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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.

Network224.0.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
224.0.0.0
Broadcast address
224.127.255.255
First usable
224.0.0.1
Last usable
224.127.255.254
Usable hosts
8,388,606 (8,388,608 less the network and broadcast addresses)
Subnet mask
255.128.0.0
Wildcard mask
0.127.255.255 (Cisco ACLs, OSPF)
Prefix length
/9
Type
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E0000000 · Integer 3758096384 to 3766484991
Reverse DNS zones
0.224.in-addr.arpa
1.224.in-addr.arpa
2.224.in-addr.arpa
3.224.in-addr.arpa
4.224.in-addr.arpa
5.224.in-addr.arpa
6.224.in-addr.arpa
7.224.in-addr.arpa
8.224.in-addr.arpa
9.224.in-addr.arpa
10.224.in-addr.arpa
11.224.in-addr.arpa
12.224.in-addr.arpa
13.224.in-addr.arpa
14.224.in-addr.arpa
15.224.in-addr.arpa
and 112 more
/9 is not on a 8-bit boundary, so it takes 128 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11100000.00000000.00000000.00000000224.0.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network11100000.00000000.00000000.00000000224.0.0.0
Broadcast11100000.01111111.11111111.11111111224.127.255.255
Split into smaller subnets/17
/10 (2)/11 (4)/12 (8)/13 (16)/14 (32)/15 (64)/16 (128)/17 (256)/18 (512)/19 (1,024)/20 (2,048)/21 (4,096)

224.0.0.0/9 makes 256 subnets of /17.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1224.0.0.0/17224.0.0.1 to 224.0.127.254224.0.127.25532,766
2224.0.128.0/17224.0.128.1 to 224.0.255.254224.0.255.25532,766
3224.1.0.0/17224.1.0.1 to 224.1.127.254224.1.127.25532,766
4224.1.128.0/17224.1.128.1 to 224.1.255.254224.1.255.25532,766
5224.2.0.0/17224.2.0.1 to 224.2.127.254224.2.127.25532,766
6224.2.128.0/17224.2.128.1 to 224.2.255.254224.2.255.25532,766
7224.3.0.0/17224.3.0.1 to 224.3.127.254224.3.127.25532,766
8224.3.128.0/17224.3.128.1 to 224.3.255.254224.3.255.25532,766
9224.4.0.0/17224.4.0.1 to 224.4.127.254224.4.127.25532,766
10224.4.128.0/17224.4.128.1 to 224.4.255.254224.4.255.25532,766
11224.5.0.0/17224.5.0.1 to 224.5.127.254224.5.127.25532,766
12224.5.128.0/17224.5.128.1 to 224.5.255.254224.5.255.25532,766
13224.6.0.0/17224.6.0.1 to 224.6.127.254224.6.127.25532,766
14224.6.128.0/17224.6.128.1 to 224.6.255.254224.6.255.25532,766
15224.7.0.0/17224.7.0.1 to 224.7.127.254224.7.127.25532,766
16224.7.128.0/17224.7.128.1 to 224.7.255.254224.7.255.25532,766
17224.8.0.0/17224.8.0.1 to 224.8.127.254224.8.127.25532,766
18224.8.128.0/17224.8.128.1 to 224.8.255.254224.8.255.25532,766
19224.9.0.0/17224.9.0.1 to 224.9.127.254224.9.127.25532,766
20224.9.128.0/17224.9.128.1 to 224.9.255.254224.9.255.25532,766
21224.10.0.0/17224.10.0.1 to 224.10.127.254224.10.127.25532,766
22224.10.128.0/17224.10.128.1 to 224.10.255.254224.10.255.25532,766
23224.11.0.0/17224.11.0.1 to 224.11.127.254224.11.127.25532,766
24224.11.128.0/17224.11.128.1 to 224.11.255.254224.11.255.25532,766
25224.12.0.0/17224.12.0.1 to 224.12.127.254224.12.127.25532,766
26224.12.128.0/17224.12.128.1 to 224.12.255.254224.12.255.25532,766
27224.13.0.0/17224.13.0.1 to 224.13.127.254224.13.127.25532,766
