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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.

Network201.167.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
201.167.0.0
Broadcast address
201.167.255.255
First usable
201.167.0.1
Last usable
201.167.255.254
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
C (default /24)
As numbers
Hex C9A70000 · Integer 3383164928 to 3383230463
Reverse DNS zone
167.201.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11001001.10100111..00000000.00000000201.167.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network11001001.10100111..00000000.00000000201.167.0.0
Broadcast11001001.10100111..11111111.11111111201.167.255.255
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)

201.167.0.0/16 makes 256 subnets of /24.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1201.167.0.0/24201.167.0.1 to 201.167.0.254201.167.0.255254
2201.167.1.0/24201.167.1.1 to 201.167.1.254201.167.1.255254
3201.167.2.0/24201.167.2.1 to 201.167.2.254201.167.2.255254
4201.167.3.0/24201.167.3.1 to 201.167.3.254201.167.3.255254
5201.167.4.0/24201.167.4.1 to 201.167.4.254201.167.4.255254
6201.167.5.0/24201.167.5.1 to 201.167.5.254201.167.5.255254
7201.167.6.0/24201.167.6.1 to 201.167.6.254201.167.6.255254
8201.167.7.0/24201.167.7.1 to 201.167.7.254201.167.7.255254
9201.167.8.0/24201.167.8.1 to 201.167.8.254201.167.8.255254
10201.167.9.0/24201.167.9.1 to 201.167.9.254201.167.9.255254
11201.167.10.0/24201.167.10.1 to 201.167.10.254201.167.10.255254
12201.167.11.0/24201.167.11.1 to 201.167.11.254201.167.11.255254
13201.167.12.0/24201.167.12.1 to 201.167.12.254201.167.12.255254
14201.167.13.0/24201.167.13.1 to 201.167.13.254201.167.13.255254
15201.167.14.0/24201.167.14.1 to 201.167.14.254201.167.14.255254
16201.167.15.0/24201.167.15.1 to 201.167.15.254201.167.15.255254
17201.167.16.0/24201.167.16.1 to 201.167.16.254201.167.16.255254
18201.167.17.0/24201.167.17.1 to 201.167.17.254201.167.17.255254
19201.167.18.0/24201.167.18.1 to 201.167.18.254201.167.18.255254
20201.167.19.0/24201.167.19.1 to 201.167.19.254201.167.19.255254
21201.167.20.0/24201.167.20.1 to 201.167.20.254201.167.20.255254
22201.167.21.0/24201.167.21.1 to 201.167.21.254201.167.21.255254
23201.167.22.0/24201.167.22.1 to 201.167.22.254201.167.22.255254
24201.167.23.0/24201.167.23.1 to 201.167.23.254201.167.23.255254
25201.167.24.0/24201.167.24.1 to 201.167.24.254201.167.24.255254
26201.167.25.0/24201.167.25.1 to 201.167.25.254201.167.25.255254
27201.167.26.0/24201.167.26.1 to 201.167.26.254201.167.26.255254
28201.167.27.0/24201.167.27.1 to 201.167.27.254201.167.27.255254
29201.167.28.0/24201.167.28.1 to 201.167.28.254201.167.28.255254
30201.167.29.0/24201.167.29.1 to 201.167.29.254201.167.29.255254
31201.167.30.0/24201.167.30.1 to 201.167.30.254201.167.30.255254
32201.167.31.0/24201.167.31.1 to 201.167.31.254201.167.31.255254
33201.167.32.0/24201.167.32.1 to 201.167.32.254201.167.32.255254
34201.167.33.0/24201.167.33.1 to 201.167.33.254201.167.33.255254
35201.167.34.0/24201.167.34.1 to 201.167.34.254201.167.34.255254
