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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.

Network124.22.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
124.22.0.0
Broadcast address
124.23.255.255
First usable
124.22.0.1
Last usable
124.23.255.254
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
A (default /8)
As numbers
Hex 7C160000 · Integer 2081816576 to 2081947647
Reverse DNS zones
22.124.in-addr.arpa
23.124.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
Address01111100.00010110.00000000.00000000124.22.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network01111100.00010110.00000000.00000000124.22.0.0
Broadcast01111100.00010111.11111111.11111111124.23.255.255
Split into smaller subnets/24
/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)

124.22.0.0/15 makes 512 subnets of /24; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1124.22.0.0/24124.22.0.1 to 124.22.0.254124.22.0.255254
2124.22.1.0/24124.22.1.1 to 124.22.1.254124.22.1.255254
3124.22.2.0/24124.22.2.1 to 124.22.2.254124.22.2.255254
4124.22.3.0/24124.22.3.1 to 124.22.3.254124.22.3.255254
5124.22.4.0/24124.22.4.1 to 124.22.4.254124.22.4.255254
6124.22.5.0/24124.22.5.1 to 124.22.5.254124.22.5.255254
7124.22.6.0/24124.22.6.1 to 124.22.6.254124.22.6.255254
8124.22.7.0/24124.22.7.1 to 124.22.7.254124.22.7.255254
9124.22.8.0/24124.22.8.1 to 124.22.8.254124.22.8.255254
10124.22.9.0/24124.22.9.1 to 124.22.9.254124.22.9.255254
11124.22.10.0/24124.22.10.1 to 124.22.10.254124.22.10.255254
12124.22.11.0/24124.22.11.1 to 124.22.11.254124.22.11.255254
13124.22.12.0/24124.22.12.1 to 124.22.12.254124.22.12.255254
14124.22.13.0/24124.22.13.1 to 124.22.13.254124.22.13.255254
15124.22.14.0/24124.22.14.1 to 124.22.14.254124.22.14.255254
16124.22.15.0/24124.22.15.1 to 124.22.15.254124.22.15.255254
17124.22.16.0/24124.22.16.1 to 124.22.16.254124.22.16.255254
18124.22.17.0/24124.22.17.1 to 124.22.17.254124.22.17.255254
19124.22.18.0/24124.22.18.1 to 124.22.18.254124.22.18.255254
20124.22.19.0/24124.22.19.1 to 124.22.19.254124.22.19.255254
21124.22.20.0/24124.22.20.1 to 124.22.20.254124.22.20.255254
22124.22.21.0/24124.22.21.1 to 124.22.21.254124.22.21.255254
23124.22.22.0/24124.22.22.1 to 124.22.22.254124.22.22.255254
24124.22.23.0/24124.22.23.1 to 124.22.23.254124.22.23.255254
25124.22.24.0/24124.22.24.1 to 124.22.24.254124.22.24.255254
26124.22.25.0/24124.22.25.1 to 124.22.25.254124.22.25.255254
27124.22.26.0/24124.22.26.1 to 124.22.26.254124.22.26.255254
28124.22.27.0/24124.22.27.1 to 124.22.27.254124.22.27.255254
29124.22.28.0/24124.22.28.1 to 124.22.28.254124.22.28.255254
30124.22.29.0/24124.22.29.1 to 124.22.29.254124.22.29.255254
31124.22.30.0/24124.22.30.1 to 124.22.30.254124.22.30.255254
32124.22.31.0/24124.22.31.1 to 124.22.31.254124.22.31.255254
33124.22.32.0/24124.22.32.1 to 124.22.32.254124.22.32.255254
