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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.

Network143.136.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
143.136.0.0
Broadcast address
143.137.255.255
First usable
143.136.0.1
Last usable
143.137.255.254
Usable hosts
131,070 (131,072 less the network and broadcast addresses)
Subnet mask
255.254.0.0
Wildcard mask
0.1.255.255 (Cisco ACLs, OSPF)
Prefix length
/15
Type
Public public
Old class
B (default /16)
As numbers
Hex 8F880000 · Integer 2408054784 to 2408185855
Reverse DNS zones
136.143.in-addr.arpa
137.143.in-addr.arpa
/15 is not on a 8-bit boundary, so it takes 2 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10001111.10001000.00000000.00000000143.136.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network10001111.10001000.00000000.00000000143.136.0.0
Broadcast10001111.10001001.11111111.11111111143.137.255.255
Split into smaller subnets/23
/16 (2)/17 (4)/18 (8)/19 (16)/20 (32)/21 (64)/22 (128)/23 (256)/24 (512)/25 (1,024)/26 (2,048)/27 (4,096)

143.136.0.0/15 makes 256 subnets of /23.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1143.136.0.0/23143.136.0.1 to 143.136.1.254143.136.1.255510
2143.136.2.0/23143.136.2.1 to 143.136.3.254143.136.3.255510
3143.136.4.0/23143.136.4.1 to 143.136.5.254143.136.5.255510
4143.136.6.0/23143.136.6.1 to 143.136.7.254143.136.7.255510
5143.136.8.0/23143.136.8.1 to 143.136.9.254143.136.9.255510
6143.136.10.0/23143.136.10.1 to 143.136.11.254143.136.11.255510
7143.136.12.0/23143.136.12.1 to 143.136.13.254143.136.13.255510
8143.136.14.0/23143.136.14.1 to 143.136.15.254143.136.15.255510
9143.136.16.0/23143.136.16.1 to 143.136.17.254143.136.17.255510
10143.136.18.0/23143.136.18.1 to 143.136.19.254143.136.19.255510
11143.136.20.0/23143.136.20.1 to 143.136.21.254143.136.21.255510
12143.136.22.0/23143.136.22.1 to 143.136.23.254143.136.23.255510
13143.136.24.0/23143.136.24.1 to 143.136.25.254143.136.25.255510
14143.136.26.0/23143.136.26.1 to 143.136.27.254143.136.27.255510
15143.136.28.0/23143.136.28.1 to 143.136.29.254143.136.29.255510
16143.136.30.0/23143.136.30.1 to 143.136.31.254143.136.31.255510
17143.136.32.0/23143.136.32.1 to 143.136.33.254143.136.33.255510
18143.136.34.0/23143.136.34.1 to 143.136.35.254143.136.35.255510
19143.136.36.0/23143.136.36.1 to 143.136.37.254143.136.37.255510
20143.136.38.0/23143.136.38.1 to 143.136.39.254143.136.39.255510
21143.136.40.0/23143.136.40.1 to 143.136.41.254143.136.41.255510
22143.136.42.0/23143.136.42.1 to 143.136.43.254143.136.43.255510
23143.136.44.0/23143.136.44.1 to 143.136.45.254143.136.45.255510
24143.136.46.0/23143.136.46.1 to 143.136.47.254143.136.47.255510
25143.136.48.0/23143.136.48.1 to 143.136.49.254143.136.49.255510
26143.136.50.0/23143.136.50.1 to 143.136.51.254143.136.51.255510
27143.136.52.0/23143.136.52.1 to 143.136.53.254143.136.53.255510
28143.136.54.0/23143.136.54.1 to 143.136.55.254143.136.55.255510
29143.136.56.0/23143.136.56.1 to 143.136.57.254143.136.57.255510
30143.136.58.0/23143.136.58.1 to 143.136.59.254143.136.59.255510
31143.136.60.0/23143.136.60.1 to 143.136.61.254143.136.61.255510
