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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.

Network232.112.0.0/12
Usable hosts1,048,574
Subnet mask255.240.0.0
Addresses1,048,576
Network address
232.112.0.0
Broadcast address
232.127.255.255
First usable
232.112.0.1
Last usable
232.127.255.254
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
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E8700000 · Integer 3899654144 to 3900702719
Reverse DNS zones
112.232.in-addr.arpa
113.232.in-addr.arpa
114.232.in-addr.arpa
115.232.in-addr.arpa
116.232.in-addr.arpa
117.232.in-addr.arpa
118.232.in-addr.arpa
119.232.in-addr.arpa
120.232.in-addr.arpa
121.232.in-addr.arpa
122.232.in-addr.arpa
123.232.in-addr.arpa
124.232.in-addr.arpa
125.232.in-addr.arpa
126.232.in-addr.arpa
127.232.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
Address11101000.01110000.00000000.00000000232.112.0.0
Subnet mask11111111.11110000.00000000.00000000255.240.0.0
Network11101000.01110000.00000000.00000000232.112.0.0
Broadcast11101000.01111111.11111111.11111111232.127.255.255
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)

232.112.0.0/12 makes 4,096 subnets of /24; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1232.112.0.0/24232.112.0.1 to 232.112.0.254232.112.0.255254
2232.112.1.0/24232.112.1.1 to 232.112.1.254232.112.1.255254
3232.112.2.0/24232.112.2.1 to 232.112.2.254232.112.2.255254
4232.112.3.0/24232.112.3.1 to 232.112.3.254232.112.3.255254
5232.112.4.0/24232.112.4.1 to 232.112.4.254232.112.4.255254
6232.112.5.0/24232.112.5.1 to 232.112.5.254232.112.5.255254
7232.112.6.0/24232.112.6.1 to 232.112.6.254232.112.6.255254
8232.112.7.0/24232.112.7.1 to 232.112.7.254232.112.7.255254
9232.112.8.0/24232.112.8.1 to 232.112.8.254232.112.8.255254
10232.112.9.0/24232.112.9.1 to 232.112.9.254232.112.9.255254
11232.112.10.0/24232.112.10.1 to 232.112.10.254232.112.10.255254
12232.112.11.0/24232.112.11.1 to 232.112.11.254232.112.11.255254
13232.112.12.0/24232.112.12.1 to 232.112.12.254232.112.12.255254
14232.112.13.0/24232.112.13.1 to 232.112.13.254232.112.13.255254
15232.112.14.0/24232.112.14.1 to 232.112.14.254232.112.14.255254
16232.112.15.0/24232.112.15.1 to 232.112.15.254232.112.15.255254
17232.112.16.0/24232.112.16.1 to 232.112.16.254232.112.16.255254
18232.112.17.0/24232.112.17.1 to 232.112.17.254232.112.17.255254
19232.112.18.0/24232.112.18.1 to 232.112.18.254232.112.18.255254
20232.112.19.0/24232.112.19.1 to 232.112.19.254232.112.19.255254
21232.112.20.0/24232.112.20.1 to 232.112.20.254232.112.20.255254
22232.112.21.0/24232.112.21.1 to 232.112.21.254232.112.21.255254
23232.112.22.0/24232.112.22.1 to 232.112.22.254232.112.22.255254
24232.112.23.0/24232.112.23.1 to 232.112.23.254232.112.23.255254
25232.112.24.0/24232.112.24.1 to 232.112.24.254232.112.24.255254
26232.112.25.0/24232.112.25.1 to 232.112.25.254232.112.25.255254
27232.112.26.0/24232.112.26.1 to 232.112.26.254232.112.26.255254
28232.112.27.0/24232.112.27.1 to 232.112.27.254232.112.27.255254
29232.112.28.0/24232.112.28.1 to 232.112.28.254232.112.28.255254
30232.112.29.0/24232.112.29.1 to 232.112.29.254232.112.29.255254
