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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.

Network238.48.0.0/12
Usable hosts1,048,574
Subnet mask255.240.0.0
Addresses1,048,576
Network address
238.48.0.0
Broadcast address
238.63.255.255
First usable
238.48.0.1
Last usable
238.63.255.254
Usable hosts
1,048,574 (1,048,576 less the network and broadcast addresses)
Subnet mask
255.240.0.0
Wildcard mask
0.15.255.255 (Cisco ACLs, OSPF)
Prefix length
/12
Type
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex EE300000 · Integer 3996123136 to 3997171711
Reverse DNS zones
48.238.in-addr.arpa
49.238.in-addr.arpa
50.238.in-addr.arpa
51.238.in-addr.arpa
52.238.in-addr.arpa
53.238.in-addr.arpa
54.238.in-addr.arpa
55.238.in-addr.arpa
56.238.in-addr.arpa
57.238.in-addr.arpa
58.238.in-addr.arpa
59.238.in-addr.arpa
60.238.in-addr.arpa
61.238.in-addr.arpa
62.238.in-addr.arpa
63.238.in-addr.arpa
/12 is not on a 8-bit boundary, so it takes 16 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11101110.00110000.00000000.00000000238.48.0.0
Subnet mask11111111.11110000.00000000.00000000255.240.0.0
Network11101110.00110000.00000000.00000000238.48.0.0
Broadcast11101110.00111111.11111111.11111111238.63.255.255
Split into smaller subnets/24
/13 (2)/14 (4)/15 (8)/16 (16)/17 (32)/18 (64)/19 (128)/20 (256)/21 (512)/22 (1,024)/23 (2,048)/24 (4,096)

238.48.0.0/12 makes 4,096 subnets of /24; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1238.48.0.0/24238.48.0.1 to 238.48.0.254238.48.0.255254
2238.48.1.0/24238.48.1.1 to 238.48.1.254238.48.1.255254
3238.48.2.0/24238.48.2.1 to 238.48.2.254238.48.2.255254
4238.48.3.0/24238.48.3.1 to 238.48.3.254238.48.3.255254
5238.48.4.0/24238.48.4.1 to 238.48.4.254238.48.4.255254
6238.48.5.0/24238.48.5.1 to 238.48.5.254238.48.5.255254
7238.48.6.0/24238.48.6.1 to 238.48.6.254238.48.6.255254
8238.48.7.0/24238.48.7.1 to 238.48.7.254238.48.7.255254
9238.48.8.0/24238.48.8.1 to 238.48.8.254238.48.8.255254
10238.48.9.0/24238.48.9.1 to 238.48.9.254238.48.9.255254
11238.48.10.0/24238.48.10.1 to 238.48.10.254238.48.10.255254
12238.48.11.0/24238.48.11.1 to 238.48.11.254238.48.11.255254
13238.48.12.0/24238.48.12.1 to 238.48.12.254238.48.12.255254
14238.48.13.0/24238.48.13.1 to 238.48.13.254238.48.13.255254
15238.48.14.0/24238.48.14.1 to 238.48.14.254238.48.14.255254
16238.48.15.0/24238.48.15.1 to 238.48.15.254238.48.15.255254
17238.48.16.0/24238.48.16.1 to 238.48.16.254238.48.16.255254
18238.48.17.0/24238.48.17.1 to 238.48.17.254238.48.17.255254
19238.48.18.0/24238.48.18.1 to 238.48.18.254238.48.18.255254
20238.48.19.0/24238.48.19.1 to 238.48.19.254238.48.19.255254
21238.48.20.0/24238.48.20.1 to 238.48.20.254238.48.20.255254
22238.48.21.0/24238.48.21.1 to 238.48.21.254238.48.21.255254
23238.48.22.0/24238.48.22.1 to 238.48.22.254238.48.22.255254
24238.48.23.0/24238.48.23.1 to 238.48.23.254238.48.23.255254
25238.48.24.0/24238.48.24.1 to 238.48.24.254238.48.24.255254
26238.48.25.0/24238.48.25.1 to 238.48.25.254238.48.25.255254