34124.22.33.0/24124.22.33.1 to 124.22.33.254124.22.33.255254
35124.22.34.0/24124.22.34.1 to 124.22.34.254124.22.34.255254
36124.22.35.0/24124.22.35.1 to 124.22.35.254124.22.35.255254
37124.22.36.0/24124.22.36.1 to 124.22.36.254124.22.36.255254
38124.22.37.0/24124.22.37.1 to 124.22.37.254124.22.37.255254
39124.22.38.0/24124.22.38.1 to 124.22.38.254124.22.38.255254
40124.22.39.0/24124.22.39.1 to 124.22.39.254124.22.39.255254
41124.22.40.0/24124.22.40.1 to 124.22.40.254124.22.40.255254
42124.22.41.0/24124.22.41.1 to 124.22.41.254124.22.41.255254
43124.22.42.0/24124.22.42.1 to 124.22.42.254124.22.42.255254
44124.22.43.0/24124.22.43.1 to 124.22.43.254124.22.43.255254
45124.22.44.0/24124.22.44.1 to 124.22.44.254124.22.44.255254
46124.22.45.0/24124.22.45.1 to 124.22.45.254124.22.45.255254
47124.22.46.0/24124.22.46.1 to 124.22.46.254124.22.46.255254
48124.22.47.0/24124.22.47.1 to 124.22.47.254124.22.47.255254
49124.22.48.0/24124.22.48.1 to 124.22.48.254124.22.48.255254
50124.22.49.0/24124.22.49.1 to 124.22.49.254124.22.49.255254
51124.22.50.0/24124.22.50.1 to 124.22.50.254124.22.50.255254
52124.22.51.0/24124.22.51.1 to 124.22.51.254124.22.51.255254
53124.22.52.0/24124.22.52.1 to 124.22.52.254124.22.52.255254
54124.22.53.0/24124.22.53.1 to 124.22.53.254124.22.53.255254
55124.22.54.0/24124.22.54.1 to 124.22.54.254124.22.54.255254
56124.22.55.0/24124.22.55.1 to 124.22.55.254124.22.55.255254
57124.22.56.0/24124.22.56.1 to 124.22.56.254124.22.56.255254
58124.22.57.0/24124.22.57.1 to 124.22.57.254124.22.57.255254
59124.22.58.0/24124.22.58.1 to 124.22.58.254124.22.58.255254
60124.22.59.0/24124.22.59.1 to 124.22.59.254124.22.59.255254
61124.22.60.0/24124.22.60.1 to 124.22.60.254124.22.60.255254
62124.22.61.0/24124.22.61.1 to 124.22.61.254124.22.61.255254
63124.22.62.0/24124.22.62.1 to 124.22.62.254124.22.62.255254
64124.22.63.0/24124.22.63.1 to 124.22.63.254124.22.63.255254
65124.22.64.0/24124.22.64.1 to 124.22.64.254124.22.64.255254
66124.22.65.0/24124.22.65.1 to 124.22.65.254124.22.65.255254
67124.22.66.0/24124.22.66.1 to 124.22.66.254124.22.66.255254
68124.22.67.0/24124.22.67.1 to 124.22.67.254124.22.67.255254
69124.22.68.0/24124.22.68.1 to 124.22.68.254124.22.68.255254
70124.22.69.0/24124.22.69.1 to 124.22.69.254124.22.69.255254
71124.22.70.0/24124.22.70.1 to 124.22.70.254124.22.70.255254
72124.22.71.0/24124.22.71.1 to 124.22.71.254124.22.71.255254
73124.22.72.0/24124.22.72.1 to 124.22.72.254124.22.72.255254
74124.22.73.0/24124.22.73.1 to 124.22.73.254124.22.73.255254
75124.22.74.0/24124.22.74.1 to 124.22.74.254124.22.74.255254
76124.22.75.0/24124.22.75.1 to 124.22.75.254124.22.75.255254
77124.22.76.0/24124.22.76.1 to 124.22.76.254124.22.76.255254
78124.22.77.0/24124.22.77.1 to 124.22.77.254124.22.77.255254
79124.22.78.0/24124.22.78.1 to 124.22.78.254124.22.78.255254
80124.22.79.0/24124.22.79.1 to 124.22.79.254124.22.79.255254
81124.22.80.0/24124.22.80.1 to 124.22.80.254124.22.80.255254
