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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.

Network209.16.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
209.16.0.0
Broadcast address
209.23.255.255
First usable
209.16.0.1
Last usable
209.23.255.254
Usable hosts
524,286 (524,288 less the network and broadcast addresses)
Subnet mask
255.248.0.0
Wildcard mask
0.7.255.255 (Cisco ACLs, OSPF)
Prefix length
/13
Type
Public public
Old class
C (default /24)
As numbers
Hex D1100000 · Integer 3507486720 to 3508011007
Reverse DNS zones
16.209.in-addr.arpa
17.209.in-addr.arpa
18.209.in-addr.arpa
19.209.in-addr.arpa
20.209.in-addr.arpa
21.209.in-addr.arpa
22.209.in-addr.arpa
23.209.in-addr.arpa
/13 is not on a 8-bit boundary, so it takes 8 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11010001.00010000.00000000.00000000209.16.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network11010001.00010000.00000000.00000000209.16.0.0
Broadcast11010001.00010111.11111111.11111111209.23.255.255
Split into smaller subnets/23
/14 (2)/15 (4)/16 (8)/17 (16)/18 (32)/19 (64)/20 (128)/21 (256)/22 (512)/23 (1,024)/24 (2,048)/25 (4,096)

209.16.0.0/13 makes 1,024 subnets of /23; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1209.16.0.0/23209.16.0.1 to 209.16.1.254209.16.1.255510
2209.16.2.0/23209.16.2.1 to 209.16.3.254209.16.3.255510
3209.16.4.0/23209.16.4.1 to 209.16.5.254209.16.5.255510
4209.16.6.0/23209.16.6.1 to 209.16.7.254209.16.7.255510
5209.16.8.0/23209.16.8.1 to 209.16.9.254209.16.9.255510
6209.16.10.0/23209.16.10.1 to 209.16.11.254209.16.11.255510
7209.16.12.0/23209.16.12.1 to 209.16.13.254209.16.13.255510
8209.16.14.0/23209.16.14.1 to 209.16.15.254209.16.15.255510
9209.16.16.0/23209.16.16.1 to 209.16.17.254209.16.17.255510
10209.16.18.0/23209.16.18.1 to 209.16.19.254209.16.19.255510
11209.16.20.0/23209.16.20.1 to 209.16.21.254209.16.21.255510
12209.16.22.0/23209.16.22.1 to 209.16.23.254209.16.23.255510
13209.16.24.0/23209.16.24.1 to 209.16.25.254209.16.25.255510
14209.16.26.0/23209.16.26.1 to 209.16.27.254209.16.27.255510
15209.16.28.0/23209.16.28.1 to 209.16.29.254209.16.29.255510
16209.16.30.0/23209.16.30.1 to 209.16.31.254209.16.31.255510
17209.16.32.0/23209.16.32.1 to 209.16.33.254209.16.33.255510
18209.16.34.0/23209.16.34.1 to 209.16.35.254209.16.35.255510
19209.16.36.0/23209.16.36.1 to 209.16.37.254209.16.37.255510
20209.16.38.0/23209.16.38.1 to 209.16.39.254209.16.39.255510
21209.16.40.0/23209.16.40.1 to 209.16.41.254209.16.41.255510
22209.16.42.0/23209.16.42.1 to 209.16.43.254209.16.43.255510
23209.16.44.0/23209.16.44.1 to 209.16.45.254209.16.45.255510
24209.16.46.0/23209.16.46.1 to 209.16.47.254209.16.47.255510
25209.16.48.0/23209.16.48.1 to 209.16.49.254209.16.49.255510
26209.16.50.0/23209.16.50.1 to 209.16.51.254209.16.51.255510
27209.16.52.0/23209.16.52.1 to 209.16.53.254209.16.53.255510
28209.16.54.0/23209.16.54.1 to 209.16.55.254209.16.55.255510