36201.167.35.0/24201.167.35.1 to 201.167.35.254201.167.35.255254
37201.167.36.0/24201.167.36.1 to 201.167.36.254201.167.36.255254
38201.167.37.0/24201.167.37.1 to 201.167.37.254201.167.37.255254
39201.167.38.0/24201.167.38.1 to 201.167.38.254201.167.38.255254
40201.167.39.0/24201.167.39.1 to 201.167.39.254201.167.39.255254
41201.167.40.0/24201.167.40.1 to 201.167.40.254201.167.40.255254
42201.167.41.0/24201.167.41.1 to 201.167.41.254201.167.41.255254
43201.167.42.0/24201.167.42.1 to 201.167.42.254201.167.42.255254
44201.167.43.0/24201.167.43.1 to 201.167.43.254201.167.43.255254
45201.167.44.0/24201.167.44.1 to 201.167.44.254201.167.44.255254
46201.167.45.0/24201.167.45.1 to 201.167.45.254201.167.45.255254
47201.167.46.0/24201.167.46.1 to 201.167.46.254201.167.46.255254
48201.167.47.0/24201.167.47.1 to 201.167.47.254201.167.47.255254
49201.167.48.0/24201.167.48.1 to 201.167.48.254201.167.48.255254
50201.167.49.0/24201.167.49.1 to 201.167.49.254201.167.49.255254
51201.167.50.0/24201.167.50.1 to 201.167.50.254201.167.50.255254
52201.167.51.0/24201.167.51.1 to 201.167.51.254201.167.51.255254
53201.167.52.0/24201.167.52.1 to 201.167.52.254201.167.52.255254
54201.167.53.0/24201.167.53.1 to 201.167.53.254201.167.53.255254
55201.167.54.0/24201.167.54.1 to 201.167.54.254201.167.54.255254
56201.167.55.0/24201.167.55.1 to 201.167.55.254201.167.55.255254
57201.167.56.0/24201.167.56.1 to 201.167.56.254201.167.56.255254
58201.167.57.0/24201.167.57.1 to 201.167.57.254201.167.57.255254
59201.167.58.0/24201.167.58.1 to 201.167.58.254201.167.58.255254
60201.167.59.0/24201.167.59.1 to 201.167.59.254201.167.59.255254
61201.167.60.0/24201.167.60.1 to 201.167.60.254201.167.60.255254
62201.167.61.0/24201.167.61.1 to 201.167.61.254201.167.61.255254
63201.167.62.0/24201.167.62.1 to 201.167.62.254201.167.62.255254
64201.167.63.0/24201.167.63.1 to 201.167.63.254201.167.63.255254
65201.167.64.0/24201.167.64.1 to 201.167.64.254201.167.64.255254
66201.167.65.0/24201.167.65.1 to 201.167.65.254201.167.65.255254
67201.167.66.0/24201.167.66.1 to 201.167.66.254201.167.66.255254
68201.167.67.0/24201.167.67.1 to 201.167.67.254201.167.67.255254
69201.167.68.0/24201.167.68.1 to 201.167.68.254201.167.68.255254
70201.167.69.0/24201.167.69.1 to 201.167.69.254201.167.69.255254
71201.167.70.0/24201.167.70.1 to 201.167.70.254201.167.70.255254
72201.167.71.0/24201.167.71.1 to 201.167.71.254201.167.71.255254
73201.167.72.0/24201.167.72.1 to 201.167.72.254201.167.72.255254
74201.167.73.0/24201.167.73.1 to 201.167.73.254201.167.73.255254
75201.167.74.0/24201.167.74.1 to 201.167.74.254201.167.74.255254
76201.167.75.0/24201.167.75.1 to 201.167.75.254201.167.75.255254
77201.167.76.0/24201.167.76.1 to 201.167.76.254201.167.76.255254
78201.167.77.0/24201.167.77.1 to 201.167.77.254201.167.77.255254
79201.167.78.0/24201.167.78.1 to 201.167.78.254201.167.78.255254
80201.167.79.0/24201.167.79.1 to 201.167.79.254201.167.79.255254
81201.167.80.0/24201.167.80.1 to 201.167.80.254201.167.80.255254
