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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.

Network129.0.0.0/14
Usable hosts262,142
Subnet mask255.252.0.0
Addresses262,144
Network address
129.0.0.0
Broadcast address
129.3.255.255
First usable
129.0.0.1
Last usable
129.3.255.254
Usable hosts
262,142 (262,144 less the network and broadcast addresses)
Subnet mask
255.252.0.0
Wildcard mask
0.3.255.255 (Cisco ACLs, OSPF)
Prefix length
/14
Type
Public public
Old class
B (default /16)
As numbers
Hex 81000000 · Integer 2164260864 to 2164523007
Reverse DNS zones
0.129.in-addr.arpa
1.129.in-addr.arpa
2.129.in-addr.arpa
3.129.in-addr.arpa
/14 is not on a 8-bit boundary, so it takes 4 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10000001.00000000.00000000.00000000129.0.0.0
Subnet mask11111111.11111100.00000000.00000000255.252.0.0
Network10000001.00000000.00000000.00000000129.0.0.0
Broadcast10000001.00000011.11111111.11111111129.3.255.255
Split into smaller subnets/24
/15 (2)/16 (4)/17 (8)/18 (16)/19 (32)/20 (64)/21 (128)/22 (256)/23 (512)/24 (1,024)/25 (2,048)/26 (4,096)

129.0.0.0/14 makes 1,024 subnets of /24; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1129.0.0.0/24129.0.0.1 to 129.0.0.254129.0.0.255254
2129.0.1.0/24129.0.1.1 to 129.0.1.254129.0.1.255254
3129.0.2.0/24129.0.2.1 to 129.0.2.254129.0.2.255254
4129.0.3.0/24129.0.3.1 to 129.0.3.254129.0.3.255254
5129.0.4.0/24129.0.4.1 to 129.0.4.254129.0.4.255254
6129.0.5.0/24129.0.5.1 to 129.0.5.254129.0.5.255254
7129.0.6.0/24129.0.6.1 to 129.0.6.254129.0.6.255254
8129.0.7.0/24129.0.7.1 to 129.0.7.254129.0.7.255254
9129.0.8.0/24129.0.8.1 to 129.0.8.254129.0.8.255254
10129.0.9.0/24129.0.9.1 to 129.0.9.254129.0.9.255254
11129.0.10.0/24129.0.10.1 to 129.0.10.254129.0.10.255254
12129.0.11.0/24129.0.11.1 to 129.0.11.254129.0.11.255254
13129.0.12.0/24129.0.12.1 to 129.0.12.254129.0.12.255254
14129.0.13.0/24129.0.13.1 to 129.0.13.254129.0.13.255254
15129.0.14.0/24129.0.14.1 to 129.0.14.254129.0.14.255254
16129.0.15.0/24129.0.15.1 to 129.0.15.254129.0.15.255254
17129.0.16.0/24129.0.16.1 to 129.0.16.254129.0.16.255254
18129.0.17.0/24129.0.17.1 to 129.0.17.254129.0.17.255254
19129.0.18.0/24129.0.18.1 to 129.0.18.254129.0.18.255254
20129.0.19.0/24129.0.19.1 to 129.0.19.254129.0.19.255254
21129.0.20.0/24129.0.20.1 to 129.0.20.254129.0.20.255254
22129.0.21.0/24129.0.21.1 to 129.0.21.254129.0.21.255254
23129.0.22.0/24129.0.22.1 to 129.0.22.254129.0.22.255254
24129.0.23.0/24129.0.23.1 to 129.0.23.254129.0.23.255254
25129.0.24.0/24129.0.24.1 to 129.0.24.254129.0.24.255254
26129.0.25.0/24129.0.25.1 to 129.0.25.254129.0.25.255254
27129.0.26.0/24129.0.26.1 to 129.0.26.254129.0.26.255254
28129.0.27.0/24129.0.27.1 to 129.0.27.254129.0.27.255254