28224.13.128.0/17224.13.128.1 to 224.13.255.254224.13.255.25532,766
29224.14.0.0/17224.14.0.1 to 224.14.127.254224.14.127.25532,766
30224.14.128.0/17224.14.128.1 to 224.14.255.254224.14.255.25532,766
31224.15.0.0/17224.15.0.1 to 224.15.127.254224.15.127.25532,766
32224.15.128.0/17224.15.128.1 to 224.15.255.254224.15.255.25532,766
33224.16.0.0/17224.16.0.1 to 224.16.127.254224.16.127.25532,766
34224.16.128.0/17224.16.128.1 to 224.16.255.254224.16.255.25532,766
35224.17.0.0/17224.17.0.1 to 224.17.127.254224.17.127.25532,766
36224.17.128.0/17224.17.128.1 to 224.17.255.254224.17.255.25532,766
37224.18.0.0/17224.18.0.1 to 224.18.127.254224.18.127.25532,766
38224.18.128.0/17224.18.128.1 to 224.18.255.254224.18.255.25532,766
39224.19.0.0/17224.19.0.1 to 224.19.127.254224.19.127.25532,766
40224.19.128.0/17224.19.128.1 to 224.19.255.254224.19.255.25532,766
41224.20.0.0/17224.20.0.1 to 224.20.127.254224.20.127.25532,766
42224.20.128.0/17224.20.128.1 to 224.20.255.254224.20.255.25532,766
43224.21.0.0/17224.21.0.1 to 224.21.127.254224.21.127.25532,766
44224.21.128.0/17224.21.128.1 to 224.21.255.254224.21.255.25532,766
45224.22.0.0/17224.22.0.1 to 224.22.127.254224.22.127.25532,766
46224.22.128.0/17224.22.128.1 to 224.22.255.254224.22.255.25532,766
47224.23.0.0/17224.23.0.1 to 224.23.127.254224.23.127.25532,766
48224.23.128.0/17224.23.128.1 to 224.23.255.254224.23.255.25532,766
49224.24.0.0/17224.24.0.1 to 224.24.127.254224.24.127.25532,766
50224.24.128.0/17224.24.128.1 to 224.24.255.254224.24.255.25532,766
51224.25.0.0/17224.25.0.1 to 224.25.127.254224.25.127.25532,766
52224.25.128.0/17224.25.128.1 to 224.25.255.254224.25.255.25532,766
53224.26.0.0/17224.26.0.1 to 224.26.127.254224.26.127.25532,766
54224.26.128.0/17224.26.128.1 to 224.26.255.254224.26.255.25532,766
55224.27.0.0/17224.27.0.1 to 224.27.127.254224.27.127.25532,766
56224.27.128.0/17224.27.128.1 to 224.27.255.254224.27.255.25532,766
57224.28.0.0/17224.28.0.1 to 224.28.127.254224.28.127.25532,766
58224.28.128.0/17224.28.128.1 to 224.28.255.254224.28.255.25532,766
59224.29.0.0/17224.29.0.1 to 224.29.127.254224.29.127.25532,766
60224.29.128.0/17224.29.128.1 to 224.29.255.254224.29.255.25532,766
61224.30.0.0/17224.30.0.1 to 224.30.127.254224.30.127.25532,766
62224.30.128.0/17224.30.128.1 to 224.30.255.254224.30.255.25532,766
63224.31.0.0/17224.31.0.1 to 224.31.127.254224.31.127.25532,766
64224.31.128.0/17224.31.128.1 to 224.31.255.254224.31.255.25532,766
65224.32.0.0/17224.32.0.1 to 224.32.127.254224.32.127.25532,766
66224.32.128.0/17224.32.128.1 to 224.32.255.254224.32.255.25532,766
67224.33.0.0/17224.33.0.1 to 224.33.127.254224.33.127.25532,766
68224.33.128.0/17224.33.128.1 to 224.33.255.254224.33.255.25532,766
69224.34.0.0/17224.34.0.1 to 224.34.127.254224.34.127.25532,766
70224.34.128.0/17224.34.128.1 to 224.34.255.254224.34.255.25532,766
71224.35.0.0/17224.35.0.1 to 224.35.127.254224.35.127.25532,766
72224.35.128.0/17224.35.128.1 to 224.35.255.254224.35.255.25532,766
73224.36.0.0/17224.36.0.1 to 224.36.127.254224.36.127.25532,766
74224.36.128.0/17224.36.128.1 to 224.36.255.254224.36.255.25532,766
