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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.

Network213.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
213.0.0.0
Broadcast address
213.255.255.255
First usable
213.0.0.1
Last usable
213.255.255.254
Usable hosts
16,777,214 (16,777,216 less the network and broadcast addresses)
Subnet mask
255.0.0.0
Wildcard mask
0.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/8
Type
Public public
Old class
C (default /24)
As numbers
Hex D5000000 · Integer 3573547008 to 3590324223
Reverse DNS zone
213.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11010101..00000000.00000000.00000000213.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network11010101..00000000.00000000.00000000213.0.0.0
Broadcast11010101..11111111.11111111.11111111213.255.255.255
Split into smaller subnets/17
/9 (2)/10 (4)/11 (8)/12 (16)/13 (32)/14 (64)/15 (128)/16 (256)/17 (512)/18 (1,024)/19 (2,048)/20 (4,096)

213.0.0.0/8 makes 512 subnets of /17; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1213.0.0.0/17213.0.0.1 to 213.0.127.254213.0.127.25532,766
2213.0.128.0/17213.0.128.1 to 213.0.255.254213.0.255.25532,766
3213.1.0.0/17213.1.0.1 to 213.1.127.254213.1.127.25532,766
4213.1.128.0/17213.1.128.1 to 213.1.255.254213.1.255.25532,766
5213.2.0.0/17213.2.0.1 to 213.2.127.254213.2.127.25532,766
6213.2.128.0/17213.2.128.1 to 213.2.255.254213.2.255.25532,766
7213.3.0.0/17213.3.0.1 to 213.3.127.254213.3.127.25532,766
8213.3.128.0/17213.3.128.1 to 213.3.255.254213.3.255.25532,766
9213.4.0.0/17213.4.0.1 to 213.4.127.254213.4.127.25532,766
10213.4.128.0/17213.4.128.1 to 213.4.255.254213.4.255.25532,766
11213.5.0.0/17213.5.0.1 to 213.5.127.254213.5.127.25532,766
12213.5.128.0/17213.5.128.1 to 213.5.255.254213.5.255.25532,766
13213.6.0.0/17213.6.0.1 to 213.6.127.254213.6.127.25532,766
14213.6.128.0/17213.6.128.1 to 213.6.255.254213.6.255.25532,766
15213.7.0.0/17213.7.0.1 to 213.7.127.254213.7.127.25532,766
16213.7.128.0/17213.7.128.1 to 213.7.255.254213.7.255.25532,766
17213.8.0.0/17213.8.0.1 to 213.8.127.254213.8.127.25532,766
18213.8.128.0/17213.8.128.1 to 213.8.255.254213.8.255.25532,766
19213.9.0.0/17213.9.0.1 to 213.9.127.254213.9.127.25532,766
20213.9.128.0/17213.9.128.1 to 213.9.255.254213.9.255.25532,766
21213.10.0.0/17213.10.0.1 to 213.10.127.254213.10.127.25532,766
22213.10.128.0/17213.10.128.1 to 213.10.255.254213.10.255.25532,766
23213.11.0.0/17213.11.0.1 to 213.11.127.254213.11.127.25532,766
24213.11.128.0/17213.11.128.1 to 213.11.255.254213.11.255.25532,766
25213.12.0.0/17213.12.0.1 to 213.12.127.254213.12.127.25532,766
26213.12.128.0/17213.12.128.1 to 213.12.255.254213.12.255.25532,766
27213.13.0.0/17213.13.0.1 to 213.13.127.254213.13.127.25532,766
28213.13.128.0/17213.13.128.1 to 213.13.255.254213.13.255.25532,766
29213.14.0.0/17213.14.0.1 to 213.14.127.254213.14.127.25532,766
30213.14.128.0/17213.14.128.1 to 213.14.255.254213.14.255.25532,766
31213.15.0.0/17213.15.0.1 to 213.15.127.254213.15.127.25532,766
32213.15.128.0/17213.15.128.1 to 213.15.255.254213.15.255.25532,766