29129.0.28.0/24129.0.28.1 to 129.0.28.254129.0.28.255254
30129.0.29.0/24129.0.29.1 to 129.0.29.254129.0.29.255254
31129.0.30.0/24129.0.30.1 to 129.0.30.254129.0.30.255254
32129.0.31.0/24129.0.31.1 to 129.0.31.254129.0.31.255254
33129.0.32.0/24129.0.32.1 to 129.0.32.254129.0.32.255254
34129.0.33.0/24129.0.33.1 to 129.0.33.254129.0.33.255254
35129.0.34.0/24129.0.34.1 to 129.0.34.254129.0.34.255254
36129.0.35.0/24129.0.35.1 to 129.0.35.254129.0.35.255254
37129.0.36.0/24129.0.36.1 to 129.0.36.254129.0.36.255254
38129.0.37.0/24129.0.37.1 to 129.0.37.254129.0.37.255254
39129.0.38.0/24129.0.38.1 to 129.0.38.254129.0.38.255254
40129.0.39.0/24129.0.39.1 to 129.0.39.254129.0.39.255254
41129.0.40.0/24129.0.40.1 to 129.0.40.254129.0.40.255254
42129.0.41.0/24129.0.41.1 to 129.0.41.254129.0.41.255254
43129.0.42.0/24129.0.42.1 to 129.0.42.254129.0.42.255254
44129.0.43.0/24129.0.43.1 to 129.0.43.254129.0.43.255254
45129.0.44.0/24129.0.44.1 to 129.0.44.254129.0.44.255254
46129.0.45.0/24129.0.45.1 to 129.0.45.254129.0.45.255254
47129.0.46.0/24129.0.46.1 to 129.0.46.254129.0.46.255254
48129.0.47.0/24129.0.47.1 to 129.0.47.254129.0.47.255254
49129.0.48.0/24129.0.48.1 to 129.0.48.254129.0.48.255254
50129.0.49.0/24129.0.49.1 to 129.0.49.254129.0.49.255254
51129.0.50.0/24129.0.50.1 to 129.0.50.254129.0.50.255254
52129.0.51.0/24129.0.51.1 to 129.0.51.254129.0.51.255254
53129.0.52.0/24129.0.52.1 to 129.0.52.254129.0.52.255254
54129.0.53.0/24129.0.53.1 to 129.0.53.254129.0.53.255254
55129.0.54.0/24129.0.54.1 to 129.0.54.254129.0.54.255254
56129.0.55.0/24129.0.55.1 to 129.0.55.254129.0.55.255254
57129.0.56.0/24129.0.56.1 to 129.0.56.254129.0.56.255254
58129.0.57.0/24129.0.57.1 to 129.0.57.254129.0.57.255254
59129.0.58.0/24129.0.58.1 to 129.0.58.254129.0.58.255254
60129.0.59.0/24129.0.59.1 to 129.0.59.254129.0.59.255254
61129.0.60.0/24129.0.60.1 to 129.0.60.254129.0.60.255254
62129.0.61.0/24129.0.61.1 to 129.0.61.254129.0.61.255254
63129.0.62.0/24129.0.62.1 to 129.0.62.254129.0.62.255254
64129.0.63.0/24129.0.63.1 to 129.0.63.254129.0.63.255254
65129.0.64.0/24129.0.64.1 to 129.0.64.254129.0.64.255254
66129.0.65.0/24129.0.65.1 to 129.0.65.254129.0.65.255254
67129.0.66.0/24129.0.66.1 to 129.0.66.254129.0.66.255254
68129.0.67.0/24129.0.67.1 to 129.0.67.254129.0.67.255254
69129.0.68.0/24129.0.68.1 to 129.0.68.254129.0.68.255254
70129.0.69.0/24129.0.69.1 to 129.0.69.254129.0.69.255254
71129.0.70.0/24129.0.70.1 to 129.0.70.254129.0.70.255254
72129.0.71.0/24129.0.71.1 to 129.0.71.254129.0.71.255254
73129.0.72.0/24129.0.72.1 to 129.0.72.254129.0.72.255254
74129.0.73.0/24129.0.73.1 to 129.0.73.254129.0.73.255254
75129.0.74.0/24129.0.74.1 to 129.0.74.254129.0.74.255254
76129.0.75.0/24129.0.75.1 to 129.0.75.254129.0.75.255254
77129.0.76.0/24129.0.76.1 to 129.0.76.254129.0.76.255254
