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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.

Network246.40.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
246.40.0.0
Broadcast address
246.47.255.255
First usable
246.40.0.1
Last usable
246.47.255.254
Usable hosts
524,286 (524,288 less the network and broadcast addresses)
Subnet mask
255.248.0.0
Wildcard mask
0.7.255.255 (Cisco ACLs, OSPF)
Prefix length
/13
Type
Reserved 240.0.0.0/4
Future use; not usable on most systems
Old class
E (reserved)
As numbers
Hex F6280000 · Integer 4129816576 to 4130340863
Reverse DNS zones
40.246.in-addr.arpa
41.246.in-addr.arpa
42.246.in-addr.arpa
43.246.in-addr.arpa
44.246.in-addr.arpa
45.246.in-addr.arpa
46.246.in-addr.arpa
47.246.in-addr.arpa
/13 is not on a 8-bit boundary, so it takes 8 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11110110.00101000.00000000.00000000246.40.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network11110110.00101000.00000000.00000000246.40.0.0
Broadcast11110110.00101111.11111111.11111111246.47.255.255
Split into smaller subnets/25
/14 (2)/15 (4)/16 (8)/17 (16)/18 (32)/19 (64)/20 (128)/21 (256)/22 (512)/23 (1,024)/24 (2,048)/25 (4,096)

246.40.0.0/13 makes 4,096 subnets of /25; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1246.40.0.0/25246.40.0.1 to 246.40.0.126246.40.0.127126
2246.40.0.128/25246.40.0.129 to 246.40.0.254246.40.0.255126
3246.40.1.0/25246.40.1.1 to 246.40.1.126246.40.1.127126
4246.40.1.128/25246.40.1.129 to 246.40.1.254246.40.1.255126
5246.40.2.0/25246.40.2.1 to 246.40.2.126246.40.2.127126
6246.40.2.128/25246.40.2.129 to 246.40.2.254246.40.2.255126
7246.40.3.0/25246.40.3.1 to 246.40.3.126246.40.3.127126
8246.40.3.128/25246.40.3.129 to 246.40.3.254246.40.3.255126
9246.40.4.0/25246.40.4.1 to 246.40.4.126246.40.4.127126
10246.40.4.128/25246.40.4.129 to 246.40.4.254246.40.4.255126
11246.40.5.0/25246.40.5.1 to 246.40.5.126246.40.5.127126
12246.40.5.128/25246.40.5.129 to 246.40.5.254246.40.5.255126
13246.40.6.0/25246.40.6.1 to 246.40.6.126246.40.6.127126
14246.40.6.128/25246.40.6.129 to 246.40.6.254246.40.6.255126
15246.40.7.0/25246.40.7.1 to 246.40.7.126246.40.7.127126
16246.40.7.128/25246.40.7.129 to 246.40.7.254246.40.7.255126
17246.40.8.0/25246.40.8.1 to 246.40.8.126246.40.8.127126
18246.40.8.128/25246.40.8.129 to 246.40.8.254246.40.8.255126
19246.40.9.0/25246.40.9.1 to 246.40.9.126246.40.9.127126
20246.40.9.128/25246.40.9.129 to 246.40.9.254246.40.9.255126
21246.40.10.0/25246.40.10.1 to 246.40.10.126246.40.10.127126
22246.40.10.128/25246.40.10.129 to 246.40.10.254246.40.10.255126
23246.40.11.0/25246.40.11.1 to 246.40.11.126246.40.11.127126
24246.40.11.128/25246.40.11.129 to 246.40.11.254246.40.11.255126
25246.40.12.0/25246.40.12.1 to 246.40.12.126246.40.12.127126
26246.40.12.128/25246.40.12.129 to 246.40.12.254246.40.12.255126
27246.40.13.0/25246.40.13.1 to 246.40.13.126246.40.13.127126
28246.40.13.128/25246.40.13.129 to 246.40.13.254246.40.13.255126