75224.37.0.0/17224.37.0.1 to 224.37.127.254224.37.127.25532,766
76224.37.128.0/17224.37.128.1 to 224.37.255.254224.37.255.25532,766
77224.38.0.0/17224.38.0.1 to 224.38.127.254224.38.127.25532,766
78224.38.128.0/17224.38.128.1 to 224.38.255.254224.38.255.25532,766
79224.39.0.0/17224.39.0.1 to 224.39.127.254224.39.127.25532,766
80224.39.128.0/17224.39.128.1 to 224.39.255.254224.39.255.25532,766
81224.40.0.0/17224.40.0.1 to 224.40.127.254224.40.127.25532,766
82224.40.128.0/17224.40.128.1 to 224.40.255.254224.40.255.25532,766
83224.41.0.0/17224.41.0.1 to 224.41.127.254224.41.127.25532,766
84224.41.128.0/17224.41.128.1 to 224.41.255.254224.41.255.25532,766
85224.42.0.0/17224.42.0.1 to 224.42.127.254224.42.127.25532,766
86224.42.128.0/17224.42.128.1 to 224.42.255.254224.42.255.25532,766
87224.43.0.0/17224.43.0.1 to 224.43.127.254224.43.127.25532,766
88224.43.128.0/17224.43.128.1 to 224.43.255.254224.43.255.25532,766
89224.44.0.0/17224.44.0.1 to 224.44.127.254224.44.127.25532,766
90224.44.128.0/17224.44.128.1 to 224.44.255.254224.44.255.25532,766
91224.45.0.0/17224.45.0.1 to 224.45.127.254224.45.127.25532,766
92224.45.128.0/17224.45.128.1 to 224.45.255.254224.45.255.25532,766
93224.46.0.0/17224.46.0.1 to 224.46.127.254224.46.127.25532,766
94224.46.128.0/17224.46.128.1 to 224.46.255.254224.46.255.25532,766
95224.47.0.0/17224.47.0.1 to 224.47.127.254224.47.127.25532,766
96224.47.128.0/17224.47.128.1 to 224.47.255.254224.47.255.25532,766
97224.48.0.0/17224.48.0.1 to 224.48.127.254224.48.127.25532,766
98224.48.128.0/17224.48.128.1 to 224.48.255.254224.48.255.25532,766
99224.49.0.0/17224.49.0.1 to 224.49.127.254224.49.127.25532,766
100224.49.128.0/17224.49.128.1 to 224.49.255.254224.49.255.25532,766
101224.50.0.0/17224.50.0.1 to 224.50.127.254224.50.127.25532,766
102224.50.128.0/17224.50.128.1 to 224.50.255.254224.50.255.25532,766
103224.51.0.0/17224.51.0.1 to 224.51.127.254224.51.127.25532,766
104224.51.128.0/17224.51.128.1 to 224.51.255.254224.51.255.25532,766
105224.52.0.0/17224.52.0.1 to 224.52.127.254224.52.127.25532,766
106224.52.128.0/17224.52.128.1 to 224.52.255.254224.52.255.25532,766
107224.53.0.0/17224.53.0.1 to 224.53.127.254224.53.127.25532,766
108224.53.128.0/17224.53.128.1 to 224.53.255.254224.53.255.25532,766
109224.54.0.0/17224.54.0.1 to 224.54.127.254224.54.127.25532,766
110224.54.128.0/17224.54.128.1 to 224.54.255.254224.54.255.25532,766
111224.55.0.0/17224.55.0.1 to 224.55.127.254224.55.127.25532,766
112224.55.128.0/17224.55.128.1 to 224.55.255.254224.55.255.25532,766
113224.56.0.0/17224.56.0.1 to 224.56.127.254224.56.127.25532,766
114224.56.128.0/17224.56.128.1 to 224.56.255.254224.56.255.25532,766
115224.57.0.0/17224.57.0.1 to 224.57.127.254224.57.127.25532,766
116224.57.128.0/17224.57.128.1 to 224.57.255.254224.57.255.25532,766
117224.58.0.0/17224.58.0.1 to 224.58.127.254224.58.127.25532,766
118224.58.128.0/17224.58.128.1 to 224.58.255.254224.58.255.25532,766
119224.59.0.0/17224.59.0.1 to 224.59.127.254224.59.127.25532,766
120224.59.128.0/17224.59.128.1 to 224.59.255.254224.59.255.25532,766
121224.60.0.0/17224.60.0.1 to 224.60.127.254224.60.127.25532,766