78129.0.77.0/24129.0.77.1 to 129.0.77.254129.0.77.255254
79129.0.78.0/24129.0.78.1 to 129.0.78.254129.0.78.255254
80129.0.79.0/24129.0.79.1 to 129.0.79.254129.0.79.255254
81129.0.80.0/24129.0.80.1 to 129.0.80.254129.0.80.255254
82129.0.81.0/24129.0.81.1 to 129.0.81.254129.0.81.255254
83129.0.82.0/24129.0.82.1 to 129.0.82.254129.0.82.255254
84129.0.83.0/24129.0.83.1 to 129.0.83.254129.0.83.255254
85129.0.84.0/24129.0.84.1 to 129.0.84.254129.0.84.255254
86129.0.85.0/24129.0.85.1 to 129.0.85.254129.0.85.255254
87129.0.86.0/24129.0.86.1 to 129.0.86.254129.0.86.255254
88129.0.87.0/24129.0.87.1 to 129.0.87.254129.0.87.255254
89129.0.88.0/24129.0.88.1 to 129.0.88.254129.0.88.255254
90129.0.89.0/24129.0.89.1 to 129.0.89.254129.0.89.255254
91129.0.90.0/24129.0.90.1 to 129.0.90.254129.0.90.255254
92129.0.91.0/24129.0.91.1 to 129.0.91.254129.0.91.255254
93129.0.92.0/24129.0.92.1 to 129.0.92.254129.0.92.255254
94129.0.93.0/24129.0.93.1 to 129.0.93.254129.0.93.255254
95129.0.94.0/24129.0.94.1 to 129.0.94.254129.0.94.255254
96129.0.95.0/24129.0.95.1 to 129.0.95.254129.0.95.255254
97129.0.96.0/24129.0.96.1 to 129.0.96.254129.0.96.255254
98129.0.97.0/24129.0.97.1 to 129.0.97.254129.0.97.255254
99129.0.98.0/24129.0.98.1 to 129.0.98.254129.0.98.255254
100129.0.99.0/24129.0.99.1 to 129.0.99.254129.0.99.255254
101129.0.100.0/24129.0.100.1 to 129.0.100.254129.0.100.255254
102129.0.101.0/24129.0.101.1 to 129.0.101.254129.0.101.255254
103129.0.102.0/24129.0.102.1 to 129.0.102.254129.0.102.255254
104129.0.103.0/24129.0.103.1 to 129.0.103.254129.0.103.255254
105129.0.104.0/24129.0.104.1 to 129.0.104.254129.0.104.255254
106129.0.105.0/24129.0.105.1 to 129.0.105.254129.0.105.255254
107129.0.106.0/24129.0.106.1 to 129.0.106.254129.0.106.255254
108129.0.107.0/24129.0.107.1 to 129.0.107.254129.0.107.255254
109129.0.108.0/24129.0.108.1 to 129.0.108.254129.0.108.255254
110129.0.109.0/24129.0.109.1 to 129.0.109.254129.0.109.255254
111129.0.110.0/24129.0.110.1 to 129.0.110.254129.0.110.255254
112129.0.111.0/24129.0.111.1 to 129.0.111.254129.0.111.255254
113129.0.112.0/24129.0.112.1 to 129.0.112.254129.0.112.255254
114129.0.113.0/24129.0.113.1 to 129.0.113.254129.0.113.255254
115129.0.114.0/24129.0.114.1 to 129.0.114.254129.0.114.255254
116129.0.115.0/24129.0.115.1 to 129.0.115.254129.0.115.255254
117129.0.116.0/24129.0.116.1 to 129.0.116.254129.0.116.255254
118129.0.117.0/24129.0.117.1 to 129.0.117.254129.0.117.255254
119129.0.118.0/24129.0.118.1 to 129.0.118.254129.0.118.255254
120129.0.119.0/24129.0.119.1 to 129.0.119.254129.0.119.255254
121129.0.120.0/24129.0.120.1 to 129.0.120.254129.0.120.255254
122129.0.121.0/24129.0.121.1 to 129.0.121.254129.0.121.255254
123129.0.122.0/24129.0.122.1 to 129.0.122.254129.0.122.255254
