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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.

Network224.242.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
224.242.0.0
Broadcast address
224.243.255.255
First usable
224.242.0.1
Last usable
224.243.255.254
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
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E0F20000 · Integer 3773956096 to 3774087167
Reverse DNS zones
242.224.in-addr.arpa
243.224.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
Address11100000.11110010.00000000.00000000224.242.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network11100000.11110010.00000000.00000000224.242.0.0
Broadcast11100000.11110011.11111111.11111111224.243.255.255
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)

224.242.0.0/15 makes 512 subnets of /24; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1224.242.0.0/24224.242.0.1 to 224.242.0.254224.242.0.255254
2224.242.1.0/24224.242.1.1 to 224.242.1.254224.242.1.255254
3224.242.2.0/24224.242.2.1 to 224.242.2.254224.242.2.255254
4224.242.3.0/24224.242.3.1 to 224.242.3.254224.242.3.255254
5224.242.4.0/24224.242.4.1 to 224.242.4.254224.242.4.255254
6224.242.5.0/24224.242.5.1 to 224.242.5.254224.242.5.255254
7224.242.6.0/24224.242.6.1 to 224.242.6.254224.242.6.255254
8224.242.7.0/24224.242.7.1 to 224.242.7.254224.242.7.255254
9224.242.8.0/24224.242.8.1 to 224.242.8.254224.242.8.255254
10224.242.9.0/24224.242.9.1 to 224.242.9.254224.242.9.255254
11224.242.10.0/24224.242.10.1 to 224.242.10.254224.242.10.255254
12224.242.11.0/24224.242.11.1 to 224.242.11.254224.242.11.255254
13224.242.12.0/24224.242.12.1 to 224.242.12.254224.242.12.255254
14224.242.13.0/24224.242.13.1 to 224.242.13.254224.242.13.255254
15224.242.14.0/24224.242.14.1 to 224.242.14.254224.242.14.255254
16224.242.15.0/24224.242.15.1 to 224.242.15.254224.242.15.255254
17224.242.16.0/24224.242.16.1 to 224.242.16.254224.242.16.255254
18224.242.17.0/24224.242.17.1 to 224.242.17.254224.242.17.255254
19224.242.18.0/24224.242.18.1 to 224.242.18.254224.242.18.255254
20224.242.19.0/24224.242.19.1 to 224.242.19.254224.242.19.255254
21224.242.20.0/24224.242.20.1 to 224.242.20.254224.242.20.255254
22224.242.21.0/24224.242.21.1 to 224.242.21.254224.242.21.255254
23224.242.22.0/24224.242.22.1 to 224.242.22.254224.242.22.255254
24224.242.23.0/24224.242.23.1 to 224.242.23.254224.242.23.255254
25224.242.24.0/24224.242.24.1 to 224.242.24.254224.242.24.255254
26224.242.25.0/24224.242.25.1 to 224.242.25.254224.242.25.255254
27224.242.26.0/24224.242.26.1 to 224.242.26.254224.242.26.255254
28224.242.27.0/24224.242.27.1 to 224.242.27.254224.242.27.255254
29224.242.28.0/24224.242.28.1 to 224.242.28.254224.242.28.255254
30224.242.29.0/24224.242.29.1 to 224.242.29.254224.242.29.255254
31224.242.30.0/24224.242.30.1 to 224.242.30.254224.242.30.255254
32224.242.31.0/24224.242.31.1 to 224.242.31.254224.242.31.255254
33224.242.32.0/24224.242.32.1 to 224.242.32.254224.242.32.255254
34224.242.33.0/24224.242.33.1 to 224.242.33.254224.242.33.255254
