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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.

Network224.0.0.0/3
Usable hosts536,870,910
Subnet mask224.0.0.0
Addresses536,870,912
Network address
224.0.0.0
Broadcast address
255.255.255.255
First usable
224.0.0.1
Last usable
255.255.255.254
Usable hosts
536,870,910 (536,870,912 less the network and broadcast addresses)
Subnet mask
224.0.0.0
Wildcard mask
31.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/3
Type
Public public
Old class
D (multicast)
As numbers
Hex E0000000 · Integer 3758096384 to 4294967295
Reverse DNS zones
224.in-addr.arpa
225.in-addr.arpa
226.in-addr.arpa
227.in-addr.arpa
228.in-addr.arpa
229.in-addr.arpa
230.in-addr.arpa
231.in-addr.arpa
232.in-addr.arpa
233.in-addr.arpa
234.in-addr.arpa
235.in-addr.arpa
236.in-addr.arpa
237.in-addr.arpa
238.in-addr.arpa
239.in-addr.arpa
and 16 more
/3 is not on a 8-bit boundary, so it takes 32 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11100000.00000000.00000000.00000000224.0.0.0
Subnet mask11100000.00000000.00000000.00000000224.0.0.0
Network11100000.00000000.00000000.00000000224.0.0.0
Broadcast11111111.11111111.11111111.11111111255.255.255.255
Split into smaller subnets/15
/4 (2)/5 (4)/6 (8)/7 (16)/8 (32)/9 (64)/10 (128)/11 (256)/12 (512)/13 (1,024)/14 (2,048)/15 (4,096)

224.0.0.0/3 makes 4,096 subnets of /15; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1224.0.0.0/15224.0.0.1 to 224.1.255.254224.1.255.255131,070
2224.2.0.0/15224.2.0.1 to 224.3.255.254224.3.255.255131,070
3224.4.0.0/15224.4.0.1 to 224.5.255.254224.5.255.255131,070
4224.6.0.0/15224.6.0.1 to 224.7.255.254224.7.255.255131,070
5224.8.0.0/15224.8.0.1 to 224.9.255.254224.9.255.255131,070
6224.10.0.0/15224.10.0.1 to 224.11.255.254224.11.255.255131,070
7224.12.0.0/15224.12.0.1 to 224.13.255.254224.13.255.255131,070
8224.14.0.0/15224.14.0.1 to 224.15.255.254224.15.255.255131,070
9224.16.0.0/15224.16.0.1 to 224.17.255.254224.17.255.255131,070
10224.18.0.0/15224.18.0.1 to 224.19.255.254224.19.255.255131,070
11224.20.0.0/15224.20.0.1 to 224.21.255.254224.21.255.255131,070
12224.22.0.0/15224.22.0.1 to 224.23.255.254224.23.255.255131,070
13224.24.0.0/15224.24.0.1 to 224.25.255.254224.25.255.255131,070
14224.26.0.0/15224.26.0.1 to 224.27.255.254224.27.255.255131,070
15224.28.0.0/15224.28.0.1 to 224.29.255.254224.29.255.255131,070
16224.30.0.0/15224.30.0.1 to 224.31.255.254224.31.255.255131,070
17224.32.0.0/15224.32.0.1 to 224.33.255.254224.33.255.255131,070
18224.34.0.0/15224.34.0.1 to 224.35.255.254224.35.255.255131,070
19224.36.0.0/15224.36.0.1 to 224.37.255.254224.37.255.255131,070
20224.38.0.0/15224.38.0.1 to 224.39.255.254224.39.255.255131,070
21224.40.0.0/15224.40.0.1 to 224.41.255.254224.41.255.255131,070
22224.42.0.0/15224.42.0.1 to 224.43.255.254224.43.255.255131,070
23224.44.0.0/15224.44.0.1 to 224.45.255.254224.45.255.255131,070
24224.46.0.0/15224.46.0.1 to 224.47.255.254224.47.255.255131,070
25224.48.0.0/15224.48.0.1 to 224.49.255.254224.49.255.255131,070
26224.50.0.0/15224.50.0.1 to 224.51.255.254224.51.255.255131,070
27224.52.0.0/15224.52.0.1 to 224.53.255.254224.53.255.255131,070