27238.48.26.0/24238.48.26.1 to 238.48.26.254238.48.26.255254
28238.48.27.0/24238.48.27.1 to 238.48.27.254238.48.27.255254
29238.48.28.0/24238.48.28.1 to 238.48.28.254238.48.28.255254
30238.48.29.0/24238.48.29.1 to 238.48.29.254238.48.29.255254
31238.48.30.0/24238.48.30.1 to 238.48.30.254238.48.30.255254
32238.48.31.0/24238.48.31.1 to 238.48.31.254238.48.31.255254
33238.48.32.0/24238.48.32.1 to 238.48.32.254238.48.32.255254
34238.48.33.0/24238.48.33.1 to 238.48.33.254238.48.33.255254
35238.48.34.0/24238.48.34.1 to 238.48.34.254238.48.34.255254
36238.48.35.0/24238.48.35.1 to 238.48.35.254238.48.35.255254
37238.48.36.0/24238.48.36.1 to 238.48.36.254238.48.36.255254
38238.48.37.0/24238.48.37.1 to 238.48.37.254238.48.37.255254
39238.48.38.0/24238.48.38.1 to 238.48.38.254238.48.38.255254
40238.48.39.0/24238.48.39.1 to 238.48.39.254238.48.39.255254
41238.48.40.0/24238.48.40.1 to 238.48.40.254238.48.40.255254
42238.48.41.0/24238.48.41.1 to 238.48.41.254238.48.41.255254
43238.48.42.0/24238.48.42.1 to 238.48.42.254238.48.42.255254
44238.48.43.0/24238.48.43.1 to 238.48.43.254238.48.43.255254
45238.48.44.0/24238.48.44.1 to 238.48.44.254238.48.44.255254
46238.48.45.0/24238.48.45.1 to 238.48.45.254238.48.45.255254
47238.48.46.0/24238.48.46.1 to 238.48.46.254238.48.46.255254
48238.48.47.0/24238.48.47.1 to 238.48.47.254238.48.47.255254
49238.48.48.0/24238.48.48.1 to 238.48.48.254238.48.48.255254
50238.48.49.0/24238.48.49.1 to 238.48.49.254238.48.49.255254
51238.48.50.0/24238.48.50.1 to 238.48.50.254238.48.50.255254
52238.48.51.0/24238.48.51.1 to 238.48.51.254238.48.51.255254
53238.48.52.0/24238.48.52.1 to 238.48.52.254238.48.52.255254
54238.48.53.0/24238.48.53.1 to 238.48.53.254238.48.53.255254
55238.48.54.0/24238.48.54.1 to 238.48.54.254238.48.54.255254
56238.48.55.0/24238.48.55.1 to 238.48.55.254238.48.55.255254
57238.48.56.0/24238.48.56.1 to 238.48.56.254238.48.56.255254
58238.48.57.0/24238.48.57.1 to 238.48.57.254238.48.57.255254
59238.48.58.0/24238.48.58.1 to 238.48.58.254238.48.58.255254
60238.48.59.0/24238.48.59.1 to 238.48.59.254238.48.59.255254
61238.48.60.0/24238.48.60.1 to 238.48.60.254238.48.60.255254
62238.48.61.0/24238.48.61.1 to 238.48.61.254238.48.61.255254
63238.48.62.0/24238.48.62.1 to 238.48.62.254238.48.62.255254
64238.48.63.0/24238.48.63.1 to 238.48.63.254238.48.63.255254
65238.48.64.0/24238.48.64.1 to 238.48.64.254238.48.64.255254
66238.48.65.0/24238.48.65.1 to 238.48.65.254238.48.65.255254
67238.48.66.0/24238.48.66.1 to 238.48.66.254238.48.66.255254
68238.48.67.0/24238.48.67.1 to 238.48.67.254238.48.67.255254
69238.48.68.0/24238.48.68.1 to 238.48.68.254238.48.68.255254
70238.48.69.0/24238.48.69.1 to 238.48.69.254238.48.69.255254
71238.48.70.0/24238.48.70.1 to 238.48.70.254238.48.70.255254
72238.48.71.0/24238.48.71.1 to 238.48.71.254238.48.71.255254
73238.48.72.0/24238.48.72.1 to 238.48.72.254238.48.72.255254
74238.48.73.0/24238.48.73.1 to 238.48.73.254238.48.73.255254