29209.16.56.0/23209.16.56.1 to 209.16.57.254209.16.57.255510
30209.16.58.0/23209.16.58.1 to 209.16.59.254209.16.59.255510
31209.16.60.0/23209.16.60.1 to 209.16.61.254209.16.61.255510
32209.16.62.0/23209.16.62.1 to 209.16.63.254209.16.63.255510
33209.16.64.0/23209.16.64.1 to 209.16.65.254209.16.65.255510
34209.16.66.0/23209.16.66.1 to 209.16.67.254209.16.67.255510
35209.16.68.0/23209.16.68.1 to 209.16.69.254209.16.69.255510
36209.16.70.0/23209.16.70.1 to 209.16.71.254209.16.71.255510
37209.16.72.0/23209.16.72.1 to 209.16.73.254209.16.73.255510
38209.16.74.0/23209.16.74.1 to 209.16.75.254209.16.75.255510
39209.16.76.0/23209.16.76.1 to 209.16.77.254209.16.77.255510
40209.16.78.0/23209.16.78.1 to 209.16.79.254209.16.79.255510
41209.16.80.0/23209.16.80.1 to 209.16.81.254209.16.81.255510
42209.16.82.0/23209.16.82.1 to 209.16.83.254209.16.83.255510
43209.16.84.0/23209.16.84.1 to 209.16.85.254209.16.85.255510
44209.16.86.0/23209.16.86.1 to 209.16.87.254209.16.87.255510
45209.16.88.0/23209.16.88.1 to 209.16.89.254209.16.89.255510
46209.16.90.0/23209.16.90.1 to 209.16.91.254209.16.91.255510
47209.16.92.0/23209.16.92.1 to 209.16.93.254209.16.93.255510
48209.16.94.0/23209.16.94.1 to 209.16.95.254209.16.95.255510
49209.16.96.0/23209.16.96.1 to 209.16.97.254209.16.97.255510
50209.16.98.0/23209.16.98.1 to 209.16.99.254209.16.99.255510
51209.16.100.0/23209.16.100.1 to 209.16.101.254209.16.101.255510
52209.16.102.0/23209.16.102.1 to 209.16.103.254209.16.103.255510
53209.16.104.0/23209.16.104.1 to 209.16.105.254209.16.105.255510
54209.16.106.0/23209.16.106.1 to 209.16.107.254209.16.107.255510
55209.16.108.0/23209.16.108.1 to 209.16.109.254209.16.109.255510
56209.16.110.0/23209.16.110.1 to 209.16.111.254209.16.111.255510
57209.16.112.0/23209.16.112.1 to 209.16.113.254209.16.113.255510
58209.16.114.0/23209.16.114.1 to 209.16.115.254209.16.115.255510
59209.16.116.0/23209.16.116.1 to 209.16.117.254209.16.117.255510
60209.16.118.0/23209.16.118.1 to 209.16.119.254209.16.119.255510
61209.16.120.0/23209.16.120.1 to 209.16.121.254209.16.121.255510
62209.16.122.0/23209.16.122.1 to 209.16.123.254209.16.123.255510
63209.16.124.0/23209.16.124.1 to 209.16.125.254209.16.125.255510
64209.16.126.0/23209.16.126.1 to 209.16.127.254209.16.127.255510
65209.16.128.0/23209.16.128.1 to 209.16.129.254209.16.129.255510
66209.16.130.0/23209.16.130.1 to 209.16.131.254209.16.131.255510
67209.16.132.0/23209.16.132.1 to 209.16.133.254209.16.133.255510
68209.16.134.0/23209.16.134.1 to 209.16.135.254209.16.135.255510
69209.16.136.0/23209.16.136.1 to 209.16.137.254209.16.137.255510
70209.16.138.0/23209.16.138.1 to 209.16.139.254209.16.139.255510
71209.16.140.0/23209.16.140.1 to 209.16.141.254209.16.141.255510
72209.16.142.0/23209.16.142.1 to 209.16.143.254209.16.143.255510
73209.16.144.0/23209.16.144.1 to 209.16.145.254209.16.145.255510
74209.16.146.0/23209.16.146.1 to 209.16.147.254209.16.147.255510
75209.16.148.0/23209.16.148.1 to 209.16.149.254209.16.149.255510