32143.136.62.0/23143.136.62.1 to 143.136.63.254143.136.63.255510
33143.136.64.0/23143.136.64.1 to 143.136.65.254143.136.65.255510
34143.136.66.0/23143.136.66.1 to 143.136.67.254143.136.67.255510
35143.136.68.0/23143.136.68.1 to 143.136.69.254143.136.69.255510
36143.136.70.0/23143.136.70.1 to 143.136.71.254143.136.71.255510
37143.136.72.0/23143.136.72.1 to 143.136.73.254143.136.73.255510
38143.136.74.0/23143.136.74.1 to 143.136.75.254143.136.75.255510
39143.136.76.0/23143.136.76.1 to 143.136.77.254143.136.77.255510
40143.136.78.0/23143.136.78.1 to 143.136.79.254143.136.79.255510
41143.136.80.0/23143.136.80.1 to 143.136.81.254143.136.81.255510
42143.136.82.0/23143.136.82.1 to 143.136.83.254143.136.83.255510
43143.136.84.0/23143.136.84.1 to 143.136.85.254143.136.85.255510
44143.136.86.0/23143.136.86.1 to 143.136.87.254143.136.87.255510
45143.136.88.0/23143.136.88.1 to 143.136.89.254143.136.89.255510
46143.136.90.0/23143.136.90.1 to 143.136.91.254143.136.91.255510
47143.136.92.0/23143.136.92.1 to 143.136.93.254143.136.93.255510
48143.136.94.0/23143.136.94.1 to 143.136.95.254143.136.95.255510
49143.136.96.0/23143.136.96.1 to 143.136.97.254143.136.97.255510
50143.136.98.0/23143.136.98.1 to 143.136.99.254143.136.99.255510
51143.136.100.0/23143.136.100.1 to 143.136.101.254143.136.101.255510
52143.136.102.0/23143.136.102.1 to 143.136.103.254143.136.103.255510
53143.136.104.0/23143.136.104.1 to 143.136.105.254143.136.105.255510
54143.136.106.0/23143.136.106.1 to 143.136.107.254143.136.107.255510
55143.136.108.0/23143.136.108.1 to 143.136.109.254143.136.109.255510
56143.136.110.0/23143.136.110.1 to 143.136.111.254143.136.111.255510
57143.136.112.0/23143.136.112.1 to 143.136.113.254143.136.113.255510
58143.136.114.0/23143.136.114.1 to 143.136.115.254143.136.115.255510
59143.136.116.0/23143.136.116.1 to 143.136.117.254143.136.117.255510
60143.136.118.0/23143.136.118.1 to 143.136.119.254143.136.119.255510
61143.136.120.0/23143.136.120.1 to 143.136.121.254143.136.121.255510
62143.136.122.0/23143.136.122.1 to 143.136.123.254143.136.123.255510
63143.136.124.0/23143.136.124.1 to 143.136.125.254143.136.125.255510
64143.136.126.0/23143.136.126.1 to 143.136.127.254143.136.127.255510
65143.136.128.0/23143.136.128.1 to 143.136.129.254143.136.129.255510
66143.136.130.0/23143.136.130.1 to 143.136.131.254143.136.131.255510
67143.136.132.0/23143.136.132.1 to 143.136.133.254143.136.133.255510
68143.136.134.0/23143.136.134.1 to 143.136.135.254143.136.135.255510
69143.136.136.0/23143.136.136.1 to 143.136.137.254143.136.137.255510
70143.136.138.0/23143.136.138.1 to 143.136.139.254143.136.139.255510
71143.136.140.0/23143.136.140.1 to 143.136.141.254143.136.141.255510
72143.136.142.0/23143.136.142.1 to 143.136.143.254143.136.143.255510
73143.136.144.0/23143.136.144.1 to 143.136.145.254143.136.145.255510
74143.136.146.0/23143.136.146.1 to 143.136.147.254143.136.147.255510
75143.136.148.0/23143.136.148.1 to 143.136.149.254143.136.149.255510
76143.136.150.0/23143.136.150.1 to 143.136.151.254143.136.151.255510
77143.136.152.0/23143.136.152.1 to 143.136.153.254143.136.153.255510
