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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.

Network176.71.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
176.71.0.0
Broadcast address
176.71.255.255
First usable
176.71.0.1
Last usable
176.71.255.254
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 B0470000 · Integer 2957443072 to 2957508607
Reverse DNS zone
71.176.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10110000.01000111..00000000.00000000176.71.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network10110000.01000111..00000000.00000000176.71.0.0
Broadcast10110000.01000111..11111111.11111111176.71.255.255
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)

176.71.0.0/16 makes 256 subnets of /24.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1176.71.0.0/24176.71.0.1 to 176.71.0.254176.71.0.255254
2176.71.1.0/24176.71.1.1 to 176.71.1.254176.71.1.255254
3176.71.2.0/24176.71.2.1 to 176.71.2.254176.71.2.255254
4176.71.3.0/24176.71.3.1 to 176.71.3.254176.71.3.255254
5176.71.4.0/24176.71.4.1 to 176.71.4.254176.71.4.255254
6176.71.5.0/24176.71.5.1 to 176.71.5.254176.71.5.255254
7176.71.6.0/24176.71.6.1 to 176.71.6.254176.71.6.255254
8176.71.7.0/24176.71.7.1 to 176.71.7.254176.71.7.255254
9176.71.8.0/24176.71.8.1 to 176.71.8.254176.71.8.255254
10176.71.9.0/24176.71.9.1 to 176.71.9.254176.71.9.255254
11176.71.10.0/24176.71.10.1 to 176.71.10.254176.71.10.255254
12176.71.11.0/24176.71.11.1 to 176.71.11.254176.71.11.255254
13176.71.12.0/24176.71.12.1 to 176.71.12.254176.71.12.255254
14176.71.13.0/24176.71.13.1 to 176.71.13.254176.71.13.255254
15176.71.14.0/24176.71.14.1 to 176.71.14.254176.71.14.255254
16176.71.15.0/24176.71.15.1 to 176.71.15.254176.71.15.255254
17176.71.16.0/24176.71.16.1 to 176.71.16.254176.71.16.255254
18176.71.17.0/24176.71.17.1 to 176.71.17.254176.71.17.255254
19176.71.18.0/24176.71.18.1 to 176.71.18.254176.71.18.255254
20176.71.19.0/24176.71.19.1 to 176.71.19.254176.71.19.255254
21176.71.20.0/24176.71.20.1 to 176.71.20.254176.71.20.255254
22176.71.21.0/24176.71.21.1 to 176.71.21.254176.71.21.255254
23176.71.22.0/24176.71.22.1 to 176.71.22.254176.71.22.255254
24176.71.23.0/24176.71.23.1 to 176.71.23.254176.71.23.255254
25176.71.24.0/24176.71.24.1 to 176.71.24.254176.71.24.255254
26176.71.25.0/24176.71.25.1 to 176.71.25.254176.71.25.255254
27176.71.26.0/24176.71.26.1 to 176.71.26.254176.71.26.255254
28176.71.27.0/24176.71.27.1 to 176.71.27.254176.71.27.255254
29176.71.28.0/24176.71.28.1 to 176.71.28.254176.71.28.255254
30176.71.29.0/24176.71.29.1 to 176.71.29.254176.71.29.255254
31176.71.30.0/24176.71.30.1 to 176.71.30.254176.71.30.255254
32176.71.31.0/24176.71.31.1 to 176.71.31.254176.71.31.255254
33176.71.32.0/24176.71.32.1 to 176.71.32.254176.71.32.255254
34176.71.33.0/24176.71.33.1 to 176.71.33.254176.71.33.255254
35176.71.34.0/24176.71.34.1 to 176.71.34.254176.71.34.255254