82201.167.81.0/24201.167.81.1 to 201.167.81.254201.167.81.255254
83201.167.82.0/24201.167.82.1 to 201.167.82.254201.167.82.255254
84201.167.83.0/24201.167.83.1 to 201.167.83.254201.167.83.255254
85201.167.84.0/24201.167.84.1 to 201.167.84.254201.167.84.255254
86201.167.85.0/24201.167.85.1 to 201.167.85.254201.167.85.255254
87201.167.86.0/24201.167.86.1 to 201.167.86.254201.167.86.255254
88201.167.87.0/24201.167.87.1 to 201.167.87.254201.167.87.255254
89201.167.88.0/24201.167.88.1 to 201.167.88.254201.167.88.255254
90201.167.89.0/24201.167.89.1 to 201.167.89.254201.167.89.255254
91201.167.90.0/24201.167.90.1 to 201.167.90.254201.167.90.255254
92201.167.91.0/24201.167.91.1 to 201.167.91.254201.167.91.255254
93201.167.92.0/24201.167.92.1 to 201.167.92.254201.167.92.255254
94201.167.93.0/24201.167.93.1 to 201.167.93.254201.167.93.255254
95201.167.94.0/24201.167.94.1 to 201.167.94.254201.167.94.255254
96201.167.95.0/24201.167.95.1 to 201.167.95.254201.167.95.255254
97201.167.96.0/24201.167.96.1 to 201.167.96.254201.167.96.255254
98201.167.97.0/24201.167.97.1 to 201.167.97.254201.167.97.255254
99201.167.98.0/24201.167.98.1 to 201.167.98.254201.167.98.255254
100201.167.99.0/24201.167.99.1 to 201.167.99.254201.167.99.255254
101201.167.100.0/24201.167.100.1 to 201.167.100.254201.167.100.255254
102201.167.101.0/24201.167.101.1 to 201.167.101.254201.167.101.255254
103201.167.102.0/24201.167.102.1 to 201.167.102.254201.167.102.255254
104201.167.103.0/24201.167.103.1 to 201.167.103.254201.167.103.255254
105201.167.104.0/24201.167.104.1 to 201.167.104.254201.167.104.255254
106201.167.105.0/24201.167.105.1 to 201.167.105.254201.167.105.255254
107201.167.106.0/24201.167.106.1 to 201.167.106.254201.167.106.255254
108201.167.107.0/24201.167.107.1 to 201.167.107.254201.167.107.255254
109201.167.108.0/24201.167.108.1 to 201.167.108.254201.167.108.255254
110201.167.109.0/24201.167.109.1 to 201.167.109.254201.167.109.255254
111201.167.110.0/24201.167.110.1 to 201.167.110.254201.167.110.255254
112201.167.111.0/24201.167.111.1 to 201.167.111.254201.167.111.255254
113201.167.112.0/24201.167.112.1 to 201.167.112.254201.167.112.255254
114201.167.113.0/24201.167.113.1 to 201.167.113.254201.167.113.255254
115201.167.114.0/24201.167.114.1 to 201.167.114.254201.167.114.255254
116201.167.115.0/24201.167.115.1 to 201.167.115.254201.167.115.255254
117201.167.116.0/24201.167.116.1 to 201.167.116.254201.167.116.255254
118201.167.117.0/24201.167.117.1 to 201.167.117.254201.167.117.255254
119201.167.118.0/24201.167.118.1 to 201.167.118.254201.167.118.255254
120201.167.119.0/24201.167.119.1 to 201.167.119.254201.167.119.255254
121201.167.120.0/24201.167.120.1 to 201.167.120.254201.167.120.255254
122201.167.121.0/24201.167.121.1 to 201.167.121.254201.167.121.255254
123201.167.122.0/24201.167.122.1 to 201.167.122.254201.167.122.255254
124201.167.123.0/24201.167.123.1 to 201.167.123.254201.167.123.255254
125201.167.124.0/24201.167.124.1 to 201.167.124.254201.167.124.255254
126201.167.125.0/24201.167.125.1 to 201.167.125.254201.167.125.255254