82124.22.81.0/24124.22.81.1 to 124.22.81.254124.22.81.255254
83124.22.82.0/24124.22.82.1 to 124.22.82.254124.22.82.255254
84124.22.83.0/24124.22.83.1 to 124.22.83.254124.22.83.255254
85124.22.84.0/24124.22.84.1 to 124.22.84.254124.22.84.255254
86124.22.85.0/24124.22.85.1 to 124.22.85.254124.22.85.255254
87124.22.86.0/24124.22.86.1 to 124.22.86.254124.22.86.255254
88124.22.87.0/24124.22.87.1 to 124.22.87.254124.22.87.255254
89124.22.88.0/24124.22.88.1 to 124.22.88.254124.22.88.255254
90124.22.89.0/24124.22.89.1 to 124.22.89.254124.22.89.255254
91124.22.90.0/24124.22.90.1 to 124.22.90.254124.22.90.255254
92124.22.91.0/24124.22.91.1 to 124.22.91.254124.22.91.255254
93124.22.92.0/24124.22.92.1 to 124.22.92.254124.22.92.255254
94124.22.93.0/24124.22.93.1 to 124.22.93.254124.22.93.255254
95124.22.94.0/24124.22.94.1 to 124.22.94.254124.22.94.255254
96124.22.95.0/24124.22.95.1 to 124.22.95.254124.22.95.255254
97124.22.96.0/24124.22.96.1 to 124.22.96.254124.22.96.255254
98124.22.97.0/24124.22.97.1 to 124.22.97.254124.22.97.255254
99124.22.98.0/24124.22.98.1 to 124.22.98.254124.22.98.255254
100124.22.99.0/24124.22.99.1 to 124.22.99.254124.22.99.255254
101124.22.100.0/24124.22.100.1 to 124.22.100.254124.22.100.255254
102124.22.101.0/24124.22.101.1 to 124.22.101.254124.22.101.255254
103124.22.102.0/24124.22.102.1 to 124.22.102.254124.22.102.255254
104124.22.103.0/24124.22.103.1 to 124.22.103.254124.22.103.255254
105124.22.104.0/24124.22.104.1 to 124.22.104.254124.22.104.255254
106124.22.105.0/24124.22.105.1 to 124.22.105.254124.22.105.255254
107124.22.106.0/24124.22.106.1 to 124.22.106.254124.22.106.255254
108124.22.107.0/24124.22.107.1 to 124.22.107.254124.22.107.255254
109124.22.108.0/24124.22.108.1 to 124.22.108.254124.22.108.255254
110124.22.109.0/24124.22.109.1 to 124.22.109.254124.22.109.255254
111124.22.110.0/24124.22.110.1 to 124.22.110.254124.22.110.255254
112124.22.111.0/24124.22.111.1 to 124.22.111.254124.22.111.255254
113124.22.112.0/24124.22.112.1 to 124.22.112.254124.22.112.255254
114124.22.113.0/24124.22.113.1 to 124.22.113.254124.22.113.255254
115124.22.114.0/24124.22.114.1 to 124.22.114.254124.22.114.255254
116124.22.115.0/24124.22.115.1 to 124.22.115.254124.22.115.255254
117124.22.116.0/24124.22.116.1 to 124.22.116.254124.22.116.255254
118124.22.117.0/24124.22.117.1 to 124.22.117.254124.22.117.255254
119124.22.118.0/24124.22.118.1 to 124.22.118.254124.22.118.255254
120124.22.119.0/24124.22.119.1 to 124.22.119.254124.22.119.255254
121124.22.120.0/24124.22.120.1 to 124.22.120.254124.22.120.255254
122124.22.121.0/24124.22.121.1 to 124.22.121.254124.22.121.255254
123124.22.122.0/24124.22.122.1 to 124.22.122.254124.22.122.255254
124124.22.123.0/24124.22.123.1 to 124.22.123.254124.22.123.255254
125124.22.124.0/24124.22.124.1 to 124.22.124.254124.22.124.255254
126124.22.125.0/24124.22.125.1 to 124.22.125.254124.22.125.255254