28224.54.0.0/15224.54.0.1 to 224.55.255.254224.55.255.255131,070
29224.56.0.0/15224.56.0.1 to 224.57.255.254224.57.255.255131,070
30224.58.0.0/15224.58.0.1 to 224.59.255.254224.59.255.255131,070
31224.60.0.0/15224.60.0.1 to 224.61.255.254224.61.255.255131,070
32224.62.0.0/15224.62.0.1 to 224.63.255.254224.63.255.255131,070
33224.64.0.0/15224.64.0.1 to 224.65.255.254224.65.255.255131,070
34224.66.0.0/15224.66.0.1 to 224.67.255.254224.67.255.255131,070
35224.68.0.0/15224.68.0.1 to 224.69.255.254224.69.255.255131,070
36224.70.0.0/15224.70.0.1 to 224.71.255.254224.71.255.255131,070
37224.72.0.0/15224.72.0.1 to 224.73.255.254224.73.255.255131,070
38224.74.0.0/15224.74.0.1 to 224.75.255.254224.75.255.255131,070
39224.76.0.0/15224.76.0.1 to 224.77.255.254224.77.255.255131,070
40224.78.0.0/15224.78.0.1 to 224.79.255.254224.79.255.255131,070
41224.80.0.0/15224.80.0.1 to 224.81.255.254224.81.255.255131,070
42224.82.0.0/15224.82.0.1 to 224.83.255.254224.83.255.255131,070
43224.84.0.0/15224.84.0.1 to 224.85.255.254224.85.255.255131,070
44224.86.0.0/15224.86.0.1 to 224.87.255.254224.87.255.255131,070
45224.88.0.0/15224.88.0.1 to 224.89.255.254224.89.255.255131,070
46224.90.0.0/15224.90.0.1 to 224.91.255.254224.91.255.255131,070
47224.92.0.0/15224.92.0.1 to 224.93.255.254224.93.255.255131,070
48224.94.0.0/15224.94.0.1 to 224.95.255.254224.95.255.255131,070
49224.96.0.0/15224.96.0.1 to 224.97.255.254224.97.255.255131,070
50224.98.0.0/15224.98.0.1 to 224.99.255.254224.99.255.255131,070
51224.100.0.0/15224.100.0.1 to 224.101.255.254224.101.255.255131,070
52224.102.0.0/15224.102.0.1 to 224.103.255.254224.103.255.255131,070
53224.104.0.0/15224.104.0.1 to 224.105.255.254224.105.255.255131,070
54224.106.0.0/15224.106.0.1 to 224.107.255.254224.107.255.255131,070
55224.108.0.0/15224.108.0.1 to 224.109.255.254224.109.255.255131,070
56224.110.0.0/15224.110.0.1 to 224.111.255.254224.111.255.255131,070
57224.112.0.0/15224.112.0.1 to 224.113.255.254224.113.255.255131,070
58224.114.0.0/15224.114.0.1 to 224.115.255.254224.115.255.255131,070
59224.116.0.0/15224.116.0.1 to 224.117.255.254224.117.255.255131,070
60224.118.0.0/15224.118.0.1 to 224.119.255.254224.119.255.255131,070
61224.120.0.0/15224.120.0.1 to 224.121.255.254224.121.255.255131,070
62224.122.0.0/15224.122.0.1 to 224.123.255.254224.123.255.255131,070
63224.124.0.0/15224.124.0.1 to 224.125.255.254224.125.255.255131,070
64224.126.0.0/15224.126.0.1 to 224.127.255.254224.127.255.255131,070
65224.128.0.0/15224.128.0.1 to 224.129.255.254224.129.255.255131,070
66224.130.0.0/15224.130.0.1 to 224.131.255.254224.131.255.255131,070
67224.132.0.0/15224.132.0.1 to 224.133.255.254224.133.255.255131,070
68224.134.0.0/15224.134.0.1 to 224.135.255.254224.135.255.255131,070
69224.136.0.0/15224.136.0.1 to 224.137.255.254224.137.255.255131,070
70224.138.0.0/15224.138.0.1 to 224.139.255.254224.139.255.255131,070
71224.140.0.0/15224.140.0.1 to 224.141.255.254224.141.255.255131,070
72224.142.0.0/15224.142.0.1 to 224.143.255.254224.143.255.255131,070
73224.144.0.0/15224.144.0.1 to 224.145.255.254224.145.255.255131,070
74224.146.0.0/15224.146.0.1 to 224.147.255.254224.147.255.255131,070