127201.167.126.0/24201.167.126.1 to 201.167.126.254201.167.126.255254
128201.167.127.0/24201.167.127.1 to 201.167.127.254201.167.127.255254
129201.167.128.0/24201.167.128.1 to 201.167.128.254201.167.128.255254
130201.167.129.0/24201.167.129.1 to 201.167.129.254201.167.129.255254
131201.167.130.0/24201.167.130.1 to 201.167.130.254201.167.130.255254
132201.167.131.0/24201.167.131.1 to 201.167.131.254201.167.131.255254
133201.167.132.0/24201.167.132.1 to 201.167.132.254201.167.132.255254
134201.167.133.0/24201.167.133.1 to 201.167.133.254201.167.133.255254
135201.167.134.0/24201.167.134.1 to 201.167.134.254201.167.134.255254
136201.167.135.0/24201.167.135.1 to 201.167.135.254201.167.135.255254
137201.167.136.0/24201.167.136.1 to 201.167.136.254201.167.136.255254
138201.167.137.0/24201.167.137.1 to 201.167.137.254201.167.137.255254
139201.167.138.0/24201.167.138.1 to 201.167.138.254201.167.138.255254
140201.167.139.0/24201.167.139.1 to 201.167.139.254201.167.139.255254
141201.167.140.0/24201.167.140.1 to 201.167.140.254201.167.140.255254
142201.167.141.0/24201.167.141.1 to 201.167.141.254201.167.141.255254
143201.167.142.0/24201.167.142.1 to 201.167.142.254201.167.142.255254
144201.167.143.0/24201.167.143.1 to 201.167.143.254201.167.143.255254
145201.167.144.0/24201.167.144.1 to 201.167.144.254201.167.144.255254
146201.167.145.0/24201.167.145.1 to 201.167.145.254201.167.145.255254
147201.167.146.0/24201.167.146.1 to 201.167.146.254201.167.146.255254
148201.167.147.0/24201.167.147.1 to 201.167.147.254201.167.147.255254
149201.167.148.0/24201.167.148.1 to 201.167.148.254201.167.148.255254
150201.167.149.0/24201.167.149.1 to 201.167.149.254201.167.149.255254
151201.167.150.0/24201.167.150.1 to 201.167.150.254201.167.150.255254
152201.167.151.0/24201.167.151.1 to 201.167.151.254201.167.151.255254
153201.167.152.0/24201.167.152.1 to 201.167.152.254201.167.152.255254
154201.167.153.0/24201.167.153.1 to 201.167.153.254201.167.153.255254
155201.167.154.0/24201.167.154.1 to 201.167.154.254201.167.154.255254
156201.167.155.0/24201.167.155.1 to 201.167.155.254201.167.155.255254
157201.167.156.0/24201.167.156.1 to 201.167.156.254201.167.156.255254
158201.167.157.0/24201.167.157.1 to 201.167.157.254201.167.157.255254
159201.167.158.0/24201.167.158.1 to 201.167.158.254201.167.158.255254
160201.167.159.0/24201.167.159.1 to 201.167.159.254201.167.159.255254
161201.167.160.0/24201.167.160.1 to 201.167.160.254201.167.160.255254
162201.167.161.0/24201.167.161.1 to 201.167.161.254201.167.161.255254
163201.167.162.0/24201.167.162.1 to 201.167.162.254201.167.162.255254
164201.167.163.0/24201.167.163.1 to 201.167.163.254201.167.163.255254
165201.167.164.0/24201.167.164.1 to 201.167.164.254201.167.164.255254
166201.167.165.0/24201.167.165.1 to 201.167.165.254201.167.165.255254
167201.167.166.0/24201.167.166.1 to 201.167.166.254201.167.166.255254
168201.167.167.0/24201.167.167.1 to 201.167.167.254201.167.167.255254
169201.167.168.0/24201.167.168.1 to 201.167.168.254201.167.168.255254
170201.167.169.0/24201.167.169.1 to 201.167.169.254201.167.169.255254