35224.242.34.0/24224.242.34.1 to 224.242.34.254224.242.34.255254
36224.242.35.0/24224.242.35.1 to 224.242.35.254224.242.35.255254
37224.242.36.0/24224.242.36.1 to 224.242.36.254224.242.36.255254
38224.242.37.0/24224.242.37.1 to 224.242.37.254224.242.37.255254
39224.242.38.0/24224.242.38.1 to 224.242.38.254224.242.38.255254
40224.242.39.0/24224.242.39.1 to 224.242.39.254224.242.39.255254
41224.242.40.0/24224.242.40.1 to 224.242.40.254224.242.40.255254
42224.242.41.0/24224.242.41.1 to 224.242.41.254224.242.41.255254
43224.242.42.0/24224.242.42.1 to 224.242.42.254224.242.42.255254
44224.242.43.0/24224.242.43.1 to 224.242.43.254224.242.43.255254
45224.242.44.0/24224.242.44.1 to 224.242.44.254224.242.44.255254
46224.242.45.0/24224.242.45.1 to 224.242.45.254224.242.45.255254
47224.242.46.0/24224.242.46.1 to 224.242.46.254224.242.46.255254
48224.242.47.0/24224.242.47.1 to 224.242.47.254224.242.47.255254
49224.242.48.0/24224.242.48.1 to 224.242.48.254224.242.48.255254
50224.242.49.0/24224.242.49.1 to 224.242.49.254224.242.49.255254
51224.242.50.0/24224.242.50.1 to 224.242.50.254224.242.50.255254
52224.242.51.0/24224.242.51.1 to 224.242.51.254224.242.51.255254
53224.242.52.0/24224.242.52.1 to 224.242.52.254224.242.52.255254
54224.242.53.0/24224.242.53.1 to 224.242.53.254224.242.53.255254
55224.242.54.0/24224.242.54.1 to 224.242.54.254224.242.54.255254
56224.242.55.0/24224.242.55.1 to 224.242.55.254224.242.55.255254
57224.242.56.0/24224.242.56.1 to 224.242.56.254224.242.56.255254
58224.242.57.0/24224.242.57.1 to 224.242.57.254224.242.57.255254
59224.242.58.0/24224.242.58.1 to 224.242.58.254224.242.58.255254
60224.242.59.0/24224.242.59.1 to 224.242.59.254224.242.59.255254
61224.242.60.0/24224.242.60.1 to 224.242.60.254224.242.60.255254
62224.242.61.0/24224.242.61.1 to 224.242.61.254224.242.61.255254
63224.242.62.0/24224.242.62.1 to 224.242.62.254224.242.62.255254
64224.242.63.0/24224.242.63.1 to 224.242.63.254224.242.63.255254
65224.242.64.0/24224.242.64.1 to 224.242.64.254224.242.64.255254
66224.242.65.0/24224.242.65.1 to 224.242.65.254224.242.65.255254
67224.242.66.0/24224.242.66.1 to 224.242.66.254224.242.66.255254
68224.242.67.0/24224.242.67.1 to 224.242.67.254224.242.67.255254
69224.242.68.0/24224.242.68.1 to 224.242.68.254224.242.68.255254
70224.242.69.0/24224.242.69.1 to 224.242.69.254224.242.69.255254
71224.242.70.0/24224.242.70.1 to 224.242.70.254224.242.70.255254
72224.242.71.0/24224.242.71.1 to 224.242.71.254224.242.71.255254
73224.242.72.0/24224.242.72.1 to 224.242.72.254224.242.72.255254
74224.242.73.0/24224.242.73.1 to 224.242.73.254224.242.73.255254
75224.242.74.0/24224.242.74.1 to 224.242.74.254224.242.74.255254
76224.242.75.0/24224.242.75.1 to 224.242.75.254224.242.75.255254
77224.242.76.0/24224.242.76.1 to 224.242.76.254224.242.76.255254
78224.242.77.0/24224.242.77.1 to 224.242.77.254224.242.77.255254
79224.242.78.0/24224.242.78.1 to 224.242.78.254224.242.78.255254
80224.242.79.0/24224.242.79.1 to 224.242.79.254224.242.79.255254
81224.242.80.0/24224.242.80.1 to 224.242.80.254224.242.80.255254