33213.16.0.0/17213.16.0.1 to 213.16.127.254213.16.127.25532,766
34213.16.128.0/17213.16.128.1 to 213.16.255.254213.16.255.25532,766
35213.17.0.0/17213.17.0.1 to 213.17.127.254213.17.127.25532,766
36213.17.128.0/17213.17.128.1 to 213.17.255.254213.17.255.25532,766
37213.18.0.0/17213.18.0.1 to 213.18.127.254213.18.127.25532,766
38213.18.128.0/17213.18.128.1 to 213.18.255.254213.18.255.25532,766
39213.19.0.0/17213.19.0.1 to 213.19.127.254213.19.127.25532,766
40213.19.128.0/17213.19.128.1 to 213.19.255.254213.19.255.25532,766
41213.20.0.0/17213.20.0.1 to 213.20.127.254213.20.127.25532,766
42213.20.128.0/17213.20.128.1 to 213.20.255.254213.20.255.25532,766
43213.21.0.0/17213.21.0.1 to 213.21.127.254213.21.127.25532,766
44213.21.128.0/17213.21.128.1 to 213.21.255.254213.21.255.25532,766
45213.22.0.0/17213.22.0.1 to 213.22.127.254213.22.127.25532,766
46213.22.128.0/17213.22.128.1 to 213.22.255.254213.22.255.25532,766
47213.23.0.0/17213.23.0.1 to 213.23.127.254213.23.127.25532,766
48213.23.128.0/17213.23.128.1 to 213.23.255.254213.23.255.25532,766
49213.24.0.0/17213.24.0.1 to 213.24.127.254213.24.127.25532,766
50213.24.128.0/17213.24.128.1 to 213.24.255.254213.24.255.25532,766
51213.25.0.0/17213.25.0.1 to 213.25.127.254213.25.127.25532,766
52213.25.128.0/17213.25.128.1 to 213.25.255.254213.25.255.25532,766
53213.26.0.0/17213.26.0.1 to 213.26.127.254213.26.127.25532,766
54213.26.128.0/17213.26.128.1 to 213.26.255.254213.26.255.25532,766
55213.27.0.0/17213.27.0.1 to 213.27.127.254213.27.127.25532,766
56213.27.128.0/17213.27.128.1 to 213.27.255.254213.27.255.25532,766
57213.28.0.0/17213.28.0.1 to 213.28.127.254213.28.127.25532,766
58213.28.128.0/17213.28.128.1 to 213.28.255.254213.28.255.25532,766
59213.29.0.0/17213.29.0.1 to 213.29.127.254213.29.127.25532,766
60213.29.128.0/17213.29.128.1 to 213.29.255.254213.29.255.25532,766
61213.30.0.0/17213.30.0.1 to 213.30.127.254213.30.127.25532,766
62213.30.128.0/17213.30.128.1 to 213.30.255.254213.30.255.25532,766
63213.31.0.0/17213.31.0.1 to 213.31.127.254213.31.127.25532,766
64213.31.128.0/17213.31.128.1 to 213.31.255.254213.31.255.25532,766
65213.32.0.0/17213.32.0.1 to 213.32.127.254213.32.127.25532,766
66213.32.128.0/17213.32.128.1 to 213.32.255.254213.32.255.25532,766
67213.33.0.0/17213.33.0.1 to 213.33.127.254213.33.127.25532,766
68213.33.128.0/17213.33.128.1 to 213.33.255.254213.33.255.25532,766
69213.34.0.0/17213.34.0.1 to 213.34.127.254213.34.127.25532,766
70213.34.128.0/17213.34.128.1 to 213.34.255.254213.34.255.25532,766
71213.35.0.0/17213.35.0.1 to 213.35.127.254213.35.127.25532,766
72213.35.128.0/17213.35.128.1 to 213.35.255.254213.35.255.25532,766
73213.36.0.0/17213.36.0.1 to 213.36.127.254213.36.127.25532,766
74213.36.128.0/17213.36.128.1 to 213.36.255.254213.36.255.25532,766
75213.37.0.0/17213.37.0.1 to 213.37.127.254213.37.127.25532,766
76213.37.128.0/17213.37.128.1 to 213.37.255.254213.37.255.25532,766
77213.38.0.0/17213.38.0.1 to 213.38.127.254213.38.127.25532,766
78213.38.128.0/17213.38.128.1 to 213.38.255.254213.38.255.25532,766
