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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.

Network210.41.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
210.41.0.0
Broadcast address
210.41.255.255
First usable
210.41.0.1
Last usable
210.41.255.254
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 D2290000 · Integer 3525902336 to 3525967871
Reverse DNS zone
41.210.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11010010.00101001..00000000.00000000210.41.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network11010010.00101001..00000000.00000000210.41.0.0
Broadcast11010010.00101001..11111111.11111111210.41.255.255
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)

210.41.0.0/16 makes 256 subnets of /24.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1210.41.0.0/24210.41.0.1 to 210.41.0.254210.41.0.255254
2210.41.1.0/24210.41.1.1 to 210.41.1.254210.41.1.255254
3210.41.2.0/24210.41.2.1 to 210.41.2.254210.41.2.255254
4210.41.3.0/24210.41.3.1 to 210.41.3.254210.41.3.255254
5210.41.4.0/24210.41.4.1 to 210.41.4.254210.41.4.255254
6210.41.5.0/24210.41.5.1 to 210.41.5.254210.41.5.255254
7210.41.6.0/24210.41.6.1 to 210.41.6.254210.41.6.255254
8210.41.7.0/24210.41.7.1 to 210.41.7.254210.41.7.255254
9210.41.8.0/24210.41.8.1 to 210.41.8.254210.41.8.255254
10210.41.9.0/24210.41.9.1 to 210.41.9.254210.41.9.255254
11210.41.10.0/24210.41.10.1 to 210.41.10.254210.41.10.255254
12210.41.11.0/24210.41.11.1 to 210.41.11.254210.41.11.255254
13210.41.12.0/24210.41.12.1 to 210.41.12.254210.41.12.255254
14210.41.13.0/24210.41.13.1 to 210.41.13.254210.41.13.255254
15210.41.14.0/24210.41.14.1 to 210.41.14.254210.41.14.255254
16210.41.15.0/24210.41.15.1 to 210.41.15.254210.41.15.255254
17210.41.16.0/24210.41.16.1 to 210.41.16.254210.41.16.255254
18210.41.17.0/24210.41.17.1 to 210.41.17.254210.41.17.255254
19210.41.18.0/24210.41.18.1 to 210.41.18.254210.41.18.255254
20210.41.19.0/24210.41.19.1 to 210.41.19.254210.41.19.255254
21210.41.20.0/24210.41.20.1 to 210.41.20.254210.41.20.255254
22210.41.21.0/24210.41.21.1 to 210.41.21.254210.41.21.255254
23210.41.22.0/24210.41.22.1 to 210.41.22.254210.41.22.255254
24210.41.23.0/24210.41.23.1 to 210.41.23.254210.41.23.255254
25210.41.24.0/24210.41.24.1 to 210.41.24.254210.41.24.255254
26210.41.25.0/24210.41.25.1 to 210.41.25.254210.41.25.255254
27210.41.26.0/24210.41.26.1 to 210.41.26.254210.41.26.255254
28210.41.27.0/24210.41.27.1 to 210.41.27.254210.41.27.255254
29210.41.28.0/24210.41.28.1 to 210.41.28.254210.41.28.255254
30210.41.29.0/24210.41.29.1 to 210.41.29.254210.41.29.255254
31210.41.30.0/24210.41.30.1 to 210.41.30.254210.41.30.255254
32210.41.31.0/24210.41.31.1 to 210.41.31.254210.41.31.255254
33210.41.32.0/24210.41.32.1 to 210.41.32.254210.41.32.255254
34210.41.33.0/24210.41.33.1 to 210.41.33.254210.41.33.255254
35210.41.34.0/24210.41.34.1 to 210.41.34.254210.41.34.255254
