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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.

Network222.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
222.0.0.0
Broadcast address
223.255.255.255
First usable
222.0.0.1
Last usable
223.255.255.254
Usable hosts
33,554,430 (33,554,432 less the network and broadcast addresses)
Subnet mask
254.0.0.0
Wildcard mask
1.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/7
Type
Public public
Old class
C (default /24)
As numbers
Hex DE000000 · Integer 3724541952 to 3758096383
Reverse DNS zones
222.in-addr.arpa
223.in-addr.arpa
/7 is not on a 8-bit boundary, so it takes 2 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11011110.00000000.00000000.00000000222.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network11011110.00000000.00000000.00000000222.0.0.0
Broadcast11011111.11111111.11111111.11111111223.255.255.255
Split into smaller subnets/15
/8 (2)/9 (4)/10 (8)/11 (16)/12 (32)/13 (64)/14 (128)/15 (256)/16 (512)/17 (1,024)/18 (2,048)/19 (4,096)

222.0.0.0/7 makes 256 subnets of /15.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1222.0.0.0/15222.0.0.1 to 222.1.255.254222.1.255.255131,070
2222.2.0.0/15222.2.0.1 to 222.3.255.254222.3.255.255131,070
3222.4.0.0/15222.4.0.1 to 222.5.255.254222.5.255.255131,070
4222.6.0.0/15222.6.0.1 to 222.7.255.254222.7.255.255131,070
5222.8.0.0/15222.8.0.1 to 222.9.255.254222.9.255.255131,070
6222.10.0.0/15222.10.0.1 to 222.11.255.254222.11.255.255131,070
7222.12.0.0/15222.12.0.1 to 222.13.255.254222.13.255.255131,070
8222.14.0.0/15222.14.0.1 to 222.15.255.254222.15.255.255131,070
9222.16.0.0/15222.16.0.1 to 222.17.255.254222.17.255.255131,070
10222.18.0.0/15222.18.0.1 to 222.19.255.254222.19.255.255131,070
11222.20.0.0/15222.20.0.1 to 222.21.255.254222.21.255.255131,070
12222.22.0.0/15222.22.0.1 to 222.23.255.254222.23.255.255131,070
13222.24.0.0/15222.24.0.1 to 222.25.255.254222.25.255.255131,070
14222.26.0.0/15222.26.0.1 to 222.27.255.254222.27.255.255131,070
15222.28.0.0/15222.28.0.1 to 222.29.255.254222.29.255.255131,070
16222.30.0.0/15222.30.0.1 to 222.31.255.254222.31.255.255131,070
17222.32.0.0/15222.32.0.1 to 222.33.255.254222.33.255.255131,070
18222.34.0.0/15222.34.0.1 to 222.35.255.254222.35.255.255131,070
19222.36.0.0/15222.36.0.1 to 222.37.255.254222.37.255.255131,070
20222.38.0.0/15222.38.0.1 to 222.39.255.254222.39.255.255131,070
21222.40.0.0/15222.40.0.1 to 222.41.255.254222.41.255.255131,070
22222.42.0.0/15222.42.0.1 to 222.43.255.254222.43.255.255131,070
23222.44.0.0/15222.44.0.1 to 222.45.255.254222.45.255.255131,070
24222.46.0.0/15222.46.0.1 to 222.47.255.254222.47.255.255131,070
25222.48.0.0/15222.48.0.1 to 222.49.255.254222.49.255.255131,070
26222.50.0.0/15222.50.0.1 to 222.51.255.254222.51.255.255131,070
27222.52.0.0/15222.52.0.1 to 222.53.255.254222.53.255.255131,070
28222.54.0.0/15222.54.0.1 to 222.55.255.254222.55.255.255131,070
29222.56.0.0/15222.56.0.1 to 222.57.255.254222.57.255.255131,070
30222.58.0.0/15222.58.0.1 to 222.59.255.254222.59.255.255131,070
31222.60.0.0/15222.60.0.1 to 222.61.255.254222.61.255.255131,070