82224.242.81.0/24224.242.81.1 to 224.242.81.254224.242.81.255254
83224.242.82.0/24224.242.82.1 to 224.242.82.254224.242.82.255254
84224.242.83.0/24224.242.83.1 to 224.242.83.254224.242.83.255254
85224.242.84.0/24224.242.84.1 to 224.242.84.254224.242.84.255254
86224.242.85.0/24224.242.85.1 to 224.242.85.254224.242.85.255254
87224.242.86.0/24224.242.86.1 to 224.242.86.254224.242.86.255254
88224.242.87.0/24224.242.87.1 to 224.242.87.254224.242.87.255254
89224.242.88.0/24224.242.88.1 to 224.242.88.254224.242.88.255254
90224.242.89.0/24224.242.89.1 to 224.242.89.254224.242.89.255254
91224.242.90.0/24224.242.90.1 to 224.242.90.254224.242.90.255254
92224.242.91.0/24224.242.91.1 to 224.242.91.254224.242.91.255254
93224.242.92.0/24224.242.92.1 to 224.242.92.254224.242.92.255254
94224.242.93.0/24224.242.93.1 to 224.242.93.254224.242.93.255254
95224.242.94.0/24224.242.94.1 to 224.242.94.254224.242.94.255254
96224.242.95.0/24224.242.95.1 to 224.242.95.254224.242.95.255254
97224.242.96.0/24224.242.96.1 to 224.242.96.254224.242.96.255254
98224.242.97.0/24224.242.97.1 to 224.242.97.254224.242.97.255254
99224.242.98.0/24224.242.98.1 to 224.242.98.254224.242.98.255254
100224.242.99.0/24224.242.99.1 to 224.242.99.254224.242.99.255254
101224.242.100.0/24224.242.100.1 to 224.242.100.254224.242.100.255254
102224.242.101.0/24224.242.101.1 to 224.242.101.254224.242.101.255254
103224.242.102.0/24224.242.102.1 to 224.242.102.254224.242.102.255254
104224.242.103.0/24224.242.103.1 to 224.242.103.254224.242.103.255254
105224.242.104.0/24224.242.104.1 to 224.242.104.254224.242.104.255254
106224.242.105.0/24224.242.105.1 to 224.242.105.254224.242.105.255254
107224.242.106.0/24224.242.106.1 to 224.242.106.254224.242.106.255254
108224.242.107.0/24224.242.107.1 to 224.242.107.254224.242.107.255254
109224.242.108.0/24224.242.108.1 to 224.242.108.254224.242.108.255254
110224.242.109.0/24224.242.109.1 to 224.242.109.254224.242.109.255254
111224.242.110.0/24224.242.110.1 to 224.242.110.254224.242.110.255254
112224.242.111.0/24224.242.111.1 to 224.242.111.254224.242.111.255254
113224.242.112.0/24224.242.112.1 to 224.242.112.254224.242.112.255254
114224.242.113.0/24224.242.113.1 to 224.242.113.254224.242.113.255254
115224.242.114.0/24224.242.114.1 to 224.242.114.254224.242.114.255254
116224.242.115.0/24224.242.115.1 to 224.242.115.254224.242.115.255254
117224.242.116.0/24224.242.116.1 to 224.242.116.254224.242.116.255254
118224.242.117.0/24224.242.117.1 to 224.242.117.254224.242.117.255254
119224.242.118.0/24224.242.118.1 to 224.242.118.254224.242.118.255254
120224.242.119.0/24224.242.119.1 to 224.242.119.254224.242.119.255254
121224.242.120.0/24224.242.120.1 to 224.242.120.254224.242.120.255254
122224.242.121.0/24224.242.121.1 to 224.242.121.254224.242.121.255254
123224.242.122.0/24224.242.122.1 to 224.242.122.254224.242.122.255254
124224.242.123.0/24224.242.123.1 to 224.242.123.254224.242.123.255254
125224.242.124.0/24224.242.124.1 to 224.242.124.254224.242.124.255254
126224.242.125.0/24224.242.125.1 to 224.242.125.254224.242.125.255254
