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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.

Network197.4.0.0/14
Usable hosts262,142
Subnet mask255.252.0.0
Addresses262,144
Network address
197.4.0.0
Broadcast address
197.7.255.255
First usable
197.4.0.1
Last usable
197.7.255.254
Usable hosts
262,142 (262,144 less the network and broadcast addresses)
Subnet mask
255.252.0.0
Wildcard mask
0.3.255.255 (Cisco ACLs, OSPF)
Prefix length
/14
Type
Public public
Old class
C (default /24)
As numbers
Hex C5040000 · Integer 3305373696 to 3305635839
Reverse DNS zones
4.197.in-addr.arpa
5.197.in-addr.arpa
6.197.in-addr.arpa
7.197.in-addr.arpa
/14 is not on a 8-bit boundary, so it takes 4 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11000101.00000100.00000000.00000000197.4.0.0
Subnet mask11111111.11111100.00000000.00000000255.252.0.0
Network11000101.00000100.00000000.00000000197.4.0.0
Broadcast11000101.00000111.11111111.11111111197.7.255.255
Split into smaller subnets/23
/15 (2)/16 (4)/17 (8)/18 (16)/19 (32)/20 (64)/21 (128)/22 (256)/23 (512)/24 (1,024)/25 (2,048)/26 (4,096)

197.4.0.0/14 makes 512 subnets of /23; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1197.4.0.0/23197.4.0.1 to 197.4.1.254197.4.1.255510
2197.4.2.0/23197.4.2.1 to 197.4.3.254197.4.3.255510
3197.4.4.0/23197.4.4.1 to 197.4.5.254197.4.5.255510
4197.4.6.0/23197.4.6.1 to 197.4.7.254197.4.7.255510
5197.4.8.0/23197.4.8.1 to 197.4.9.254197.4.9.255510
6197.4.10.0/23197.4.10.1 to 197.4.11.254197.4.11.255510
7197.4.12.0/23197.4.12.1 to 197.4.13.254197.4.13.255510
8197.4.14.0/23197.4.14.1 to 197.4.15.254197.4.15.255510
9197.4.16.0/23197.4.16.1 to 197.4.17.254197.4.17.255510
10197.4.18.0/23197.4.18.1 to 197.4.19.254197.4.19.255510
11197.4.20.0/23197.4.20.1 to 197.4.21.254197.4.21.255510
12197.4.22.0/23197.4.22.1 to 197.4.23.254197.4.23.255510
13197.4.24.0/23197.4.24.1 to 197.4.25.254197.4.25.255510
14197.4.26.0/23197.4.26.1 to 197.4.27.254197.4.27.255510
15197.4.28.0/23197.4.28.1 to 197.4.29.254197.4.29.255510
16197.4.30.0/23197.4.30.1 to 197.4.31.254197.4.31.255510
17197.4.32.0/23197.4.32.1 to 197.4.33.254197.4.33.255510
18197.4.34.0/23197.4.34.1 to 197.4.35.254197.4.35.255510
19197.4.36.0/23197.4.36.1 to 197.4.37.254197.4.37.255510
20197.4.38.0/23197.4.38.1 to 197.4.39.254197.4.39.255510
21197.4.40.0/23197.4.40.1 to 197.4.41.254197.4.41.255510
22197.4.42.0/23197.4.42.1 to 197.4.43.254197.4.43.255510
23197.4.44.0/23197.4.44.1 to 197.4.45.254197.4.45.255510
24197.4.46.0/23197.4.46.1 to 197.4.47.254197.4.47.255510
25197.4.48.0/23197.4.48.1 to 197.4.49.254197.4.49.255510
26197.4.50.0/23197.4.50.1 to 197.4.51.254197.4.51.255510
27197.4.52.0/23197.4.52.1 to 197.4.53.254197.4.53.255510
28197.4.54.0/23197.4.54.1 to 197.4.55.254197.4.55.255510