29246.40.14.0/25246.40.14.1 to 246.40.14.126246.40.14.127126
30246.40.14.128/25246.40.14.129 to 246.40.14.254246.40.14.255126
31246.40.15.0/25246.40.15.1 to 246.40.15.126246.40.15.127126
32246.40.15.128/25246.40.15.129 to 246.40.15.254246.40.15.255126
33246.40.16.0/25246.40.16.1 to 246.40.16.126246.40.16.127126
34246.40.16.128/25246.40.16.129 to 246.40.16.254246.40.16.255126
35246.40.17.0/25246.40.17.1 to 246.40.17.126246.40.17.127126
36246.40.17.128/25246.40.17.129 to 246.40.17.254246.40.17.255126
37246.40.18.0/25246.40.18.1 to 246.40.18.126246.40.18.127126
38246.40.18.128/25246.40.18.129 to 246.40.18.254246.40.18.255126
39246.40.19.0/25246.40.19.1 to 246.40.19.126246.40.19.127126
40246.40.19.128/25246.40.19.129 to 246.40.19.254246.40.19.255126
41246.40.20.0/25246.40.20.1 to 246.40.20.126246.40.20.127126
42246.40.20.128/25246.40.20.129 to 246.40.20.254246.40.20.255126
43246.40.21.0/25246.40.21.1 to 246.40.21.126246.40.21.127126
44246.40.21.128/25246.40.21.129 to 246.40.21.254246.40.21.255126
45246.40.22.0/25246.40.22.1 to 246.40.22.126246.40.22.127126
46246.40.22.128/25246.40.22.129 to 246.40.22.254246.40.22.255126
47246.40.23.0/25246.40.23.1 to 246.40.23.126246.40.23.127126
48246.40.23.128/25246.40.23.129 to 246.40.23.254246.40.23.255126
49246.40.24.0/25246.40.24.1 to 246.40.24.126246.40.24.127126
50246.40.24.128/25246.40.24.129 to 246.40.24.254246.40.24.255126
51246.40.25.0/25246.40.25.1 to 246.40.25.126246.40.25.127126
52246.40.25.128/25246.40.25.129 to 246.40.25.254246.40.25.255126
53246.40.26.0/25246.40.26.1 to 246.40.26.126246.40.26.127126
54246.40.26.128/25246.40.26.129 to 246.40.26.254246.40.26.255126
55246.40.27.0/25246.40.27.1 to 246.40.27.126246.40.27.127126
56246.40.27.128/25246.40.27.129 to 246.40.27.254246.40.27.255126
57246.40.28.0/25246.40.28.1 to 246.40.28.126246.40.28.127126
58246.40.28.128/25246.40.28.129 to 246.40.28.254246.40.28.255126
59246.40.29.0/25246.40.29.1 to 246.40.29.126246.40.29.127126
60246.40.29.128/25246.40.29.129 to 246.40.29.254246.40.29.255126
61246.40.30.0/25246.40.30.1 to 246.40.30.126246.40.30.127126
62246.40.30.128/25246.40.30.129 to 246.40.30.254246.40.30.255126
63246.40.31.0/25246.40.31.1 to 246.40.31.126246.40.31.127126
64246.40.31.128/25246.40.31.129 to 246.40.31.254246.40.31.255126
65246.40.32.0/25246.40.32.1 to 246.40.32.126246.40.32.127126
66246.40.32.128/25246.40.32.129 to 246.40.32.254246.40.32.255126
67246.40.33.0/25246.40.33.1 to 246.40.33.126246.40.33.127126
68246.40.33.128/25246.40.33.129 to 246.40.33.254246.40.33.255126
69246.40.34.0/25246.40.34.1 to 246.40.34.126246.40.34.127126
70246.40.34.128/25246.40.34.129 to 246.40.34.254246.40.34.255126
71246.40.35.0/25246.40.35.1 to 246.40.35.126246.40.35.127126
72246.40.35.128/25246.40.35.129 to 246.40.35.254246.40.35.255126
73246.40.36.0/25246.40.36.1 to 246.40.36.126246.40.36.127126
74246.40.36.128/25246.40.36.129 to 246.40.36.254246.40.36.255126
75246.40.37.0/25246.40.37.1 to 246.40.37.126246.40.37.127126