36210.41.35.0/24210.41.35.1 to 210.41.35.254210.41.35.255254
37210.41.36.0/24210.41.36.1 to 210.41.36.254210.41.36.255254
38210.41.37.0/24210.41.37.1 to 210.41.37.254210.41.37.255254
39210.41.38.0/24210.41.38.1 to 210.41.38.254210.41.38.255254
40210.41.39.0/24210.41.39.1 to 210.41.39.254210.41.39.255254
41210.41.40.0/24210.41.40.1 to 210.41.40.254210.41.40.255254
42210.41.41.0/24210.41.41.1 to 210.41.41.254210.41.41.255254
43210.41.42.0/24210.41.42.1 to 210.41.42.254210.41.42.255254
44210.41.43.0/24210.41.43.1 to 210.41.43.254210.41.43.255254
45210.41.44.0/24210.41.44.1 to 210.41.44.254210.41.44.255254
46210.41.45.0/24210.41.45.1 to 210.41.45.254210.41.45.255254
47210.41.46.0/24210.41.46.1 to 210.41.46.254210.41.46.255254
48210.41.47.0/24210.41.47.1 to 210.41.47.254210.41.47.255254
49210.41.48.0/24210.41.48.1 to 210.41.48.254210.41.48.255254
50210.41.49.0/24210.41.49.1 to 210.41.49.254210.41.49.255254
51210.41.50.0/24210.41.50.1 to 210.41.50.254210.41.50.255254
52210.41.51.0/24210.41.51.1 to 210.41.51.254210.41.51.255254
53210.41.52.0/24210.41.52.1 to 210.41.52.254210.41.52.255254
54210.41.53.0/24210.41.53.1 to 210.41.53.254210.41.53.255254
55210.41.54.0/24210.41.54.1 to 210.41.54.254210.41.54.255254
56210.41.55.0/24210.41.55.1 to 210.41.55.254210.41.55.255254
57210.41.56.0/24210.41.56.1 to 210.41.56.254210.41.56.255254
58210.41.57.0/24210.41.57.1 to 210.41.57.254210.41.57.255254
59210.41.58.0/24210.41.58.1 to 210.41.58.254210.41.58.255254
60210.41.59.0/24210.41.59.1 to 210.41.59.254210.41.59.255254
61210.41.60.0/24210.41.60.1 to 210.41.60.254210.41.60.255254
62210.41.61.0/24210.41.61.1 to 210.41.61.254210.41.61.255254
63210.41.62.0/24210.41.62.1 to 210.41.62.254210.41.62.255254
64210.41.63.0/24210.41.63.1 to 210.41.63.254210.41.63.255254
65210.41.64.0/24210.41.64.1 to 210.41.64.254210.41.64.255254
66210.41.65.0/24210.41.65.1 to 210.41.65.254210.41.65.255254
67210.41.66.0/24210.41.66.1 to 210.41.66.254210.41.66.255254
68210.41.67.0/24210.41.67.1 to 210.41.67.254210.41.67.255254
69210.41.68.0/24210.41.68.1 to 210.41.68.254210.41.68.255254
70210.41.69.0/24210.41.69.1 to 210.41.69.254210.41.69.255254
71210.41.70.0/24210.41.70.1 to 210.41.70.254210.41.70.255254
72210.41.71.0/24210.41.71.1 to 210.41.71.254210.41.71.255254
73210.41.72.0/24210.41.72.1 to 210.41.72.254210.41.72.255254
74210.41.73.0/24210.41.73.1 to 210.41.73.254210.41.73.255254
75210.41.74.0/24210.41.74.1 to 210.41.74.254210.41.74.255254
76210.41.75.0/24210.41.75.1 to 210.41.75.254210.41.75.255254
77210.41.76.0/24210.41.76.1 to 210.41.76.254210.41.76.255254
78210.41.77.0/24210.41.77.1 to 210.41.77.254210.41.77.255254
79210.41.78.0/24210.41.78.1 to 210.41.78.254210.41.78.255254
80210.41.79.0/24210.41.79.1 to 210.41.79.254210.41.79.255254
81210.41.80.0/24210.41.80.1 to 210.41.80.254210.41.80.255254
82210.41.81.0/24210.41.81.1 to 210.41.81.254210.41.81.255254