75224.148.0.0/15224.148.0.1 to 224.149.255.254224.149.255.255131,070
76224.150.0.0/15224.150.0.1 to 224.151.255.254224.151.255.255131,070
77224.152.0.0/15224.152.0.1 to 224.153.255.254224.153.255.255131,070
78224.154.0.0/15224.154.0.1 to 224.155.255.254224.155.255.255131,070
79224.156.0.0/15224.156.0.1 to 224.157.255.254224.157.255.255131,070
80224.158.0.0/15224.158.0.1 to 224.159.255.254224.159.255.255131,070
81224.160.0.0/15224.160.0.1 to 224.161.255.254224.161.255.255131,070
82224.162.0.0/15224.162.0.1 to 224.163.255.254224.163.255.255131,070
83224.164.0.0/15224.164.0.1 to 224.165.255.254224.165.255.255131,070
84224.166.0.0/15224.166.0.1 to 224.167.255.254224.167.255.255131,070
85224.168.0.0/15224.168.0.1 to 224.169.255.254224.169.255.255131,070
86224.170.0.0/15224.170.0.1 to 224.171.255.254224.171.255.255131,070
87224.172.0.0/15224.172.0.1 to 224.173.255.254224.173.255.255131,070
88224.174.0.0/15224.174.0.1 to 224.175.255.254224.175.255.255131,070
89224.176.0.0/15224.176.0.1 to 224.177.255.254224.177.255.255131,070
90224.178.0.0/15224.178.0.1 to 224.179.255.254224.179.255.255131,070
91224.180.0.0/15224.180.0.1 to 224.181.255.254224.181.255.255131,070
92224.182.0.0/15224.182.0.1 to 224.183.255.254224.183.255.255131,070
93224.184.0.0/15224.184.0.1 to 224.185.255.254224.185.255.255131,070
94224.186.0.0/15224.186.0.1 to 224.187.255.254224.187.255.255131,070
95224.188.0.0/15224.188.0.1 to 224.189.255.254224.189.255.255131,070
96224.190.0.0/15224.190.0.1 to 224.191.255.254224.191.255.255131,070
97224.192.0.0/15224.192.0.1 to 224.193.255.254224.193.255.255131,070
98224.194.0.0/15224.194.0.1 to 224.195.255.254224.195.255.255131,070
99224.196.0.0/15224.196.0.1 to 224.197.255.254224.197.255.255131,070
100224.198.0.0/15224.198.0.1 to 224.199.255.254224.199.255.255131,070
101224.200.0.0/15224.200.0.1 to 224.201.255.254224.201.255.255131,070
102224.202.0.0/15224.202.0.1 to 224.203.255.254224.203.255.255131,070
103224.204.0.0/15224.204.0.1 to 224.205.255.254224.205.255.255131,070
104224.206.0.0/15224.206.0.1 to 224.207.255.254224.207.255.255131,070
105224.208.0.0/15224.208.0.1 to 224.209.255.254224.209.255.255131,070
106224.210.0.0/15224.210.0.1 to 224.211.255.254224.211.255.255131,070
107224.212.0.0/15224.212.0.1 to 224.213.255.254224.213.255.255131,070
108224.214.0.0/15224.214.0.1 to 224.215.255.254224.215.255.255131,070
109224.216.0.0/15224.216.0.1 to 224.217.255.254224.217.255.255131,070
110224.218.0.0/15224.218.0.1 to 224.219.255.254224.219.255.255131,070
111224.220.0.0/15224.220.0.1 to 224.221.255.254224.221.255.255131,070
112224.222.0.0/15224.222.0.1 to 224.223.255.254224.223.255.255131,070
113224.224.0.0/15224.224.0.1 to 224.225.255.254224.225.255.255131,070
114224.226.0.0/15224.226.0.1 to 224.227.255.254224.227.255.255131,070
115224.228.0.0/15224.228.0.1 to 224.229.255.254224.229.255.255131,070
116224.230.0.0/15224.230.0.1 to 224.231.255.254224.231.255.255131,070
117224.232.0.0/15224.232.0.1 to 224.233.255.254224.233.255.255131,070
118224.234.0.0/15224.234.0.1 to 224.235.255.254224.235.255.255131,070
119224.236.0.0/15224.236.0.1 to 224.237.255.254224.237.255.255131,070