78143.136.154.0/23143.136.154.1 to 143.136.155.254143.136.155.255510
79143.136.156.0/23143.136.156.1 to 143.136.157.254143.136.157.255510
80143.136.158.0/23143.136.158.1 to 143.136.159.254143.136.159.255510
81143.136.160.0/23143.136.160.1 to 143.136.161.254143.136.161.255510
82143.136.162.0/23143.136.162.1 to 143.136.163.254143.136.163.255510
83143.136.164.0/23143.136.164.1 to 143.136.165.254143.136.165.255510
84143.136.166.0/23143.136.166.1 to 143.136.167.254143.136.167.255510
85143.136.168.0/23143.136.168.1 to 143.136.169.254143.136.169.255510
86143.136.170.0/23143.136.170.1 to 143.136.171.254143.136.171.255510
87143.136.172.0/23143.136.172.1 to 143.136.173.254143.136.173.255510
88143.136.174.0/23143.136.174.1 to 143.136.175.254143.136.175.255510
89143.136.176.0/23143.136.176.1 to 143.136.177.254143.136.177.255510
90143.136.178.0/23143.136.178.1 to 143.136.179.254143.136.179.255510
91143.136.180.0/23143.136.180.1 to 143.136.181.254143.136.181.255510
92143.136.182.0/23143.136.182.1 to 143.136.183.254143.136.183.255510
93143.136.184.0/23143.136.184.1 to 143.136.185.254143.136.185.255510
94143.136.186.0/23143.136.186.1 to 143.136.187.254143.136.187.255510
95143.136.188.0/23143.136.188.1 to 143.136.189.254143.136.189.255510
96143.136.190.0/23143.136.190.1 to 143.136.191.254143.136.191.255510
97143.136.192.0/23143.136.192.1 to 143.136.193.254143.136.193.255510
98143.136.194.0/23143.136.194.1 to 143.136.195.254143.136.195.255510
99143.136.196.0/23143.136.196.1 to 143.136.197.254143.136.197.255510
100143.136.198.0/23143.136.198.1 to 143.136.199.254143.136.199.255510
101143.136.200.0/23143.136.200.1 to 143.136.201.254143.136.201.255510
102143.136.202.0/23143.136.202.1 to 143.136.203.254143.136.203.255510
103143.136.204.0/23143.136.204.1 to 143.136.205.254143.136.205.255510
104143.136.206.0/23143.136.206.1 to 143.136.207.254143.136.207.255510
105143.136.208.0/23143.136.208.1 to 143.136.209.254143.136.209.255510
106143.136.210.0/23143.136.210.1 to 143.136.211.254143.136.211.255510
107143.136.212.0/23143.136.212.1 to 143.136.213.254143.136.213.255510
108143.136.214.0/23143.136.214.1 to 143.136.215.254143.136.215.255510
109143.136.216.0/23143.136.216.1 to 143.136.217.254143.136.217.255510
110143.136.218.0/23143.136.218.1 to 143.136.219.254143.136.219.255510
111143.136.220.0/23143.136.220.1 to 143.136.221.254143.136.221.255510
112143.136.222.0/23143.136.222.1 to 143.136.223.254143.136.223.255510
113143.136.224.0/23143.136.224.1 to 143.136.225.254143.136.225.255510
114143.136.226.0/23143.136.226.1 to 143.136.227.254143.136.227.255510
115143.136.228.0/23143.136.228.1 to 143.136.229.254143.136.229.255510
116143.136.230.0/23143.136.230.1 to 143.136.231.254143.136.231.255510
117143.136.232.0/23143.136.232.1 to 143.136.233.254143.136.233.255510
118143.136.234.0/23143.136.234.1 to 143.136.235.254143.136.235.255510
119143.136.236.0/23143.136.236.1 to 143.136.237.254143.136.237.255510
120143.136.238.0/23143.136.238.1 to 143.136.239.254143.136.239.255510
121143.136.240.0/23143.136.240.1 to 143.136.241.254143.136.241.255510
