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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.

Network178.76.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
178.76.0.0
Broadcast address
178.76.255.255
First usable
178.76.0.1
Last usable
178.76.255.254
Usable hosts
65,534 (65,536 less the network and broadcast addresses)
Subnet mask
255.255.0.0
Wildcard mask
0.0.255.255 (Cisco ACLs, OSPF)
Prefix length
/16
Type
Public public
Old class
B (default /16)
As numbers
Hex B24C0000 · Integer 2991325184 to 2991390719
Reverse DNS zone
76.178.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10110010.01001100..00000000.00000000178.76.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network10110010.01001100..00000000.00000000178.76.0.0
Broadcast10110010.01001100..11111111.11111111178.76.255.255
Split into smaller subnets/24
/17 (2)/18 (4)/19 (8)/20 (16)/21 (32)/22 (64)/23 (128)/24 (256)/25 (512)/26 (1,024)/27 (2,048)/28 (4,096)

178.76.0.0/16 makes 256 subnets of /24.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1178.76.0.0/24178.76.0.1 to 178.76.0.254178.76.0.255254
2178.76.1.0/24178.76.1.1 to 178.76.1.254178.76.1.255254
3178.76.2.0/24178.76.2.1 to 178.76.2.254178.76.2.255254
4178.76.3.0/24178.76.3.1 to 178.76.3.254178.76.3.255254
5178.76.4.0/24178.76.4.1 to 178.76.4.254178.76.4.255254
6178.76.5.0/24178.76.5.1 to 178.76.5.254178.76.5.255254
7178.76.6.0/24178.76.6.1 to 178.76.6.254178.76.6.255254
8178.76.7.0/24178.76.7.1 to 178.76.7.254178.76.7.255254
9178.76.8.0/24178.76.8.1 to 178.76.8.254178.76.8.255254
10178.76.9.0/24178.76.9.1 to 178.76.9.254178.76.9.255254
11178.76.10.0/24178.76.10.1 to 178.76.10.254178.76.10.255254
12178.76.11.0/24178.76.11.1 to 178.76.11.254178.76.11.255254
13178.76.12.0/24178.76.12.1 to 178.76.12.254178.76.12.255254
14178.76.13.0/24178.76.13.1 to 178.76.13.254178.76.13.255254
15178.76.14.0/24178.76.14.1 to 178.76.14.254178.76.14.255254
16178.76.15.0/24178.76.15.1 to 178.76.15.254178.76.15.255254
17178.76.16.0/24178.76.16.1 to 178.76.16.254178.76.16.255254
18178.76.17.0/24178.76.17.1 to 178.76.17.254178.76.17.255254
19178.76.18.0/24178.76.18.1 to 178.76.18.254178.76.18.255254
20178.76.19.0/24178.76.19.1 to 178.76.19.254178.76.19.255254
21178.76.20.0/24178.76.20.1 to 178.76.20.254178.76.20.255254
22178.76.21.0/24178.76.21.1 to 178.76.21.254178.76.21.255254
23178.76.22.0/24178.76.22.1 to 178.76.22.254178.76.22.255254
24178.76.23.0/24178.76.23.1 to 178.76.23.254178.76.23.255254
25178.76.24.0/24178.76.24.1 to 178.76.24.254178.76.24.255254
26178.76.25.0/24178.76.25.1 to 178.76.25.254178.76.25.255254
27178.76.26.0/24178.76.26.1 to 178.76.26.254178.76.26.255254
28178.76.27.0/24178.76.27.1 to 178.76.27.254178.76.27.255254
29178.76.28.0/24178.76.28.1 to 178.76.28.254178.76.28.255254
