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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.

Network250.112.0.0/12
Usable hosts1,048,574
Subnet mask255.240.0.0
Addresses1,048,576
Network address
250.112.0.0
Broadcast address
250.127.255.255
First usable
250.112.0.1
Last usable
250.127.255.254
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
Reserved 240.0.0.0/4
Future use; not usable on most systems
Old class
E (reserved)
As numbers
Hex FA700000 · Integer 4201644032 to 4202692607
Reverse DNS zones
112.250.in-addr.arpa
113.250.in-addr.arpa
114.250.in-addr.arpa
115.250.in-addr.arpa
116.250.in-addr.arpa
117.250.in-addr.arpa
118.250.in-addr.arpa
119.250.in-addr.arpa
120.250.in-addr.arpa
121.250.in-addr.arpa
122.250.in-addr.arpa
123.250.in-addr.arpa
124.250.in-addr.arpa
125.250.in-addr.arpa
126.250.in-addr.arpa
127.250.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
Address11111010.01110000.00000000.00000000250.112.0.0
Subnet mask11111111.11110000.00000000.00000000255.240.0.0
Network11111010.01110000.00000000.00000000250.112.0.0
Broadcast11111010.01111111.11111111.11111111250.127.255.255
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)

250.112.0.0/12 makes 4,096 subnets of /24; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1250.112.0.0/24250.112.0.1 to 250.112.0.254250.112.0.255254
2250.112.1.0/24250.112.1.1 to 250.112.1.254250.112.1.255254
3250.112.2.0/24250.112.2.1 to 250.112.2.254250.112.2.255254
4250.112.3.0/24250.112.3.1 to 250.112.3.254250.112.3.255254
5250.112.4.0/24250.112.4.1 to 250.112.4.254250.112.4.255254
6250.112.5.0/24250.112.5.1 to 250.112.5.254250.112.5.255254
7250.112.6.0/24250.112.6.1 to 250.112.6.254250.112.6.255254
8250.112.7.0/24250.112.7.1 to 250.112.7.254250.112.7.255254
9250.112.8.0/24250.112.8.1 to 250.112.8.254250.112.8.255254
10250.112.9.0/24250.112.9.1 to 250.112.9.254250.112.9.255254
11250.112.10.0/24250.112.10.1 to 250.112.10.254250.112.10.255254
12250.112.11.0/24250.112.11.1 to 250.112.11.254250.112.11.255254
13250.112.12.0/24250.112.12.1 to 250.112.12.254250.112.12.255254
14250.112.13.0/24250.112.13.1 to 250.112.13.254250.112.13.255254
15250.112.14.0/24250.112.14.1 to 250.112.14.254250.112.14.255254
16250.112.15.0/24250.112.15.1 to 250.112.15.254250.112.15.255254
17250.112.16.0/24250.112.16.1 to 250.112.16.254250.112.16.255254
18250.112.17.0/24250.112.17.1 to 250.112.17.254250.112.17.255254
19250.112.18.0/24250.112.18.1 to 250.112.18.254250.112.18.255254
20250.112.19.0/24250.112.19.1 to 250.112.19.254250.112.19.255254
21250.112.20.0/24250.112.20.1 to 250.112.20.254250.112.20.255254
22250.112.21.0/24250.112.21.1 to 250.112.21.254250.112.21.255254
23250.112.22.0/24250.112.22.1 to 250.112.22.254250.112.22.255254
24250.112.23.0/24250.112.23.1 to 250.112.23.254250.112.23.255254
25250.112.24.0/24250.112.24.1 to 250.112.24.254250.112.24.255254
26250.112.25.0/24250.112.25.1 to 250.112.25.254250.112.25.255254
27250.112.26.0/24250.112.26.1 to 250.112.26.254250.112.26.255254
28250.112.27.0/24250.112.27.1 to 250.112.27.254250.112.27.255254
29250.112.28.0/24250.112.28.1 to 250.112.28.254250.112.28.255254