122143.136.242.0/23143.136.242.1 to 143.136.243.254143.136.243.255510
123143.136.244.0/23143.136.244.1 to 143.136.245.254143.136.245.255510
124143.136.246.0/23143.136.246.1 to 143.136.247.254143.136.247.255510
125143.136.248.0/23143.136.248.1 to 143.136.249.254143.136.249.255510
126143.136.250.0/23143.136.250.1 to 143.136.251.254143.136.251.255510
127143.136.252.0/23143.136.252.1 to 143.136.253.254143.136.253.255510
128143.136.254.0/23143.136.254.1 to 143.136.255.254143.136.255.255510
129143.137.0.0/23143.137.0.1 to 143.137.1.254143.137.1.255510
130143.137.2.0/23143.137.2.1 to 143.137.3.254143.137.3.255510
131143.137.4.0/23143.137.4.1 to 143.137.5.254143.137.5.255510
132143.137.6.0/23143.137.6.1 to 143.137.7.254143.137.7.255510
133143.137.8.0/23143.137.8.1 to 143.137.9.254143.137.9.255510
134143.137.10.0/23143.137.10.1 to 143.137.11.254143.137.11.255510
135143.137.12.0/23143.137.12.1 to 143.137.13.254143.137.13.255510
136143.137.14.0/23143.137.14.1 to 143.137.15.254143.137.15.255510
137143.137.16.0/23143.137.16.1 to 143.137.17.254143.137.17.255510
138143.137.18.0/23143.137.18.1 to 143.137.19.254143.137.19.255510
139143.137.20.0/23143.137.20.1 to 143.137.21.254143.137.21.255510
140143.137.22.0/23143.137.22.1 to 143.137.23.254143.137.23.255510
141143.137.24.0/23143.137.24.1 to 143.137.25.254143.137.25.255510
142143.137.26.0/23143.137.26.1 to 143.137.27.254143.137.27.255510
143143.137.28.0/23143.137.28.1 to 143.137.29.254143.137.29.255510
144143.137.30.0/23143.137.30.1 to 143.137.31.254143.137.31.255510
145143.137.32.0/23143.137.32.1 to 143.137.33.254143.137.33.255510
146143.137.34.0/23143.137.34.1 to 143.137.35.254143.137.35.255510
147143.137.36.0/23143.137.36.1 to 143.137.37.254143.137.37.255510
148143.137.38.0/23143.137.38.1 to 143.137.39.254143.137.39.255510
149143.137.40.0/23143.137.40.1 to 143.137.41.254143.137.41.255510
150143.137.42.0/23143.137.42.1 to 143.137.43.254143.137.43.255510
151143.137.44.0/23143.137.44.1 to 143.137.45.254143.137.45.255510
152143.137.46.0/23143.137.46.1 to 143.137.47.254143.137.47.255510
153143.137.48.0/23143.137.48.1 to 143.137.49.254143.137.49.255510
154143.137.50.0/23143.137.50.1 to 143.137.51.254143.137.51.255510
155143.137.52.0/23143.137.52.1 to 143.137.53.254143.137.53.255510
156143.137.54.0/23143.137.54.1 to 143.137.55.254143.137.55.255510
157143.137.56.0/23143.137.56.1 to 143.137.57.254143.137.57.255510
158143.137.58.0/23143.137.58.1 to 143.137.59.254143.137.59.255510
159143.137.60.0/23143.137.60.1 to 143.137.61.254143.137.61.255510
160143.137.62.0/23143.137.62.1 to 143.137.63.254143.137.63.255510
161143.137.64.0/23143.137.64.1 to 143.137.65.254143.137.65.255510
162143.137.66.0/23143.137.66.1 to 143.137.67.254143.137.67.255510
163143.137.68.0/23143.137.68.1 to 143.137.69.254143.137.69.255510
164143.137.70.0/23143.137.70.1 to 143.137.71.254143.137.71.255510
165143.137.72.0/23143.137.72.1 to 143.137.73.254143.137.73.255510
166143.137.74.0/23143.137.74.1 to 143.137.75.254143.137.75.255510
167143.137.76.0/23143.137.76.1 to 143.137.77.254143.137.77.255510
168143.137.78.0/23143.137.78.1 to 143.137.79.254143.137.79.255510