127124.22.126.0/24124.22.126.1 to 124.22.126.254124.22.126.255254
128124.22.127.0/24124.22.127.1 to 124.22.127.254124.22.127.255254
129124.22.128.0/24124.22.128.1 to 124.22.128.254124.22.128.255254
130124.22.129.0/24124.22.129.1 to 124.22.129.254124.22.129.255254
131124.22.130.0/24124.22.130.1 to 124.22.130.254124.22.130.255254
132124.22.131.0/24124.22.131.1 to 124.22.131.254124.22.131.255254
133124.22.132.0/24124.22.132.1 to 124.22.132.254124.22.132.255254
134124.22.133.0/24124.22.133.1 to 124.22.133.254124.22.133.255254
135124.22.134.0/24124.22.134.1 to 124.22.134.254124.22.134.255254
136124.22.135.0/24124.22.135.1 to 124.22.135.254124.22.135.255254
137124.22.136.0/24124.22.136.1 to 124.22.136.254124.22.136.255254
138124.22.137.0/24124.22.137.1 to 124.22.137.254124.22.137.255254
139124.22.138.0/24124.22.138.1 to 124.22.138.254124.22.138.255254
140124.22.139.0/24124.22.139.1 to 124.22.139.254124.22.139.255254
141124.22.140.0/24124.22.140.1 to 124.22.140.254124.22.140.255254
142124.22.141.0/24124.22.141.1 to 124.22.141.254124.22.141.255254
143124.22.142.0/24124.22.142.1 to 124.22.142.254124.22.142.255254
144124.22.143.0/24124.22.143.1 to 124.22.143.254124.22.143.255254
145124.22.144.0/24124.22.144.1 to 124.22.144.254124.22.144.255254
146124.22.145.0/24124.22.145.1 to 124.22.145.254124.22.145.255254
147124.22.146.0/24124.22.146.1 to 124.22.146.254124.22.146.255254
148124.22.147.0/24124.22.147.1 to 124.22.147.254124.22.147.255254
149124.22.148.0/24124.22.148.1 to 124.22.148.254124.22.148.255254
150124.22.149.0/24124.22.149.1 to 124.22.149.254124.22.149.255254
151124.22.150.0/24124.22.150.1 to 124.22.150.254124.22.150.255254
152124.22.151.0/24124.22.151.1 to 124.22.151.254124.22.151.255254
153124.22.152.0/24124.22.152.1 to 124.22.152.254124.22.152.255254
154124.22.153.0/24124.22.153.1 to 124.22.153.254124.22.153.255254
155124.22.154.0/24124.22.154.1 to 124.22.154.254124.22.154.255254
156124.22.155.0/24124.22.155.1 to 124.22.155.254124.22.155.255254
157124.22.156.0/24124.22.156.1 to 124.22.156.254124.22.156.255254
158124.22.157.0/24124.22.157.1 to 124.22.157.254124.22.157.255254
159124.22.158.0/24124.22.158.1 to 124.22.158.254124.22.158.255254
160124.22.159.0/24124.22.159.1 to 124.22.159.254124.22.159.255254
161124.22.160.0/24124.22.160.1 to 124.22.160.254124.22.160.255254
162124.22.161.0/24124.22.161.1 to 124.22.161.254124.22.161.255254
163124.22.162.0/24124.22.162.1 to 124.22.162.254124.22.162.255254
164124.22.163.0/24124.22.163.1 to 124.22.163.254124.22.163.255254
165124.22.164.0/24124.22.164.1 to 124.22.164.254124.22.164.255254
166124.22.165.0/24124.22.165.1 to 124.22.165.254124.22.165.255254
167124.22.166.0/24124.22.166.1 to 124.22.166.254124.22.166.255254
168124.22.167.0/24124.22.167.1 to 124.22.167.254124.22.167.255254
169124.22.168.0/24124.22.168.1 to 124.22.168.254124.22.168.255254