32222.62.0.0/15222.62.0.1 to 222.63.255.254222.63.255.255131,070
33222.64.0.0/15222.64.0.1 to 222.65.255.254222.65.255.255131,070
34222.66.0.0/15222.66.0.1 to 222.67.255.254222.67.255.255131,070
35222.68.0.0/15222.68.0.1 to 222.69.255.254222.69.255.255131,070
36222.70.0.0/15222.70.0.1 to 222.71.255.254222.71.255.255131,070
37222.72.0.0/15222.72.0.1 to 222.73.255.254222.73.255.255131,070
38222.74.0.0/15222.74.0.1 to 222.75.255.254222.75.255.255131,070
39222.76.0.0/15222.76.0.1 to 222.77.255.254222.77.255.255131,070
40222.78.0.0/15222.78.0.1 to 222.79.255.254222.79.255.255131,070
41222.80.0.0/15222.80.0.1 to 222.81.255.254222.81.255.255131,070
42222.82.0.0/15222.82.0.1 to 222.83.255.254222.83.255.255131,070
43222.84.0.0/15222.84.0.1 to 222.85.255.254222.85.255.255131,070
44222.86.0.0/15222.86.0.1 to 222.87.255.254222.87.255.255131,070
45222.88.0.0/15222.88.0.1 to 222.89.255.254222.89.255.255131,070
46222.90.0.0/15222.90.0.1 to 222.91.255.254222.91.255.255131,070
47222.92.0.0/15222.92.0.1 to 222.93.255.254222.93.255.255131,070
48222.94.0.0/15222.94.0.1 to 222.95.255.254222.95.255.255131,070
49222.96.0.0/15222.96.0.1 to 222.97.255.254222.97.255.255131,070
50222.98.0.0/15222.98.0.1 to 222.99.255.254222.99.255.255131,070
51222.100.0.0/15222.100.0.1 to 222.101.255.254222.101.255.255131,070
52222.102.0.0/15222.102.0.1 to 222.103.255.254222.103.255.255131,070
53222.104.0.0/15222.104.0.1 to 222.105.255.254222.105.255.255131,070
54222.106.0.0/15222.106.0.1 to 222.107.255.254222.107.255.255131,070
55222.108.0.0/15222.108.0.1 to 222.109.255.254222.109.255.255131,070
56222.110.0.0/15222.110.0.1 to 222.111.255.254222.111.255.255131,070
57222.112.0.0/15222.112.0.1 to 222.113.255.254222.113.255.255131,070
58222.114.0.0/15222.114.0.1 to 222.115.255.254222.115.255.255131,070
59222.116.0.0/15222.116.0.1 to 222.117.255.254222.117.255.255131,070
60222.118.0.0/15222.118.0.1 to 222.119.255.254222.119.255.255131,070
61222.120.0.0/15222.120.0.1 to 222.121.255.254222.121.255.255131,070
62222.122.0.0/15222.122.0.1 to 222.123.255.254222.123.255.255131,070
63222.124.0.0/15222.124.0.1 to 222.125.255.254222.125.255.255131,070
64222.126.0.0/15222.126.0.1 to 222.127.255.254222.127.255.255131,070
65222.128.0.0/15222.128.0.1 to 222.129.255.254222.129.255.255131,070
66222.130.0.0/15222.130.0.1 to 222.131.255.254222.131.255.255131,070
67222.132.0.0/15222.132.0.1 to 222.133.255.254222.133.255.255131,070
68222.134.0.0/15222.134.0.1 to 222.135.255.254222.135.255.255131,070
69222.136.0.0/15222.136.0.1 to 222.137.255.254222.137.255.255131,070
70222.138.0.0/15222.138.0.1 to 222.139.255.254222.139.255.255131,070
71222.140.0.0/15222.140.0.1 to 222.141.255.254222.141.255.255131,070
72222.142.0.0/15222.142.0.1 to 222.143.255.254222.143.255.255131,070
73222.144.0.0/15222.144.0.1 to 222.145.255.254222.145.255.255131,070
74222.146.0.0/15222.146.0.1 to 222.147.255.254222.147.255.255131,070
75222.148.0.0/15222.148.0.1 to 222.149.255.254222.149.255.255131,070
76222.150.0.0/15222.150.0.1 to 222.151.255.254222.151.255.255131,070
77222.152.0.0/15222.152.0.1 to 222.153.255.254222.153.255.255131,070