79213.39.0.0/17213.39.0.1 to 213.39.127.254213.39.127.25532,766
80213.39.128.0/17213.39.128.1 to 213.39.255.254213.39.255.25532,766
81213.40.0.0/17213.40.0.1 to 213.40.127.254213.40.127.25532,766
82213.40.128.0/17213.40.128.1 to 213.40.255.254213.40.255.25532,766
83213.41.0.0/17213.41.0.1 to 213.41.127.254213.41.127.25532,766
84213.41.128.0/17213.41.128.1 to 213.41.255.254213.41.255.25532,766
85213.42.0.0/17213.42.0.1 to 213.42.127.254213.42.127.25532,766
86213.42.128.0/17213.42.128.1 to 213.42.255.254213.42.255.25532,766
87213.43.0.0/17213.43.0.1 to 213.43.127.254213.43.127.25532,766
88213.43.128.0/17213.43.128.1 to 213.43.255.254213.43.255.25532,766
89213.44.0.0/17213.44.0.1 to 213.44.127.254213.44.127.25532,766
90213.44.128.0/17213.44.128.1 to 213.44.255.254213.44.255.25532,766
91213.45.0.0/17213.45.0.1 to 213.45.127.254213.45.127.25532,766
92213.45.128.0/17213.45.128.1 to 213.45.255.254213.45.255.25532,766
93213.46.0.0/17213.46.0.1 to 213.46.127.254213.46.127.25532,766
94213.46.128.0/17213.46.128.1 to 213.46.255.254213.46.255.25532,766
95213.47.0.0/17213.47.0.1 to 213.47.127.254213.47.127.25532,766
96213.47.128.0/17213.47.128.1 to 213.47.255.254213.47.255.25532,766
97213.48.0.0/17213.48.0.1 to 213.48.127.254213.48.127.25532,766
98213.48.128.0/17213.48.128.1 to 213.48.255.254213.48.255.25532,766
99213.49.0.0/17213.49.0.1 to 213.49.127.254213.49.127.25532,766
100213.49.128.0/17213.49.128.1 to 213.49.255.254213.49.255.25532,766
101213.50.0.0/17213.50.0.1 to 213.50.127.254213.50.127.25532,766
102213.50.128.0/17213.50.128.1 to 213.50.255.254213.50.255.25532,766
103213.51.0.0/17213.51.0.1 to 213.51.127.254213.51.127.25532,766
104213.51.128.0/17213.51.128.1 to 213.51.255.254213.51.255.25532,766
105213.52.0.0/17213.52.0.1 to 213.52.127.254213.52.127.25532,766
106213.52.128.0/17213.52.128.1 to 213.52.255.254213.52.255.25532,766
107213.53.0.0/17213.53.0.1 to 213.53.127.254213.53.127.25532,766
108213.53.128.0/17213.53.128.1 to 213.53.255.254213.53.255.25532,766
109213.54.0.0/17213.54.0.1 to 213.54.127.254213.54.127.25532,766
110213.54.128.0/17213.54.128.1 to 213.54.255.254213.54.255.25532,766
111213.55.0.0/17213.55.0.1 to 213.55.127.254213.55.127.25532,766
112213.55.128.0/17213.55.128.1 to 213.55.255.254213.55.255.25532,766
113213.56.0.0/17213.56.0.1 to 213.56.127.254213.56.127.25532,766
114213.56.128.0/17213.56.128.1 to 213.56.255.254213.56.255.25532,766
115213.57.0.0/17213.57.0.1 to 213.57.127.254213.57.127.25532,766
116213.57.128.0/17213.57.128.1 to 213.57.255.254213.57.255.25532,766
117213.58.0.0/17213.58.0.1 to 213.58.127.254213.58.127.25532,766
118213.58.128.0/17213.58.128.1 to 213.58.255.254213.58.255.25532,766
119213.59.0.0/17213.59.0.1 to 213.59.127.254213.59.127.25532,766
120213.59.128.0/17213.59.128.1 to 213.59.255.254213.59.255.25532,766
121213.60.0.0/17213.60.0.1 to 213.60.127.254213.60.127.25532,766
122213.60.128.0/17213.60.128.1 to 213.60.255.254213.60.255.25532,766
123213.61.0.0/17213.61.0.1 to 213.61.127.254213.61.127.25532,766
124213.61.128.0/17213.61.128.1 to 213.61.255.254213.61.255.25532,766