122224.60.128.0/17224.60.128.1 to 224.60.255.254224.60.255.25532,766
123224.61.0.0/17224.61.0.1 to 224.61.127.254224.61.127.25532,766
124224.61.128.0/17224.61.128.1 to 224.61.255.254224.61.255.25532,766
125224.62.0.0/17224.62.0.1 to 224.62.127.254224.62.127.25532,766
126224.62.128.0/17224.62.128.1 to 224.62.255.254224.62.255.25532,766
127224.63.0.0/17224.63.0.1 to 224.63.127.254224.63.127.25532,766
128224.63.128.0/17224.63.128.1 to 224.63.255.254224.63.255.25532,766
129224.64.0.0/17224.64.0.1 to 224.64.127.254224.64.127.25532,766
130224.64.128.0/17224.64.128.1 to 224.64.255.254224.64.255.25532,766
131224.65.0.0/17224.65.0.1 to 224.65.127.254224.65.127.25532,766
132224.65.128.0/17224.65.128.1 to 224.65.255.254224.65.255.25532,766
133224.66.0.0/17224.66.0.1 to 224.66.127.254224.66.127.25532,766
134224.66.128.0/17224.66.128.1 to 224.66.255.254224.66.255.25532,766
135224.67.0.0/17224.67.0.1 to 224.67.127.254224.67.127.25532,766
136224.67.128.0/17224.67.128.1 to 224.67.255.254224.67.255.25532,766
137224.68.0.0/17224.68.0.1 to 224.68.127.254224.68.127.25532,766
138224.68.128.0/17224.68.128.1 to 224.68.255.254224.68.255.25532,766
139224.69.0.0/17224.69.0.1 to 224.69.127.254224.69.127.25532,766
140224.69.128.0/17224.69.128.1 to 224.69.255.254224.69.255.25532,766
141224.70.0.0/17224.70.0.1 to 224.70.127.254224.70.127.25532,766
142224.70.128.0/17224.70.128.1 to 224.70.255.254224.70.255.25532,766
143224.71.0.0/17224.71.0.1 to 224.71.127.254224.71.127.25532,766
144224.71.128.0/17224.71.128.1 to 224.71.255.254224.71.255.25532,766
145224.72.0.0/17224.72.0.1 to 224.72.127.254224.72.127.25532,766
146224.72.128.0/17224.72.128.1 to 224.72.255.254224.72.255.25532,766
147224.73.0.0/17224.73.0.1 to 224.73.127.254224.73.127.25532,766
148224.73.128.0/17224.73.128.1 to 224.73.255.254224.73.255.25532,766
149224.74.0.0/17224.74.0.1 to 224.74.127.254224.74.127.25532,766
150224.74.128.0/17224.74.128.1 to 224.74.255.254224.74.255.25532,766
151224.75.0.0/17224.75.0.1 to 224.75.127.254224.75.127.25532,766
152224.75.128.0/17224.75.128.1 to 224.75.255.254224.75.255.25532,766
153224.76.0.0/17224.76.0.1 to 224.76.127.254224.76.127.25532,766
154224.76.128.0/17224.76.128.1 to 224.76.255.254224.76.255.25532,766
155224.77.0.0/17224.77.0.1 to 224.77.127.254224.77.127.25532,766
156224.77.128.0/17224.77.128.1 to 224.77.255.254224.77.255.25532,766
157224.78.0.0/17224.78.0.1 to 224.78.127.254224.78.127.25532,766
158224.78.128.0/17224.78.128.1 to 224.78.255.254224.78.255.25532,766
159224.79.0.0/17224.79.0.1 to 224.79.127.254224.79.127.25532,766
160224.79.128.0/17224.79.128.1 to 224.79.255.254224.79.255.25532,766
161224.80.0.0/17224.80.0.1 to 224.80.127.254224.80.127.25532,766
162224.80.128.0/17224.80.128.1 to 224.80.255.254224.80.255.25532,766
163224.81.0.0/17224.81.0.1 to 224.81.127.254224.81.127.25532,766
164224.81.128.0/17224.81.128.1 to 224.81.255.254224.81.255.25532,766
165224.82.0.0/17224.82.0.1 to 224.82.127.254224.82.127.25532,766
166224.82.128.0/17224.82.128.1 to 224.82.255.254224.82.255.25532,766
167224.83.0.0/17224.83.0.1 to 224.83.127.254224.83.127.25532,766