78222.154.0.0/15222.154.0.1 to 222.155.255.254222.155.255.255131,070
79222.156.0.0/15222.156.0.1 to 222.157.255.254222.157.255.255131,070
80222.158.0.0/15222.158.0.1 to 222.159.255.254222.159.255.255131,070
81222.160.0.0/15222.160.0.1 to 222.161.255.254222.161.255.255131,070
82222.162.0.0/15222.162.0.1 to 222.163.255.254222.163.255.255131,070
83222.164.0.0/15222.164.0.1 to 222.165.255.254222.165.255.255131,070
84222.166.0.0/15222.166.0.1 to 222.167.255.254222.167.255.255131,070
85222.168.0.0/15222.168.0.1 to 222.169.255.254222.169.255.255131,070
86222.170.0.0/15222.170.0.1 to 222.171.255.254222.171.255.255131,070
87222.172.0.0/15222.172.0.1 to 222.173.255.254222.173.255.255131,070
88222.174.0.0/15222.174.0.1 to 222.175.255.254222.175.255.255131,070
89222.176.0.0/15222.176.0.1 to 222.177.255.254222.177.255.255131,070
90222.178.0.0/15222.178.0.1 to 222.179.255.254222.179.255.255131,070
91222.180.0.0/15222.180.0.1 to 222.181.255.254222.181.255.255131,070
92222.182.0.0/15222.182.0.1 to 222.183.255.254222.183.255.255131,070
93222.184.0.0/15222.184.0.1 to 222.185.255.254222.185.255.255131,070
94222.186.0.0/15222.186.0.1 to 222.187.255.254222.187.255.255131,070
95222.188.0.0/15222.188.0.1 to 222.189.255.254222.189.255.255131,070
96222.190.0.0/15222.190.0.1 to 222.191.255.254222.191.255.255131,070
97222.192.0.0/15222.192.0.1 to 222.193.255.254222.193.255.255131,070
98222.194.0.0/15222.194.0.1 to 222.195.255.254222.195.255.255131,070
99222.196.0.0/15222.196.0.1 to 222.197.255.254222.197.255.255131,070
100222.198.0.0/15222.198.0.1 to 222.199.255.254222.199.255.255131,070
101222.200.0.0/15222.200.0.1 to 222.201.255.254222.201.255.255131,070
102222.202.0.0/15222.202.0.1 to 222.203.255.254222.203.255.255131,070
103222.204.0.0/15222.204.0.1 to 222.205.255.254222.205.255.255131,070
104222.206.0.0/15222.206.0.1 to 222.207.255.254222.207.255.255131,070
105222.208.0.0/15222.208.0.1 to 222.209.255.254222.209.255.255131,070
106222.210.0.0/15222.210.0.1 to 222.211.255.254222.211.255.255131,070
107222.212.0.0/15222.212.0.1 to 222.213.255.254222.213.255.255131,070
108222.214.0.0/15222.214.0.1 to 222.215.255.254222.215.255.255131,070
109222.216.0.0/15222.216.0.1 to 222.217.255.254222.217.255.255131,070
110222.218.0.0/15222.218.0.1 to 222.219.255.254222.219.255.255131,070
111222.220.0.0/15222.220.0.1 to 222.221.255.254222.221.255.255131,070
112222.222.0.0/15222.222.0.1 to 222.223.255.254222.223.255.255131,070
113222.224.0.0/15222.224.0.1 to 222.225.255.254222.225.255.255131,070
114222.226.0.0/15222.226.0.1 to 222.227.255.254222.227.255.255131,070
115222.228.0.0/15222.228.0.1 to 222.229.255.254222.229.255.255131,070
116222.230.0.0/15222.230.0.1 to 222.231.255.254222.231.255.255131,070
117222.232.0.0/15222.232.0.1 to 222.233.255.254222.233.255.255131,070
118222.234.0.0/15222.234.0.1 to 222.235.255.254222.235.255.255131,070
119222.236.0.0/15222.236.0.1 to 222.237.255.254222.237.255.255131,070
120222.238.0.0/15222.238.0.1 to 222.239.255.254222.239.255.255131,070
121222.240.0.0/15222.240.0.1 to 222.241.255.254222.241.255.255131,070