124129.0.123.0/24129.0.123.1 to 129.0.123.254129.0.123.255254
125129.0.124.0/24129.0.124.1 to 129.0.124.254129.0.124.255254
126129.0.125.0/24129.0.125.1 to 129.0.125.254129.0.125.255254
127129.0.126.0/24129.0.126.1 to 129.0.126.254129.0.126.255254
128129.0.127.0/24129.0.127.1 to 129.0.127.254129.0.127.255254
129129.0.128.0/24129.0.128.1 to 129.0.128.254129.0.128.255254
130129.0.129.0/24129.0.129.1 to 129.0.129.254129.0.129.255254
131129.0.130.0/24129.0.130.1 to 129.0.130.254129.0.130.255254
132129.0.131.0/24129.0.131.1 to 129.0.131.254129.0.131.255254
133129.0.132.0/24129.0.132.1 to 129.0.132.254129.0.132.255254
134129.0.133.0/24129.0.133.1 to 129.0.133.254129.0.133.255254
135129.0.134.0/24129.0.134.1 to 129.0.134.254129.0.134.255254
136129.0.135.0/24129.0.135.1 to 129.0.135.254129.0.135.255254
137129.0.136.0/24129.0.136.1 to 129.0.136.254129.0.136.255254
138129.0.137.0/24129.0.137.1 to 129.0.137.254129.0.137.255254
139129.0.138.0/24129.0.138.1 to 129.0.138.254129.0.138.255254
140129.0.139.0/24129.0.139.1 to 129.0.139.254129.0.139.255254
141129.0.140.0/24129.0.140.1 to 129.0.140.254129.0.140.255254
142129.0.141.0/24129.0.141.1 to 129.0.141.254129.0.141.255254
143129.0.142.0/24129.0.142.1 to 129.0.142.254129.0.142.255254
144129.0.143.0/24129.0.143.1 to 129.0.143.254129.0.143.255254
145129.0.144.0/24129.0.144.1 to 129.0.144.254129.0.144.255254
146129.0.145.0/24129.0.145.1 to 129.0.145.254129.0.145.255254
147129.0.146.0/24129.0.146.1 to 129.0.146.254129.0.146.255254
148129.0.147.0/24129.0.147.1 to 129.0.147.254129.0.147.255254
149129.0.148.0/24129.0.148.1 to 129.0.148.254129.0.148.255254
150129.0.149.0/24129.0.149.1 to 129.0.149.254129.0.149.255254
151129.0.150.0/24129.0.150.1 to 129.0.150.254129.0.150.255254
152129.0.151.0/24129.0.151.1 to 129.0.151.254129.0.151.255254
153129.0.152.0/24129.0.152.1 to 129.0.152.254129.0.152.255254
154129.0.153.0/24129.0.153.1 to 129.0.153.254129.0.153.255254
155129.0.154.0/24129.0.154.1 to 129.0.154.254129.0.154.255254
156129.0.155.0/24129.0.155.1 to 129.0.155.254129.0.155.255254
157129.0.156.0/24129.0.156.1 to 129.0.156.254129.0.156.255254
158129.0.157.0/24129.0.157.1 to 129.0.157.254129.0.157.255254
159129.0.158.0/24129.0.158.1 to 129.0.158.254129.0.158.255254
160129.0.159.0/24129.0.159.1 to 129.0.159.254129.0.159.255254
161129.0.160.0/24129.0.160.1 to 129.0.160.254129.0.160.255254
162129.0.161.0/24129.0.161.1 to 129.0.161.254129.0.161.255254
163129.0.162.0/24129.0.162.1 to 129.0.162.254129.0.162.255254
164129.0.163.0/24129.0.163.1 to 129.0.163.254129.0.163.255254
165129.0.164.0/24129.0.164.1 to 129.0.164.254129.0.164.255254
166129.0.165.0/24129.0.165.1 to 129.0.165.254129.0.165.255254
167129.0.166.0/24129.0.166.1 to 129.0.166.254129.0.166.255254
168129.0.167.0/24129.0.167.1 to 129.0.167.254129.0.167.255254