30250.112.29.0/24250.112.29.1 to 250.112.29.254250.112.29.255254
31250.112.30.0/24250.112.30.1 to 250.112.30.254250.112.30.255254
32250.112.31.0/24250.112.31.1 to 250.112.31.254250.112.31.255254
33250.112.32.0/24250.112.32.1 to 250.112.32.254250.112.32.255254
34250.112.33.0/24250.112.33.1 to 250.112.33.254250.112.33.255254
35250.112.34.0/24250.112.34.1 to 250.112.34.254250.112.34.255254
36250.112.35.0/24250.112.35.1 to 250.112.35.254250.112.35.255254
37250.112.36.0/24250.112.36.1 to 250.112.36.254250.112.36.255254
38250.112.37.0/24250.112.37.1 to 250.112.37.254250.112.37.255254
39250.112.38.0/24250.112.38.1 to 250.112.38.254250.112.38.255254
40250.112.39.0/24250.112.39.1 to 250.112.39.254250.112.39.255254
41250.112.40.0/24250.112.40.1 to 250.112.40.254250.112.40.255254
42250.112.41.0/24250.112.41.1 to 250.112.41.254250.112.41.255254
43250.112.42.0/24250.112.42.1 to 250.112.42.254250.112.42.255254
44250.112.43.0/24250.112.43.1 to 250.112.43.254250.112.43.255254
45250.112.44.0/24250.112.44.1 to 250.112.44.254250.112.44.255254
46250.112.45.0/24250.112.45.1 to 250.112.45.254250.112.45.255254
47250.112.46.0/24250.112.46.1 to 250.112.46.254250.112.46.255254
48250.112.47.0/24250.112.47.1 to 250.112.47.254250.112.47.255254
49250.112.48.0/24250.112.48.1 to 250.112.48.254250.112.48.255254
50250.112.49.0/24250.112.49.1 to 250.112.49.254250.112.49.255254
51250.112.50.0/24250.112.50.1 to 250.112.50.254250.112.50.255254
52250.112.51.0/24250.112.51.1 to 250.112.51.254250.112.51.255254
53250.112.52.0/24250.112.52.1 to 250.112.52.254250.112.52.255254
54250.112.53.0/24250.112.53.1 to 250.112.53.254250.112.53.255254
55250.112.54.0/24250.112.54.1 to 250.112.54.254250.112.54.255254
56250.112.55.0/24250.112.55.1 to 250.112.55.254250.112.55.255254
57250.112.56.0/24250.112.56.1 to 250.112.56.254250.112.56.255254
58250.112.57.0/24250.112.57.1 to 250.112.57.254250.112.57.255254
59250.112.58.0/24250.112.58.1 to 250.112.58.254250.112.58.255254
60250.112.59.0/24250.112.59.1 to 250.112.59.254250.112.59.255254
61250.112.60.0/24250.112.60.1 to 250.112.60.254250.112.60.255254
62250.112.61.0/24250.112.61.1 to 250.112.61.254250.112.61.255254
63250.112.62.0/24250.112.62.1 to 250.112.62.254250.112.62.255254
64250.112.63.0/24250.112.63.1 to 250.112.63.254250.112.63.255254
65250.112.64.0/24250.112.64.1 to 250.112.64.254250.112.64.255254
66250.112.65.0/24250.112.65.1 to 250.112.65.254250.112.65.255254
67250.112.66.0/24250.112.66.1 to 250.112.66.254250.112.66.255254
68250.112.67.0/24250.112.67.1 to 250.112.67.254250.112.67.255254
69250.112.68.0/24250.112.68.1 to 250.112.68.254250.112.68.255254
70250.112.69.0/24250.112.69.1 to 250.112.69.254250.112.69.255254
71250.112.70.0/24250.112.70.1 to 250.112.70.254250.112.70.255254
72250.112.71.0/24250.112.71.1 to 250.112.71.254250.112.71.255254
73250.112.72.0/24250.112.72.1 to 250.112.72.254250.112.72.255254
74250.112.73.0/24250.112.73.1 to 250.112.73.254250.112.73.255254
75250.112.74.0/24250.112.74.1 to 250.112.74.254250.112.74.255254
76250.112.75.0/24250.112.75.1 to 250.112.75.254250.112.75.255254
77250.112.76.0/24250.112.76.1 to 250.112.76.254250.112.76.255254