76209.16.150.0/23209.16.150.1 to 209.16.151.254209.16.151.255510
77209.16.152.0/23209.16.152.1 to 209.16.153.254209.16.153.255510
78209.16.154.0/23209.16.154.1 to 209.16.155.254209.16.155.255510
79209.16.156.0/23209.16.156.1 to 209.16.157.254209.16.157.255510
80209.16.158.0/23209.16.158.1 to 209.16.159.254209.16.159.255510
81209.16.160.0/23209.16.160.1 to 209.16.161.254209.16.161.255510
82209.16.162.0/23209.16.162.1 to 209.16.163.254209.16.163.255510
83209.16.164.0/23209.16.164.1 to 209.16.165.254209.16.165.255510
84209.16.166.0/23209.16.166.1 to 209.16.167.254209.16.167.255510
85209.16.168.0/23209.16.168.1 to 209.16.169.254209.16.169.255510
86209.16.170.0/23209.16.170.1 to 209.16.171.254209.16.171.255510
87209.16.172.0/23209.16.172.1 to 209.16.173.254209.16.173.255510
88209.16.174.0/23209.16.174.1 to 209.16.175.254209.16.175.255510
89209.16.176.0/23209.16.176.1 to 209.16.177.254209.16.177.255510
90209.16.178.0/23209.16.178.1 to 209.16.179.254209.16.179.255510
91209.16.180.0/23209.16.180.1 to 209.16.181.254209.16.181.255510
92209.16.182.0/23209.16.182.1 to 209.16.183.254209.16.183.255510
93209.16.184.0/23209.16.184.1 to 209.16.185.254209.16.185.255510
94209.16.186.0/23209.16.186.1 to 209.16.187.254209.16.187.255510
95209.16.188.0/23209.16.188.1 to 209.16.189.254209.16.189.255510
96209.16.190.0/23209.16.190.1 to 209.16.191.254209.16.191.255510
97209.16.192.0/23209.16.192.1 to 209.16.193.254209.16.193.255510
98209.16.194.0/23209.16.194.1 to 209.16.195.254209.16.195.255510
99209.16.196.0/23209.16.196.1 to 209.16.197.254209.16.197.255510
100209.16.198.0/23209.16.198.1 to 209.16.199.254209.16.199.255510
101209.16.200.0/23209.16.200.1 to 209.16.201.254209.16.201.255510
102209.16.202.0/23209.16.202.1 to 209.16.203.254209.16.203.255510
103209.16.204.0/23209.16.204.1 to 209.16.205.254209.16.205.255510
104209.16.206.0/23209.16.206.1 to 209.16.207.254209.16.207.255510
105209.16.208.0/23209.16.208.1 to 209.16.209.254209.16.209.255510
106209.16.210.0/23209.16.210.1 to 209.16.211.254209.16.211.255510
107209.16.212.0/23209.16.212.1 to 209.16.213.254209.16.213.255510
108209.16.214.0/23209.16.214.1 to 209.16.215.254209.16.215.255510
109209.16.216.0/23209.16.216.1 to 209.16.217.254209.16.217.255510
110209.16.218.0/23209.16.218.1 to 209.16.219.254209.16.219.255510
111209.16.220.0/23209.16.220.1 to 209.16.221.254209.16.221.255510
112209.16.222.0/23209.16.222.1 to 209.16.223.254209.16.223.255510
113209.16.224.0/23209.16.224.1 to 209.16.225.254209.16.225.255510
114209.16.226.0/23209.16.226.1 to 209.16.227.254209.16.227.255510
115209.16.228.0/23209.16.228.1 to 209.16.229.254209.16.229.255510
116209.16.230.0/23209.16.230.1 to 209.16.231.254209.16.231.255510
117209.16.232.0/23209.16.232.1 to 209.16.233.254209.16.233.255510
118209.16.234.0/23209.16.234.1 to 209.16.235.254209.16.235.255510
119209.16.236.0/23209.16.236.1 to 209.16.237.254209.16.237.255510
120209.16.238.0/23209.16.238.1 to 209.16.239.254209.16.239.255510