120224.238.0.0/15224.238.0.1 to 224.239.255.254224.239.255.255131,070
121224.240.0.0/15224.240.0.1 to 224.241.255.254224.241.255.255131,070
122224.242.0.0/15224.242.0.1 to 224.243.255.254224.243.255.255131,070
123224.244.0.0/15224.244.0.1 to 224.245.255.254224.245.255.255131,070
124224.246.0.0/15224.246.0.1 to 224.247.255.254224.247.255.255131,070
125224.248.0.0/15224.248.0.1 to 224.249.255.254224.249.255.255131,070
126224.250.0.0/15224.250.0.1 to 224.251.255.254224.251.255.255131,070
127224.252.0.0/15224.252.0.1 to 224.253.255.254224.253.255.255131,070
128224.254.0.0/15224.254.0.1 to 224.255.255.254224.255.255.255131,070
129225.0.0.0/15225.0.0.1 to 225.1.255.254225.1.255.255131,070
130225.2.0.0/15225.2.0.1 to 225.3.255.254225.3.255.255131,070
131225.4.0.0/15225.4.0.1 to 225.5.255.254225.5.255.255131,070
132225.6.0.0/15225.6.0.1 to 225.7.255.254225.7.255.255131,070
133225.8.0.0/15225.8.0.1 to 225.9.255.254225.9.255.255131,070
134225.10.0.0/15225.10.0.1 to 225.11.255.254225.11.255.255131,070
135225.12.0.0/15225.12.0.1 to 225.13.255.254225.13.255.255131,070
136225.14.0.0/15225.14.0.1 to 225.15.255.254225.15.255.255131,070
137225.16.0.0/15225.16.0.1 to 225.17.255.254225.17.255.255131,070
138225.18.0.0/15225.18.0.1 to 225.19.255.254225.19.255.255131,070
139225.20.0.0/15225.20.0.1 to 225.21.255.254225.21.255.255131,070
140225.22.0.0/15225.22.0.1 to 225.23.255.254225.23.255.255131,070
141225.24.0.0/15225.24.0.1 to 225.25.255.254225.25.255.255131,070
142225.26.0.0/15225.26.0.1 to 225.27.255.254225.27.255.255131,070
143225.28.0.0/15225.28.0.1 to 225.29.255.254225.29.255.255131,070
144225.30.0.0/15225.30.0.1 to 225.31.255.254225.31.255.255131,070
145225.32.0.0/15225.32.0.1 to 225.33.255.254225.33.255.255131,070
146225.34.0.0/15225.34.0.1 to 225.35.255.254225.35.255.255131,070
147225.36.0.0/15225.36.0.1 to 225.37.255.254225.37.255.255131,070
148225.38.0.0/15225.38.0.1 to 225.39.255.254225.39.255.255131,070
149225.40.0.0/15225.40.0.1 to 225.41.255.254225.41.255.255131,070
150225.42.0.0/15225.42.0.1 to 225.43.255.254225.43.255.255131,070
151225.44.0.0/15225.44.0.1 to 225.45.255.254225.45.255.255131,070
152225.46.0.0/15225.46.0.1 to 225.47.255.254225.47.255.255131,070
153225.48.0.0/15225.48.0.1 to 225.49.255.254225.49.255.255131,070
154225.50.0.0/15225.50.0.1 to 225.51.255.254225.51.255.255131,070
155225.52.0.0/15225.52.0.1 to 225.53.255.254225.53.255.255131,070
156225.54.0.0/15225.54.0.1 to 225.55.255.254225.55.255.255131,070
157225.56.0.0/15225.56.0.1 to 225.57.255.254225.57.255.255131,070
158225.58.0.0/15225.58.0.1 to 225.59.255.254225.59.255.255131,070
159225.60.0.0/15225.60.0.1 to 225.61.255.254225.61.255.255131,070
160225.62.0.0/15225.62.0.1 to 225.63.255.254225.63.255.255131,070
161225.64.0.0/15225.64.0.1 to 225.65.255.254225.65.255.255131,070
162225.66.0.0/15225.66.0.1 to 225.67.255.254225.67.255.255131,070
163225.68.0.0/15225.68.0.1 to 225.69.255.254225.69.255.255131,070
164225.70.0.0/15225.70.0.1 to 225.71.255.254225.71.255.255131,070
165225.72.0.0/15225.72.0.1 to 225.73.255.254225.73.255.255131,070
166225.74.0.0/15225.74.0.1 to 225.75.255.254225.75.255.255131,070