83210.41.82.0/24210.41.82.1 to 210.41.82.254210.41.82.255254
84210.41.83.0/24210.41.83.1 to 210.41.83.254210.41.83.255254
85210.41.84.0/24210.41.84.1 to 210.41.84.254210.41.84.255254
86210.41.85.0/24210.41.85.1 to 210.41.85.254210.41.85.255254
87210.41.86.0/24210.41.86.1 to 210.41.86.254210.41.86.255254
88210.41.87.0/24210.41.87.1 to 210.41.87.254210.41.87.255254
89210.41.88.0/24210.41.88.1 to 210.41.88.254210.41.88.255254
90210.41.89.0/24210.41.89.1 to 210.41.89.254210.41.89.255254
91210.41.90.0/24210.41.90.1 to 210.41.90.254210.41.90.255254
92210.41.91.0/24210.41.91.1 to 210.41.91.254210.41.91.255254
93210.41.92.0/24210.41.92.1 to 210.41.92.254210.41.92.255254
94210.41.93.0/24210.41.93.1 to 210.41.93.254210.41.93.255254
95210.41.94.0/24210.41.94.1 to 210.41.94.254210.41.94.255254
96210.41.95.0/24210.41.95.1 to 210.41.95.254210.41.95.255254
97210.41.96.0/24210.41.96.1 to 210.41.96.254210.41.96.255254
98210.41.97.0/24210.41.97.1 to 210.41.97.254210.41.97.255254
99210.41.98.0/24210.41.98.1 to 210.41.98.254210.41.98.255254
100210.41.99.0/24210.41.99.1 to 210.41.99.254210.41.99.255254
101210.41.100.0/24210.41.100.1 to 210.41.100.254210.41.100.255254
102210.41.101.0/24210.41.101.1 to 210.41.101.254210.41.101.255254
103210.41.102.0/24210.41.102.1 to 210.41.102.254210.41.102.255254
104210.41.103.0/24210.41.103.1 to 210.41.103.254210.41.103.255254
105210.41.104.0/24210.41.104.1 to 210.41.104.254210.41.104.255254
106210.41.105.0/24210.41.105.1 to 210.41.105.254210.41.105.255254
107210.41.106.0/24210.41.106.1 to 210.41.106.254210.41.106.255254
108210.41.107.0/24210.41.107.1 to 210.41.107.254210.41.107.255254
109210.41.108.0/24210.41.108.1 to 210.41.108.254210.41.108.255254
110210.41.109.0/24210.41.109.1 to 210.41.109.254210.41.109.255254
111210.41.110.0/24210.41.110.1 to 210.41.110.254210.41.110.255254
112210.41.111.0/24210.41.111.1 to 210.41.111.254210.41.111.255254
113210.41.112.0/24210.41.112.1 to 210.41.112.254210.41.112.255254
114210.41.113.0/24210.41.113.1 to 210.41.113.254210.41.113.255254
115210.41.114.0/24210.41.114.1 to 210.41.114.254210.41.114.255254
116210.41.115.0/24210.41.115.1 to 210.41.115.254210.41.115.255254
117210.41.116.0/24210.41.116.1 to 210.41.116.254210.41.116.255254
118210.41.117.0/24210.41.117.1 to 210.41.117.254210.41.117.255254
119210.41.118.0/24210.41.118.1 to 210.41.118.254210.41.118.255254
120210.41.119.0/24210.41.119.1 to 210.41.119.254210.41.119.255254
121210.41.120.0/24210.41.120.1 to 210.41.120.254210.41.120.255254
122210.41.121.0/24210.41.121.1 to 210.41.121.254210.41.121.255254
123210.41.122.0/24210.41.122.1 to 210.41.122.254210.41.122.255254
124210.41.123.0/24210.41.123.1 to 210.41.123.254210.41.123.255254
125210.41.124.0/24210.41.124.1 to 210.41.124.254210.41.124.255254
126210.41.125.0/24210.41.125.1 to 210.41.125.254210.41.125.255254