168224.83.128.0/17224.83.128.1 to 224.83.255.254224.83.255.25532,766
169224.84.0.0/17224.84.0.1 to 224.84.127.254224.84.127.25532,766
170224.84.128.0/17224.84.128.1 to 224.84.255.254224.84.255.25532,766
171224.85.0.0/17224.85.0.1 to 224.85.127.254224.85.127.25532,766
172224.85.128.0/17224.85.128.1 to 224.85.255.254224.85.255.25532,766
173224.86.0.0/17224.86.0.1 to 224.86.127.254224.86.127.25532,766
174224.86.128.0/17224.86.128.1 to 224.86.255.254224.86.255.25532,766
175224.87.0.0/17224.87.0.1 to 224.87.127.254224.87.127.25532,766
176224.87.128.0/17224.87.128.1 to 224.87.255.254224.87.255.25532,766
177224.88.0.0/17224.88.0.1 to 224.88.127.254224.88.127.25532,766
178224.88.128.0/17224.88.128.1 to 224.88.255.254224.88.255.25532,766
179224.89.0.0/17224.89.0.1 to 224.89.127.254224.89.127.25532,766
180224.89.128.0/17224.89.128.1 to 224.89.255.254224.89.255.25532,766
181224.90.0.0/17224.90.0.1 to 224.90.127.254224.90.127.25532,766
182224.90.128.0/17224.90.128.1 to 224.90.255.254224.90.255.25532,766
183224.91.0.0/17224.91.0.1 to 224.91.127.254224.91.127.25532,766
184224.91.128.0/17224.91.128.1 to 224.91.255.254224.91.255.25532,766
185224.92.0.0/17224.92.0.1 to 224.92.127.254224.92.127.25532,766
186224.92.128.0/17224.92.128.1 to 224.92.255.254224.92.255.25532,766
187224.93.0.0/17224.93.0.1 to 224.93.127.254224.93.127.25532,766
188224.93.128.0/17224.93.128.1 to 224.93.255.254224.93.255.25532,766
189224.94.0.0/17224.94.0.1 to 224.94.127.254224.94.127.25532,766
190224.94.128.0/17224.94.128.1 to 224.94.255.254224.94.255.25532,766
191224.95.0.0/17224.95.0.1 to 224.95.127.254224.95.127.25532,766
192224.95.128.0/17224.95.128.1 to 224.95.255.254224.95.255.25532,766
193224.96.0.0/17224.96.0.1 to 224.96.127.254224.96.127.25532,766
194224.96.128.0/17224.96.128.1 to 224.96.255.254224.96.255.25532,766
195224.97.0.0/17224.97.0.1 to 224.97.127.254224.97.127.25532,766
196224.97.128.0/17224.97.128.1 to 224.97.255.254224.97.255.25532,766
197224.98.0.0/17224.98.0.1 to 224.98.127.254224.98.127.25532,766
198224.98.128.0/17224.98.128.1 to 224.98.255.254224.98.255.25532,766
199224.99.0.0/17224.99.0.1 to 224.99.127.254224.99.127.25532,766
200224.99.128.0/17224.99.128.1 to 224.99.255.254224.99.255.25532,766
201224.100.0.0/17224.100.0.1 to 224.100.127.254224.100.127.25532,766
202224.100.128.0/17224.100.128.1 to 224.100.255.254224.100.255.25532,766
203224.101.0.0/17224.101.0.1 to 224.101.127.254224.101.127.25532,766
204224.101.128.0/17224.101.128.1 to 224.101.255.254224.101.255.25532,766
205224.102.0.0/17224.102.0.1 to 224.102.127.254224.102.127.25532,766
206224.102.128.0/17224.102.128.1 to 224.102.255.254224.102.255.25532,766
207224.103.0.0/17224.103.0.1 to 224.103.127.254224.103.127.25532,766
208224.103.128.0/17224.103.128.1 to 224.103.255.254224.103.255.25532,766
209224.104.0.0/17224.104.0.1 to 224.104.127.254224.104.127.25532,766
210224.104.128.0/17224.104.128.1 to 224.104.255.254224.104.255.25532,766
211224.105.0.0/17224.105.0.1 to 224.105.127.254224.105.127.25532,766
212224.105.128.0/17224.105.128.1 to 224.105.255.254224.105.255.25532,766
213224.106.0.0/17224.106.0.1 to 224.106.127.254224.106.127.25532,766