167225.76.0.0/15225.76.0.1 to 225.77.255.254225.77.255.255131,070
168225.78.0.0/15225.78.0.1 to 225.79.255.254225.79.255.255131,070
169225.80.0.0/15225.80.0.1 to 225.81.255.254225.81.255.255131,070
170225.82.0.0/15225.82.0.1 to 225.83.255.254225.83.255.255131,070
171225.84.0.0/15225.84.0.1 to 225.85.255.254225.85.255.255131,070
172225.86.0.0/15225.86.0.1 to 225.87.255.254225.87.255.255131,070
173225.88.0.0/15225.88.0.1 to 225.89.255.254225.89.255.255131,070
174225.90.0.0/15225.90.0.1 to 225.91.255.254225.91.255.255131,070
175225.92.0.0/15225.92.0.1 to 225.93.255.254225.93.255.255131,070
176225.94.0.0/15225.94.0.1 to 225.95.255.254225.95.255.255131,070
177225.96.0.0/15225.96.0.1 to 225.97.255.254225.97.255.255131,070
178225.98.0.0/15225.98.0.1 to 225.99.255.254225.99.255.255131,070
179225.100.0.0/15225.100.0.1 to 225.101.255.254225.101.255.255131,070
180225.102.0.0/15225.102.0.1 to 225.103.255.254225.103.255.255131,070
181225.104.0.0/15225.104.0.1 to 225.105.255.254225.105.255.255131,070
182225.106.0.0/15225.106.0.1 to 225.107.255.254225.107.255.255131,070
183225.108.0.0/15225.108.0.1 to 225.109.255.254225.109.255.255131,070
184225.110.0.0/15225.110.0.1 to 225.111.255.254225.111.255.255131,070
185225.112.0.0/15225.112.0.1 to 225.113.255.254225.113.255.255131,070
186225.114.0.0/15225.114.0.1 to 225.115.255.254225.115.255.255131,070
187225.116.0.0/15225.116.0.1 to 225.117.255.254225.117.255.255131,070
188225.118.0.0/15225.118.0.1 to 225.119.255.254225.119.255.255131,070
189225.120.0.0/15225.120.0.1 to 225.121.255.254225.121.255.255131,070
190225.122.0.0/15225.122.0.1 to 225.123.255.254225.123.255.255131,070
191225.124.0.0/15225.124.0.1 to 225.125.255.254225.125.255.255131,070
192225.126.0.0/15225.126.0.1 to 225.127.255.254225.127.255.255131,070
193225.128.0.0/15225.128.0.1 to 225.129.255.254225.129.255.255131,070
194225.130.0.0/15225.130.0.1 to 225.131.255.254225.131.255.255131,070
195225.132.0.0/15225.132.0.1 to 225.133.255.254225.133.255.255131,070
196225.134.0.0/15225.134.0.1 to 225.135.255.254225.135.255.255131,070
197225.136.0.0/15225.136.0.1 to 225.137.255.254225.137.255.255131,070
198225.138.0.0/15225.138.0.1 to 225.139.255.254225.139.255.255131,070
199225.140.0.0/15225.140.0.1 to 225.141.255.254225.141.255.255131,070
200225.142.0.0/15225.142.0.1 to 225.143.255.254225.143.255.255131,070
201225.144.0.0/15225.144.0.1 to 225.145.255.254225.145.255.255131,070
202225.146.0.0/15225.146.0.1 to 225.147.255.254225.147.255.255131,070
203225.148.0.0/15225.148.0.1 to 225.149.255.254225.149.255.255131,070
204225.150.0.0/15225.150.0.1 to 225.151.255.254225.151.255.255131,070
205225.152.0.0/15225.152.0.1 to 225.153.255.254225.153.255.255131,070
206225.154.0.0/15225.154.0.1 to 225.155.255.254225.155.255.255131,070
207225.156.0.0/15225.156.0.1 to 225.157.255.254225.157.255.255131,070
208225.158.0.0/15225.158.0.1 to 225.159.255.254225.159.255.255131,070
209225.160.0.0/15225.160.0.1 to 225.161.255.254225.161.255.255131,070
210225.162.0.0/15225.162.0.1 to 225.163.255.254225.163.255.255131,070
211225.164.0.0/15225.164.0.1 to 225.165.255.254225.165.255.255131,070
212225.166.0.0/15225.166.0.1 to 225.167.255.254225.167.255.255131,070