36176.71.35.0/24176.71.35.1 to 176.71.35.254176.71.35.255254
37176.71.36.0/24176.71.36.1 to 176.71.36.254176.71.36.255254
38176.71.37.0/24176.71.37.1 to 176.71.37.254176.71.37.255254
39176.71.38.0/24176.71.38.1 to 176.71.38.254176.71.38.255254
40176.71.39.0/24176.71.39.1 to 176.71.39.254176.71.39.255254
41176.71.40.0/24176.71.40.1 to 176.71.40.254176.71.40.255254
42176.71.41.0/24176.71.41.1 to 176.71.41.254176.71.41.255254
43176.71.42.0/24176.71.42.1 to 176.71.42.254176.71.42.255254
44176.71.43.0/24176.71.43.1 to 176.71.43.254176.71.43.255254
45176.71.44.0/24176.71.44.1 to 176.71.44.254176.71.44.255254
46176.71.45.0/24176.71.45.1 to 176.71.45.254176.71.45.255254
47176.71.46.0/24176.71.46.1 to 176.71.46.254176.71.46.255254
48176.71.47.0/24176.71.47.1 to 176.71.47.254176.71.47.255254
49176.71.48.0/24176.71.48.1 to 176.71.48.254176.71.48.255254
50176.71.49.0/24176.71.49.1 to 176.71.49.254176.71.49.255254
51176.71.50.0/24176.71.50.1 to 176.71.50.254176.71.50.255254
52176.71.51.0/24176.71.51.1 to 176.71.51.254176.71.51.255254
53176.71.52.0/24176.71.52.1 to 176.71.52.254176.71.52.255254
54176.71.53.0/24176.71.53.1 to 176.71.53.254176.71.53.255254
55176.71.54.0/24176.71.54.1 to 176.71.54.254176.71.54.255254
56176.71.55.0/24176.71.55.1 to 176.71.55.254176.71.55.255254
57176.71.56.0/24176.71.56.1 to 176.71.56.254176.71.56.255254
58176.71.57.0/24176.71.57.1 to 176.71.57.254176.71.57.255254
59176.71.58.0/24176.71.58.1 to 176.71.58.254176.71.58.255254
60176.71.59.0/24176.71.59.1 to 176.71.59.254176.71.59.255254
61176.71.60.0/24176.71.60.1 to 176.71.60.254176.71.60.255254
62176.71.61.0/24176.71.61.1 to 176.71.61.254176.71.61.255254
63176.71.62.0/24176.71.62.1 to 176.71.62.254176.71.62.255254
64176.71.63.0/24176.71.63.1 to 176.71.63.254176.71.63.255254
65176.71.64.0/24176.71.64.1 to 176.71.64.254176.71.64.255254
66176.71.65.0/24176.71.65.1 to 176.71.65.254176.71.65.255254
67176.71.66.0/24176.71.66.1 to 176.71.66.254176.71.66.255254
68176.71.67.0/24176.71.67.1 to 176.71.67.254176.71.67.255254
69176.71.68.0/24176.71.68.1 to 176.71.68.254176.71.68.255254
70176.71.69.0/24176.71.69.1 to 176.71.69.254176.71.69.255254
71176.71.70.0/24176.71.70.1 to 176.71.70.254176.71.70.255254
72176.71.71.0/24176.71.71.1 to 176.71.71.254176.71.71.255254
73176.71.72.0/24176.71.72.1 to 176.71.72.254176.71.72.255254
74176.71.73.0/24176.71.73.1 to 176.71.73.254176.71.73.255254
75176.71.74.0/24176.71.74.1 to 176.71.74.254176.71.74.255254
76176.71.75.0/24176.71.75.1 to 176.71.75.254176.71.75.255254
77176.71.76.0/24176.71.76.1 to 176.71.76.254176.71.76.255254
78176.71.77.0/24176.71.77.1 to 176.71.77.254176.71.77.255254
79176.71.78.0/24176.71.78.1 to 176.71.78.254176.71.78.255254
80176.71.79.0/24176.71.79.1 to 176.71.79.254176.71.79.255254
81176.71.80.0/24176.71.80.1 to 176.71.80.254176.71.80.255254
82176.71.81.0/24176.71.81.1 to 176.71.81.254176.71.81.255254