121209.16.240.0/23209.16.240.1 to 209.16.241.254209.16.241.255510
122209.16.242.0/23209.16.242.1 to 209.16.243.254209.16.243.255510
123209.16.244.0/23209.16.244.1 to 209.16.245.254209.16.245.255510
124209.16.246.0/23209.16.246.1 to 209.16.247.254209.16.247.255510
125209.16.248.0/23209.16.248.1 to 209.16.249.254209.16.249.255510
126209.16.250.0/23209.16.250.1 to 209.16.251.254209.16.251.255510
127209.16.252.0/23209.16.252.1 to 209.16.253.254209.16.253.255510
128209.16.254.0/23209.16.254.1 to 209.16.255.254209.16.255.255510
129209.17.0.0/23209.17.0.1 to 209.17.1.254209.17.1.255510
130209.17.2.0/23209.17.2.1 to 209.17.3.254209.17.3.255510
131209.17.4.0/23209.17.4.1 to 209.17.5.254209.17.5.255510
132209.17.6.0/23209.17.6.1 to 209.17.7.254209.17.7.255510
133209.17.8.0/23209.17.8.1 to 209.17.9.254209.17.9.255510
134209.17.10.0/23209.17.10.1 to 209.17.11.254209.17.11.255510
135209.17.12.0/23209.17.12.1 to 209.17.13.254209.17.13.255510
136209.17.14.0/23209.17.14.1 to 209.17.15.254209.17.15.255510
137209.17.16.0/23209.17.16.1 to 209.17.17.254209.17.17.255510
138209.17.18.0/23209.17.18.1 to 209.17.19.254209.17.19.255510
139209.17.20.0/23209.17.20.1 to 209.17.21.254209.17.21.255510
140209.17.22.0/23209.17.22.1 to 209.17.23.254209.17.23.255510
141209.17.24.0/23209.17.24.1 to 209.17.25.254209.17.25.255510
142209.17.26.0/23209.17.26.1 to 209.17.27.254209.17.27.255510
143209.17.28.0/23209.17.28.1 to 209.17.29.254209.17.29.255510
144209.17.30.0/23209.17.30.1 to 209.17.31.254209.17.31.255510
145209.17.32.0/23209.17.32.1 to 209.17.33.254209.17.33.255510
146209.17.34.0/23209.17.34.1 to 209.17.35.254209.17.35.255510
147209.17.36.0/23209.17.36.1 to 209.17.37.254209.17.37.255510
148209.17.38.0/23209.17.38.1 to 209.17.39.254209.17.39.255510
149209.17.40.0/23209.17.40.1 to 209.17.41.254209.17.41.255510
150209.17.42.0/23209.17.42.1 to 209.17.43.254209.17.43.255510
151209.17.44.0/23209.17.44.1 to 209.17.45.254209.17.45.255510
152209.17.46.0/23209.17.46.1 to 209.17.47.254209.17.47.255510
153209.17.48.0/23209.17.48.1 to 209.17.49.254209.17.49.255510
154209.17.50.0/23209.17.50.1 to 209.17.51.254209.17.51.255510
155209.17.52.0/23209.17.52.1 to 209.17.53.254209.17.53.255510
156209.17.54.0/23209.17.54.1 to 209.17.55.254209.17.55.255510
157209.17.56.0/23209.17.56.1 to 209.17.57.254209.17.57.255510
158209.17.58.0/23209.17.58.1 to 209.17.59.254209.17.59.255510
159209.17.60.0/23209.17.60.1 to 209.17.61.254209.17.61.255510
160209.17.62.0/23209.17.62.1 to 209.17.63.254209.17.63.255510
161209.17.64.0/23209.17.64.1 to 209.17.65.254209.17.65.255510
162209.17.66.0/23209.17.66.1 to 209.17.67.254209.17.67.255510
163209.17.68.0/23209.17.68.1 to 209.17.69.254209.17.69.255510
164209.17.70.0/23209.17.70.1 to 209.17.71.254209.17.71.255510
165209.17.72.0/23209.17.72.1 to 209.17.73.254209.17.73.255510
166209.17.74.0/23209.17.74.1 to 209.17.75.254209.17.75.255510
167209.17.76.0/23209.17.76.1 to 209.17.77.254209.17.77.255510