122222.242.0.0/15222.242.0.1 to 222.243.255.254222.243.255.255131,070
123222.244.0.0/15222.244.0.1 to 222.245.255.254222.245.255.255131,070
124222.246.0.0/15222.246.0.1 to 222.247.255.254222.247.255.255131,070
125222.248.0.0/15222.248.0.1 to 222.249.255.254222.249.255.255131,070
126222.250.0.0/15222.250.0.1 to 222.251.255.254222.251.255.255131,070
127222.252.0.0/15222.252.0.1 to 222.253.255.254222.253.255.255131,070
128222.254.0.0/15222.254.0.1 to 222.255.255.254222.255.255.255131,070
129223.0.0.0/15223.0.0.1 to 223.1.255.254223.1.255.255131,070
130223.2.0.0/15223.2.0.1 to 223.3.255.254223.3.255.255131,070
131223.4.0.0/15223.4.0.1 to 223.5.255.254223.5.255.255131,070
132223.6.0.0/15223.6.0.1 to 223.7.255.254223.7.255.255131,070
133223.8.0.0/15223.8.0.1 to 223.9.255.254223.9.255.255131,070
134223.10.0.0/15223.10.0.1 to 223.11.255.254223.11.255.255131,070
135223.12.0.0/15223.12.0.1 to 223.13.255.254223.13.255.255131,070
136223.14.0.0/15223.14.0.1 to 223.15.255.254223.15.255.255131,070
137223.16.0.0/15223.16.0.1 to 223.17.255.254223.17.255.255131,070
138223.18.0.0/15223.18.0.1 to 223.19.255.254223.19.255.255131,070
139223.20.0.0/15223.20.0.1 to 223.21.255.254223.21.255.255131,070
140223.22.0.0/15223.22.0.1 to 223.23.255.254223.23.255.255131,070
141223.24.0.0/15223.24.0.1 to 223.25.255.254223.25.255.255131,070
142223.26.0.0/15223.26.0.1 to 223.27.255.254223.27.255.255131,070
143223.28.0.0/15223.28.0.1 to 223.29.255.254223.29.255.255131,070
144223.30.0.0/15223.30.0.1 to 223.31.255.254223.31.255.255131,070
145223.32.0.0/15223.32.0.1 to 223.33.255.254223.33.255.255131,070
146223.34.0.0/15223.34.0.1 to 223.35.255.254223.35.255.255131,070
147223.36.0.0/15223.36.0.1 to 223.37.255.254223.37.255.255131,070
148223.38.0.0/15223.38.0.1 to 223.39.255.254223.39.255.255131,070
149223.40.0.0/15223.40.0.1 to 223.41.255.254223.41.255.255131,070
150223.42.0.0/15223.42.0.1 to 223.43.255.254223.43.255.255131,070
151223.44.0.0/15223.44.0.1 to 223.45.255.254223.45.255.255131,070
152223.46.0.0/15223.46.0.1 to 223.47.255.254223.47.255.255131,070
153223.48.0.0/15223.48.0.1 to 223.49.255.254223.49.255.255131,070
154223.50.0.0/15223.50.0.1 to 223.51.255.254223.51.255.255131,070
155223.52.0.0/15223.52.0.1 to 223.53.255.254223.53.255.255131,070
156223.54.0.0/15223.54.0.1 to 223.55.255.254223.55.255.255131,070
157223.56.0.0/15223.56.0.1 to 223.57.255.254223.57.255.255131,070
158223.58.0.0/15223.58.0.1 to 223.59.255.254223.59.255.255131,070
159223.60.0.0/15223.60.0.1 to 223.61.255.254223.61.255.255131,070
160223.62.0.0/15223.62.0.1 to 223.63.255.254223.63.255.255131,070
161223.64.0.0/15223.64.0.1 to 223.65.255.254223.65.255.255131,070
162223.66.0.0/15223.66.0.1 to 223.67.255.254223.67.255.255131,070
163223.68.0.0/15223.68.0.1 to 223.69.255.254223.69.255.255131,070
164223.70.0.0/15223.70.0.1 to 223.71.255.254223.71.255.255131,070
165223.72.0.0/15223.72.0.1 to 223.73.255.254223.73.255.255131,070
166223.74.0.0/15223.74.0.1 to 223.75.255.254223.75.255.255131,070
167223.76.0.0/15223.76.0.1 to 223.77.255.254223.77.255.255131,070
168223.78.0.0/15223.78.0.1 to 223.79.255.254223.79.255.255131,070