127210.41.126.0/24210.41.126.1 to 210.41.126.254210.41.126.255254
128210.41.127.0/24210.41.127.1 to 210.41.127.254210.41.127.255254
129210.41.128.0/24210.41.128.1 to 210.41.128.254210.41.128.255254
130210.41.129.0/24210.41.129.1 to 210.41.129.254210.41.129.255254
131210.41.130.0/24210.41.130.1 to 210.41.130.254210.41.130.255254
132210.41.131.0/24210.41.131.1 to 210.41.131.254210.41.131.255254
133210.41.132.0/24210.41.132.1 to 210.41.132.254210.41.132.255254
134210.41.133.0/24210.41.133.1 to 210.41.133.254210.41.133.255254
135210.41.134.0/24210.41.134.1 to 210.41.134.254210.41.134.255254
136210.41.135.0/24210.41.135.1 to 210.41.135.254210.41.135.255254
137210.41.136.0/24210.41.136.1 to 210.41.136.254210.41.136.255254
138210.41.137.0/24210.41.137.1 to 210.41.137.254210.41.137.255254
139210.41.138.0/24210.41.138.1 to 210.41.138.254210.41.138.255254
140210.41.139.0/24210.41.139.1 to 210.41.139.254210.41.139.255254
141210.41.140.0/24210.41.140.1 to 210.41.140.254210.41.140.255254
142210.41.141.0/24210.41.141.1 to 210.41.141.254210.41.141.255254
143210.41.142.0/24210.41.142.1 to 210.41.142.254210.41.142.255254
144210.41.143.0/24210.41.143.1 to 210.41.143.254210.41.143.255254
145210.41.144.0/24210.41.144.1 to 210.41.144.254210.41.144.255254
146210.41.145.0/24210.41.145.1 to 210.41.145.254210.41.145.255254
147210.41.146.0/24210.41.146.1 to 210.41.146.254210.41.146.255254
148210.41.147.0/24210.41.147.1 to 210.41.147.254210.41.147.255254
149210.41.148.0/24210.41.148.1 to 210.41.148.254210.41.148.255254
150210.41.149.0/24210.41.149.1 to 210.41.149.254210.41.149.255254
151210.41.150.0/24210.41.150.1 to 210.41.150.254210.41.150.255254
152210.41.151.0/24210.41.151.1 to 210.41.151.254210.41.151.255254
153210.41.152.0/24210.41.152.1 to 210.41.152.254210.41.152.255254
154210.41.153.0/24210.41.153.1 to 210.41.153.254210.41.153.255254
155210.41.154.0/24210.41.154.1 to 210.41.154.254210.41.154.255254
156210.41.155.0/24210.41.155.1 to 210.41.155.254210.41.155.255254
157210.41.156.0/24210.41.156.1 to 210.41.156.254210.41.156.255254
158210.41.157.0/24210.41.157.1 to 210.41.157.254210.41.157.255254
159210.41.158.0/24210.41.158.1 to 210.41.158.254210.41.158.255254
160210.41.159.0/24210.41.159.1 to 210.41.159.254210.41.159.255254
161210.41.160.0/24210.41.160.1 to 210.41.160.254210.41.160.255254
162210.41.161.0/24210.41.161.1 to 210.41.161.254210.41.161.255254
163210.41.162.0/24210.41.162.1 to 210.41.162.254210.41.162.255254
164210.41.163.0/24210.41.163.1 to 210.41.163.254210.41.163.255254
165210.41.164.0/24210.41.164.1 to 210.41.164.254210.41.164.255254
166210.41.165.0/24210.41.165.1 to 210.41.165.254210.41.165.255254
167210.41.166.0/24210.41.166.1 to 210.41.166.254210.41.166.255254
168210.41.167.0/24210.41.167.1 to 210.41.167.254210.41.167.255254
169210.41.168.0/24210.41.168.1 to 210.41.168.254210.41.168.255254
170210.41.169.0/24210.41.169.1 to 210.41.169.254210.41.169.255254