29197.4.56.0/23197.4.56.1 to 197.4.57.254197.4.57.255510
30197.4.58.0/23197.4.58.1 to 197.4.59.254197.4.59.255510
31197.4.60.0/23197.4.60.1 to 197.4.61.254197.4.61.255510
32197.4.62.0/23197.4.62.1 to 197.4.63.254197.4.63.255510
33197.4.64.0/23197.4.64.1 to 197.4.65.254197.4.65.255510
34197.4.66.0/23197.4.66.1 to 197.4.67.254197.4.67.255510
35197.4.68.0/23197.4.68.1 to 197.4.69.254197.4.69.255510
36197.4.70.0/23197.4.70.1 to 197.4.71.254197.4.71.255510
37197.4.72.0/23197.4.72.1 to 197.4.73.254197.4.73.255510
38197.4.74.0/23197.4.74.1 to 197.4.75.254197.4.75.255510
39197.4.76.0/23197.4.76.1 to 197.4.77.254197.4.77.255510
40197.4.78.0/23197.4.78.1 to 197.4.79.254197.4.79.255510
41197.4.80.0/23197.4.80.1 to 197.4.81.254197.4.81.255510
42197.4.82.0/23197.4.82.1 to 197.4.83.254197.4.83.255510
43197.4.84.0/23197.4.84.1 to 197.4.85.254197.4.85.255510
44197.4.86.0/23197.4.86.1 to 197.4.87.254197.4.87.255510
45197.4.88.0/23197.4.88.1 to 197.4.89.254197.4.89.255510
46197.4.90.0/23197.4.90.1 to 197.4.91.254197.4.91.255510
47197.4.92.0/23197.4.92.1 to 197.4.93.254197.4.93.255510
48197.4.94.0/23197.4.94.1 to 197.4.95.254197.4.95.255510
49197.4.96.0/23197.4.96.1 to 197.4.97.254197.4.97.255510
50197.4.98.0/23197.4.98.1 to 197.4.99.254197.4.99.255510
51197.4.100.0/23197.4.100.1 to 197.4.101.254197.4.101.255510
52197.4.102.0/23197.4.102.1 to 197.4.103.254197.4.103.255510
53197.4.104.0/23197.4.104.1 to 197.4.105.254197.4.105.255510
54197.4.106.0/23197.4.106.1 to 197.4.107.254197.4.107.255510
55197.4.108.0/23197.4.108.1 to 197.4.109.254197.4.109.255510
56197.4.110.0/23197.4.110.1 to 197.4.111.254197.4.111.255510
57197.4.112.0/23197.4.112.1 to 197.4.113.254197.4.113.255510
58197.4.114.0/23197.4.114.1 to 197.4.115.254197.4.115.255510
59197.4.116.0/23197.4.116.1 to 197.4.117.254197.4.117.255510
60197.4.118.0/23197.4.118.1 to 197.4.119.254197.4.119.255510
61197.4.120.0/23197.4.120.1 to 197.4.121.254197.4.121.255510
62197.4.122.0/23197.4.122.1 to 197.4.123.254197.4.123.255510
63197.4.124.0/23197.4.124.1 to 197.4.125.254197.4.125.255510
64197.4.126.0/23197.4.126.1 to 197.4.127.254197.4.127.255510
65197.4.128.0/23197.4.128.1 to 197.4.129.254197.4.129.255510
66197.4.130.0/23197.4.130.1 to 197.4.131.254197.4.131.255510
67197.4.132.0/23197.4.132.1 to 197.4.133.254197.4.133.255510
68197.4.134.0/23197.4.134.1 to 197.4.135.254197.4.135.255510
69197.4.136.0/23197.4.136.1 to 197.4.137.254197.4.137.255510
70197.4.138.0/23197.4.138.1 to 197.4.139.254197.4.139.255510
71197.4.140.0/23197.4.140.1 to 197.4.141.254197.4.141.255510
72197.4.142.0/23197.4.142.1 to 197.4.143.254197.4.143.255510
73197.4.144.0/23197.4.144.1 to 197.4.145.254197.4.145.255510
74197.4.146.0/23197.4.146.1 to 197.4.147.254197.4.147.255510
75197.4.148.0/23197.4.148.1 to 197.4.149.254197.4.149.255510