170124.22.169.0/24124.22.169.1 to 124.22.169.254124.22.169.255254
171124.22.170.0/24124.22.170.1 to 124.22.170.254124.22.170.255254
172124.22.171.0/24124.22.171.1 to 124.22.171.254124.22.171.255254
173124.22.172.0/24124.22.172.1 to 124.22.172.254124.22.172.255254
174124.22.173.0/24124.22.173.1 to 124.22.173.254124.22.173.255254
175124.22.174.0/24124.22.174.1 to 124.22.174.254124.22.174.255254
176124.22.175.0/24124.22.175.1 to 124.22.175.254124.22.175.255254
177124.22.176.0/24124.22.176.1 to 124.22.176.254124.22.176.255254
178124.22.177.0/24124.22.177.1 to 124.22.177.254124.22.177.255254
179124.22.178.0/24124.22.178.1 to 124.22.178.254124.22.178.255254
180124.22.179.0/24124.22.179.1 to 124.22.179.254124.22.179.255254
181124.22.180.0/24124.22.180.1 to 124.22.180.254124.22.180.255254
182124.22.181.0/24124.22.181.1 to 124.22.181.254124.22.181.255254
183124.22.182.0/24124.22.182.1 to 124.22.182.254124.22.182.255254
184124.22.183.0/24124.22.183.1 to 124.22.183.254124.22.183.255254
185124.22.184.0/24124.22.184.1 to 124.22.184.254124.22.184.255254
186124.22.185.0/24124.22.185.1 to 124.22.185.254124.22.185.255254
187124.22.186.0/24124.22.186.1 to 124.22.186.254124.22.186.255254
188124.22.187.0/24124.22.187.1 to 124.22.187.254124.22.187.255254
189124.22.188.0/24124.22.188.1 to 124.22.188.254124.22.188.255254
190124.22.189.0/24124.22.189.1 to 124.22.189.254124.22.189.255254
191124.22.190.0/24124.22.190.1 to 124.22.190.254124.22.190.255254
192124.22.191.0/24124.22.191.1 to 124.22.191.254124.22.191.255254
193124.22.192.0/24124.22.192.1 to 124.22.192.254124.22.192.255254
194124.22.193.0/24124.22.193.1 to 124.22.193.254124.22.193.255254
195124.22.194.0/24124.22.194.1 to 124.22.194.254124.22.194.255254
196124.22.195.0/24124.22.195.1 to 124.22.195.254124.22.195.255254
197124.22.196.0/24124.22.196.1 to 124.22.196.254124.22.196.255254
198124.22.197.0/24124.22.197.1 to 124.22.197.254124.22.197.255254
199124.22.198.0/24124.22.198.1 to 124.22.198.254124.22.198.255254
200124.22.199.0/24124.22.199.1 to 124.22.199.254124.22.199.255254
201124.22.200.0/24124.22.200.1 to 124.22.200.254124.22.200.255254
202124.22.201.0/24124.22.201.1 to 124.22.201.254124.22.201.255254
203124.22.202.0/24124.22.202.1 to 124.22.202.254124.22.202.255254
204124.22.203.0/24124.22.203.1 to 124.22.203.254124.22.203.255254
205124.22.204.0/24124.22.204.1 to 124.22.204.254124.22.204.255254
206124.22.205.0/24124.22.205.1 to 124.22.205.254124.22.205.255254
207124.22.206.0/24124.22.206.1 to 124.22.206.254124.22.206.255254
208124.22.207.0/24124.22.207.1 to 124.22.207.254124.22.207.255254
209124.22.208.0/24124.22.208.1 to 124.22.208.254124.22.208.255254
210124.22.209.0/24124.22.209.1 to 124.22.209.254124.22.209.255254
211124.22.210.0/24124.22.210.1 to 124.22.210.254124.22.210.255254
212124.22.211.0/24124.22.211.1 to 124.22.211.254124.22.211.255254
213124.22.212.0/24124.22.212.1 to 124.22.212.254124.22.212.255254