31232.112.30.0/24232.112.30.1 to 232.112.30.254232.112.30.255254
32232.112.31.0/24232.112.31.1 to 232.112.31.254232.112.31.255254
33232.112.32.0/24232.112.32.1 to 232.112.32.254232.112.32.255254
34232.112.33.0/24232.112.33.1 to 232.112.33.254232.112.33.255254
35232.112.34.0/24232.112.34.1 to 232.112.34.254232.112.34.255254
36232.112.35.0/24232.112.35.1 to 232.112.35.254232.112.35.255254
37232.112.36.0/24232.112.36.1 to 232.112.36.254232.112.36.255254
38232.112.37.0/24232.112.37.1 to 232.112.37.254232.112.37.255254
39232.112.38.0/24232.112.38.1 to 232.112.38.254232.112.38.255254
40232.112.39.0/24232.112.39.1 to 232.112.39.254232.112.39.255254
41232.112.40.0/24232.112.40.1 to 232.112.40.254232.112.40.255254
42232.112.41.0/24232.112.41.1 to 232.112.41.254232.112.41.255254
43232.112.42.0/24232.112.42.1 to 232.112.42.254232.112.42.255254
44232.112.43.0/24232.112.43.1 to 232.112.43.254232.112.43.255254
45232.112.44.0/24232.112.44.1 to 232.112.44.254232.112.44.255254
46232.112.45.0/24232.112.45.1 to 232.112.45.254232.112.45.255254
47232.112.46.0/24232.112.46.1 to 232.112.46.254232.112.46.255254
48232.112.47.0/24232.112.47.1 to 232.112.47.254232.112.47.255254
49232.112.48.0/24232.112.48.1 to 232.112.48.254232.112.48.255254
50232.112.49.0/24232.112.49.1 to 232.112.49.254232.112.49.255254
51232.112.50.0/24232.112.50.1 to 232.112.50.254232.112.50.255254
52232.112.51.0/24232.112.51.1 to 232.112.51.254232.112.51.255254
53232.112.52.0/24232.112.52.1 to 232.112.52.254232.112.52.255254
54232.112.53.0/24232.112.53.1 to 232.112.53.254232.112.53.255254
55232.112.54.0/24232.112.54.1 to 232.112.54.254232.112.54.255254
56232.112.55.0/24232.112.55.1 to 232.112.55.254232.112.55.255254
57232.112.56.0/24232.112.56.1 to 232.112.56.254232.112.56.255254
58232.112.57.0/24232.112.57.1 to 232.112.57.254232.112.57.255254
59232.112.58.0/24232.112.58.1 to 232.112.58.254232.112.58.255254
60232.112.59.0/24232.112.59.1 to 232.112.59.254232.112.59.255254
61232.112.60.0/24232.112.60.1 to 232.112.60.254232.112.60.255254
62232.112.61.0/24232.112.61.1 to 232.112.61.254232.112.61.255254
63232.112.62.0/24232.112.62.1 to 232.112.62.254232.112.62.255254
64232.112.63.0/24232.112.63.1 to 232.112.63.254232.112.63.255254
65232.112.64.0/24232.112.64.1 to 232.112.64.254232.112.64.255254
66232.112.65.0/24232.112.65.1 to 232.112.65.254232.112.65.255254
67232.112.66.0/24232.112.66.1 to 232.112.66.254232.112.66.255254
68232.112.67.0/24232.112.67.1 to 232.112.67.254232.112.67.255254
69232.112.68.0/24232.112.68.1 to 232.112.68.254232.112.68.255254
70232.112.69.0/24232.112.69.1 to 232.112.69.254232.112.69.255254
71232.112.70.0/24232.112.70.1 to 232.112.70.254232.112.70.255254
72232.112.71.0/24232.112.71.1 to 232.112.71.254232.112.71.255254
73232.112.72.0/24232.112.72.1 to 232.112.72.254232.112.72.255254
74232.112.73.0/24232.112.73.1 to 232.112.73.254232.112.73.255254
75232.112.74.0/24232.112.74.1 to 232.112.74.254232.112.74.255254
76232.112.75.0/24232.112.75.1 to 232.112.75.254232.112.75.255254
77232.112.76.0/24232.112.76.1 to 232.112.76.254232.112.76.255254