125213.62.0.0/17213.62.0.1 to 213.62.127.254213.62.127.25532,766
126213.62.128.0/17213.62.128.1 to 213.62.255.254213.62.255.25532,766
127213.63.0.0/17213.63.0.1 to 213.63.127.254213.63.127.25532,766
128213.63.128.0/17213.63.128.1 to 213.63.255.254213.63.255.25532,766
129213.64.0.0/17213.64.0.1 to 213.64.127.254213.64.127.25532,766
130213.64.128.0/17213.64.128.1 to 213.64.255.254213.64.255.25532,766
131213.65.0.0/17213.65.0.1 to 213.65.127.254213.65.127.25532,766
132213.65.128.0/17213.65.128.1 to 213.65.255.254213.65.255.25532,766
133213.66.0.0/17213.66.0.1 to 213.66.127.254213.66.127.25532,766
134213.66.128.0/17213.66.128.1 to 213.66.255.254213.66.255.25532,766
135213.67.0.0/17213.67.0.1 to 213.67.127.254213.67.127.25532,766
136213.67.128.0/17213.67.128.1 to 213.67.255.254213.67.255.25532,766
137213.68.0.0/17213.68.0.1 to 213.68.127.254213.68.127.25532,766
138213.68.128.0/17213.68.128.1 to 213.68.255.254213.68.255.25532,766
139213.69.0.0/17213.69.0.1 to 213.69.127.254213.69.127.25532,766
140213.69.128.0/17213.69.128.1 to 213.69.255.254213.69.255.25532,766
141213.70.0.0/17213.70.0.1 to 213.70.127.254213.70.127.25532,766
142213.70.128.0/17213.70.128.1 to 213.70.255.254213.70.255.25532,766
143213.71.0.0/17213.71.0.1 to 213.71.127.254213.71.127.25532,766
144213.71.128.0/17213.71.128.1 to 213.71.255.254213.71.255.25532,766
145213.72.0.0/17213.72.0.1 to 213.72.127.254213.72.127.25532,766
146213.72.128.0/17213.72.128.1 to 213.72.255.254213.72.255.25532,766
147213.73.0.0/17213.73.0.1 to 213.73.127.254213.73.127.25532,766
148213.73.128.0/17213.73.128.1 to 213.73.255.254213.73.255.25532,766
149213.74.0.0/17213.74.0.1 to 213.74.127.254213.74.127.25532,766
150213.74.128.0/17213.74.128.1 to 213.74.255.254213.74.255.25532,766
151213.75.0.0/17213.75.0.1 to 213.75.127.254213.75.127.25532,766
152213.75.128.0/17213.75.128.1 to 213.75.255.254213.75.255.25532,766
153213.76.0.0/17213.76.0.1 to 213.76.127.254213.76.127.25532,766
154213.76.128.0/17213.76.128.1 to 213.76.255.254213.76.255.25532,766
155213.77.0.0/17213.77.0.1 to 213.77.127.254213.77.127.25532,766
156213.77.128.0/17213.77.128.1 to 213.77.255.254213.77.255.25532,766
157213.78.0.0/17213.78.0.1 to 213.78.127.254213.78.127.25532,766
158213.78.128.0/17213.78.128.1 to 213.78.255.254213.78.255.25532,766
159213.79.0.0/17213.79.0.1 to 213.79.127.254213.79.127.25532,766
160213.79.128.0/17213.79.128.1 to 213.79.255.254213.79.255.25532,766
161213.80.0.0/17213.80.0.1 to 213.80.127.254213.80.127.25532,766
162213.80.128.0/17213.80.128.1 to 213.80.255.254213.80.255.25532,766
163213.81.0.0/17213.81.0.1 to 213.81.127.254213.81.127.25532,766
164213.81.128.0/17213.81.128.1 to 213.81.255.254213.81.255.25532,766
165213.82.0.0/17213.82.0.1 to 213.82.127.254213.82.127.25532,766
166213.82.128.0/17213.82.128.1 to 213.82.255.254213.82.255.25532,766
167213.83.0.0/17213.83.0.1 to 213.83.127.254213.83.127.25532,766
168213.83.128.0/17213.83.128.1 to 213.83.255.254213.83.255.25532,766
169213.84.0.0/17213.84.0.1 to 213.84.127.254213.84.127.25532,766