75238.48.74.0/24238.48.74.1 to 238.48.74.254238.48.74.255254
76238.48.75.0/24238.48.75.1 to 238.48.75.254238.48.75.255254
77238.48.76.0/24238.48.76.1 to 238.48.76.254238.48.76.255254
78238.48.77.0/24238.48.77.1 to 238.48.77.254238.48.77.255254
79238.48.78.0/24238.48.78.1 to 238.48.78.254238.48.78.255254
80238.48.79.0/24238.48.79.1 to 238.48.79.254238.48.79.255254
81238.48.80.0/24238.48.80.1 to 238.48.80.254238.48.80.255254
82238.48.81.0/24238.48.81.1 to 238.48.81.254238.48.81.255254
83238.48.82.0/24238.48.82.1 to 238.48.82.254238.48.82.255254
84238.48.83.0/24238.48.83.1 to 238.48.83.254238.48.83.255254
85238.48.84.0/24238.48.84.1 to 238.48.84.254238.48.84.255254
86238.48.85.0/24238.48.85.1 to 238.48.85.254238.48.85.255254
87238.48.86.0/24238.48.86.1 to 238.48.86.254238.48.86.255254
88238.48.87.0/24238.48.87.1 to 238.48.87.254238.48.87.255254
89238.48.88.0/24238.48.88.1 to 238.48.88.254238.48.88.255254
90238.48.89.0/24238.48.89.1 to 238.48.89.254238.48.89.255254
91238.48.90.0/24238.48.90.1 to 238.48.90.254238.48.90.255254
92238.48.91.0/24238.48.91.1 to 238.48.91.254238.48.91.255254
93238.48.92.0/24238.48.92.1 to 238.48.92.254238.48.92.255254
94238.48.93.0/24238.48.93.1 to 238.48.93.254238.48.93.255254
95238.48.94.0/24238.48.94.1 to 238.48.94.254238.48.94.255254
96238.48.95.0/24238.48.95.1 to 238.48.95.254238.48.95.255254
97238.48.96.0/24238.48.96.1 to 238.48.96.254238.48.96.255254
98238.48.97.0/24238.48.97.1 to 238.48.97.254238.48.97.255254
99238.48.98.0/24238.48.98.1 to 238.48.98.254238.48.98.255254
100238.48.99.0/24238.48.99.1 to 238.48.99.254238.48.99.255254
101238.48.100.0/24238.48.100.1 to 238.48.100.254238.48.100.255254
102238.48.101.0/24238.48.101.1 to 238.48.101.254238.48.101.255254
103238.48.102.0/24238.48.102.1 to 238.48.102.254238.48.102.255254
104238.48.103.0/24238.48.103.1 to 238.48.103.254238.48.103.255254
105238.48.104.0/24238.48.104.1 to 238.48.104.254238.48.104.255254
106238.48.105.0/24238.48.105.1 to 238.48.105.254238.48.105.255254
107238.48.106.0/24238.48.106.1 to 238.48.106.254238.48.106.255254
108238.48.107.0/24238.48.107.1 to 238.48.107.254238.48.107.255254
109238.48.108.0/24238.48.108.1 to 238.48.108.254238.48.108.255254
110238.48.109.0/24238.48.109.1 to 238.48.109.254238.48.109.255254
111238.48.110.0/24238.48.110.1 to 238.48.110.254238.48.110.255254
112238.48.111.0/24238.48.111.1 to 238.48.111.254238.48.111.255254
113238.48.112.0/24238.48.112.1 to 238.48.112.254238.48.112.255254
114238.48.113.0/24238.48.113.1 to 238.48.113.254238.48.113.255254
115238.48.114.0/24238.48.114.1 to 238.48.114.254238.48.114.255254
116238.48.115.0/24238.48.115.1 to 238.48.115.254238.48.115.255254
117238.48.116.0/24238.48.116.1 to 238.48.116.254238.48.116.255254
118238.48.117.0/24238.48.117.1 to 238.48.117.254238.48.117.255254
119238.48.118.0/24238.48.118.1 to 238.48.118.254238.48.118.255254
120238.48.119.0/24238.48.119.1 to 238.48.119.254238.48.119.255254
121238.48.120.0/24238.48.120.1 to 238.48.120.254238.48.120.255254
122238.48.121.0/24238.48.121.1 to 238.48.121.254238.48.121.255254