78250.112.77.0/24250.112.77.1 to 250.112.77.254250.112.77.255254
79250.112.78.0/24250.112.78.1 to 250.112.78.254250.112.78.255254
80250.112.79.0/24250.112.79.1 to 250.112.79.254250.112.79.255254
81250.112.80.0/24250.112.80.1 to 250.112.80.254250.112.80.255254
82250.112.81.0/24250.112.81.1 to 250.112.81.254250.112.81.255254
83250.112.82.0/24250.112.82.1 to 250.112.82.254250.112.82.255254
84250.112.83.0/24250.112.83.1 to 250.112.83.254250.112.83.255254
85250.112.84.0/24250.112.84.1 to 250.112.84.254250.112.84.255254
86250.112.85.0/24250.112.85.1 to 250.112.85.254250.112.85.255254
87250.112.86.0/24250.112.86.1 to 250.112.86.254250.112.86.255254
88250.112.87.0/24250.112.87.1 to 250.112.87.254250.112.87.255254
89250.112.88.0/24250.112.88.1 to 250.112.88.254250.112.88.255254
90250.112.89.0/24250.112.89.1 to 250.112.89.254250.112.89.255254
91250.112.90.0/24250.112.90.1 to 250.112.90.254250.112.90.255254
92250.112.91.0/24250.112.91.1 to 250.112.91.254250.112.91.255254
93250.112.92.0/24250.112.92.1 to 250.112.92.254250.112.92.255254
94250.112.93.0/24250.112.93.1 to 250.112.93.254250.112.93.255254
95250.112.94.0/24250.112.94.1 to 250.112.94.254250.112.94.255254
96250.112.95.0/24250.112.95.1 to 250.112.95.254250.112.95.255254
97250.112.96.0/24250.112.96.1 to 250.112.96.254250.112.96.255254
98250.112.97.0/24250.112.97.1 to 250.112.97.254250.112.97.255254
99250.112.98.0/24250.112.98.1 to 250.112.98.254250.112.98.255254
100250.112.99.0/24250.112.99.1 to 250.112.99.254250.112.99.255254
101250.112.100.0/24250.112.100.1 to 250.112.100.254250.112.100.255254
102250.112.101.0/24250.112.101.1 to 250.112.101.254250.112.101.255254
103250.112.102.0/24250.112.102.1 to 250.112.102.254250.112.102.255254
104250.112.103.0/24250.112.103.1 to 250.112.103.254250.112.103.255254
105250.112.104.0/24250.112.104.1 to 250.112.104.254250.112.104.255254
106250.112.105.0/24250.112.105.1 to 250.112.105.254250.112.105.255254
107250.112.106.0/24250.112.106.1 to 250.112.106.254250.112.106.255254
108250.112.107.0/24250.112.107.1 to 250.112.107.254250.112.107.255254
109250.112.108.0/24250.112.108.1 to 250.112.108.254250.112.108.255254
110250.112.109.0/24250.112.109.1 to 250.112.109.254250.112.109.255254
111250.112.110.0/24250.112.110.1 to 250.112.110.254250.112.110.255254
112250.112.111.0/24250.112.111.1 to 250.112.111.254250.112.111.255254
113250.112.112.0/24250.112.112.1 to 250.112.112.254250.112.112.255254
114250.112.113.0/24250.112.113.1 to 250.112.113.254250.112.113.255254
115250.112.114.0/24250.112.114.1 to 250.112.114.254250.112.114.255254
116250.112.115.0/24250.112.115.1 to 250.112.115.254250.112.115.255254
117250.112.116.0/24250.112.116.1 to 250.112.116.254250.112.116.255254
118250.112.117.0/24250.112.117.1 to 250.112.117.254250.112.117.255254
119250.112.118.0/24250.112.118.1 to 250.112.118.254250.112.118.255254
120250.112.119.0/24250.112.119.1 to 250.112.119.254250.112.119.255254
121250.112.120.0/24250.112.120.1 to 250.112.120.254250.112.120.255254
122250.112.121.0/24250.112.121.1 to 250.112.121.254250.112.121.255254
123250.112.122.0/24250.112.122.1 to 250.112.122.254250.112.122.255254