76246.40.37.128/25246.40.37.129 to 246.40.37.254246.40.37.255126
77246.40.38.0/25246.40.38.1 to 246.40.38.126246.40.38.127126
78246.40.38.128/25246.40.38.129 to 246.40.38.254246.40.38.255126
79246.40.39.0/25246.40.39.1 to 246.40.39.126246.40.39.127126
80246.40.39.128/25246.40.39.129 to 246.40.39.254246.40.39.255126
81246.40.40.0/25246.40.40.1 to 246.40.40.126246.40.40.127126
82246.40.40.128/25246.40.40.129 to 246.40.40.254246.40.40.255126
83246.40.41.0/25246.40.41.1 to 246.40.41.126246.40.41.127126
84246.40.41.128/25246.40.41.129 to 246.40.41.254246.40.41.255126
85246.40.42.0/25246.40.42.1 to 246.40.42.126246.40.42.127126
86246.40.42.128/25246.40.42.129 to 246.40.42.254246.40.42.255126
87246.40.43.0/25246.40.43.1 to 246.40.43.126246.40.43.127126
88246.40.43.128/25246.40.43.129 to 246.40.43.254246.40.43.255126
89246.40.44.0/25246.40.44.1 to 246.40.44.126246.40.44.127126
90246.40.44.128/25246.40.44.129 to 246.40.44.254246.40.44.255126
91246.40.45.0/25246.40.45.1 to 246.40.45.126246.40.45.127126
92246.40.45.128/25246.40.45.129 to 246.40.45.254246.40.45.255126
93246.40.46.0/25246.40.46.1 to 246.40.46.126246.40.46.127126
94246.40.46.128/25246.40.46.129 to 246.40.46.254246.40.46.255126
95246.40.47.0/25246.40.47.1 to 246.40.47.126246.40.47.127126
96246.40.47.128/25246.40.47.129 to 246.40.47.254246.40.47.255126
97246.40.48.0/25246.40.48.1 to 246.40.48.126246.40.48.127126
98246.40.48.128/25246.40.48.129 to 246.40.48.254246.40.48.255126
99246.40.49.0/25246.40.49.1 to 246.40.49.126246.40.49.127126
100246.40.49.128/25246.40.49.129 to 246.40.49.254246.40.49.255126
101246.40.50.0/25246.40.50.1 to 246.40.50.126246.40.50.127126
102246.40.50.128/25246.40.50.129 to 246.40.50.254246.40.50.255126
103246.40.51.0/25246.40.51.1 to 246.40.51.126246.40.51.127126
104246.40.51.128/25246.40.51.129 to 246.40.51.254246.40.51.255126
105246.40.52.0/25246.40.52.1 to 246.40.52.126246.40.52.127126
106246.40.52.128/25246.40.52.129 to 246.40.52.254246.40.52.255126
107246.40.53.0/25246.40.53.1 to 246.40.53.126246.40.53.127126
108246.40.53.128/25246.40.53.129 to 246.40.53.254246.40.53.255126
109246.40.54.0/25246.40.54.1 to 246.40.54.126246.40.54.127126
110246.40.54.128/25246.40.54.129 to 246.40.54.254246.40.54.255126
111246.40.55.0/25246.40.55.1 to 246.40.55.126246.40.55.127126
112246.40.55.128/25246.40.55.129 to 246.40.55.254246.40.55.255126
113246.40.56.0/25246.40.56.1 to 246.40.56.126246.40.56.127126
114246.40.56.128/25246.40.56.129 to 246.40.56.254246.40.56.255126
115246.40.57.0/25246.40.57.1 to 246.40.57.126246.40.57.127126
116246.40.57.128/25246.40.57.129 to 246.40.57.254246.40.57.255126
117246.40.58.0/25246.40.58.1 to 246.40.58.126246.40.58.127126
118246.40.58.128/25246.40.58.129 to 246.40.58.254246.40.58.255126
119246.40.59.0/25246.40.59.1 to 246.40.59.126246.40.59.127126
120246.40.59.128/25246.40.59.129 to 246.40.59.254246.40.59.255126
121246.40.60.0/25246.40.60.1 to 246.40.60.126246.40.60.127126
122246.40.60.128/25246.40.60.129 to 246.40.60.254246.40.60.255126