169143.137.80.0/23143.137.80.1 to 143.137.81.254143.137.81.255510
170143.137.82.0/23143.137.82.1 to 143.137.83.254143.137.83.255510
171143.137.84.0/23143.137.84.1 to 143.137.85.254143.137.85.255510
172143.137.86.0/23143.137.86.1 to 143.137.87.254143.137.87.255510
173143.137.88.0/23143.137.88.1 to 143.137.89.254143.137.89.255510
174143.137.90.0/23143.137.90.1 to 143.137.91.254143.137.91.255510
175143.137.92.0/23143.137.92.1 to 143.137.93.254143.137.93.255510
176143.137.94.0/23143.137.94.1 to 143.137.95.254143.137.95.255510
177143.137.96.0/23143.137.96.1 to 143.137.97.254143.137.97.255510
178143.137.98.0/23143.137.98.1 to 143.137.99.254143.137.99.255510
179143.137.100.0/23143.137.100.1 to 143.137.101.254143.137.101.255510
180143.137.102.0/23143.137.102.1 to 143.137.103.254143.137.103.255510
181143.137.104.0/23143.137.104.1 to 143.137.105.254143.137.105.255510
182143.137.106.0/23143.137.106.1 to 143.137.107.254143.137.107.255510
183143.137.108.0/23143.137.108.1 to 143.137.109.254143.137.109.255510
184143.137.110.0/23143.137.110.1 to 143.137.111.254143.137.111.255510
185143.137.112.0/23143.137.112.1 to 143.137.113.254143.137.113.255510
186143.137.114.0/23143.137.114.1 to 143.137.115.254143.137.115.255510
187143.137.116.0/23143.137.116.1 to 143.137.117.254143.137.117.255510
188143.137.118.0/23143.137.118.1 to 143.137.119.254143.137.119.255510
189143.137.120.0/23143.137.120.1 to 143.137.121.254143.137.121.255510
190143.137.122.0/23143.137.122.1 to 143.137.123.254143.137.123.255510
191143.137.124.0/23143.137.124.1 to 143.137.125.254143.137.125.255510
192143.137.126.0/23143.137.126.1 to 143.137.127.254143.137.127.255510
193143.137.128.0/23143.137.128.1 to 143.137.129.254143.137.129.255510
194143.137.130.0/23143.137.130.1 to 143.137.131.254143.137.131.255510
195143.137.132.0/23143.137.132.1 to 143.137.133.254143.137.133.255510
196143.137.134.0/23143.137.134.1 to 143.137.135.254143.137.135.255510
197143.137.136.0/23143.137.136.1 to 143.137.137.254143.137.137.255510
198143.137.138.0/23143.137.138.1 to 143.137.139.254143.137.139.255510
199143.137.140.0/23143.137.140.1 to 143.137.141.254143.137.141.255510
200143.137.142.0/23143.137.142.1 to 143.137.143.254143.137.143.255510
201143.137.144.0/23143.137.144.1 to 143.137.145.254143.137.145.255510
202143.137.146.0/23143.137.146.1 to 143.137.147.254143.137.147.255510
203143.137.148.0/23143.137.148.1 to 143.137.149.254143.137.149.255510
204143.137.150.0/23143.137.150.1 to 143.137.151.254143.137.151.255510
205143.137.152.0/23143.137.152.1 to 143.137.153.254143.137.153.255510
206143.137.154.0/23143.137.154.1 to 143.137.155.254143.137.155.255510
207143.137.156.0/23143.137.156.1 to 143.137.157.254143.137.157.255510
208143.137.158.0/23143.137.158.1 to 143.137.159.254143.137.159.255510
209143.137.160.0/23143.137.160.1 to 143.137.161.254143.137.161.255510
210143.137.162.0/23143.137.162.1 to 143.137.163.254143.137.163.255510
211143.137.164.0/23143.137.164.1 to 143.137.165.254143.137.165.255510
212143.137.166.0/23143.137.166.1 to 143.137.167.254143.137.167.255510
213143.137.168.0/23143.137.168.1 to 143.137.169.254143.137.169.255510