78232.112.77.0/24232.112.77.1 to 232.112.77.254232.112.77.255254
79232.112.78.0/24232.112.78.1 to 232.112.78.254232.112.78.255254
80232.112.79.0/24232.112.79.1 to 232.112.79.254232.112.79.255254
81232.112.80.0/24232.112.80.1 to 232.112.80.254232.112.80.255254
82232.112.81.0/24232.112.81.1 to 232.112.81.254232.112.81.255254
83232.112.82.0/24232.112.82.1 to 232.112.82.254232.112.82.255254
84232.112.83.0/24232.112.83.1 to 232.112.83.254232.112.83.255254
85232.112.84.0/24232.112.84.1 to 232.112.84.254232.112.84.255254
86232.112.85.0/24232.112.85.1 to 232.112.85.254232.112.85.255254
87232.112.86.0/24232.112.86.1 to 232.112.86.254232.112.86.255254
88232.112.87.0/24232.112.87.1 to 232.112.87.254232.112.87.255254
89232.112.88.0/24232.112.88.1 to 232.112.88.254232.112.88.255254
90232.112.89.0/24232.112.89.1 to 232.112.89.254232.112.89.255254
91232.112.90.0/24232.112.90.1 to 232.112.90.254232.112.90.255254
92232.112.91.0/24232.112.91.1 to 232.112.91.254232.112.91.255254
93232.112.92.0/24232.112.92.1 to 232.112.92.254232.112.92.255254
94232.112.93.0/24232.112.93.1 to 232.112.93.254232.112.93.255254
95232.112.94.0/24232.112.94.1 to 232.112.94.254232.112.94.255254
96232.112.95.0/24232.112.95.1 to 232.112.95.254232.112.95.255254
97232.112.96.0/24232.112.96.1 to 232.112.96.254232.112.96.255254
98232.112.97.0/24232.112.97.1 to 232.112.97.254232.112.97.255254
99232.112.98.0/24232.112.98.1 to 232.112.98.254232.112.98.255254
100232.112.99.0/24232.112.99.1 to 232.112.99.254232.112.99.255254
101232.112.100.0/24232.112.100.1 to 232.112.100.254232.112.100.255254
102232.112.101.0/24232.112.101.1 to 232.112.101.254232.112.101.255254
103232.112.102.0/24232.112.102.1 to 232.112.102.254232.112.102.255254
104232.112.103.0/24232.112.103.1 to 232.112.103.254232.112.103.255254
105232.112.104.0/24232.112.104.1 to 232.112.104.254232.112.104.255254
106232.112.105.0/24232.112.105.1 to 232.112.105.254232.112.105.255254
107232.112.106.0/24232.112.106.1 to 232.112.106.254232.112.106.255254
108232.112.107.0/24232.112.107.1 to 232.112.107.254232.112.107.255254
109232.112.108.0/24232.112.108.1 to 232.112.108.254232.112.108.255254
110232.112.109.0/24232.112.109.1 to 232.112.109.254232.112.109.255254
111232.112.110.0/24232.112.110.1 to 232.112.110.254232.112.110.255254
112232.112.111.0/24232.112.111.1 to 232.112.111.254232.112.111.255254
113232.112.112.0/24232.112.112.1 to 232.112.112.254232.112.112.255254
114232.112.113.0/24232.112.113.1 to 232.112.113.254232.112.113.255254
115232.112.114.0/24232.112.114.1 to 232.112.114.254232.112.114.255254
116232.112.115.0/24232.112.115.1 to 232.112.115.254232.112.115.255254
117232.112.116.0/24232.112.116.1 to 232.112.116.254232.112.116.255254
118232.112.117.0/24232.112.117.1 to 232.112.117.254232.112.117.255254
119232.112.118.0/24232.112.118.1 to 232.112.118.254232.112.118.255254
120232.112.119.0/24232.112.119.1 to 232.112.119.254232.112.119.255254
121232.112.120.0/24232.112.120.1 to 232.112.120.254232.112.120.255254
122232.112.121.0/24232.112.121.1 to 232.112.121.254232.112.121.255254
123232.112.122.0/24232.112.122.1 to 232.112.122.254232.112.122.255254