170213.84.128.0/17213.84.128.1 to 213.84.255.254213.84.255.25532,766
171213.85.0.0/17213.85.0.1 to 213.85.127.254213.85.127.25532,766
172213.85.128.0/17213.85.128.1 to 213.85.255.254213.85.255.25532,766
173213.86.0.0/17213.86.0.1 to 213.86.127.254213.86.127.25532,766
174213.86.128.0/17213.86.128.1 to 213.86.255.254213.86.255.25532,766
175213.87.0.0/17213.87.0.1 to 213.87.127.254213.87.127.25532,766
176213.87.128.0/17213.87.128.1 to 213.87.255.254213.87.255.25532,766
177213.88.0.0/17213.88.0.1 to 213.88.127.254213.88.127.25532,766
178213.88.128.0/17213.88.128.1 to 213.88.255.254213.88.255.25532,766
179213.89.0.0/17213.89.0.1 to 213.89.127.254213.89.127.25532,766
180213.89.128.0/17213.89.128.1 to 213.89.255.254213.89.255.25532,766
181213.90.0.0/17213.90.0.1 to 213.90.127.254213.90.127.25532,766
182213.90.128.0/17213.90.128.1 to 213.90.255.254213.90.255.25532,766
183213.91.0.0/17213.91.0.1 to 213.91.127.254213.91.127.25532,766
184213.91.128.0/17213.91.128.1 to 213.91.255.254213.91.255.25532,766
185213.92.0.0/17213.92.0.1 to 213.92.127.254213.92.127.25532,766
186213.92.128.0/17213.92.128.1 to 213.92.255.254213.92.255.25532,766
187213.93.0.0/17213.93.0.1 to 213.93.127.254213.93.127.25532,766
188213.93.128.0/17213.93.128.1 to 213.93.255.254213.93.255.25532,766
189213.94.0.0/17213.94.0.1 to 213.94.127.254213.94.127.25532,766
190213.94.128.0/17213.94.128.1 to 213.94.255.254213.94.255.25532,766
191213.95.0.0/17213.95.0.1 to 213.95.127.254213.95.127.25532,766
192213.95.128.0/17213.95.128.1 to 213.95.255.254213.95.255.25532,766
193213.96.0.0/17213.96.0.1 to 213.96.127.254213.96.127.25532,766
194213.96.128.0/17213.96.128.1 to 213.96.255.254213.96.255.25532,766
195213.97.0.0/17213.97.0.1 to 213.97.127.254213.97.127.25532,766
196213.97.128.0/17213.97.128.1 to 213.97.255.254213.97.255.25532,766
197213.98.0.0/17213.98.0.1 to 213.98.127.254213.98.127.25532,766
198213.98.128.0/17213.98.128.1 to 213.98.255.254213.98.255.25532,766
199213.99.0.0/17213.99.0.1 to 213.99.127.254213.99.127.25532,766
200213.99.128.0/17213.99.128.1 to 213.99.255.254213.99.255.25532,766
201213.100.0.0/17213.100.0.1 to 213.100.127.254213.100.127.25532,766
202213.100.128.0/17213.100.128.1 to 213.100.255.254213.100.255.25532,766
203213.101.0.0/17213.101.0.1 to 213.101.127.254213.101.127.25532,766
204213.101.128.0/17213.101.128.1 to 213.101.255.254213.101.255.25532,766
205213.102.0.0/17213.102.0.1 to 213.102.127.254213.102.127.25532,766
206213.102.128.0/17213.102.128.1 to 213.102.255.254213.102.255.25532,766
207213.103.0.0/17213.103.0.1 to 213.103.127.254213.103.127.25532,766
208213.103.128.0/17213.103.128.1 to 213.103.255.254213.103.255.25532,766
209213.104.0.0/17213.104.0.1 to 213.104.127.254213.104.127.25532,766
210213.104.128.0/17213.104.128.1 to 213.104.255.254213.104.255.25532,766
211213.105.0.0/17213.105.0.1 to 213.105.127.254213.105.127.25532,766
212213.105.128.0/17213.105.128.1 to 213.105.255.254213.105.255.25532,766
213213.106.0.0/17213.106.0.1 to 213.106.127.254213.106.127.25532,766
214213.106.128.0/17213.106.128.1 to 213.106.255.254213.106.255.25532,766