83176.71.82.0/24176.71.82.1 to 176.71.82.254176.71.82.255254
84176.71.83.0/24176.71.83.1 to 176.71.83.254176.71.83.255254
85176.71.84.0/24176.71.84.1 to 176.71.84.254176.71.84.255254
86176.71.85.0/24176.71.85.1 to 176.71.85.254176.71.85.255254
87176.71.86.0/24176.71.86.1 to 176.71.86.254176.71.86.255254
88176.71.87.0/24176.71.87.1 to 176.71.87.254176.71.87.255254
89176.71.88.0/24176.71.88.1 to 176.71.88.254176.71.88.255254
90176.71.89.0/24176.71.89.1 to 176.71.89.254176.71.89.255254
91176.71.90.0/24176.71.90.1 to 176.71.90.254176.71.90.255254
92176.71.91.0/24176.71.91.1 to 176.71.91.254176.71.91.255254
93176.71.92.0/24176.71.92.1 to 176.71.92.254176.71.92.255254
94176.71.93.0/24176.71.93.1 to 176.71.93.254176.71.93.255254
95176.71.94.0/24176.71.94.1 to 176.71.94.254176.71.94.255254
96176.71.95.0/24176.71.95.1 to 176.71.95.254176.71.95.255254
97176.71.96.0/24176.71.96.1 to 176.71.96.254176.71.96.255254
98176.71.97.0/24176.71.97.1 to 176.71.97.254176.71.97.255254
99176.71.98.0/24176.71.98.1 to 176.71.98.254176.71.98.255254
100176.71.99.0/24176.71.99.1 to 176.71.99.254176.71.99.255254
101176.71.100.0/24176.71.100.1 to 176.71.100.254176.71.100.255254
102176.71.101.0/24176.71.101.1 to 176.71.101.254176.71.101.255254
103176.71.102.0/24176.71.102.1 to 176.71.102.254176.71.102.255254
104176.71.103.0/24176.71.103.1 to 176.71.103.254176.71.103.255254
105176.71.104.0/24176.71.104.1 to 176.71.104.254176.71.104.255254
106176.71.105.0/24176.71.105.1 to 176.71.105.254176.71.105.255254
107176.71.106.0/24176.71.106.1 to 176.71.106.254176.71.106.255254
108176.71.107.0/24176.71.107.1 to 176.71.107.254176.71.107.255254
109176.71.108.0/24176.71.108.1 to 176.71.108.254176.71.108.255254
110176.71.109.0/24176.71.109.1 to 176.71.109.254176.71.109.255254
111176.71.110.0/24176.71.110.1 to 176.71.110.254176.71.110.255254
112176.71.111.0/24176.71.111.1 to 176.71.111.254176.71.111.255254
113176.71.112.0/24176.71.112.1 to 176.71.112.254176.71.112.255254
114176.71.113.0/24176.71.113.1 to 176.71.113.254176.71.113.255254
115176.71.114.0/24176.71.114.1 to 176.71.114.254176.71.114.255254
116176.71.115.0/24176.71.115.1 to 176.71.115.254176.71.115.255254
117176.71.116.0/24176.71.116.1 to 176.71.116.254176.71.116.255254
118176.71.117.0/24176.71.117.1 to 176.71.117.254176.71.117.255254
119176.71.118.0/24176.71.118.1 to 176.71.118.254176.71.118.255254
120176.71.119.0/24176.71.119.1 to 176.71.119.254176.71.119.255254
121176.71.120.0/24176.71.120.1 to 176.71.120.254176.71.120.255254
122176.71.121.0/24176.71.121.1 to 176.71.121.254176.71.121.255254
123176.71.122.0/24176.71.122.1 to 176.71.122.254176.71.122.255254
124176.71.123.0/24176.71.123.1 to 176.71.123.254176.71.123.255254
125176.71.124.0/24176.71.124.1 to 176.71.124.254176.71.124.255254
126176.71.125.0/24176.71.125.1 to 176.71.125.254176.71.125.255254