169129.0.168.0/24129.0.168.1 to 129.0.168.254129.0.168.255254
170129.0.169.0/24129.0.169.1 to 129.0.169.254129.0.169.255254
171129.0.170.0/24129.0.170.1 to 129.0.170.254129.0.170.255254
172129.0.171.0/24129.0.171.1 to 129.0.171.254129.0.171.255254
173129.0.172.0/24129.0.172.1 to 129.0.172.254129.0.172.255254
174129.0.173.0/24129.0.173.1 to 129.0.173.254129.0.173.255254
175129.0.174.0/24129.0.174.1 to 129.0.174.254129.0.174.255254
176129.0.175.0/24129.0.175.1 to 129.0.175.254129.0.175.255254
177129.0.176.0/24129.0.176.1 to 129.0.176.254129.0.176.255254
178129.0.177.0/24129.0.177.1 to 129.0.177.254129.0.177.255254
179129.0.178.0/24129.0.178.1 to 129.0.178.254129.0.178.255254
180129.0.179.0/24129.0.179.1 to 129.0.179.254129.0.179.255254
181129.0.180.0/24129.0.180.1 to 129.0.180.254129.0.180.255254
182129.0.181.0/24129.0.181.1 to 129.0.181.254129.0.181.255254
183129.0.182.0/24129.0.182.1 to 129.0.182.254129.0.182.255254
184129.0.183.0/24129.0.183.1 to 129.0.183.254129.0.183.255254
185129.0.184.0/24129.0.184.1 to 129.0.184.254129.0.184.255254
186129.0.185.0/24129.0.185.1 to 129.0.185.254129.0.185.255254
187129.0.186.0/24129.0.186.1 to 129.0.186.254129.0.186.255254
188129.0.187.0/24129.0.187.1 to 129.0.187.254129.0.187.255254
189129.0.188.0/24129.0.188.1 to 129.0.188.254129.0.188.255254
190129.0.189.0/24129.0.189.1 to 129.0.189.254129.0.189.255254
191129.0.190.0/24129.0.190.1 to 129.0.190.254129.0.190.255254
192129.0.191.0/24129.0.191.1 to 129.0.191.254129.0.191.255254
193129.0.192.0/24129.0.192.1 to 129.0.192.254129.0.192.255254
194129.0.193.0/24129.0.193.1 to 129.0.193.254129.0.193.255254
195129.0.194.0/24129.0.194.1 to 129.0.194.254129.0.194.255254
196129.0.195.0/24129.0.195.1 to 129.0.195.254129.0.195.255254
197129.0.196.0/24129.0.196.1 to 129.0.196.254129.0.196.255254
198129.0.197.0/24129.0.197.1 to 129.0.197.254129.0.197.255254
199129.0.198.0/24129.0.198.1 to 129.0.198.254129.0.198.255254
200129.0.199.0/24129.0.199.1 to 129.0.199.254129.0.199.255254
201129.0.200.0/24129.0.200.1 to 129.0.200.254129.0.200.255254
202129.0.201.0/24129.0.201.1 to 129.0.201.254129.0.201.255254
203129.0.202.0/24129.0.202.1 to 129.0.202.254129.0.202.255254
204129.0.203.0/24129.0.203.1 to 129.0.203.254129.0.203.255254
205129.0.204.0/24129.0.204.1 to 129.0.204.254129.0.204.255254
206129.0.205.0/24129.0.205.1 to 129.0.205.254129.0.205.255254
207129.0.206.0/24129.0.206.1 to 129.0.206.254129.0.206.255254
208129.0.207.0/24129.0.207.1 to 129.0.207.254129.0.207.255254
209129.0.208.0/24129.0.208.1 to 129.0.208.254129.0.208.255254
210129.0.209.0/24129.0.209.1 to 129.0.209.254129.0.209.255254
211129.0.210.0/24129.0.210.1 to 129.0.210.254129.0.210.255254
212129.0.211.0/24129.0.211.1 to 129.0.211.254129.0.211.255254