171201.167.170.0/24201.167.170.1 to 201.167.170.254201.167.170.255254
172201.167.171.0/24201.167.171.1 to 201.167.171.254201.167.171.255254
173201.167.172.0/24201.167.172.1 to 201.167.172.254201.167.172.255254
174201.167.173.0/24201.167.173.1 to 201.167.173.254201.167.173.255254
175201.167.174.0/24201.167.174.1 to 201.167.174.254201.167.174.255254
176201.167.175.0/24201.167.175.1 to 201.167.175.254201.167.175.255254
177201.167.176.0/24201.167.176.1 to 201.167.176.254201.167.176.255254
178201.167.177.0/24201.167.177.1 to 201.167.177.254201.167.177.255254
179201.167.178.0/24201.167.178.1 to 201.167.178.254201.167.178.255254
180201.167.179.0/24201.167.179.1 to 201.167.179.254201.167.179.255254
181201.167.180.0/24201.167.180.1 to 201.167.180.254201.167.180.255254
182201.167.181.0/24201.167.181.1 to 201.167.181.254201.167.181.255254
183201.167.182.0/24201.167.182.1 to 201.167.182.254201.167.182.255254
184201.167.183.0/24201.167.183.1 to 201.167.183.254201.167.183.255254
185201.167.184.0/24201.167.184.1 to 201.167.184.254201.167.184.255254
186201.167.185.0/24201.167.185.1 to 201.167.185.254201.167.185.255254
187201.167.186.0/24201.167.186.1 to 201.167.186.254201.167.186.255254
188201.167.187.0/24201.167.187.1 to 201.167.187.254201.167.187.255254
189201.167.188.0/24201.167.188.1 to 201.167.188.254201.167.188.255254
190201.167.189.0/24201.167.189.1 to 201.167.189.254201.167.189.255254
191201.167.190.0/24201.167.190.1 to 201.167.190.254201.167.190.255254
192201.167.191.0/24201.167.191.1 to 201.167.191.254201.167.191.255254
193201.167.192.0/24201.167.192.1 to 201.167.192.254201.167.192.255254
194201.167.193.0/24201.167.193.1 to 201.167.193.254201.167.193.255254
195201.167.194.0/24201.167.194.1 to 201.167.194.254201.167.194.255254
196201.167.195.0/24201.167.195.1 to 201.167.195.254201.167.195.255254
197201.167.196.0/24201.167.196.1 to 201.167.196.254201.167.196.255254
198201.167.197.0/24201.167.197.1 to 201.167.197.254201.167.197.255254
199201.167.198.0/24201.167.198.1 to 201.167.198.254201.167.198.255254
200201.167.199.0/24201.167.199.1 to 201.167.199.254201.167.199.255254
201201.167.200.0/24201.167.200.1 to 201.167.200.254201.167.200.255254
202201.167.201.0/24201.167.201.1 to 201.167.201.254201.167.201.255254
203201.167.202.0/24201.167.202.1 to 201.167.202.254201.167.202.255254
204201.167.203.0/24201.167.203.1 to 201.167.203.254201.167.203.255254
205201.167.204.0/24201.167.204.1 to 201.167.204.254201.167.204.255254
206201.167.205.0/24201.167.205.1 to 201.167.205.254201.167.205.255254
207201.167.206.0/24201.167.206.1 to 201.167.206.254201.167.206.255254
208201.167.207.0/24201.167.207.1 to 201.167.207.254201.167.207.255254
209201.167.208.0/24201.167.208.1 to 201.167.208.254201.167.208.255254
210201.167.209.0/24201.167.209.1 to 201.167.209.254201.167.209.255254
211201.167.210.0/24201.167.210.1 to 201.167.210.254201.167.210.255254
212201.167.211.0/24201.167.211.1 to 201.167.211.254201.167.211.255254
213201.167.212.0/24201.167.212.1 to 201.167.212.254201.167.212.255254