171210.41.170.0/24210.41.170.1 to 210.41.170.254210.41.170.255254
172210.41.171.0/24210.41.171.1 to 210.41.171.254210.41.171.255254
173210.41.172.0/24210.41.172.1 to 210.41.172.254210.41.172.255254
174210.41.173.0/24210.41.173.1 to 210.41.173.254210.41.173.255254
175210.41.174.0/24210.41.174.1 to 210.41.174.254210.41.174.255254
176210.41.175.0/24210.41.175.1 to 210.41.175.254210.41.175.255254
177210.41.176.0/24210.41.176.1 to 210.41.176.254210.41.176.255254
178210.41.177.0/24210.41.177.1 to 210.41.177.254210.41.177.255254
179210.41.178.0/24210.41.178.1 to 210.41.178.254210.41.178.255254
180210.41.179.0/24210.41.179.1 to 210.41.179.254210.41.179.255254
181210.41.180.0/24210.41.180.1 to 210.41.180.254210.41.180.255254
182210.41.181.0/24210.41.181.1 to 210.41.181.254210.41.181.255254
183210.41.182.0/24210.41.182.1 to 210.41.182.254210.41.182.255254
184210.41.183.0/24210.41.183.1 to 210.41.183.254210.41.183.255254
185210.41.184.0/24210.41.184.1 to 210.41.184.254210.41.184.255254
186210.41.185.0/24210.41.185.1 to 210.41.185.254210.41.185.255254
187210.41.186.0/24210.41.186.1 to 210.41.186.254210.41.186.255254
188210.41.187.0/24210.41.187.1 to 210.41.187.254210.41.187.255254
189210.41.188.0/24210.41.188.1 to 210.41.188.254210.41.188.255254
190210.41.189.0/24210.41.189.1 to 210.41.189.254210.41.189.255254
191210.41.190.0/24210.41.190.1 to 210.41.190.254210.41.190.255254
192210.41.191.0/24210.41.191.1 to 210.41.191.254210.41.191.255254
193210.41.192.0/24210.41.192.1 to 210.41.192.254210.41.192.255254
194210.41.193.0/24210.41.193.1 to 210.41.193.254210.41.193.255254
195210.41.194.0/24210.41.194.1 to 210.41.194.254210.41.194.255254
196210.41.195.0/24210.41.195.1 to 210.41.195.254210.41.195.255254
197210.41.196.0/24210.41.196.1 to 210.41.196.254210.41.196.255254
198210.41.197.0/24210.41.197.1 to 210.41.197.254210.41.197.255254
199210.41.198.0/24210.41.198.1 to 210.41.198.254210.41.198.255254
200210.41.199.0/24210.41.199.1 to 210.41.199.254210.41.199.255254
201210.41.200.0/24210.41.200.1 to 210.41.200.254210.41.200.255254
202210.41.201.0/24210.41.201.1 to 210.41.201.254210.41.201.255254
203210.41.202.0/24210.41.202.1 to 210.41.202.254210.41.202.255254
204210.41.203.0/24210.41.203.1 to 210.41.203.254210.41.203.255254
205210.41.204.0/24210.41.204.1 to 210.41.204.254210.41.204.255254
206210.41.205.0/24210.41.205.1 to 210.41.205.254210.41.205.255254
207210.41.206.0/24210.41.206.1 to 210.41.206.254210.41.206.255254
208210.41.207.0/24210.41.207.1 to 210.41.207.254210.41.207.255254
209210.41.208.0/24210.41.208.1 to 210.41.208.254210.41.208.255254
210210.41.209.0/24210.41.209.1 to 210.41.209.254210.41.209.255254
211210.41.210.0/24210.41.210.1 to 210.41.210.254210.41.210.255254
212210.41.211.0/24210.41.211.1 to 210.41.211.254210.41.211.255254
213210.41.212.0/24210.41.212.1 to 210.41.212.254210.41.212.255254