124250.112.123.0/24250.112.123.1 to 250.112.123.254250.112.123.255254
125250.112.124.0/24250.112.124.1 to 250.112.124.254250.112.124.255254
126250.112.125.0/24250.112.125.1 to 250.112.125.254250.112.125.255254
127250.112.126.0/24250.112.126.1 to 250.112.126.254250.112.126.255254
128250.112.127.0/24250.112.127.1 to 250.112.127.254250.112.127.255254
129250.112.128.0/24250.112.128.1 to 250.112.128.254250.112.128.255254
130250.112.129.0/24250.112.129.1 to 250.112.129.254250.112.129.255254
131250.112.130.0/24250.112.130.1 to 250.112.130.254250.112.130.255254
132250.112.131.0/24250.112.131.1 to 250.112.131.254250.112.131.255254
133250.112.132.0/24250.112.132.1 to 250.112.132.254250.112.132.255254
134250.112.133.0/24250.112.133.1 to 250.112.133.254250.112.133.255254
135250.112.134.0/24250.112.134.1 to 250.112.134.254250.112.134.255254
136250.112.135.0/24250.112.135.1 to 250.112.135.254250.112.135.255254
137250.112.136.0/24250.112.136.1 to 250.112.136.254250.112.136.255254
138250.112.137.0/24250.112.137.1 to 250.112.137.254250.112.137.255254
139250.112.138.0/24250.112.138.1 to 250.112.138.254250.112.138.255254
140250.112.139.0/24250.112.139.1 to 250.112.139.254250.112.139.255254
141250.112.140.0/24250.112.140.1 to 250.112.140.254250.112.140.255254
142250.112.141.0/24250.112.141.1 to 250.112.141.254250.112.141.255254
143250.112.142.0/24250.112.142.1 to 250.112.142.254250.112.142.255254
144250.112.143.0/24250.112.143.1 to 250.112.143.254250.112.143.255254
145250.112.144.0/24250.112.144.1 to 250.112.144.254250.112.144.255254
146250.112.145.0/24250.112.145.1 to 250.112.145.254250.112.145.255254
147250.112.146.0/24250.112.146.1 to 250.112.146.254250.112.146.255254
148250.112.147.0/24250.112.147.1 to 250.112.147.254250.112.147.255254
149250.112.148.0/24250.112.148.1 to 250.112.148.254250.112.148.255254
150250.112.149.0/24250.112.149.1 to 250.112.149.254250.112.149.255254
151250.112.150.0/24250.112.150.1 to 250.112.150.254250.112.150.255254
152250.112.151.0/24250.112.151.1 to 250.112.151.254250.112.151.255254
153250.112.152.0/24250.112.152.1 to 250.112.152.254250.112.152.255254
154250.112.153.0/24250.112.153.1 to 250.112.153.254250.112.153.255254
155250.112.154.0/24250.112.154.1 to 250.112.154.254250.112.154.255254
156250.112.155.0/24250.112.155.1 to 250.112.155.254250.112.155.255254
157250.112.156.0/24250.112.156.1 to 250.112.156.254250.112.156.255254
158250.112.157.0/24250.112.157.1 to 250.112.157.254250.112.157.255254
159250.112.158.0/24250.112.158.1 to 250.112.158.254250.112.158.255254
160250.112.159.0/24250.112.159.1 to 250.112.159.254250.112.159.255254
161250.112.160.0/24250.112.160.1 to 250.112.160.254250.112.160.255254
162250.112.161.0/24250.112.161.1 to 250.112.161.254250.112.161.255254
163250.112.162.0/24250.112.162.1 to 250.112.162.254250.112.162.255254
164250.112.163.0/24250.112.163.1 to 250.112.163.254250.112.163.255254
165250.112.164.0/24250.112.164.1 to 250.112.164.254250.112.164.255254
166250.112.165.0/24250.112.165.1 to 250.112.165.254250.112.165.255254
167250.112.166.0/24250.112.166.1 to 250.112.166.254250.112.166.255254
168250.112.167.0/24250.112.167.1 to 250.112.167.254250.112.167.255254