76197.4.150.0/23197.4.150.1 to 197.4.151.254197.4.151.255510
77197.4.152.0/23197.4.152.1 to 197.4.153.254197.4.153.255510
78197.4.154.0/23197.4.154.1 to 197.4.155.254197.4.155.255510
79197.4.156.0/23197.4.156.1 to 197.4.157.254197.4.157.255510
80197.4.158.0/23197.4.158.1 to 197.4.159.254197.4.159.255510
81197.4.160.0/23197.4.160.1 to 197.4.161.254197.4.161.255510
82197.4.162.0/23197.4.162.1 to 197.4.163.254197.4.163.255510
83197.4.164.0/23197.4.164.1 to 197.4.165.254197.4.165.255510
84197.4.166.0/23197.4.166.1 to 197.4.167.254197.4.167.255510
85197.4.168.0/23197.4.168.1 to 197.4.169.254197.4.169.255510
86197.4.170.0/23197.4.170.1 to 197.4.171.254197.4.171.255510
87197.4.172.0/23197.4.172.1 to 197.4.173.254197.4.173.255510
88197.4.174.0/23197.4.174.1 to 197.4.175.254197.4.175.255510
89197.4.176.0/23197.4.176.1 to 197.4.177.254197.4.177.255510
90197.4.178.0/23197.4.178.1 to 197.4.179.254197.4.179.255510
91197.4.180.0/23197.4.180.1 to 197.4.181.254197.4.181.255510
92197.4.182.0/23197.4.182.1 to 197.4.183.254197.4.183.255510
93197.4.184.0/23197.4.184.1 to 197.4.185.254197.4.185.255510
94197.4.186.0/23197.4.186.1 to 197.4.187.254197.4.187.255510
95197.4.188.0/23197.4.188.1 to 197.4.189.254197.4.189.255510
96197.4.190.0/23197.4.190.1 to 197.4.191.254197.4.191.255510
97197.4.192.0/23197.4.192.1 to 197.4.193.254197.4.193.255510
98197.4.194.0/23197.4.194.1 to 197.4.195.254197.4.195.255510
99197.4.196.0/23197.4.196.1 to 197.4.197.254197.4.197.255510
100197.4.198.0/23197.4.198.1 to 197.4.199.254197.4.199.255510
101197.4.200.0/23197.4.200.1 to 197.4.201.254197.4.201.255510
102197.4.202.0/23197.4.202.1 to 197.4.203.254197.4.203.255510
103197.4.204.0/23197.4.204.1 to 197.4.205.254197.4.205.255510
104197.4.206.0/23197.4.206.1 to 197.4.207.254197.4.207.255510
105197.4.208.0/23197.4.208.1 to 197.4.209.254197.4.209.255510
106197.4.210.0/23197.4.210.1 to 197.4.211.254197.4.211.255510
107197.4.212.0/23197.4.212.1 to 197.4.213.254197.4.213.255510
108197.4.214.0/23197.4.214.1 to 197.4.215.254197.4.215.255510
109197.4.216.0/23197.4.216.1 to 197.4.217.254197.4.217.255510
110197.4.218.0/23197.4.218.1 to 197.4.219.254197.4.219.255510
111197.4.220.0/23197.4.220.1 to 197.4.221.254197.4.221.255510
112197.4.222.0/23197.4.222.1 to 197.4.223.254197.4.223.255510
113197.4.224.0/23197.4.224.1 to 197.4.225.254197.4.225.255510
114197.4.226.0/23197.4.226.1 to 197.4.227.254197.4.227.255510
115197.4.228.0/23197.4.228.1 to 197.4.229.254197.4.229.255510
116197.4.230.0/23197.4.230.1 to 197.4.231.254197.4.231.255510
117197.4.232.0/23197.4.232.1 to 197.4.233.254197.4.233.255510
118197.4.234.0/23197.4.234.1 to 197.4.235.254197.4.235.255510
119197.4.236.0/23197.4.236.1 to 197.4.237.254197.4.237.255510
120197.4.238.0/23197.4.238.1 to 197.4.239.254197.4.239.255510