168209.17.78.0/23209.17.78.1 to 209.17.79.254209.17.79.255510
169209.17.80.0/23209.17.80.1 to 209.17.81.254209.17.81.255510
170209.17.82.0/23209.17.82.1 to 209.17.83.254209.17.83.255510
171209.17.84.0/23209.17.84.1 to 209.17.85.254209.17.85.255510
172209.17.86.0/23209.17.86.1 to 209.17.87.254209.17.87.255510
173209.17.88.0/23209.17.88.1 to 209.17.89.254209.17.89.255510
174209.17.90.0/23209.17.90.1 to 209.17.91.254209.17.91.255510
175209.17.92.0/23209.17.92.1 to 209.17.93.254209.17.93.255510
176209.17.94.0/23209.17.94.1 to 209.17.95.254209.17.95.255510
177209.17.96.0/23209.17.96.1 to 209.17.97.254209.17.97.255510
178209.17.98.0/23209.17.98.1 to 209.17.99.254209.17.99.255510
179209.17.100.0/23209.17.100.1 to 209.17.101.254209.17.101.255510
180209.17.102.0/23209.17.102.1 to 209.17.103.254209.17.103.255510
181209.17.104.0/23209.17.104.1 to 209.17.105.254209.17.105.255510
182209.17.106.0/23209.17.106.1 to 209.17.107.254209.17.107.255510
183209.17.108.0/23209.17.108.1 to 209.17.109.254209.17.109.255510
184209.17.110.0/23209.17.110.1 to 209.17.111.254209.17.111.255510
185209.17.112.0/23209.17.112.1 to 209.17.113.254209.17.113.255510
186209.17.114.0/23209.17.114.1 to 209.17.115.254209.17.115.255510
187209.17.116.0/23209.17.116.1 to 209.17.117.254209.17.117.255510
188209.17.118.0/23209.17.118.1 to 209.17.119.254209.17.119.255510
189209.17.120.0/23209.17.120.1 to 209.17.121.254209.17.121.255510
190209.17.122.0/23209.17.122.1 to 209.17.123.254209.17.123.255510
191209.17.124.0/23209.17.124.1 to 209.17.125.254209.17.125.255510
192209.17.126.0/23209.17.126.1 to 209.17.127.254209.17.127.255510
193209.17.128.0/23209.17.128.1 to 209.17.129.254209.17.129.255510
194209.17.130.0/23209.17.130.1 to 209.17.131.254209.17.131.255510
195209.17.132.0/23209.17.132.1 to 209.17.133.254209.17.133.255510
196209.17.134.0/23209.17.134.1 to 209.17.135.254209.17.135.255510
197209.17.136.0/23209.17.136.1 to 209.17.137.254209.17.137.255510
198209.17.138.0/23209.17.138.1 to 209.17.139.254209.17.139.255510
199209.17.140.0/23209.17.140.1 to 209.17.141.254209.17.141.255510
200209.17.142.0/23209.17.142.1 to 209.17.143.254209.17.143.255510
201209.17.144.0/23209.17.144.1 to 209.17.145.254209.17.145.255510
202209.17.146.0/23209.17.146.1 to 209.17.147.254209.17.147.255510
203209.17.148.0/23209.17.148.1 to 209.17.149.254209.17.149.255510
204209.17.150.0/23209.17.150.1 to 209.17.151.254209.17.151.255510
205209.17.152.0/23209.17.152.1 to 209.17.153.254209.17.153.255510
206209.17.154.0/23209.17.154.1 to 209.17.155.254209.17.155.255510
207209.17.156.0/23209.17.156.1 to 209.17.157.254209.17.157.255510
208209.17.158.0/23209.17.158.1 to 209.17.159.254209.17.159.255510
209209.17.160.0/23209.17.160.1 to 209.17.161.254209.17.161.255510
210209.17.162.0/23209.17.162.1 to 209.17.163.254209.17.163.255510
211209.17.164.0/23209.17.164.1 to 209.17.165.254209.17.165.255510
212209.17.166.0/23209.17.166.1 to 209.17.167.254209.17.167.255510