169223.80.0.0/15223.80.0.1 to 223.81.255.254223.81.255.255131,070
170223.82.0.0/15223.82.0.1 to 223.83.255.254223.83.255.255131,070
171223.84.0.0/15223.84.0.1 to 223.85.255.254223.85.255.255131,070
172223.86.0.0/15223.86.0.1 to 223.87.255.254223.87.255.255131,070
173223.88.0.0/15223.88.0.1 to 223.89.255.254223.89.255.255131,070
174223.90.0.0/15223.90.0.1 to 223.91.255.254223.91.255.255131,070
175223.92.0.0/15223.92.0.1 to 223.93.255.254223.93.255.255131,070
176223.94.0.0/15223.94.0.1 to 223.95.255.254223.95.255.255131,070
177223.96.0.0/15223.96.0.1 to 223.97.255.254223.97.255.255131,070
178223.98.0.0/15223.98.0.1 to 223.99.255.254223.99.255.255131,070
179223.100.0.0/15223.100.0.1 to 223.101.255.254223.101.255.255131,070
180223.102.0.0/15223.102.0.1 to 223.103.255.254223.103.255.255131,070
181223.104.0.0/15223.104.0.1 to 223.105.255.254223.105.255.255131,070
182223.106.0.0/15223.106.0.1 to 223.107.255.254223.107.255.255131,070
183223.108.0.0/15223.108.0.1 to 223.109.255.254223.109.255.255131,070
184223.110.0.0/15223.110.0.1 to 223.111.255.254223.111.255.255131,070
185223.112.0.0/15223.112.0.1 to 223.113.255.254223.113.255.255131,070
186223.114.0.0/15223.114.0.1 to 223.115.255.254223.115.255.255131,070
187223.116.0.0/15223.116.0.1 to 223.117.255.254223.117.255.255131,070
188223.118.0.0/15223.118.0.1 to 223.119.255.254223.119.255.255131,070
189223.120.0.0/15223.120.0.1 to 223.121.255.254223.121.255.255131,070
190223.122.0.0/15223.122.0.1 to 223.123.255.254223.123.255.255131,070
191223.124.0.0/15223.124.0.1 to 223.125.255.254223.125.255.255131,070
192223.126.0.0/15223.126.0.1 to 223.127.255.254223.127.255.255131,070
193223.128.0.0/15223.128.0.1 to 223.129.255.254223.129.255.255131,070
194223.130.0.0/15223.130.0.1 to 223.131.255.254223.131.255.255131,070
195223.132.0.0/15223.132.0.1 to 223.133.255.254223.133.255.255131,070
196223.134.0.0/15223.134.0.1 to 223.135.255.254223.135.255.255131,070
197223.136.0.0/15223.136.0.1 to 223.137.255.254223.137.255.255131,070
198223.138.0.0/15223.138.0.1 to 223.139.255.254223.139.255.255131,070
199223.140.0.0/15223.140.0.1 to 223.141.255.254223.141.255.255131,070
200223.142.0.0/15223.142.0.1 to 223.143.255.254223.143.255.255131,070
201223.144.0.0/15223.144.0.1 to 223.145.255.254223.145.255.255131,070
202223.146.0.0/15223.146.0.1 to 223.147.255.254223.147.255.255131,070
203223.148.0.0/15223.148.0.1 to 223.149.255.254223.149.255.255131,070
204223.150.0.0/15223.150.0.1 to 223.151.255.254223.151.255.255131,070
205223.152.0.0/15223.152.0.1 to 223.153.255.254223.153.255.255131,070
206223.154.0.0/15223.154.0.1 to 223.155.255.254223.155.255.255131,070
207223.156.0.0/15223.156.0.1 to 223.157.255.254223.157.255.255131,070
208223.158.0.0/15223.158.0.1 to 223.159.255.254223.159.255.255131,070
209223.160.0.0/15223.160.0.1 to 223.161.255.254223.161.255.255131,070
210223.162.0.0/15223.162.0.1 to 223.163.255.254223.163.255.255131,070
211223.164.0.0/15223.164.0.1 to 223.165.255.254223.165.255.255131,070
212223.166.0.0/15223.166.0.1 to 223.167.255.254223.167.255.255131,070
213223.168.0.0/15223.168.0.1 to 223.169.255.254223.169.255.255131,070