123238.48.122.0/24238.48.122.1 to 238.48.122.254238.48.122.255254
124238.48.123.0/24238.48.123.1 to 238.48.123.254238.48.123.255254
125238.48.124.0/24238.48.124.1 to 238.48.124.254238.48.124.255254
126238.48.125.0/24238.48.125.1 to 238.48.125.254238.48.125.255254
127238.48.126.0/24238.48.126.1 to 238.48.126.254238.48.126.255254
128238.48.127.0/24238.48.127.1 to 238.48.127.254238.48.127.255254
129238.48.128.0/24238.48.128.1 to 238.48.128.254238.48.128.255254
130238.48.129.0/24238.48.129.1 to 238.48.129.254238.48.129.255254
131238.48.130.0/24238.48.130.1 to 238.48.130.254238.48.130.255254
132238.48.131.0/24238.48.131.1 to 238.48.131.254238.48.131.255254
133238.48.132.0/24238.48.132.1 to 238.48.132.254238.48.132.255254
134238.48.133.0/24238.48.133.1 to 238.48.133.254238.48.133.255254
135238.48.134.0/24238.48.134.1 to 238.48.134.254238.48.134.255254
136238.48.135.0/24238.48.135.1 to 238.48.135.254238.48.135.255254
137238.48.136.0/24238.48.136.1 to 238.48.136.254238.48.136.255254
138238.48.137.0/24238.48.137.1 to 238.48.137.254238.48.137.255254
139238.48.138.0/24238.48.138.1 to 238.48.138.254238.48.138.255254
140238.48.139.0/24238.48.139.1 to 238.48.139.254238.48.139.255254
141238.48.140.0/24238.48.140.1 to 238.48.140.254238.48.140.255254
142238.48.141.0/24238.48.141.1 to 238.48.141.254238.48.141.255254
143238.48.142.0/24238.48.142.1 to 238.48.142.254238.48.142.255254
144238.48.143.0/24238.48.143.1 to 238.48.143.254238.48.143.255254
145238.48.144.0/24238.48.144.1 to 238.48.144.254238.48.144.255254
146238.48.145.0/24238.48.145.1 to 238.48.145.254238.48.145.255254
147238.48.146.0/24238.48.146.1 to 238.48.146.254238.48.146.255254
148238.48.147.0/24238.48.147.1 to 238.48.147.254238.48.147.255254
149238.48.148.0/24238.48.148.1 to 238.48.148.254238.48.148.255254
150238.48.149.0/24238.48.149.1 to 238.48.149.254238.48.149.255254
151238.48.150.0/24238.48.150.1 to 238.48.150.254238.48.150.255254
152238.48.151.0/24238.48.151.1 to 238.48.151.254238.48.151.255254
153238.48.152.0/24238.48.152.1 to 238.48.152.254238.48.152.255254
154238.48.153.0/24238.48.153.1 to 238.48.153.254238.48.153.255254
155238.48.154.0/24238.48.154.1 to 238.48.154.254238.48.154.255254
156238.48.155.0/24238.48.155.1 to 238.48.155.254238.48.155.255254
157238.48.156.0/24238.48.156.1 to 238.48.156.254238.48.156.255254
158238.48.157.0/24238.48.157.1 to 238.48.157.254238.48.157.255254
159238.48.158.0/24238.48.158.1 to 238.48.158.254238.48.158.255254
160238.48.159.0/24238.48.159.1 to 238.48.159.254238.48.159.255254
161238.48.160.0/24238.48.160.1 to 238.48.160.254238.48.160.255254
162238.48.161.0/24238.48.161.1 to 238.48.161.254238.48.161.255254
163238.48.162.0/24238.48.162.1 to 238.48.162.254238.48.162.255254
164238.48.163.0/24238.48.163.1 to 238.48.163.254238.48.163.255254
165238.48.164.0/24238.48.164.1 to 238.48.164.254238.48.164.255254
166238.48.165.0/24238.48.165.1 to 238.48.165.254238.48.165.255254
167238.48.166.0/24238.48.166.1 to 238.48.166.254238.48.166.255254