169250.112.168.0/24250.112.168.1 to 250.112.168.254250.112.168.255254
170250.112.169.0/24250.112.169.1 to 250.112.169.254250.112.169.255254
171250.112.170.0/24250.112.170.1 to 250.112.170.254250.112.170.255254
172250.112.171.0/24250.112.171.1 to 250.112.171.254250.112.171.255254
173250.112.172.0/24250.112.172.1 to 250.112.172.254250.112.172.255254
174250.112.173.0/24250.112.173.1 to 250.112.173.254250.112.173.255254
175250.112.174.0/24250.112.174.1 to 250.112.174.254250.112.174.255254
176250.112.175.0/24250.112.175.1 to 250.112.175.254250.112.175.255254
177250.112.176.0/24250.112.176.1 to 250.112.176.254250.112.176.255254
178250.112.177.0/24250.112.177.1 to 250.112.177.254250.112.177.255254
179250.112.178.0/24250.112.178.1 to 250.112.178.254250.112.178.255254
180250.112.179.0/24250.112.179.1 to 250.112.179.254250.112.179.255254
181250.112.180.0/24250.112.180.1 to 250.112.180.254250.112.180.255254
182250.112.181.0/24250.112.181.1 to 250.112.181.254250.112.181.255254
183250.112.182.0/24250.112.182.1 to 250.112.182.254250.112.182.255254
184250.112.183.0/24250.112.183.1 to 250.112.183.254250.112.183.255254
185250.112.184.0/24250.112.184.1 to 250.112.184.254250.112.184.255254
186250.112.185.0/24250.112.185.1 to 250.112.185.254250.112.185.255254
187250.112.186.0/24250.112.186.1 to 250.112.186.254250.112.186.255254
188250.112.187.0/24250.112.187.1 to 250.112.187.254250.112.187.255254
189250.112.188.0/24250.112.188.1 to 250.112.188.254250.112.188.255254
190250.112.189.0/24250.112.189.1 to 250.112.189.254250.112.189.255254
191250.112.190.0/24250.112.190.1 to 250.112.190.254250.112.190.255254
192250.112.191.0/24250.112.191.1 to 250.112.191.254250.112.191.255254
193250.112.192.0/24250.112.192.1 to 250.112.192.254250.112.192.255254
194250.112.193.0/24250.112.193.1 to 250.112.193.254250.112.193.255254
195250.112.194.0/24250.112.194.1 to 250.112.194.254250.112.194.255254
196250.112.195.0/24250.112.195.1 to 250.112.195.254250.112.195.255254
197250.112.196.0/24250.112.196.1 to 250.112.196.254250.112.196.255254
198250.112.197.0/24250.112.197.1 to 250.112.197.254250.112.197.255254
199250.112.198.0/24250.112.198.1 to 250.112.198.254250.112.198.255254
200250.112.199.0/24250.112.199.1 to 250.112.199.254250.112.199.255254
201250.112.200.0/24250.112.200.1 to 250.112.200.254250.112.200.255254
202250.112.201.0/24250.112.201.1 to 250.112.201.254250.112.201.255254
203250.112.202.0/24250.112.202.1 to 250.112.202.254250.112.202.255254
204250.112.203.0/24250.112.203.1 to 250.112.203.254250.112.203.255254
205250.112.204.0/24250.112.204.1 to 250.112.204.254250.112.204.255254
206250.112.205.0/24250.112.205.1 to 250.112.205.254250.112.205.255254
207250.112.206.0/24250.112.206.1 to 250.112.206.254250.112.206.255254
208250.112.207.0/24250.112.207.1 to 250.112.207.254250.112.207.255254
209250.112.208.0/24250.112.208.1 to 250.112.208.254250.112.208.255254
210250.112.209.0/24250.112.209.1 to 250.112.209.254250.112.209.255254
211250.112.210.0/24250.112.210.1 to 250.112.210.254250.112.210.255254
212250.112.211.0/24250.112.211.1 to 250.112.211.254250.112.211.255254