127176.71.126.0/24176.71.126.1 to 176.71.126.254176.71.126.255254
128176.71.127.0/24176.71.127.1 to 176.71.127.254176.71.127.255254
129176.71.128.0/24176.71.128.1 to 176.71.128.254176.71.128.255254
130176.71.129.0/24176.71.129.1 to 176.71.129.254176.71.129.255254
131176.71.130.0/24176.71.130.1 to 176.71.130.254176.71.130.255254
132176.71.131.0/24176.71.131.1 to 176.71.131.254176.71.131.255254
133176.71.132.0/24176.71.132.1 to 176.71.132.254176.71.132.255254
134176.71.133.0/24176.71.133.1 to 176.71.133.254176.71.133.255254
135176.71.134.0/24176.71.134.1 to 176.71.134.254176.71.134.255254
136176.71.135.0/24176.71.135.1 to 176.71.135.254176.71.135.255254
137176.71.136.0/24176.71.136.1 to 176.71.136.254176.71.136.255254
138176.71.137.0/24176.71.137.1 to 176.71.137.254176.71.137.255254
139176.71.138.0/24176.71.138.1 to 176.71.138.254176.71.138.255254
140176.71.139.0/24176.71.139.1 to 176.71.139.254176.71.139.255254
141176.71.140.0/24176.71.140.1 to 176.71.140.254176.71.140.255254
142176.71.141.0/24176.71.141.1 to 176.71.141.254176.71.141.255254
143176.71.142.0/24176.71.142.1 to 176.71.142.254176.71.142.255254
144176.71.143.0/24176.71.143.1 to 176.71.143.254176.71.143.255254
145176.71.144.0/24176.71.144.1 to 176.71.144.254176.71.144.255254
146176.71.145.0/24176.71.145.1 to 176.71.145.254176.71.145.255254
147176.71.146.0/24176.71.146.1 to 176.71.146.254176.71.146.255254
148176.71.147.0/24176.71.147.1 to 176.71.147.254176.71.147.255254
149176.71.148.0/24176.71.148.1 to 176.71.148.254176.71.148.255254
150176.71.149.0/24176.71.149.1 to 176.71.149.254176.71.149.255254
151176.71.150.0/24176.71.150.1 to 176.71.150.254176.71.150.255254
152176.71.151.0/24176.71.151.1 to 176.71.151.254176.71.151.255254
153176.71.152.0/24176.71.152.1 to 176.71.152.254176.71.152.255254
154176.71.153.0/24176.71.153.1 to 176.71.153.254176.71.153.255254
155176.71.154.0/24176.71.154.1 to 176.71.154.254176.71.154.255254
156176.71.155.0/24176.71.155.1 to 176.71.155.254176.71.155.255254
157176.71.156.0/24176.71.156.1 to 176.71.156.254176.71.156.255254
158176.71.157.0/24176.71.157.1 to 176.71.157.254176.71.157.255254
159176.71.158.0/24176.71.158.1 to 176.71.158.254176.71.158.255254
160176.71.159.0/24176.71.159.1 to 176.71.159.254176.71.159.255254
161176.71.160.0/24176.71.160.1 to 176.71.160.254176.71.160.255254
162176.71.161.0/24176.71.161.1 to 176.71.161.254176.71.161.255254
163176.71.162.0/24176.71.162.1 to 176.71.162.254176.71.162.255254
164176.71.163.0/24176.71.163.1 to 176.71.163.254176.71.163.255254
165176.71.164.0/24176.71.164.1 to 176.71.164.254176.71.164.255254
166176.71.165.0/24176.71.165.1 to 176.71.165.254176.71.165.255254
167176.71.166.0/24176.71.166.1 to 176.71.166.254176.71.166.255254
168176.71.167.0/24176.71.167.1 to 176.71.167.254176.71.167.255254
169176.71.168.0/24176.71.168.1 to 176.71.168.254176.71.168.255254
170176.71.169.0/24176.71.169.1 to 176.71.169.254176.71.169.255254