214223.170.0.0/15223.170.0.1 to 223.171.255.254223.171.255.255131,070
215223.172.0.0/15223.172.0.1 to 223.173.255.254223.173.255.255131,070
216223.174.0.0/15223.174.0.1 to 223.175.255.254223.175.255.255131,070
217223.176.0.0/15223.176.0.1 to 223.177.255.254223.177.255.255131,070
218223.178.0.0/15223.178.0.1 to 223.179.255.254223.179.255.255131,070
219223.180.0.0/15223.180.0.1 to 223.181.255.254223.181.255.255131,070
220223.182.0.0/15223.182.0.1 to 223.183.255.254223.183.255.255131,070
221223.184.0.0/15223.184.0.1 to 223.185.255.254223.185.255.255131,070
222223.186.0.0/15223.186.0.1 to 223.187.255.254223.187.255.255131,070
223223.188.0.0/15223.188.0.1 to 223.189.255.254223.189.255.255131,070
224223.190.0.0/15223.190.0.1 to 223.191.255.254223.191.255.255131,070
225223.192.0.0/15223.192.0.1 to 223.193.255.254223.193.255.255131,070
226223.194.0.0/15223.194.0.1 to 223.195.255.254223.195.255.255131,070
227223.196.0.0/15223.196.0.1 to 223.197.255.254223.197.255.255131,070
228223.198.0.0/15223.198.0.1 to 223.199.255.254223.199.255.255131,070
229223.200.0.0/15223.200.0.1 to 223.201.255.254223.201.255.255131,070
230223.202.0.0/15223.202.0.1 to 223.203.255.254223.203.255.255131,070
231223.204.0.0/15223.204.0.1 to 223.205.255.254223.205.255.255131,070
232223.206.0.0/15223.206.0.1 to 223.207.255.254223.207.255.255131,070
233223.208.0.0/15223.208.0.1 to 223.209.255.254223.209.255.255131,070
234223.210.0.0/15223.210.0.1 to 223.211.255.254223.211.255.255131,070
235223.212.0.0/15223.212.0.1 to 223.213.255.254223.213.255.255131,070
236223.214.0.0/15223.214.0.1 to 223.215.255.254223.215.255.255131,070
237223.216.0.0/15223.216.0.1 to 223.217.255.254223.217.255.255131,070
238223.218.0.0/15223.218.0.1 to 223.219.255.254223.219.255.255131,070
239223.220.0.0/15223.220.0.1 to 223.221.255.254223.221.255.255131,070
240223.222.0.0/15223.222.0.1 to 223.223.255.254223.223.255.255131,070
241223.224.0.0/15223.224.0.1 to 223.225.255.254223.225.255.255131,070
242223.226.0.0/15223.226.0.1 to 223.227.255.254223.227.255.255131,070
243223.228.0.0/15223.228.0.1 to 223.229.255.254223.229.255.255131,070
244223.230.0.0/15223.230.0.1 to 223.231.255.254223.231.255.255131,070
245223.232.0.0/15223.232.0.1 to 223.233.255.254223.233.255.255131,070
246223.234.0.0/15223.234.0.1 to 223.235.255.254223.235.255.255131,070
247223.236.0.0/15223.236.0.1 to 223.237.255.254223.237.255.255131,070
248223.238.0.0/15223.238.0.1 to 223.239.255.254223.239.255.255131,070
249223.240.0.0/15223.240.0.1 to 223.241.255.254223.241.255.255131,070
250223.242.0.0/15223.242.0.1 to 223.243.255.254223.243.255.255131,070
251223.244.0.0/15223.244.0.1 to 223.245.255.254223.245.255.255131,070
252223.246.0.0/15223.246.0.1 to 223.247.255.254223.247.255.255131,070
253223.248.0.0/15223.248.0.1 to 223.249.255.254223.249.255.255131,070
254223.250.0.0/15223.250.0.1 to 223.251.255.254223.251.255.255131,070
255223.252.0.0/15223.252.0.1 to 223.253.255.254223.253.255.255131,070
256223.254.0.0/15223.254.0.1 to 223.255.255.254223.255.255.255131,070

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.