214210.41.213.0/24210.41.213.1 to 210.41.213.254210.41.213.255254
215210.41.214.0/24210.41.214.1 to 210.41.214.254210.41.214.255254
216210.41.215.0/24210.41.215.1 to 210.41.215.254210.41.215.255254
217210.41.216.0/24210.41.216.1 to 210.41.216.254210.41.216.255254
218210.41.217.0/24210.41.217.1 to 210.41.217.254210.41.217.255254
219210.41.218.0/24210.41.218.1 to 210.41.218.254210.41.218.255254
220210.41.219.0/24210.41.219.1 to 210.41.219.254210.41.219.255254
221210.41.220.0/24210.41.220.1 to 210.41.220.254210.41.220.255254
222210.41.221.0/24210.41.221.1 to 210.41.221.254210.41.221.255254
223210.41.222.0/24210.41.222.1 to 210.41.222.254210.41.222.255254
224210.41.223.0/24210.41.223.1 to 210.41.223.254210.41.223.255254
225210.41.224.0/24210.41.224.1 to 210.41.224.254210.41.224.255254
226210.41.225.0/24210.41.225.1 to 210.41.225.254210.41.225.255254
227210.41.226.0/24210.41.226.1 to 210.41.226.254210.41.226.255254
228210.41.227.0/24210.41.227.1 to 210.41.227.254210.41.227.255254
229210.41.228.0/24210.41.228.1 to 210.41.228.254210.41.228.255254
230210.41.229.0/24210.41.229.1 to 210.41.229.254210.41.229.255254
231210.41.230.0/24210.41.230.1 to 210.41.230.254210.41.230.255254
232210.41.231.0/24210.41.231.1 to 210.41.231.254210.41.231.255254
233210.41.232.0/24210.41.232.1 to 210.41.232.254210.41.232.255254
234210.41.233.0/24210.41.233.1 to 210.41.233.254210.41.233.255254
235210.41.234.0/24210.41.234.1 to 210.41.234.254210.41.234.255254
236210.41.235.0/24210.41.235.1 to 210.41.235.254210.41.235.255254
237210.41.236.0/24210.41.236.1 to 210.41.236.254210.41.236.255254
238210.41.237.0/24210.41.237.1 to 210.41.237.254210.41.237.255254
239210.41.238.0/24210.41.238.1 to 210.41.238.254210.41.238.255254
240210.41.239.0/24210.41.239.1 to 210.41.239.254210.41.239.255254
241210.41.240.0/24210.41.240.1 to 210.41.240.254210.41.240.255254
242210.41.241.0/24210.41.241.1 to 210.41.241.254210.41.241.255254
243210.41.242.0/24210.41.242.1 to 210.41.242.254210.41.242.255254
244210.41.243.0/24210.41.243.1 to 210.41.243.254210.41.243.255254
245210.41.244.0/24210.41.244.1 to 210.41.244.254210.41.244.255254
246210.41.245.0/24210.41.245.1 to 210.41.245.254210.41.245.255254
247210.41.246.0/24210.41.246.1 to 210.41.246.254210.41.246.255254
248210.41.247.0/24210.41.247.1 to 210.41.247.254210.41.247.255254
249210.41.248.0/24210.41.248.1 to 210.41.248.254210.41.248.255254
250210.41.249.0/24210.41.249.1 to 210.41.249.254210.41.249.255254
251210.41.250.0/24210.41.250.1 to 210.41.250.254210.41.250.255254
252210.41.251.0/24210.41.251.1 to 210.41.251.254210.41.251.255254
253210.41.252.0/24210.41.252.1 to 210.41.252.254210.41.252.255254
254210.41.253.0/24210.41.253.1 to 210.41.253.254210.41.253.255254
255210.41.254.0/24210.41.254.1 to 210.41.254.254210.41.254.255254
256210.41.255.0/24210.41.255.1 to 210.41.255.254210.41.255.255254

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.