124232.112.123.0/24232.112.123.1 to 232.112.123.254232.112.123.255254
125232.112.124.0/24232.112.124.1 to 232.112.124.254232.112.124.255254
126232.112.125.0/24232.112.125.1 to 232.112.125.254232.112.125.255254
127232.112.126.0/24232.112.126.1 to 232.112.126.254232.112.126.255254
128232.112.127.0/24232.112.127.1 to 232.112.127.254232.112.127.255254
129232.112.128.0/24232.112.128.1 to 232.112.128.254232.112.128.255254
130232.112.129.0/24232.112.129.1 to 232.112.129.254232.112.129.255254
131232.112.130.0/24232.112.130.1 to 232.112.130.254232.112.130.255254
132232.112.131.0/24232.112.131.1 to 232.112.131.254232.112.131.255254
133232.112.132.0/24232.112.132.1 to 232.112.132.254232.112.132.255254
134232.112.133.0/24232.112.133.1 to 232.112.133.254232.112.133.255254
135232.112.134.0/24232.112.134.1 to 232.112.134.254232.112.134.255254
136232.112.135.0/24232.112.135.1 to 232.112.135.254232.112.135.255254
137232.112.136.0/24232.112.136.1 to 232.112.136.254232.112.136.255254
138232.112.137.0/24232.112.137.1 to 232.112.137.254232.112.137.255254
139232.112.138.0/24232.112.138.1 to 232.112.138.254232.112.138.255254
140232.112.139.0/24232.112.139.1 to 232.112.139.254232.112.139.255254
141232.112.140.0/24232.112.140.1 to 232.112.140.254232.112.140.255254
142232.112.141.0/24232.112.141.1 to 232.112.141.254232.112.141.255254
143232.112.142.0/24232.112.142.1 to 232.112.142.254232.112.142.255254
144232.112.143.0/24232.112.143.1 to 232.112.143.254232.112.143.255254
145232.112.144.0/24232.112.144.1 to 232.112.144.254232.112.144.255254
146232.112.145.0/24232.112.145.1 to 232.112.145.254232.112.145.255254
147232.112.146.0/24232.112.146.1 to 232.112.146.254232.112.146.255254
148232.112.147.0/24232.112.147.1 to 232.112.147.254232.112.147.255254
149232.112.148.0/24232.112.148.1 to 232.112.148.254232.112.148.255254
150232.112.149.0/24232.112.149.1 to 232.112.149.254232.112.149.255254
151232.112.150.0/24232.112.150.1 to 232.112.150.254232.112.150.255254
152232.112.151.0/24232.112.151.1 to 232.112.151.254232.112.151.255254
153232.112.152.0/24232.112.152.1 to 232.112.152.254232.112.152.255254
154232.112.153.0/24232.112.153.1 to 232.112.153.254232.112.153.255254
155232.112.154.0/24232.112.154.1 to 232.112.154.254232.112.154.255254
156232.112.155.0/24232.112.155.1 to 232.112.155.254232.112.155.255254
157232.112.156.0/24232.112.156.1 to 232.112.156.254232.112.156.255254
158232.112.157.0/24232.112.157.1 to 232.112.157.254232.112.157.255254
159232.112.158.0/24232.112.158.1 to 232.112.158.254232.112.158.255254
160232.112.159.0/24232.112.159.1 to 232.112.159.254232.112.159.255254
161232.112.160.0/24232.112.160.1 to 232.112.160.254232.112.160.255254
162232.112.161.0/24232.112.161.1 to 232.112.161.254232.112.161.255254
163232.112.162.0/24232.112.162.1 to 232.112.162.254232.112.162.255254
164232.112.163.0/24232.112.163.1 to 232.112.163.254232.112.163.255254
165232.112.164.0/24232.112.164.1 to 232.112.164.254232.112.164.255254
166232.112.165.0/24232.112.165.1 to 232.112.165.254232.112.165.255254
167232.112.166.0/24232.112.166.1 to 232.112.166.254232.112.166.255254
168232.112.167.0/24232.112.167.1 to 232.112.167.254232.112.167.255254