213225.168.0.0/15225.168.0.1 to 225.169.255.254225.169.255.255131,070
214225.170.0.0/15225.170.0.1 to 225.171.255.254225.171.255.255131,070
215225.172.0.0/15225.172.0.1 to 225.173.255.254225.173.255.255131,070
216225.174.0.0/15225.174.0.1 to 225.175.255.254225.175.255.255131,070
217225.176.0.0/15225.176.0.1 to 225.177.255.254225.177.255.255131,070
218225.178.0.0/15225.178.0.1 to 225.179.255.254225.179.255.255131,070
219225.180.0.0/15225.180.0.1 to 225.181.255.254225.181.255.255131,070
220225.182.0.0/15225.182.0.1 to 225.183.255.254225.183.255.255131,070
221225.184.0.0/15225.184.0.1 to 225.185.255.254225.185.255.255131,070
222225.186.0.0/15225.186.0.1 to 225.187.255.254225.187.255.255131,070
223225.188.0.0/15225.188.0.1 to 225.189.255.254225.189.255.255131,070
224225.190.0.0/15225.190.0.1 to 225.191.255.254225.191.255.255131,070
225225.192.0.0/15225.192.0.1 to 225.193.255.254225.193.255.255131,070
226225.194.0.0/15225.194.0.1 to 225.195.255.254225.195.255.255131,070
227225.196.0.0/15225.196.0.1 to 225.197.255.254225.197.255.255131,070
228225.198.0.0/15225.198.0.1 to 225.199.255.254225.199.255.255131,070
229225.200.0.0/15225.200.0.1 to 225.201.255.254225.201.255.255131,070
230225.202.0.0/15225.202.0.1 to 225.203.255.254225.203.255.255131,070
231225.204.0.0/15225.204.0.1 to 225.205.255.254225.205.255.255131,070
232225.206.0.0/15225.206.0.1 to 225.207.255.254225.207.255.255131,070
233225.208.0.0/15225.208.0.1 to 225.209.255.254225.209.255.255131,070
234225.210.0.0/15225.210.0.1 to 225.211.255.254225.211.255.255131,070
235225.212.0.0/15225.212.0.1 to 225.213.255.254225.213.255.255131,070
236225.214.0.0/15225.214.0.1 to 225.215.255.254225.215.255.255131,070
237225.216.0.0/15225.216.0.1 to 225.217.255.254225.217.255.255131,070
238225.218.0.0/15225.218.0.1 to 225.219.255.254225.219.255.255131,070
239225.220.0.0/15225.220.0.1 to 225.221.255.254225.221.255.255131,070
240225.222.0.0/15225.222.0.1 to 225.223.255.254225.223.255.255131,070
241225.224.0.0/15225.224.0.1 to 225.225.255.254225.225.255.255131,070
242225.226.0.0/15225.226.0.1 to 225.227.255.254225.227.255.255131,070
243225.228.0.0/15225.228.0.1 to 225.229.255.254225.229.255.255131,070
244225.230.0.0/15225.230.0.1 to 225.231.255.254225.231.255.255131,070
245225.232.0.0/15225.232.0.1 to 225.233.255.254225.233.255.255131,070
246225.234.0.0/15225.234.0.1 to 225.235.255.254225.235.255.255131,070
247225.236.0.0/15225.236.0.1 to 225.237.255.254225.237.255.255131,070
248225.238.0.0/15225.238.0.1 to 225.239.255.254225.239.255.255131,070
249225.240.0.0/15225.240.0.1 to 225.241.255.254225.241.255.255131,070
250225.242.0.0/15225.242.0.1 to 225.243.255.254225.243.255.255131,070
251225.244.0.0/15225.244.0.1 to 225.245.255.254225.245.255.255131,070
252225.246.0.0/15225.246.0.1 to 225.247.255.254225.247.255.255131,070
253225.248.0.0/15225.248.0.1 to 225.249.255.254225.249.255.255131,070
254225.250.0.0/15225.250.0.1 to 225.251.255.254225.251.255.255131,070
255225.252.0.0/15225.252.0.1 to 225.253.255.254225.253.255.255131,070
256225.254.0.0/15225.254.0.1 to 225.255.255.254225.255.255.255131,070

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.