123246.40.61.0/25246.40.61.1 to 246.40.61.126246.40.61.127126
124246.40.61.128/25246.40.61.129 to 246.40.61.254246.40.61.255126
125246.40.62.0/25246.40.62.1 to 246.40.62.126246.40.62.127126
126246.40.62.128/25246.40.62.129 to 246.40.62.254246.40.62.255126
127246.40.63.0/25246.40.63.1 to 246.40.63.126246.40.63.127126
128246.40.63.128/25246.40.63.129 to 246.40.63.254246.40.63.255126
129246.40.64.0/25246.40.64.1 to 246.40.64.126246.40.64.127126
130246.40.64.128/25246.40.64.129 to 246.40.64.254246.40.64.255126
131246.40.65.0/25246.40.65.1 to 246.40.65.126246.40.65.127126
132246.40.65.128/25246.40.65.129 to 246.40.65.254246.40.65.255126
133246.40.66.0/25246.40.66.1 to 246.40.66.126246.40.66.127126
134246.40.66.128/25246.40.66.129 to 246.40.66.254246.40.66.255126
135246.40.67.0/25246.40.67.1 to 246.40.67.126246.40.67.127126
136246.40.67.128/25246.40.67.129 to 246.40.67.254246.40.67.255126
137246.40.68.0/25246.40.68.1 to 246.40.68.126246.40.68.127126
138246.40.68.128/25246.40.68.129 to 246.40.68.254246.40.68.255126
139246.40.69.0/25246.40.69.1 to 246.40.69.126246.40.69.127126
140246.40.69.128/25246.40.69.129 to 246.40.69.254246.40.69.255126
141246.40.70.0/25246.40.70.1 to 246.40.70.126246.40.70.127126
142246.40.70.128/25246.40.70.129 to 246.40.70.254246.40.70.255126
143246.40.71.0/25246.40.71.1 to 246.40.71.126246.40.71.127126
144246.40.71.128/25246.40.71.129 to 246.40.71.254246.40.71.255126
145246.40.72.0/25246.40.72.1 to 246.40.72.126246.40.72.127126
146246.40.72.128/25246.40.72.129 to 246.40.72.254246.40.72.255126
147246.40.73.0/25246.40.73.1 to 246.40.73.126246.40.73.127126
148246.40.73.128/25246.40.73.129 to 246.40.73.254246.40.73.255126
149246.40.74.0/25246.40.74.1 to 246.40.74.126246.40.74.127126
150246.40.74.128/25246.40.74.129 to 246.40.74.254246.40.74.255126
151246.40.75.0/25246.40.75.1 to 246.40.75.126246.40.75.127126
152246.40.75.128/25246.40.75.129 to 246.40.75.254246.40.75.255126
153246.40.76.0/25246.40.76.1 to 246.40.76.126246.40.76.127126
154246.40.76.128/25246.40.76.129 to 246.40.76.254246.40.76.255126
155246.40.77.0/25246.40.77.1 to 246.40.77.126246.40.77.127126
156246.40.77.128/25246.40.77.129 to 246.40.77.254246.40.77.255126
157246.40.78.0/25246.40.78.1 to 246.40.78.126246.40.78.127126
158246.40.78.128/25246.40.78.129 to 246.40.78.254246.40.78.255126
159246.40.79.0/25246.40.79.1 to 246.40.79.126246.40.79.127126
160246.40.79.128/25246.40.79.129 to 246.40.79.254246.40.79.255126
161246.40.80.0/25246.40.80.1 to 246.40.80.126246.40.80.127126
162246.40.80.128/25246.40.80.129 to 246.40.80.254246.40.80.255126
163246.40.81.0/25246.40.81.1 to 246.40.81.126246.40.81.127126
164246.40.81.128/25246.40.81.129 to 246.40.81.254246.40.81.255126
165246.40.82.0/25246.40.82.1 to 246.40.82.126246.40.82.127126
166246.40.82.128/25246.40.82.129 to 246.40.82.254246.40.82.255126
167246.40.83.0/25246.40.83.1 to 246.40.83.126246.40.83.127126
168246.40.83.128/25246.40.83.129 to 246.40.83.254246.40.83.255126