127224.242.126.0/24224.242.126.1 to 224.242.126.254224.242.126.255254
128224.242.127.0/24224.242.127.1 to 224.242.127.254224.242.127.255254
129224.242.128.0/24224.242.128.1 to 224.242.128.254224.242.128.255254
130224.242.129.0/24224.242.129.1 to 224.242.129.254224.242.129.255254
131224.242.130.0/24224.242.130.1 to 224.242.130.254224.242.130.255254
132224.242.131.0/24224.242.131.1 to 224.242.131.254224.242.131.255254
133224.242.132.0/24224.242.132.1 to 224.242.132.254224.242.132.255254
134224.242.133.0/24224.242.133.1 to 224.242.133.254224.242.133.255254
135224.242.134.0/24224.242.134.1 to 224.242.134.254224.242.134.255254
136224.242.135.0/24224.242.135.1 to 224.242.135.254224.242.135.255254
137224.242.136.0/24224.242.136.1 to 224.242.136.254224.242.136.255254
138224.242.137.0/24224.242.137.1 to 224.242.137.254224.242.137.255254
139224.242.138.0/24224.242.138.1 to 224.242.138.254224.242.138.255254
140224.242.139.0/24224.242.139.1 to 224.242.139.254224.242.139.255254
141224.242.140.0/24224.242.140.1 to 224.242.140.254224.242.140.255254
142224.242.141.0/24224.242.141.1 to 224.242.141.254224.242.141.255254
143224.242.142.0/24224.242.142.1 to 224.242.142.254224.242.142.255254
144224.242.143.0/24224.242.143.1 to 224.242.143.254224.242.143.255254
145224.242.144.0/24224.242.144.1 to 224.242.144.254224.242.144.255254
146224.242.145.0/24224.242.145.1 to 224.242.145.254224.242.145.255254
147224.242.146.0/24224.242.146.1 to 224.242.146.254224.242.146.255254
148224.242.147.0/24224.242.147.1 to 224.242.147.254224.242.147.255254
149224.242.148.0/24224.242.148.1 to 224.242.148.254224.242.148.255254
150224.242.149.0/24224.242.149.1 to 224.242.149.254224.242.149.255254
151224.242.150.0/24224.242.150.1 to 224.242.150.254224.242.150.255254
152224.242.151.0/24224.242.151.1 to 224.242.151.254224.242.151.255254
153224.242.152.0/24224.242.152.1 to 224.242.152.254224.242.152.255254
154224.242.153.0/24224.242.153.1 to 224.242.153.254224.242.153.255254
155224.242.154.0/24224.242.154.1 to 224.242.154.254224.242.154.255254
156224.242.155.0/24224.242.155.1 to 224.242.155.254224.242.155.255254
157224.242.156.0/24224.242.156.1 to 224.242.156.254224.242.156.255254
158224.242.157.0/24224.242.157.1 to 224.242.157.254224.242.157.255254
159224.242.158.0/24224.242.158.1 to 224.242.158.254224.242.158.255254
160224.242.159.0/24224.242.159.1 to 224.242.159.254224.242.159.255254
161224.242.160.0/24224.242.160.1 to 224.242.160.254224.242.160.255254
162224.242.161.0/24224.242.161.1 to 224.242.161.254224.242.161.255254
163224.242.162.0/24224.242.162.1 to 224.242.162.254224.242.162.255254
164224.242.163.0/24224.242.163.1 to 224.242.163.254224.242.163.255254
165224.242.164.0/24224.242.164.1 to 224.242.164.254224.242.164.255254
166224.242.165.0/24224.242.165.1 to 224.242.165.254224.242.165.255254
167224.242.166.0/24224.242.166.1 to 224.242.166.254224.242.166.255254
168224.242.167.0/24224.242.167.1 to 224.242.167.254224.242.167.255254
169224.242.168.0/24224.242.168.1 to 224.242.168.254224.242.168.255254
170224.242.169.0/24224.242.169.1 to 224.242.169.254224.242.169.255254