171176.71.170.0/24176.71.170.1 to 176.71.170.254176.71.170.255254
172176.71.171.0/24176.71.171.1 to 176.71.171.254176.71.171.255254
173176.71.172.0/24176.71.172.1 to 176.71.172.254176.71.172.255254
174176.71.173.0/24176.71.173.1 to 176.71.173.254176.71.173.255254
175176.71.174.0/24176.71.174.1 to 176.71.174.254176.71.174.255254
176176.71.175.0/24176.71.175.1 to 176.71.175.254176.71.175.255254
177176.71.176.0/24176.71.176.1 to 176.71.176.254176.71.176.255254
178176.71.177.0/24176.71.177.1 to 176.71.177.254176.71.177.255254
179176.71.178.0/24176.71.178.1 to 176.71.178.254176.71.178.255254
180176.71.179.0/24176.71.179.1 to 176.71.179.254176.71.179.255254
181176.71.180.0/24176.71.180.1 to 176.71.180.254176.71.180.255254
182176.71.181.0/24176.71.181.1 to 176.71.181.254176.71.181.255254
183176.71.182.0/24176.71.182.1 to 176.71.182.254176.71.182.255254
184176.71.183.0/24176.71.183.1 to 176.71.183.254176.71.183.255254
185176.71.184.0/24176.71.184.1 to 176.71.184.254176.71.184.255254
186176.71.185.0/24176.71.185.1 to 176.71.185.254176.71.185.255254
187176.71.186.0/24176.71.186.1 to 176.71.186.254176.71.186.255254
188176.71.187.0/24176.71.187.1 to 176.71.187.254176.71.187.255254
189176.71.188.0/24176.71.188.1 to 176.71.188.254176.71.188.255254
190176.71.189.0/24176.71.189.1 to 176.71.189.254176.71.189.255254
191176.71.190.0/24176.71.190.1 to 176.71.190.254176.71.190.255254
192176.71.191.0/24176.71.191.1 to 176.71.191.254176.71.191.255254
193176.71.192.0/24176.71.192.1 to 176.71.192.254176.71.192.255254
194176.71.193.0/24176.71.193.1 to 176.71.193.254176.71.193.255254
195176.71.194.0/24176.71.194.1 to 176.71.194.254176.71.194.255254
196176.71.195.0/24176.71.195.1 to 176.71.195.254176.71.195.255254
197176.71.196.0/24176.71.196.1 to 176.71.196.254176.71.196.255254
198176.71.197.0/24176.71.197.1 to 176.71.197.254176.71.197.255254
199176.71.198.0/24176.71.198.1 to 176.71.198.254176.71.198.255254
200176.71.199.0/24176.71.199.1 to 176.71.199.254176.71.199.255254
201176.71.200.0/24176.71.200.1 to 176.71.200.254176.71.200.255254
202176.71.201.0/24176.71.201.1 to 176.71.201.254176.71.201.255254
203176.71.202.0/24176.71.202.1 to 176.71.202.254176.71.202.255254
204176.71.203.0/24176.71.203.1 to 176.71.203.254176.71.203.255254
205176.71.204.0/24176.71.204.1 to 176.71.204.254176.71.204.255254
206176.71.205.0/24176.71.205.1 to 176.71.205.254176.71.205.255254
207176.71.206.0/24176.71.206.1 to 176.71.206.254176.71.206.255254
208176.71.207.0/24176.71.207.1 to 176.71.207.254176.71.207.255254
209176.71.208.0/24176.71.208.1 to 176.71.208.254176.71.208.255254
210176.71.209.0/24176.71.209.1 to 176.71.209.254176.71.209.255254
211176.71.210.0/24176.71.210.1 to 176.71.210.254176.71.210.255254
212176.71.211.0/24176.71.211.1 to 176.71.211.254176.71.211.255254
213176.71.212.0/24176.71.212.1 to 176.71.212.254176.71.212.255254