214224.106.128.0/17224.106.128.1 to 224.106.255.254224.106.255.25532,766
215224.107.0.0/17224.107.0.1 to 224.107.127.254224.107.127.25532,766
216224.107.128.0/17224.107.128.1 to 224.107.255.254224.107.255.25532,766
217224.108.0.0/17224.108.0.1 to 224.108.127.254224.108.127.25532,766
218224.108.128.0/17224.108.128.1 to 224.108.255.254224.108.255.25532,766
219224.109.0.0/17224.109.0.1 to 224.109.127.254224.109.127.25532,766
220224.109.128.0/17224.109.128.1 to 224.109.255.254224.109.255.25532,766
221224.110.0.0/17224.110.0.1 to 224.110.127.254224.110.127.25532,766
222224.110.128.0/17224.110.128.1 to 224.110.255.254224.110.255.25532,766
223224.111.0.0/17224.111.0.1 to 224.111.127.254224.111.127.25532,766
224224.111.128.0/17224.111.128.1 to 224.111.255.254224.111.255.25532,766
225224.112.0.0/17224.112.0.1 to 224.112.127.254224.112.127.25532,766
226224.112.128.0/17224.112.128.1 to 224.112.255.254224.112.255.25532,766
227224.113.0.0/17224.113.0.1 to 224.113.127.254224.113.127.25532,766
228224.113.128.0/17224.113.128.1 to 224.113.255.254224.113.255.25532,766
229224.114.0.0/17224.114.0.1 to 224.114.127.254224.114.127.25532,766
230224.114.128.0/17224.114.128.1 to 224.114.255.254224.114.255.25532,766
231224.115.0.0/17224.115.0.1 to 224.115.127.254224.115.127.25532,766
232224.115.128.0/17224.115.128.1 to 224.115.255.254224.115.255.25532,766
233224.116.0.0/17224.116.0.1 to 224.116.127.254224.116.127.25532,766
234224.116.128.0/17224.116.128.1 to 224.116.255.254224.116.255.25532,766
235224.117.0.0/17224.117.0.1 to 224.117.127.254224.117.127.25532,766
236224.117.128.0/17224.117.128.1 to 224.117.255.254224.117.255.25532,766
237224.118.0.0/17224.118.0.1 to 224.118.127.254224.118.127.25532,766
238224.118.128.0/17224.118.128.1 to 224.118.255.254224.118.255.25532,766
239224.119.0.0/17224.119.0.1 to 224.119.127.254224.119.127.25532,766
240224.119.128.0/17224.119.128.1 to 224.119.255.254224.119.255.25532,766
241224.120.0.0/17224.120.0.1 to 224.120.127.254224.120.127.25532,766
242224.120.128.0/17224.120.128.1 to 224.120.255.254224.120.255.25532,766
243224.121.0.0/17224.121.0.1 to 224.121.127.254224.121.127.25532,766
244224.121.128.0/17224.121.128.1 to 224.121.255.254224.121.255.25532,766
245224.122.0.0/17224.122.0.1 to 224.122.127.254224.122.127.25532,766
246224.122.128.0/17224.122.128.1 to 224.122.255.254224.122.255.25532,766
247224.123.0.0/17224.123.0.1 to 224.123.127.254224.123.127.25532,766
248224.123.128.0/17224.123.128.1 to 224.123.255.254224.123.255.25532,766
249224.124.0.0/17224.124.0.1 to 224.124.127.254224.124.127.25532,766
250224.124.128.0/17224.124.128.1 to 224.124.255.254224.124.255.25532,766
251224.125.0.0/17224.125.0.1 to 224.125.127.254224.125.127.25532,766
252224.125.128.0/17224.125.128.1 to 224.125.255.254224.125.255.25532,766
253224.126.0.0/17224.126.0.1 to 224.126.127.254224.126.127.25532,766
254224.126.128.0/17224.126.128.1 to 224.126.255.254224.126.255.25532,766
255224.127.0.0/17224.127.0.1 to 224.127.127.254224.127.127.25532,766
256224.127.128.0/17224.127.128.1 to 224.127.255.254224.127.255.25532,766

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.