169246.40.84.0/25246.40.84.1 to 246.40.84.126246.40.84.127126
170246.40.84.128/25246.40.84.129 to 246.40.84.254246.40.84.255126
171246.40.85.0/25246.40.85.1 to 246.40.85.126246.40.85.127126
172246.40.85.128/25246.40.85.129 to 246.40.85.254246.40.85.255126
173246.40.86.0/25246.40.86.1 to 246.40.86.126246.40.86.127126
174246.40.86.128/25246.40.86.129 to 246.40.86.254246.40.86.255126
175246.40.87.0/25246.40.87.1 to 246.40.87.126246.40.87.127126
176246.40.87.128/25246.40.87.129 to 246.40.87.254246.40.87.255126
177246.40.88.0/25246.40.88.1 to 246.40.88.126246.40.88.127126
178246.40.88.128/25246.40.88.129 to 246.40.88.254246.40.88.255126
179246.40.89.0/25246.40.89.1 to 246.40.89.126246.40.89.127126
180246.40.89.128/25246.40.89.129 to 246.40.89.254246.40.89.255126
181246.40.90.0/25246.40.90.1 to 246.40.90.126246.40.90.127126
182246.40.90.128/25246.40.90.129 to 246.40.90.254246.40.90.255126
183246.40.91.0/25246.40.91.1 to 246.40.91.126246.40.91.127126
184246.40.91.128/25246.40.91.129 to 246.40.91.254246.40.91.255126
185246.40.92.0/25246.40.92.1 to 246.40.92.126246.40.92.127126
186246.40.92.128/25246.40.92.129 to 246.40.92.254246.40.92.255126
187246.40.93.0/25246.40.93.1 to 246.40.93.126246.40.93.127126
188246.40.93.128/25246.40.93.129 to 246.40.93.254246.40.93.255126
189246.40.94.0/25246.40.94.1 to 246.40.94.126246.40.94.127126
190246.40.94.128/25246.40.94.129 to 246.40.94.254246.40.94.255126
191246.40.95.0/25246.40.95.1 to 246.40.95.126246.40.95.127126
192246.40.95.128/25246.40.95.129 to 246.40.95.254246.40.95.255126
193246.40.96.0/25246.40.96.1 to 246.40.96.126246.40.96.127126
194246.40.96.128/25246.40.96.129 to 246.40.96.254246.40.96.255126
195246.40.97.0/25246.40.97.1 to 246.40.97.126246.40.97.127126
196246.40.97.128/25246.40.97.129 to 246.40.97.254246.40.97.255126
197246.40.98.0/25246.40.98.1 to 246.40.98.126246.40.98.127126
198246.40.98.128/25246.40.98.129 to 246.40.98.254246.40.98.255126
199246.40.99.0/25246.40.99.1 to 246.40.99.126246.40.99.127126
200246.40.99.128/25246.40.99.129 to 246.40.99.254246.40.99.255126
201246.40.100.0/25246.40.100.1 to 246.40.100.126246.40.100.127126
202246.40.100.128/25246.40.100.129 to 246.40.100.254246.40.100.255126
203246.40.101.0/25246.40.101.1 to 246.40.101.126246.40.101.127126
204246.40.101.128/25246.40.101.129 to 246.40.101.254246.40.101.255126
205246.40.102.0/25246.40.102.1 to 246.40.102.126246.40.102.127126
206246.40.102.128/25246.40.102.129 to 246.40.102.254246.40.102.255126
207246.40.103.0/25246.40.103.1 to 246.40.103.126246.40.103.127126
208246.40.103.128/25246.40.103.129 to 246.40.103.254246.40.103.255126
209246.40.104.0/25246.40.104.1 to 246.40.104.126246.40.104.127126
210246.40.104.128/25246.40.104.129 to 246.40.104.254246.40.104.255126
211246.40.105.0/25246.40.105.1 to 246.40.105.126246.40.105.127126
212246.40.105.128/25246.40.105.129 to 246.40.105.254246.40.105.255126
213246.40.106.0/25246.40.106.1 to 246.40.106.126246.40.106.127126