121197.4.240.0/23197.4.240.1 to 197.4.241.254197.4.241.255510
122197.4.242.0/23197.4.242.1 to 197.4.243.254197.4.243.255510
123197.4.244.0/23197.4.244.1 to 197.4.245.254197.4.245.255510
124197.4.246.0/23197.4.246.1 to 197.4.247.254197.4.247.255510
125197.4.248.0/23197.4.248.1 to 197.4.249.254197.4.249.255510
126197.4.250.0/23197.4.250.1 to 197.4.251.254197.4.251.255510
127197.4.252.0/23197.4.252.1 to 197.4.253.254197.4.253.255510
128197.4.254.0/23197.4.254.1 to 197.4.255.254197.4.255.255510
129197.5.0.0/23197.5.0.1 to 197.5.1.254197.5.1.255510
130197.5.2.0/23197.5.2.1 to 197.5.3.254197.5.3.255510
131197.5.4.0/23197.5.4.1 to 197.5.5.254197.5.5.255510
132197.5.6.0/23197.5.6.1 to 197.5.7.254197.5.7.255510
133197.5.8.0/23197.5.8.1 to 197.5.9.254197.5.9.255510
134197.5.10.0/23197.5.10.1 to 197.5.11.254197.5.11.255510
135197.5.12.0/23197.5.12.1 to 197.5.13.254197.5.13.255510
136197.5.14.0/23197.5.14.1 to 197.5.15.254197.5.15.255510
137197.5.16.0/23197.5.16.1 to 197.5.17.254197.5.17.255510
138197.5.18.0/23197.5.18.1 to 197.5.19.254197.5.19.255510
139197.5.20.0/23197.5.20.1 to 197.5.21.254197.5.21.255510
140197.5.22.0/23197.5.22.1 to 197.5.23.254197.5.23.255510
141197.5.24.0/23197.5.24.1 to 197.5.25.254197.5.25.255510
142197.5.26.0/23197.5.26.1 to 197.5.27.254197.5.27.255510
143197.5.28.0/23197.5.28.1 to 197.5.29.254197.5.29.255510
144197.5.30.0/23197.5.30.1 to 197.5.31.254197.5.31.255510
145197.5.32.0/23197.5.32.1 to 197.5.33.254197.5.33.255510
146197.5.34.0/23197.5.34.1 to 197.5.35.254197.5.35.255510
147197.5.36.0/23197.5.36.1 to 197.5.37.254197.5.37.255510
148197.5.38.0/23197.5.38.1 to 197.5.39.254197.5.39.255510
149197.5.40.0/23197.5.40.1 to 197.5.41.254197.5.41.255510
150197.5.42.0/23197.5.42.1 to 197.5.43.254197.5.43.255510
151197.5.44.0/23197.5.44.1 to 197.5.45.254197.5.45.255510
152197.5.46.0/23197.5.46.1 to 197.5.47.254197.5.47.255510
153197.5.48.0/23197.5.48.1 to 197.5.49.254197.5.49.255510
154197.5.50.0/23197.5.50.1 to 197.5.51.254197.5.51.255510
155197.5.52.0/23197.5.52.1 to 197.5.53.254197.5.53.255510
156197.5.54.0/23197.5.54.1 to 197.5.55.254197.5.55.255510
157197.5.56.0/23197.5.56.1 to 197.5.57.254197.5.57.255510
158197.5.58.0/23197.5.58.1 to 197.5.59.254197.5.59.255510
159197.5.60.0/23197.5.60.1 to 197.5.61.254197.5.61.255510
160197.5.62.0/23197.5.62.1 to 197.5.63.254197.5.63.255510
161197.5.64.0/23197.5.64.1 to 197.5.65.254197.5.65.255510
162197.5.66.0/23197.5.66.1 to 197.5.67.254197.5.67.255510
163197.5.68.0/23197.5.68.1 to 197.5.69.254197.5.69.255510
164197.5.70.0/23197.5.70.1 to 197.5.71.254197.5.71.255510
165197.5.72.0/23197.5.72.1 to 197.5.73.254197.5.73.255510
166197.5.74.0/23197.5.74.1 to 197.5.75.254197.5.75.255510
167197.5.76.0/23197.5.76.1 to 197.5.77.254197.5.77.255510