214143.137.170.0/23143.137.170.1 to 143.137.171.254143.137.171.255510
215143.137.172.0/23143.137.172.1 to 143.137.173.254143.137.173.255510
216143.137.174.0/23143.137.174.1 to 143.137.175.254143.137.175.255510
217143.137.176.0/23143.137.176.1 to 143.137.177.254143.137.177.255510
218143.137.178.0/23143.137.178.1 to 143.137.179.254143.137.179.255510
219143.137.180.0/23143.137.180.1 to 143.137.181.254143.137.181.255510
220143.137.182.0/23143.137.182.1 to 143.137.183.254143.137.183.255510
221143.137.184.0/23143.137.184.1 to 143.137.185.254143.137.185.255510
222143.137.186.0/23143.137.186.1 to 143.137.187.254143.137.187.255510
223143.137.188.0/23143.137.188.1 to 143.137.189.254143.137.189.255510
224143.137.190.0/23143.137.190.1 to 143.137.191.254143.137.191.255510
225143.137.192.0/23143.137.192.1 to 143.137.193.254143.137.193.255510
226143.137.194.0/23143.137.194.1 to 143.137.195.254143.137.195.255510
227143.137.196.0/23143.137.196.1 to 143.137.197.254143.137.197.255510
228143.137.198.0/23143.137.198.1 to 143.137.199.254143.137.199.255510
229143.137.200.0/23143.137.200.1 to 143.137.201.254143.137.201.255510
230143.137.202.0/23143.137.202.1 to 143.137.203.254143.137.203.255510
231143.137.204.0/23143.137.204.1 to 143.137.205.254143.137.205.255510
232143.137.206.0/23143.137.206.1 to 143.137.207.254143.137.207.255510
233143.137.208.0/23143.137.208.1 to 143.137.209.254143.137.209.255510
234143.137.210.0/23143.137.210.1 to 143.137.211.254143.137.211.255510
235143.137.212.0/23143.137.212.1 to 143.137.213.254143.137.213.255510
236143.137.214.0/23143.137.214.1 to 143.137.215.254143.137.215.255510
237143.137.216.0/23143.137.216.1 to 143.137.217.254143.137.217.255510
238143.137.218.0/23143.137.218.1 to 143.137.219.254143.137.219.255510
239143.137.220.0/23143.137.220.1 to 143.137.221.254143.137.221.255510
240143.137.222.0/23143.137.222.1 to 143.137.223.254143.137.223.255510
241143.137.224.0/23143.137.224.1 to 143.137.225.254143.137.225.255510
242143.137.226.0/23143.137.226.1 to 143.137.227.254143.137.227.255510
243143.137.228.0/23143.137.228.1 to 143.137.229.254143.137.229.255510
244143.137.230.0/23143.137.230.1 to 143.137.231.254143.137.231.255510
245143.137.232.0/23143.137.232.1 to 143.137.233.254143.137.233.255510
246143.137.234.0/23143.137.234.1 to 143.137.235.254143.137.235.255510
247143.137.236.0/23143.137.236.1 to 143.137.237.254143.137.237.255510
248143.137.238.0/23143.137.238.1 to 143.137.239.254143.137.239.255510
249143.137.240.0/23143.137.240.1 to 143.137.241.254143.137.241.255510
250143.137.242.0/23143.137.242.1 to 143.137.243.254143.137.243.255510
251143.137.244.0/23143.137.244.1 to 143.137.245.254143.137.245.255510
252143.137.246.0/23143.137.246.1 to 143.137.247.254143.137.247.255510
253143.137.248.0/23143.137.248.1 to 143.137.249.254143.137.249.255510
254143.137.250.0/23143.137.250.1 to 143.137.251.254143.137.251.255510
255143.137.252.0/23143.137.252.1 to 143.137.253.254143.137.253.255510
256143.137.254.0/23143.137.254.1 to 143.137.255.254143.137.255.255510

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.