171224.242.170.0/24224.242.170.1 to 224.242.170.254224.242.170.255254
172224.242.171.0/24224.242.171.1 to 224.242.171.254224.242.171.255254
173224.242.172.0/24224.242.172.1 to 224.242.172.254224.242.172.255254
174224.242.173.0/24224.242.173.1 to 224.242.173.254224.242.173.255254
175224.242.174.0/24224.242.174.1 to 224.242.174.254224.242.174.255254
176224.242.175.0/24224.242.175.1 to 224.242.175.254224.242.175.255254
177224.242.176.0/24224.242.176.1 to 224.242.176.254224.242.176.255254
178224.242.177.0/24224.242.177.1 to 224.242.177.254224.242.177.255254
179224.242.178.0/24224.242.178.1 to 224.242.178.254224.242.178.255254
180224.242.179.0/24224.242.179.1 to 224.242.179.254224.242.179.255254
181224.242.180.0/24224.242.180.1 to 224.242.180.254224.242.180.255254
182224.242.181.0/24224.242.181.1 to 224.242.181.254224.242.181.255254
183224.242.182.0/24224.242.182.1 to 224.242.182.254224.242.182.255254
184224.242.183.0/24224.242.183.1 to 224.242.183.254224.242.183.255254
185224.242.184.0/24224.242.184.1 to 224.242.184.254224.242.184.255254
186224.242.185.0/24224.242.185.1 to 224.242.185.254224.242.185.255254
187224.242.186.0/24224.242.186.1 to 224.242.186.254224.242.186.255254
188224.242.187.0/24224.242.187.1 to 224.242.187.254224.242.187.255254
189224.242.188.0/24224.242.188.1 to 224.242.188.254224.242.188.255254
190224.242.189.0/24224.242.189.1 to 224.242.189.254224.242.189.255254
191224.242.190.0/24224.242.190.1 to 224.242.190.254224.242.190.255254
192224.242.191.0/24224.242.191.1 to 224.242.191.254224.242.191.255254
193224.242.192.0/24224.242.192.1 to 224.242.192.254224.242.192.255254
194224.242.193.0/24224.242.193.1 to 224.242.193.254224.242.193.255254
195224.242.194.0/24224.242.194.1 to 224.242.194.254224.242.194.255254
196224.242.195.0/24224.242.195.1 to 224.242.195.254224.242.195.255254
197224.242.196.0/24224.242.196.1 to 224.242.196.254224.242.196.255254
198224.242.197.0/24224.242.197.1 to 224.242.197.254224.242.197.255254
199224.242.198.0/24224.242.198.1 to 224.242.198.254224.242.198.255254
200224.242.199.0/24224.242.199.1 to 224.242.199.254224.242.199.255254
201224.242.200.0/24224.242.200.1 to 224.242.200.254224.242.200.255254
202224.242.201.0/24224.242.201.1 to 224.242.201.254224.242.201.255254
203224.242.202.0/24224.242.202.1 to 224.242.202.254224.242.202.255254
204224.242.203.0/24224.242.203.1 to 224.242.203.254224.242.203.255254
205224.242.204.0/24224.242.204.1 to 224.242.204.254224.242.204.255254
206224.242.205.0/24224.242.205.1 to 224.242.205.254224.242.205.255254
207224.242.206.0/24224.242.206.1 to 224.242.206.254224.242.206.255254
208224.242.207.0/24224.242.207.1 to 224.242.207.254224.242.207.255254
209224.242.208.0/24224.242.208.1 to 224.242.208.254224.242.208.255254
210224.242.209.0/24224.242.209.1 to 224.242.209.254224.242.209.255254
211224.242.210.0/24224.242.210.1 to 224.242.210.254224.242.210.255254
212224.242.211.0/24224.242.211.1 to 224.242.211.254224.242.211.255254
213224.242.212.0/24224.242.212.1 to 224.242.212.254224.242.212.255254