168197.5.78.0/23197.5.78.1 to 197.5.79.254197.5.79.255510
169197.5.80.0/23197.5.80.1 to 197.5.81.254197.5.81.255510
170197.5.82.0/23197.5.82.1 to 197.5.83.254197.5.83.255510
171197.5.84.0/23197.5.84.1 to 197.5.85.254197.5.85.255510
172197.5.86.0/23197.5.86.1 to 197.5.87.254197.5.87.255510
173197.5.88.0/23197.5.88.1 to 197.5.89.254197.5.89.255510
174197.5.90.0/23197.5.90.1 to 197.5.91.254197.5.91.255510
175197.5.92.0/23197.5.92.1 to 197.5.93.254197.5.93.255510
176197.5.94.0/23197.5.94.1 to 197.5.95.254197.5.95.255510
177197.5.96.0/23197.5.96.1 to 197.5.97.254197.5.97.255510
178197.5.98.0/23197.5.98.1 to 197.5.99.254197.5.99.255510
179197.5.100.0/23197.5.100.1 to 197.5.101.254197.5.101.255510
180197.5.102.0/23197.5.102.1 to 197.5.103.254197.5.103.255510
181197.5.104.0/23197.5.104.1 to 197.5.105.254197.5.105.255510
182197.5.106.0/23197.5.106.1 to 197.5.107.254197.5.107.255510
183197.5.108.0/23197.5.108.1 to 197.5.109.254197.5.109.255510
184197.5.110.0/23197.5.110.1 to 197.5.111.254197.5.111.255510
185197.5.112.0/23197.5.112.1 to 197.5.113.254197.5.113.255510
186197.5.114.0/23197.5.114.1 to 197.5.115.254197.5.115.255510
187197.5.116.0/23197.5.116.1 to 197.5.117.254197.5.117.255510
188197.5.118.0/23197.5.118.1 to 197.5.119.254197.5.119.255510
189197.5.120.0/23197.5.120.1 to 197.5.121.254197.5.121.255510
190197.5.122.0/23197.5.122.1 to 197.5.123.254197.5.123.255510
191197.5.124.0/23197.5.124.1 to 197.5.125.254197.5.125.255510
192197.5.126.0/23197.5.126.1 to 197.5.127.254197.5.127.255510
193197.5.128.0/23197.5.128.1 to 197.5.129.254197.5.129.255510
194197.5.130.0/23197.5.130.1 to 197.5.131.254197.5.131.255510
195197.5.132.0/23197.5.132.1 to 197.5.133.254197.5.133.255510
196197.5.134.0/23197.5.134.1 to 197.5.135.254197.5.135.255510
197197.5.136.0/23197.5.136.1 to 197.5.137.254197.5.137.255510
198197.5.138.0/23197.5.138.1 to 197.5.139.254197.5.139.255510
199197.5.140.0/23197.5.140.1 to 197.5.141.254197.5.141.255510
200197.5.142.0/23197.5.142.1 to 197.5.143.254197.5.143.255510
201197.5.144.0/23197.5.144.1 to 197.5.145.254197.5.145.255510
202197.5.146.0/23197.5.146.1 to 197.5.147.254197.5.147.255510
203197.5.148.0/23197.5.148.1 to 197.5.149.254197.5.149.255510
204197.5.150.0/23197.5.150.1 to 197.5.151.254197.5.151.255510
205197.5.152.0/23197.5.152.1 to 197.5.153.254197.5.153.255510
206197.5.154.0/23197.5.154.1 to 197.5.155.254197.5.155.255510
207197.5.156.0/23197.5.156.1 to 197.5.157.254197.5.157.255510
208197.5.158.0/23197.5.158.1 to 197.5.159.254197.5.159.255510
209197.5.160.0/23197.5.160.1 to 197.5.161.254197.5.161.255510
210197.5.162.0/23197.5.162.1 to 197.5.163.254197.5.163.255510
211197.5.164.0/23197.5.164.1 to 197.5.165.254197.5.165.255510
212197.5.166.0/23197.5.166.1 to 197.5.167.254197.5.167.255510