214124.22.213.0/24124.22.213.1 to 124.22.213.254124.22.213.255254
215124.22.214.0/24124.22.214.1 to 124.22.214.254124.22.214.255254
216124.22.215.0/24124.22.215.1 to 124.22.215.254124.22.215.255254
217124.22.216.0/24124.22.216.1 to 124.22.216.254124.22.216.255254
218124.22.217.0/24124.22.217.1 to 124.22.217.254124.22.217.255254
219124.22.218.0/24124.22.218.1 to 124.22.218.254124.22.218.255254
220124.22.219.0/24124.22.219.1 to 124.22.219.254124.22.219.255254
221124.22.220.0/24124.22.220.1 to 124.22.220.254124.22.220.255254
222124.22.221.0/24124.22.221.1 to 124.22.221.254124.22.221.255254
223124.22.222.0/24124.22.222.1 to 124.22.222.254124.22.222.255254
224124.22.223.0/24124.22.223.1 to 124.22.223.254124.22.223.255254
225124.22.224.0/24124.22.224.1 to 124.22.224.254124.22.224.255254
226124.22.225.0/24124.22.225.1 to 124.22.225.254124.22.225.255254
227124.22.226.0/24124.22.226.1 to 124.22.226.254124.22.226.255254
228124.22.227.0/24124.22.227.1 to 124.22.227.254124.22.227.255254
229124.22.228.0/24124.22.228.1 to 124.22.228.254124.22.228.255254
230124.22.229.0/24124.22.229.1 to 124.22.229.254124.22.229.255254
231124.22.230.0/24124.22.230.1 to 124.22.230.254124.22.230.255254
232124.22.231.0/24124.22.231.1 to 124.22.231.254124.22.231.255254
233124.22.232.0/24124.22.232.1 to 124.22.232.254124.22.232.255254
234124.22.233.0/24124.22.233.1 to 124.22.233.254124.22.233.255254
235124.22.234.0/24124.22.234.1 to 124.22.234.254124.22.234.255254
236124.22.235.0/24124.22.235.1 to 124.22.235.254124.22.235.255254
237124.22.236.0/24124.22.236.1 to 124.22.236.254124.22.236.255254
238124.22.237.0/24124.22.237.1 to 124.22.237.254124.22.237.255254
239124.22.238.0/24124.22.238.1 to 124.22.238.254124.22.238.255254
240124.22.239.0/24124.22.239.1 to 124.22.239.254124.22.239.255254
241124.22.240.0/24124.22.240.1 to 124.22.240.254124.22.240.255254
242124.22.241.0/24124.22.241.1 to 124.22.241.254124.22.241.255254
243124.22.242.0/24124.22.242.1 to 124.22.242.254124.22.242.255254
244124.22.243.0/24124.22.243.1 to 124.22.243.254124.22.243.255254
245124.22.244.0/24124.22.244.1 to 124.22.244.254124.22.244.255254
246124.22.245.0/24124.22.245.1 to 124.22.245.254124.22.245.255254
247124.22.246.0/24124.22.246.1 to 124.22.246.254124.22.246.255254
248124.22.247.0/24124.22.247.1 to 124.22.247.254124.22.247.255254
249124.22.248.0/24124.22.248.1 to 124.22.248.254124.22.248.255254
250124.22.249.0/24124.22.249.1 to 124.22.249.254124.22.249.255254
251124.22.250.0/24124.22.250.1 to 124.22.250.254124.22.250.255254
252124.22.251.0/24124.22.251.1 to 124.22.251.254124.22.251.255254
253124.22.252.0/24124.22.252.1 to 124.22.252.254124.22.252.255254
254124.22.253.0/24124.22.253.1 to 124.22.253.254124.22.253.255254
255124.22.254.0/24124.22.254.1 to 124.22.254.254124.22.254.255254
256124.22.255.0/24124.22.255.1 to 124.22.255.254124.22.255.255254

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.