214224.242.213.0/24224.242.213.1 to 224.242.213.254224.242.213.255254
215224.242.214.0/24224.242.214.1 to 224.242.214.254224.242.214.255254
216224.242.215.0/24224.242.215.1 to 224.242.215.254224.242.215.255254
217224.242.216.0/24224.242.216.1 to 224.242.216.254224.242.216.255254
218224.242.217.0/24224.242.217.1 to 224.242.217.254224.242.217.255254
219224.242.218.0/24224.242.218.1 to 224.242.218.254224.242.218.255254
220224.242.219.0/24224.242.219.1 to 224.242.219.254224.242.219.255254
221224.242.220.0/24224.242.220.1 to 224.242.220.254224.242.220.255254
222224.242.221.0/24224.242.221.1 to 224.242.221.254224.242.221.255254
223224.242.222.0/24224.242.222.1 to 224.242.222.254224.242.222.255254
224224.242.223.0/24224.242.223.1 to 224.242.223.254224.242.223.255254
225224.242.224.0/24224.242.224.1 to 224.242.224.254224.242.224.255254
226224.242.225.0/24224.242.225.1 to 224.242.225.254224.242.225.255254
227224.242.226.0/24224.242.226.1 to 224.242.226.254224.242.226.255254
228224.242.227.0/24224.242.227.1 to 224.242.227.254224.242.227.255254
229224.242.228.0/24224.242.228.1 to 224.242.228.254224.242.228.255254
230224.242.229.0/24224.242.229.1 to 224.242.229.254224.242.229.255254
231224.242.230.0/24224.242.230.1 to 224.242.230.254224.242.230.255254
232224.242.231.0/24224.242.231.1 to 224.242.231.254224.242.231.255254
233224.242.232.0/24224.242.232.1 to 224.242.232.254224.242.232.255254
234224.242.233.0/24224.242.233.1 to 224.242.233.254224.242.233.255254
235224.242.234.0/24224.242.234.1 to 224.242.234.254224.242.234.255254
236224.242.235.0/24224.242.235.1 to 224.242.235.254224.242.235.255254
237224.242.236.0/24224.242.236.1 to 224.242.236.254224.242.236.255254
238224.242.237.0/24224.242.237.1 to 224.242.237.254224.242.237.255254
239224.242.238.0/24224.242.238.1 to 224.242.238.254224.242.238.255254
240224.242.239.0/24224.242.239.1 to 224.242.239.254224.242.239.255254
241224.242.240.0/24224.242.240.1 to 224.242.240.254224.242.240.255254
242224.242.241.0/24224.242.241.1 to 224.242.241.254224.242.241.255254
243224.242.242.0/24224.242.242.1 to 224.242.242.254224.242.242.255254
244224.242.243.0/24224.242.243.1 to 224.242.243.254224.242.243.255254
245224.242.244.0/24224.242.244.1 to 224.242.244.254224.242.244.255254
246224.242.245.0/24224.242.245.1 to 224.242.245.254224.242.245.255254
247224.242.246.0/24224.242.246.1 to 224.242.246.254224.242.246.255254
248224.242.247.0/24224.242.247.1 to 224.242.247.254224.242.247.255254
249224.242.248.0/24224.242.248.1 to 224.242.248.254224.242.248.255254
250224.242.249.0/24224.242.249.1 to 224.242.249.254224.242.249.255254
251224.242.250.0/24224.242.250.1 to 224.242.250.254224.242.250.255254
252224.242.251.0/24224.242.251.1 to 224.242.251.254224.242.251.255254
253224.242.252.0/24224.242.252.1 to 224.242.252.254224.242.252.255254
254224.242.253.0/24224.242.253.1 to 224.242.253.254224.242.253.255254
255224.242.254.0/24224.242.254.1 to 224.242.254.254224.242.254.255254
256224.242.255.0/24224.242.255.1 to 224.242.255.254224.242.255.255254

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.