213197.5.168.0/23197.5.168.1 to 197.5.169.254197.5.169.255510
214197.5.170.0/23197.5.170.1 to 197.5.171.254197.5.171.255510
215197.5.172.0/23197.5.172.1 to 197.5.173.254197.5.173.255510
216197.5.174.0/23197.5.174.1 to 197.5.175.254197.5.175.255510
217197.5.176.0/23197.5.176.1 to 197.5.177.254197.5.177.255510
218197.5.178.0/23197.5.178.1 to 197.5.179.254197.5.179.255510
219197.5.180.0/23197.5.180.1 to 197.5.181.254197.5.181.255510
220197.5.182.0/23197.5.182.1 to 197.5.183.254197.5.183.255510
221197.5.184.0/23197.5.184.1 to 197.5.185.254197.5.185.255510
222197.5.186.0/23197.5.186.1 to 197.5.187.254197.5.187.255510
223197.5.188.0/23197.5.188.1 to 197.5.189.254197.5.189.255510
224197.5.190.0/23197.5.190.1 to 197.5.191.254197.5.191.255510
225197.5.192.0/23197.5.192.1 to 197.5.193.254197.5.193.255510
226197.5.194.0/23197.5.194.1 to 197.5.195.254197.5.195.255510
227197.5.196.0/23197.5.196.1 to 197.5.197.254197.5.197.255510
228197.5.198.0/23197.5.198.1 to 197.5.199.254197.5.199.255510
229197.5.200.0/23197.5.200.1 to 197.5.201.254197.5.201.255510
230197.5.202.0/23197.5.202.1 to 197.5.203.254197.5.203.255510
231197.5.204.0/23197.5.204.1 to 197.5.205.254197.5.205.255510
232197.5.206.0/23197.5.206.1 to 197.5.207.254197.5.207.255510
233197.5.208.0/23197.5.208.1 to 197.5.209.254197.5.209.255510
234197.5.210.0/23197.5.210.1 to 197.5.211.254197.5.211.255510
235197.5.212.0/23197.5.212.1 to 197.5.213.254197.5.213.255510
236197.5.214.0/23197.5.214.1 to 197.5.215.254197.5.215.255510
237197.5.216.0/23197.5.216.1 to 197.5.217.254197.5.217.255510
238197.5.218.0/23197.5.218.1 to 197.5.219.254197.5.219.255510
239197.5.220.0/23197.5.220.1 to 197.5.221.254197.5.221.255510
240197.5.222.0/23197.5.222.1 to 197.5.223.254197.5.223.255510
241197.5.224.0/23197.5.224.1 to 197.5.225.254197.5.225.255510
242197.5.226.0/23197.5.226.1 to 197.5.227.254197.5.227.255510
243197.5.228.0/23197.5.228.1 to 197.5.229.254197.5.229.255510
244197.5.230.0/23197.5.230.1 to 197.5.231.254197.5.231.255510
245197.5.232.0/23197.5.232.1 to 197.5.233.254197.5.233.255510
246197.5.234.0/23197.5.234.1 to 197.5.235.254197.5.235.255510
247197.5.236.0/23197.5.236.1 to 197.5.237.254197.5.237.255510
248197.5.238.0/23197.5.238.1 to 197.5.239.254197.5.239.255510
249197.5.240.0/23197.5.240.1 to 197.5.241.254197.5.241.255510
250197.5.242.0/23197.5.242.1 to 197.5.243.254197.5.243.255510
251197.5.244.0/23197.5.244.1 to 197.5.245.254197.5.245.255510
252197.5.246.0/23197.5.246.1 to 197.5.247.254197.5.247.255510
253197.5.248.0/23197.5.248.1 to 197.5.249.254197.5.249.255510
254197.5.250.0/23197.5.250.1 to 197.5.251.254197.5.251.255510
255197.5.252.0/23197.5.252.1 to 197.5.253.254197.5.253.255510
256197.5.254.0/23197.5.254.1 to 197.5.255.254197.5.255.255510

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.