213209.17.168.0/23209.17.168.1 to 209.17.169.254209.17.169.255510
214209.17.170.0/23209.17.170.1 to 209.17.171.254209.17.171.255510
215209.17.172.0/23209.17.172.1 to 209.17.173.254209.17.173.255510
216209.17.174.0/23209.17.174.1 to 209.17.175.254209.17.175.255510
217209.17.176.0/23209.17.176.1 to 209.17.177.254209.17.177.255510
218209.17.178.0/23209.17.178.1 to 209.17.179.254209.17.179.255510
219209.17.180.0/23209.17.180.1 to 209.17.181.254209.17.181.255510
220209.17.182.0/23209.17.182.1 to 209.17.183.254209.17.183.255510
221209.17.184.0/23209.17.184.1 to 209.17.185.254209.17.185.255510
222209.17.186.0/23209.17.186.1 to 209.17.187.254209.17.187.255510
223209.17.188.0/23209.17.188.1 to 209.17.189.254209.17.189.255510
224209.17.190.0/23209.17.190.1 to 209.17.191.254209.17.191.255510
225209.17.192.0/23209.17.192.1 to 209.17.193.254209.17.193.255510
226209.17.194.0/23209.17.194.1 to 209.17.195.254209.17.195.255510
227209.17.196.0/23209.17.196.1 to 209.17.197.254209.17.197.255510
228209.17.198.0/23209.17.198.1 to 209.17.199.254209.17.199.255510
229209.17.200.0/23209.17.200.1 to 209.17.201.254209.17.201.255510
230209.17.202.0/23209.17.202.1 to 209.17.203.254209.17.203.255510
231209.17.204.0/23209.17.204.1 to 209.17.205.254209.17.205.255510
232209.17.206.0/23209.17.206.1 to 209.17.207.254209.17.207.255510
233209.17.208.0/23209.17.208.1 to 209.17.209.254209.17.209.255510
234209.17.210.0/23209.17.210.1 to 209.17.211.254209.17.211.255510
235209.17.212.0/23209.17.212.1 to 209.17.213.254209.17.213.255510
236209.17.214.0/23209.17.214.1 to 209.17.215.254209.17.215.255510
237209.17.216.0/23209.17.216.1 to 209.17.217.254209.17.217.255510
238209.17.218.0/23209.17.218.1 to 209.17.219.254209.17.219.255510
239209.17.220.0/23209.17.220.1 to 209.17.221.254209.17.221.255510
240209.17.222.0/23209.17.222.1 to 209.17.223.254209.17.223.255510
241209.17.224.0/23209.17.224.1 to 209.17.225.254209.17.225.255510
242209.17.226.0/23209.17.226.1 to 209.17.227.254209.17.227.255510
243209.17.228.0/23209.17.228.1 to 209.17.229.254209.17.229.255510
244209.17.230.0/23209.17.230.1 to 209.17.231.254209.17.231.255510
245209.17.232.0/23209.17.232.1 to 209.17.233.254209.17.233.255510
246209.17.234.0/23209.17.234.1 to 209.17.235.254209.17.235.255510
247209.17.236.0/23209.17.236.1 to 209.17.237.254209.17.237.255510
248209.17.238.0/23209.17.238.1 to 209.17.239.254209.17.239.255510
249209.17.240.0/23209.17.240.1 to 209.17.241.254209.17.241.255510
250209.17.242.0/23209.17.242.1 to 209.17.243.254209.17.243.255510
251209.17.244.0/23209.17.244.1 to 209.17.245.254209.17.245.255510
252209.17.246.0/23209.17.246.1 to 209.17.247.254209.17.247.255510
253209.17.248.0/23209.17.248.1 to 209.17.249.254209.17.249.255510
254209.17.250.0/23209.17.250.1 to 209.17.251.254209.17.251.255510
255209.17.252.0/23209.17.252.1 to 209.17.253.254209.17.253.255510
256209.17.254.0/23209.17.254.1 to 209.17.255.254209.17.255.255510

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.