186.167.254.255254
256186.167.255.0/24186.167.255.1 to 186.167.255.254186.167.255.255254

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.