168238.48.167.0/24238.48.167.1 to 238.48.167.254238.48.167.255254
169238.48.168.0/24238.48.168.1 to 238.48.168.254238.48.168.255254
170238.48.169.0/24238.48.169.1 to 238.48.169.254238.48.169.255254
171238.48.170.0/24238.48.170.1 to 238.48.170.254238.48.170.255254
172238.48.171.0/24238.48.171.1 to 238.48.171.254238.48.171.255254
173238.48.172.0/24238.48.172.1 to 238.48.172.254238.48.172.255254
174238.48.173.0/24238.48.173.1 to 238.48.173.254238.48.173.255254
175238.48.174.0/24238.48.174.1 to 238.48.174.254238.48.174.255254
176238.48.175.0/24238.48.175.1 to 238.48.175.254238.48.175.255254
177238.48.176.0/24238.48.176.1 to 238.48.176.254238.48.176.255254
178238.48.177.0/24238.48.177.1 to 238.48.177.254238.48.177.255254
179238.48.178.0/24238.48.178.1 to 238.48.178.254238.48.178.255254
180238.48.179.0/24238.48.179.1 to 238.48.179.254238.48.179.255254
181238.48.180.0/24238.48.180.1 to 238.48.180.254238.48.180.255254
182238.48.181.0/24238.48.181.1 to 238.48.181.254238.48.181.255254
183238.48.182.0/24238.48.182.1 to 238.48.182.254238.48.182.255254
184238.48.183.0/24238.48.183.1 to 238.48.183.254238.48.183.255254
185238.48.184.0/24238.48.184.1 to 238.48.184.254238.48.184.255254
186238.48.185.0/24238.48.185.1 to 238.48.185.254238.48.185.255254
187238.48.186.0/24238.48.186.1 to 238.48.186.254238.48.186.255254
188238.48.187.0/24238.48.187.1 to 238.48.187.254238.48.187.255254
189238.48.188.0/24238.48.188.1 to 238.48.188.254238.48.188.255254
190238.48.189.0/24238.48.189.1 to 238.48.189.254238.48.189.255254
191238.48.190.0/24238.48.190.1 to 238.48.190.254238.48.190.255254
192238.48.191.0/24238.48.191.1 to 238.48.191.254238.48.191.255254
193238.48.192.0/24238.48.192.1 to 238.48.192.254238.48.192.255254
194238.48.193.0/24238.48.193.1 to 238.48.193.254238.48.193.255254
195238.48.194.0/24238.48.194.1 to 238.48.194.254238.48.194.255254
196238.48.195.0/24238.48.195.1 to 238.48.195.254238.48.195.255254
197238.48.196.0/24238.48.196.1 to 238.48.196.254238.48.196.255254
198238.48.197.0/24238.48.197.1 to 238.48.197.254238.48.197.255254
199238.48.198.0/24238.48.198.1 to 238.48.198.254238.48.198.255254
200238.48.199.0/24238.48.199.1 to 238.48.199.254238.48.199.255254
201238.48.200.0/24238.48.200.1 to 238.48.200.254238.48.200.255254
202238.48.201.0/24238.48.201.1 to 238.48.201.254238.48.201.255254
203238.48.202.0/24238.48.202.1 to 238.48.202.254238.48.202.255254
204238.48.203.0/24238.48.203.1 to 238.48.203.254238.48.203.255254
205238.48.204.0/24238.48.204.1 to 238.48.204.254238.48.204.255254
206238.48.205.0/24238.48.205.1 to 238.48.205.254238.48.205.255254
207238.48.206.0/24238.48.206.1 to 238.48.206.254238.48.206.255254
208238.48.207.0/24238.48.207.1 to 238.48.207.254238.48.207.255254
209238.48.208.0/24238.48.208.1 to 238.48.208.254238.48.208.255254
210238.48.209.0/24238.48.209.1 to 238.48.209.254238.48.209.255254
211238.48.210.0/24238.48.210.1 to 238.48.210.254238.48.210.255254
212238.48.211.0/24238.48.211.1 to 238.48.211.254238.48.211.255254