214176.71.213.0/24176.71.213.1 to 176.71.213.254176.71.213.255254
215176.71.214.0/24176.71.214.1 to 176.71.214.254176.71.214.255254
216176.71.215.0/24176.71.215.1 to 176.71.215.254176.71.215.255254
217176.71.216.0/24176.71.216.1 to 176.71.216.254176.71.216.255254
218176.71.217.0/24176.71.217.1 to 176.71.217.254176.71.217.255254
219176.71.218.0/24176.71.218.1 to 176.71.218.254176.71.218.255254
220176.71.219.0/24176.71.219.1 to 176.71.219.254176.71.219.255254
221176.71.220.0/24176.71.220.1 to 176.71.220.254176.71.220.255254
222176.71.221.0/24176.71.221.1 to 176.71.221.254176.71.221.255254
223176.71.222.0/24176.71.222.1 to 176.71.222.254176.71.222.255254
224176.71.223.0/24176.71.223.1 to 176.71.223.254176.71.223.255254
225176.71.224.0/24176.71.224.1 to 176.71.224.254176.71.224.255254
226176.71.225.0/24176.71.225.1 to 176.71.225.254176.71.225.255254
227176.71.226.0/24176.71.226.1 to 176.71.226.254176.71.226.255254
228176.71.227.0/24176.71.227.1 to 176.71.227.254176.71.227.255254
229176.71.228.0/24176.71.228.1 to 176.71.228.254176.71.228.255254
230176.71.229.0/24176.71.229.1 to 176.71.229.254176.71.229.255254
231176.71.230.0/24176.71.230.1 to 176.71.230.254176.71.230.255254
232176.71.231.0/24176.71.231.1 to 176.71.231.254176.71.231.255254
233176.71.232.0/24176.71.232.1 to 176.71.232.254176.71.232.255254
234176.71.233.0/24176.71.233.1 to 176.71.233.254176.71.233.255254
235176.71.234.0/24176.71.234.1 to 176.71.234.254176.71.234.255254
236176.71.235.0/24176.71.235.1 to 176.71.235.254176.71.235.255254
237176.71.236.0/24176.71.236.1 to 176.71.236.254176.71.236.255254
238176.71.237.0/24176.71.237.1 to 176.71.237.254176.71.237.255254
239176.71.238.0/24176.71.238.1 to 176.71.238.254176.71.238.255254
240176.71.239.0/24176.71.239.1 to 176.71.239.254176.71.239.255254
241176.71.240.0/24176.71.240.1 to 176.71.240.254176.71.240.255254
242176.71.241.0/24176.71.241.1 to 176.71.241.254176.71.241.255254
243176.71.242.0/24176.71.242.1 to 176.71.242.254176.71.242.255254
244176.71.243.0/24176.71.243.1 to 176.71.243.254176.71.243.255254
245176.71.244.0/24176.71.244.1 to 176.71.244.254176.71.244.255254
246176.71.245.0/24176.71.245.1 to 176.71.245.254176.71.245.255254
247176.71.246.0/24176.71.246.1 to 176.71.246.254176.71.246.255254
248176.71.247.0/24176.71.247.1 to 176.71.247.254176.71.247.255254
249176.71.248.0/24176.71.248.1 to 176.71.248.254176.71.248.255254
250176.71.249.0/24176.71.249.1 to 176.71.249.254176.71.249.255254
251176.71.250.0/24176.71.250.1 to 176.71.250.254176.71.250.255254
252176.71.251.0/24176.71.251.1 to 176.71.251.254176.71.251.255254
253176.71.252.0/24176.71.252.1 to 176.71.252.254176.71.252.255254
254176.71.253.0/24176.71.253.1 to 176.71.253.254176.71.253.255254
255176.71.254.0/24176.71.254.1 to 176.71.254.254176.71.254.255254
256176.71.255.0/24176.71.255.1 to 176.71.255.254176.71.255.255254

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.