169232.112.168.0/24232.112.168.1 to 232.112.168.254232.112.168.255254
170232.112.169.0/24232.112.169.1 to 232.112.169.254232.112.169.255254
171232.112.170.0/24232.112.170.1 to 232.112.170.254232.112.170.255254
172232.112.171.0/24232.112.171.1 to 232.112.171.254232.112.171.255254
173232.112.172.0/24232.112.172.1 to 232.112.172.254232.112.172.255254
174232.112.173.0/24232.112.173.1 to 232.112.173.254232.112.173.255254
175232.112.174.0/24232.112.174.1 to 232.112.174.254232.112.174.255254
176232.112.175.0/24232.112.175.1 to 232.112.175.254232.112.175.255254
177232.112.176.0/24232.112.176.1 to 232.112.176.254232.112.176.255254
178232.112.177.0/24232.112.177.1 to 232.112.177.254232.112.177.255254
179232.112.178.0/24232.112.178.1 to 232.112.178.254232.112.178.255254
180232.112.179.0/24232.112.179.1 to 232.112.179.254232.112.179.255254
181232.112.180.0/24232.112.180.1 to 232.112.180.254232.112.180.255254
182232.112.181.0/24232.112.181.1 to 232.112.181.254232.112.181.255254
183232.112.182.0/24232.112.182.1 to 232.112.182.254232.112.182.255254
184232.112.183.0/24232.112.183.1 to 232.112.183.254232.112.183.255254
185232.112.184.0/24232.112.184.1 to 232.112.184.254232.112.184.255254
186232.112.185.0/24232.112.185.1 to 232.112.185.254232.112.185.255254
187232.112.186.0/24232.112.186.1 to 232.112.186.254232.112.186.255254
188232.112.187.0/24232.112.187.1 to 232.112.187.254232.112.187.255254
189232.112.188.0/24232.112.188.1 to 232.112.188.254232.112.188.255254
190232.112.189.0/24232.112.189.1 to 232.112.189.254232.112.189.255254
191232.112.190.0/24232.112.190.1 to 232.112.190.254232.112.190.255254
192232.112.191.0/24232.112.191.1 to 232.112.191.254232.112.191.255254
193232.112.192.0/24232.112.192.1 to 232.112.192.254232.112.192.255254
194232.112.193.0/24232.112.193.1 to 232.112.193.254232.112.193.255254
195232.112.194.0/24232.112.194.1 to 232.112.194.254232.112.194.255254
196232.112.195.0/24232.112.195.1 to 232.112.195.254232.112.195.255254
197232.112.196.0/24232.112.196.1 to 232.112.196.254232.112.196.255254
198232.112.197.0/24232.112.197.1 to 232.112.197.254232.112.197.255254
199232.112.198.0/24232.112.198.1 to 232.112.198.254232.112.198.255254
200232.112.199.0/24232.112.199.1 to 232.112.199.254232.112.199.255254
201232.112.200.0/24232.112.200.1 to 232.112.200.254232.112.200.255254
202232.112.201.0/24232.112.201.1 to 232.112.201.254232.112.201.255254
203232.112.202.0/24232.112.202.1 to 232.112.202.254232.112.202.255254
204232.112.203.0/24232.112.203.1 to 232.112.203.254232.112.203.255254
205232.112.204.0/24232.112.204.1 to 232.112.204.254232.112.204.255254
206232.112.205.0/24232.112.205.1 to 232.112.205.254232.112.205.255254
207232.112.206.0/24232.112.206.1 to 232.112.206.254232.112.206.255254
208232.112.207.0/24232.112.207.1 to 232.112.207.254232.112.207.255254
209232.112.208.0/24232.112.208.1 to 232.112.208.254232.112.208.255254
210232.112.209.0/24232.112.209.1 to 232.112.209.254232.112.209.255254
211232.112.210.0/24232.112.210.1 to 232.112.210.254232.112.210.255254
212232.112.211.0/24232.112.211.1 to 232.112.211.254232.112.211.255254