213238.48.212.0/24238.48.212.1 to 238.48.212.254238.48.212.255254
214238.48.213.0/24238.48.213.1 to 238.48.213.254238.48.213.255254
215238.48.214.0/24238.48.214.1 to 238.48.214.254238.48.214.255254
216238.48.215.0/24238.48.215.1 to 238.48.215.254238.48.215.255254
217238.48.216.0/24238.48.216.1 to 238.48.216.254238.48.216.255254
218238.48.217.0/24238.48.217.1 to 238.48.217.254238.48.217.255254
219238.48.218.0/24238.48.218.1 to 238.48.218.254238.48.218.255254
220238.48.219.0/24238.48.219.1 to 238.48.219.254238.48.219.255254
221238.48.220.0/24238.48.220.1 to 238.48.220.254238.48.220.255254
222238.48.221.0/24238.48.221.1 to 238.48.221.254238.48.221.255254
223238.48.222.0/24238.48.222.1 to 238.48.222.254238.48.222.255254
224238.48.223.0/24238.48.223.1 to 238.48.223.254238.48.223.255254
225238.48.224.0/24238.48.224.1 to 238.48.224.254238.48.224.255254
226238.48.225.0/24238.48.225.1 to 238.48.225.254238.48.225.255254
227238.48.226.0/24238.48.226.1 to 238.48.226.254238.48.226.255254
228238.48.227.0/24238.48.227.1 to 238.48.227.254238.48.227.255254
229238.48.228.0/24238.48.228.1 to 238.48.228.254238.48.228.255254
230238.48.229.0/24238.48.229.1 to 238.48.229.254238.48.229.255254
231238.48.230.0/24238.48.230.1 to 238.48.230.254238.48.230.255254
232238.48.231.0/24238.48.231.1 to 238.48.231.254238.48.231.255254
233238.48.232.0/24238.48.232.1 to 238.48.232.254238.48.232.255254
234238.48.233.0/24238.48.233.1 to 238.48.233.254238.48.233.255254
235238.48.234.0/24238.48.234.1 to 238.48.234.254238.48.234.255254
236238.48.235.0/24238.48.235.1 to 238.48.235.254238.48.235.255254
237238.48.236.0/24238.48.236.1 to 238.48.236.254238.48.236.255254
238238.48.237.0/24238.48.237.1 to 238.48.237.254238.48.237.255254
239238.48.238.0/24238.48.238.1 to 238.48.238.254238.48.238.255254
240238.48.239.0/24238.48.239.1 to 238.48.239.254238.48.239.255254
241238.48.240.0/24238.48.240.1 to 238.48.240.254238.48.240.255254
242238.48.241.0/24238.48.241.1 to 238.48.241.254238.48.241.255254
243238.48.242.0/24238.48.242.1 to 238.48.242.254238.48.242.255254
244238.48.243.0/24238.48.243.1 to 238.48.243.254238.48.243.255254
245238.48.244.0/24238.48.244.1 to 238.48.244.254238.48.244.255254
246238.48.245.0/24238.48.245.1 to 238.48.245.254238.48.245.255254
247238.48.246.0/24238.48.246.1 to 238.48.246.254238.48.246.255254
248238.48.247.0/24238.48.247.1 to 238.48.247.254238.48.247.255254
249238.48.248.0/24238.48.248.1 to 238.48.248.254238.48.248.255254
250238.48.249.0/24238.48.249.1 to 238.48.249.254238.48.249.255254
251238.48.250.0/24238.48.250.1 to 238.48.250.254238.48.250.255254
252238.48.251.0/24238.48.251.1 to 238.48.251.254238.48.251.255254
253238.48.252.0/24238.48.252.1 to 238.48.252.254238.48.252.255254
254238.48.253.0/24238.48.253.1 to 238.48.253.254238.48.253.255254
255238.48.254.0/24238.48.254.1 to 238.48.254.254238.48.254.255254
256238.48.255.0/24238.48.255.1 to 238.48.255.254238.48.255.255254

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.