213250.112.212.0/24250.112.212.1 to 250.112.212.254250.112.212.255254
214250.112.213.0/24250.112.213.1 to 250.112.213.254250.112.213.255254
215250.112.214.0/24250.112.214.1 to 250.112.214.254250.112.214.255254
216250.112.215.0/24250.112.215.1 to 250.112.215.254250.112.215.255254
217250.112.216.0/24250.112.216.1 to 250.112.216.254250.112.216.255254
218250.112.217.0/24250.112.217.1 to 250.112.217.254250.112.217.255254
219250.112.218.0/24250.112.218.1 to 250.112.218.254250.112.218.255254
220250.112.219.0/24250.112.219.1 to 250.112.219.254250.112.219.255254
221250.112.220.0/24250.112.220.1 to 250.112.220.254250.112.220.255254
222250.112.221.0/24250.112.221.1 to 250.112.221.254250.112.221.255254
223250.112.222.0/24250.112.222.1 to 250.112.222.254250.112.222.255254
224250.112.223.0/24250.112.223.1 to 250.112.223.254250.112.223.255254
225250.112.224.0/24250.112.224.1 to 250.112.224.254250.112.224.255254
226250.112.225.0/24250.112.225.1 to 250.112.225.254250.112.225.255254
227250.112.226.0/24250.112.226.1 to 250.112.226.254250.112.226.255254
228250.112.227.0/24250.112.227.1 to 250.112.227.254250.112.227.255254
229250.112.228.0/24250.112.228.1 to 250.112.228.254250.112.228.255254
230250.112.229.0/24250.112.229.1 to 250.112.229.254250.112.229.255254
231250.112.230.0/24250.112.230.1 to 250.112.230.254250.112.230.255254
232250.112.231.0/24250.112.231.1 to 250.112.231.254250.112.231.255254
233250.112.232.0/24250.112.232.1 to 250.112.232.254250.112.232.255254
234250.112.233.0/24250.112.233.1 to 250.112.233.254250.112.233.255254
235250.112.234.0/24250.112.234.1 to 250.112.234.254250.112.234.255254
236250.112.235.0/24250.112.235.1 to 250.112.235.254250.112.235.255254
237250.112.236.0/24250.112.236.1 to 250.112.236.254250.112.236.255254
238250.112.237.0/24250.112.237.1 to 250.112.237.254250.112.237.255254
239250.112.238.0/24250.112.238.1 to 250.112.238.254250.112.238.255254
240250.112.239.0/24250.112.239.1 to 250.112.239.254250.112.239.255254
241250.112.240.0/24250.112.240.1 to 250.112.240.254250.112.240.255254
242250.112.241.0/24250.112.241.1 to 250.112.241.254250.112.241.255254
243250.112.242.0/24250.112.242.1 to 250.112.242.254250.112.242.255254
244250.112.243.0/24250.112.243.1 to 250.112.243.254250.112.243.255254
245250.112.244.0/24250.112.244.1 to 250.112.244.254250.112.244.255254
246250.112.245.0/24250.112.245.1 to 250.112.245.254250.112.245.255254
247250.112.246.0/24250.112.246.1 to 250.112.246.254250.112.246.255254
248250.112.247.0/24250.112.247.1 to 250.112.247.254250.112.247.255254
249250.112.248.0/24250.112.248.1 to 250.112.248.254250.112.248.255254
250250.112.249.0/24250.112.249.1 to 250.112.249.254250.112.249.255254
251250.112.250.0/24250.112.250.1 to 250.112.250.254250.112.250.255254
252250.112.251.0/24250.112.251.1 to 250.112.251.254250.112.251.255254
253250.112.252.0/24250.112.252.1 to 250.112.252.254250.112.252.255254
254250.112.253.0/24250.112.253.1 to 250.112.253.254250.112.253.255254
255250.112.254.0/24250.112.254.1 to 250.112.254.254250.112.254.255254
256250.112.255.0/24250.112.255.1 to 250.112.255.254250.112.255.255254

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.