213232.112.212.0/24232.112.212.1 to 232.112.212.254232.112.212.255254
214232.112.213.0/24232.112.213.1 to 232.112.213.254232.112.213.255254
215232.112.214.0/24232.112.214.1 to 232.112.214.254232.112.214.255254
216232.112.215.0/24232.112.215.1 to 232.112.215.254232.112.215.255254
217232.112.216.0/24232.112.216.1 to 232.112.216.254232.112.216.255254
218232.112.217.0/24232.112.217.1 to 232.112.217.254232.112.217.255254
219232.112.218.0/24232.112.218.1 to 232.112.218.254232.112.218.255254
220232.112.219.0/24232.112.219.1 to 232.112.219.254232.112.219.255254
221232.112.220.0/24232.112.220.1 to 232.112.220.254232.112.220.255254
222232.112.221.0/24232.112.221.1 to 232.112.221.254232.112.221.255254
223232.112.222.0/24232.112.222.1 to 232.112.222.254232.112.222.255254
224232.112.223.0/24232.112.223.1 to 232.112.223.254232.112.223.255254
225232.112.224.0/24232.112.224.1 to 232.112.224.254232.112.224.255254
226232.112.225.0/24232.112.225.1 to 232.112.225.254232.112.225.255254
227232.112.226.0/24232.112.226.1 to 232.112.226.254232.112.226.255254
228232.112.227.0/24232.112.227.1 to 232.112.227.254232.112.227.255254
229232.112.228.0/24232.112.228.1 to 232.112.228.254232.112.228.255254
230232.112.229.0/24232.112.229.1 to 232.112.229.254232.112.229.255254
231232.112.230.0/24232.112.230.1 to 232.112.230.254232.112.230.255254
232232.112.231.0/24232.112.231.1 to 232.112.231.254232.112.231.255254
233232.112.232.0/24232.112.232.1 to 232.112.232.254232.112.232.255254
234232.112.233.0/24232.112.233.1 to 232.112.233.254232.112.233.255254
235232.112.234.0/24232.112.234.1 to 232.112.234.254232.112.234.255254
236232.112.235.0/24232.112.235.1 to 232.112.235.254232.112.235.255254
237232.112.236.0/24232.112.236.1 to 232.112.236.254232.112.236.255254
238232.112.237.0/24232.112.237.1 to 232.112.237.254232.112.237.255254
239232.112.238.0/24232.112.238.1 to 232.112.238.254232.112.238.255254
240232.112.239.0/24232.112.239.1 to 232.112.239.254232.112.239.255254
241232.112.240.0/24232.112.240.1 to 232.112.240.254232.112.240.255254
242232.112.241.0/24232.112.241.1 to 232.112.241.254232.112.241.255254
243232.112.242.0/24232.112.242.1 to 232.112.242.254232.112.242.255254
244232.112.243.0/24232.112.243.1 to 232.112.243.254232.112.243.255254
245232.112.244.0/24232.112.244.1 to 232.112.244.254232.112.244.255254
246232.112.245.0/24232.112.245.1 to 232.112.245.254232.112.245.255254
247232.112.246.0/24232.112.246.1 to 232.112.246.254232.112.246.255254
248232.112.247.0/24232.112.247.1 to 232.112.247.254232.112.247.255254
249232.112.248.0/24232.112.248.1 to 232.112.248.254232.112.248.255254
250232.112.249.0/24232.112.249.1 to 232.112.249.254232.112.249.255254
251232.112.250.0/24232.112.250.1 to 232.112.250.254232.112.250.255254
252232.112.251.0/24232.112.251.1 to 232.112.251.254232.112.251.255254
253232.112.252.0/24232.112.252.1 to 232.112.252.254232.112.252.255254
254232.112.253.0/24232.112.253.1 to 232.112.253.254232.112.253.255254
255232.112.254.0/24232.112.254.1 to 232.112.254.254232.112.254.255254
256232.112.255.0/24232.112.255.1 to 232.112.255.254232.112.255.255254

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.