215213.107.0.0/17213.107.0.1 to 213.107.127.254213.107.127.25532,766
216213.107.128.0/17213.107.128.1 to 213.107.255.254213.107.255.25532,766
217213.108.0.0/17213.108.0.1 to 213.108.127.254213.108.127.25532,766
218213.108.128.0/17213.108.128.1 to 213.108.255.254213.108.255.25532,766
219213.109.0.0/17213.109.0.1 to 213.109.127.254213.109.127.25532,766
220213.109.128.0/17213.109.128.1 to 213.109.255.254213.109.255.25532,766
221213.110.0.0/17213.110.0.1 to 213.110.127.254213.110.127.25532,766
222213.110.128.0/17213.110.128.1 to 213.110.255.254213.110.255.25532,766
223213.111.0.0/17213.111.0.1 to 213.111.127.254213.111.127.25532,766
224213.111.128.0/17213.111.128.1 to 213.111.255.254213.111.255.25532,766
225213.112.0.0/17213.112.0.1 to 213.112.127.254213.112.127.25532,766
226213.112.128.0/17213.112.128.1 to 213.112.255.254213.112.255.25532,766
227213.113.0.0/17213.113.0.1 to 213.113.127.254213.113.127.25532,766
228213.113.128.0/17213.113.128.1 to 213.113.255.254213.113.255.25532,766
229213.114.0.0/17213.114.0.1 to 213.114.127.254213.114.127.25532,766
230213.114.128.0/17213.114.128.1 to 213.114.255.254213.114.255.25532,766
231213.115.0.0/17213.115.0.1 to 213.115.127.254213.115.127.25532,766
232213.115.128.0/17213.115.128.1 to 213.115.255.254213.115.255.25532,766
233213.116.0.0/17213.116.0.1 to 213.116.127.254213.116.127.25532,766
234213.116.128.0/17213.116.128.1 to 213.116.255.254213.116.255.25532,766
235213.117.0.0/17213.117.0.1 to 213.117.127.254213.117.127.25532,766
236213.117.128.0/17213.117.128.1 to 213.117.255.254213.117.255.25532,766
237213.118.0.0/17213.118.0.1 to 213.118.127.254213.118.127.25532,766
238213.118.128.0/17213.118.128.1 to 213.118.255.254213.118.255.25532,766
239213.119.0.0/17213.119.0.1 to 213.119.127.254213.119.127.25532,766
240213.119.128.0/17213.119.128.1 to 213.119.255.254213.119.255.25532,766
241213.120.0.0/17213.120.0.1 to 213.120.127.254213.120.127.25532,766
242213.120.128.0/17213.120.128.1 to 213.120.255.254213.120.255.25532,766
243213.121.0.0/17213.121.0.1 to 213.121.127.254213.121.127.25532,766
244213.121.128.0/17213.121.128.1 to 213.121.255.254213.121.255.25532,766
245213.122.0.0/17213.122.0.1 to 213.122.127.254213.122.127.25532,766
246213.122.128.0/17213.122.128.1 to 213.122.255.254213.122.255.25532,766
247213.123.0.0/17213.123.0.1 to 213.123.127.254213.123.127.25532,766
248213.123.128.0/17213.123.128.1 to 213.123.255.254213.123.255.25532,766
249213.124.0.0/17213.124.0.1 to 213.124.127.254213.124.127.25532,766
250213.124.128.0/17213.124.128.1 to 213.124.255.254213.124.255.25532,766
251213.125.0.0/17213.125.0.1 to 213.125.127.254213.125.127.25532,766
252213.125.128.0/17213.125.128.1 to 213.125.255.254213.125.255.25532,766
253213.126.0.0/17213.126.0.1 to 213.126.127.254213.126.127.25532,766
254213.126.128.0/17213.126.128.1 to 213.126.255.254213.126.255.25532,766
255213.127.0.0/17213.127.0.1 to 213.127.127.254213.127.127.25532,766
256213.127.128.0/17213.127.128.1 to 213.127.255.254213.127.255.25532,766

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.