214201.167.213.0/24201.167.213.1 to 201.167.213.254201.167.213.255254
215201.167.214.0/24201.167.214.1 to 201.167.214.254201.167.214.255254
216201.167.215.0/24201.167.215.1 to 201.167.215.254201.167.215.255254
217201.167.216.0/24201.167.216.1 to 201.167.216.254201.167.216.255254
218201.167.217.0/24201.167.217.1 to 201.167.217.254201.167.217.255254
219201.167.218.0/24201.167.218.1 to 201.167.218.254201.167.218.255254
220201.167.219.0/24201.167.219.1 to 201.167.219.254201.167.219.255254
221201.167.220.0/24201.167.220.1 to 201.167.220.254201.167.220.255254
222201.167.221.0/24201.167.221.1 to 201.167.221.254201.167.221.255254
223201.167.222.0/24201.167.222.1 to 201.167.222.254201.167.222.255254
224201.167.223.0/24201.167.223.1 to 201.167.223.254201.167.223.255254
225201.167.224.0/24201.167.224.1 to 201.167.224.254201.167.224.255254
226201.167.225.0/24201.167.225.1 to 201.167.225.254201.167.225.255254
227201.167.226.0/24201.167.226.1 to 201.167.226.254201.167.226.255254
228201.167.227.0/24201.167.227.1 to 201.167.227.254201.167.227.255254
229201.167.228.0/24201.167.228.1 to 201.167.228.254201.167.228.255254
230201.167.229.0/24201.167.229.1 to 201.167.229.254201.167.229.255254
231201.167.230.0/24201.167.230.1 to 201.167.230.254201.167.230.255254
232201.167.231.0/24201.167.231.1 to 201.167.231.254201.167.231.255254
233201.167.232.0/24201.167.232.1 to 201.167.232.254201.167.232.255254
234201.167.233.0/24201.167.233.1 to 201.167.233.254201.167.233.255254
235201.167.234.0/24201.167.234.1 to 201.167.234.254201.167.234.255254
236201.167.235.0/24201.167.235.1 to 201.167.235.254201.167.235.255254
237201.167.236.0/24201.167.236.1 to 201.167.236.254201.167.236.255254
238201.167.237.0/24201.167.237.1 to 201.167.237.254201.167.237.255254
239201.167.238.0/24201.167.238.1 to 201.167.238.254201.167.238.255254
240201.167.239.0/24201.167.239.1 to 201.167.239.254201.167.239.255254
241201.167.240.0/24201.167.240.1 to 201.167.240.254201.167.240.255254
242201.167.241.0/24201.167.241.1 to 201.167.241.254201.167.241.255254
243201.167.242.0/24201.167.242.1 to 201.167.242.254201.167.242.255254
244201.167.243.0/24201.167.243.1 to 201.167.243.254201.167.243.255254
245201.167.244.0/24201.167.244.1 to 201.167.244.254201.167.244.255254
246201.167.245.0/24201.167.245.1 to 201.167.245.254201.167.245.255254
247201.167.246.0/24201.167.246.1 to 201.167.246.254201.167.246.255254
248201.167.247.0/24201.167.247.1 to 201.167.247.254201.167.247.255254
249201.167.248.0/24201.167.248.1 to 201.167.248.254201.167.248.255254
250201.167.249.0/24201.167.249.1 to 201.167.249.254201.167.249.255254
251201.167.250.0/24201.167.250.1 to 201.167.250.254201.167.250.255254
252201.167.251.0/24201.167.251.1 to 201.167.251.254201.167.251.255254
253201.167.252.0/24201.167.252.1 to 201.167.252.254201.167.252.255254
254201.167.253.0/24201.167.253.1 to 201.167.253.254201.167.253.255254
255201.167.254.0/24201.167.254.1 to 201.167.254.254201.167.254.255254
256201.167.255.0/24201.167.255.1 to 201.167.255.254201.167.255.255254

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.