213129.0.212.0/24129.0.212.1 to 129.0.212.254129.0.212.255254
214129.0.213.0/24129.0.213.1 to 129.0.213.254129.0.213.255254
215129.0.214.0/24129.0.214.1 to 129.0.214.254129.0.214.255254
216129.0.215.0/24129.0.215.1 to 129.0.215.254129.0.215.255254
217129.0.216.0/24129.0.216.1 to 129.0.216.254129.0.216.255254
218129.0.217.0/24129.0.217.1 to 129.0.217.254129.0.217.255254
219129.0.218.0/24129.0.218.1 to 129.0.218.254129.0.218.255254
220129.0.219.0/24129.0.219.1 to 129.0.219.254129.0.219.255254
221129.0.220.0/24129.0.220.1 to 129.0.220.254129.0.220.255254
222129.0.221.0/24129.0.221.1 to 129.0.221.254129.0.221.255254
223129.0.222.0/24129.0.222.1 to 129.0.222.254129.0.222.255254
224129.0.223.0/24129.0.223.1 to 129.0.223.254129.0.223.255254
225129.0.224.0/24129.0.224.1 to 129.0.224.254129.0.224.255254
226129.0.225.0/24129.0.225.1 to 129.0.225.254129.0.225.255254
227129.0.226.0/24129.0.226.1 to 129.0.226.254129.0.226.255254
228129.0.227.0/24129.0.227.1 to 129.0.227.254129.0.227.255254
229129.0.228.0/24129.0.228.1 to 129.0.228.254129.0.228.255254
230129.0.229.0/24129.0.229.1 to 129.0.229.254129.0.229.255254
231129.0.230.0/24129.0.230.1 to 129.0.230.254129.0.230.255254
232129.0.231.0/24129.0.231.1 to 129.0.231.254129.0.231.255254
233129.0.232.0/24129.0.232.1 to 129.0.232.254129.0.232.255254
234129.0.233.0/24129.0.233.1 to 129.0.233.254129.0.233.255254
235129.0.234.0/24129.0.234.1 to 129.0.234.254129.0.234.255254
236129.0.235.0/24129.0.235.1 to 129.0.235.254129.0.235.255254
237129.0.236.0/24129.0.236.1 to 129.0.236.254129.0.236.255254
238129.0.237.0/24129.0.237.1 to 129.0.237.254129.0.237.255254
239129.0.238.0/24129.0.238.1 to 129.0.238.254129.0.238.255254
240129.0.239.0/24129.0.239.1 to 129.0.239.254129.0.239.255254
241129.0.240.0/24129.0.240.1 to 129.0.240.254129.0.240.255254
242129.0.241.0/24129.0.241.1 to 129.0.241.254129.0.241.255254
243129.0.242.0/24129.0.242.1 to 129.0.242.254129.0.242.255254
244129.0.243.0/24129.0.243.1 to 129.0.243.254129.0.243.255254
245129.0.244.0/24129.0.244.1 to 129.0.244.254129.0.244.255254
246129.0.245.0/24129.0.245.1 to 129.0.245.254129.0.245.255254
247129.0.246.0/24129.0.246.1 to 129.0.246.254129.0.246.255254
248129.0.247.0/24129.0.247.1 to 129.0.247.254129.0.247.255254
249129.0.248.0/24129.0.248.1 to 129.0.248.254129.0.248.255254
250129.0.249.0/24129.0.249.1 to 129.0.249.254129.0.249.255254
251129.0.250.0/24129.0.250.1 to 129.0.250.254129.0.250.255254
252129.0.251.0/24129.0.251.1 to 129.0.251.254129.0.251.255254
253129.0.252.0/24129.0.252.1 to 129.0.252.254129.0.252.255254
254129.0.253.0/24129.0.253.1 to 129.0.253.254129.0.253.255254
255129.0.254.0/24129.0.254.1 to 129.0.254.254129.0.254.255254
256129.0.255.0/24129.0.255.1 to 129.0.255.254129.0.255.255254

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.