214246.40.106.128/25246.40.106.129 to 246.40.106.254246.40.106.255126
215246.40.107.0/25246.40.107.1 to 246.40.107.126246.40.107.127126
216246.40.107.128/25246.40.107.129 to 246.40.107.254246.40.107.255126
217246.40.108.0/25246.40.108.1 to 246.40.108.126246.40.108.127126
218246.40.108.128/25246.40.108.129 to 246.40.108.254246.40.108.255126
219246.40.109.0/25246.40.109.1 to 246.40.109.126246.40.109.127126
220246.40.109.128/25246.40.109.129 to 246.40.109.254246.40.109.255126
221246.40.110.0/25246.40.110.1 to 246.40.110.126246.40.110.127126
222246.40.110.128/25246.40.110.129 to 246.40.110.254246.40.110.255126
223246.40.111.0/25246.40.111.1 to 246.40.111.126246.40.111.127126
224246.40.111.128/25246.40.111.129 to 246.40.111.254246.40.111.255126
225246.40.112.0/25246.40.112.1 to 246.40.112.126246.40.112.127126
226246.40.112.128/25246.40.112.129 to 246.40.112.254246.40.112.255126
227246.40.113.0/25246.40.113.1 to 246.40.113.126246.40.113.127126
228246.40.113.128/25246.40.113.129 to 246.40.113.254246.40.113.255126
229246.40.114.0/25246.40.114.1 to 246.40.114.126246.40.114.127126
230246.40.114.128/25246.40.114.129 to 246.40.114.254246.40.114.255126
231246.40.115.0/25246.40.115.1 to 246.40.115.126246.40.115.127126
232246.40.115.128/25246.40.115.129 to 246.40.115.254246.40.115.255126
233246.40.116.0/25246.40.116.1 to 246.40.116.126246.40.116.127126
234246.40.116.128/25246.40.116.129 to 246.40.116.254246.40.116.255126
235246.40.117.0/25246.40.117.1 to 246.40.117.126246.40.117.127126
236246.40.117.128/25246.40.117.129 to 246.40.117.254246.40.117.255126
237246.40.118.0/25246.40.118.1 to 246.40.118.126246.40.118.127126
238246.40.118.128/25246.40.118.129 to 246.40.118.254246.40.118.255126
239246.40.119.0/25246.40.119.1 to 246.40.119.126246.40.119.127126
240246.40.119.128/25246.40.119.129 to 246.40.119.254246.40.119.255126
241246.40.120.0/25246.40.120.1 to 246.40.120.126246.40.120.127126
242246.40.120.128/25246.40.120.129 to 246.40.120.254246.40.120.255126
243246.40.121.0/25246.40.121.1 to 246.40.121.126246.40.121.127126
244246.40.121.128/25246.40.121.129 to 246.40.121.254246.40.121.255126
245246.40.122.0/25246.40.122.1 to 246.40.122.126246.40.122.127126
246246.40.122.128/25246.40.122.129 to 246.40.122.254246.40.122.255126
247246.40.123.0/25246.40.123.1 to 246.40.123.126246.40.123.127126
248246.40.123.128/25246.40.123.129 to 246.40.123.254246.40.123.255126
249246.40.124.0/25246.40.124.1 to 246.40.124.126246.40.124.127126
250246.40.124.128/25246.40.124.129 to 246.40.124.254246.40.124.255126
251246.40.125.0/25246.40.125.1 to 246.40.125.126246.40.125.127126
252246.40.125.128/25246.40.125.129 to 246.40.125.254246.40.125.255126
253246.40.126.0/25246.40.126.1 to 246.40.126.126246.40.126.127126
254246.40.126.128/25246.40.126.129 to 246.40.126.254246.40.126.255126
255246.40.127.0/25246.40.127.1 to 246.40.127.126246.40.127.127126
256246.40.127.128/25246.40.127.129 to 246.40.127.254246.40.127.255126

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.