30178.76.29.0/24178.76.29.1 to 178.76.29.254178.76.29.255254
31178.76.30.0/24178.76.30.1 to 178.76.30.254178.76.30.255254
32178.76.31.0/24178.76.31.1 to 178.76.31.254178.76.31.255254
33178.76.32.0/24178.76.32.1 to 178.76.32.254178.76.32.255254
34178.76.33.0/24178.76.33.1 to 178.76.33.254178.76.33.255254
35178.76.34.0/24178.76.34.1 to 178.76.34.254178.76.34.255254
36178.76.35.0/24178.76.35.1 to 178.76.35.254178.76.35.255254
37178.76.36.0/24178.76.36.1 to 178.76.36.254178.76.36.255254
38178.76.37.0/24178.76.37.1 to 178.76.37.254178.76.37.255254
39178.76.38.0/24178.76.38.1 to 178.76.38.254178.76.38.255254
40178.76.39.0/24178.76.39.1 to 178.76.39.254178.76.39.255254
41178.76.40.0/24178.76.40.1 to 178.76.40.254178.76.40.255254
42178.76.41.0/24178.76.41.1 to 178.76.41.254178.76.41.255254
43178.76.42.0/24178.76.42.1 to 178.76.42.254178.76.42.255254
44178.76.43.0/24178.76.43.1 to 178.76.43.254178.76.43.255254
45178.76.44.0/24178.76.44.1 to 178.76.44.254178.76.44.255254
46178.76.45.0/24178.76.45.1 to 178.76.45.254178.76.45.255254
47178.76.46.0/24178.76.46.1 to 178.76.46.254178.76.46.255254
48178.76.47.0/24178.76.47.1 to 178.76.47.254178.76.47.255254
49178.76.48.0/24178.76.48.1 to 178.76.48.254178.76.48.255254
50178.76.49.0/24178.76.49.1 to 178.76.49.254178.76.49.255254
51178.76.50.0/24178.76.50.1 to 178.76.50.254178.76.50.255254
52178.76.51.0/24178.76.51.1 to 178.76.51.254178.76.51.255254
53178.76.52.0/24178.76.52.1 to 178.76.52.254178.76.52.255254
54178.76.53.0/24178.76.53.1 to 178.76.53.254178.76.53.255254
55178.76.54.0/24178.76.54.1 to 178.76.54.254178.76.54.255254
56178.76.55.0/24178.76.55.1 to 178.76.55.254178.76.55.255254
57178.76.56.0/24178.76.56.1 to 178.76.56.254178.76.56.255254
58178.76.57.0/24178.76.57.1 to 178.76.57.254178.76.57.255254
59178.76.58.0/24178.76.58.1 to 178.76.58.254178.76.58.255254
60178.76.59.0/24178.76.59.1 to 178.76.59.254178.76.59.255254
61178.76.60.0/24178.76.60.1 to 178.76.60.254178.76.60.255254
62178.76.61.0/24178.76.61.1 to 178.76.61.254178.76.61.255254
63178.76.62.0/24178.76.62.1 to 178.76.62.254178.76.62.255254
64178.76.63.0/24178.76.63.1 to 178.76.63.254178.76.63.255254
65178.76.64.0/24178.76.64.1 to 178.76.64.254178.76.64.255254
66178.76.65.0/24178.76.65.1 to 178.76.65.254178.76.65.255254
67178.76.66.0/24178.76.66.1 to 178.76.66.254178.76.66.255254
68178.76.67.0/24178.76.67.1 to 178.76.67.254178.76.67.255254
69178.76.68.0/24178.76.68.1 to 178.76.68.254178.76.68.255254
70178.76.69.0/24178.76.69.1 to 178.76.69.254178.76.69.255254
71178.76.70.0/24178.76.70.1 to 178.76.70.254178.76.70.255254
72178.76.71.0/24178.76.71.1 to 178.76.71.254178.76.71.255254
73178.76.72.0/24178.76.72.1 to 178.76.72.254178.76.72.255254
74178.76.73.0/24178.76.73.1 to 178.76.73.254178.76.73.255254
75178.76.74.0/24178.76.74.1 to 178.76.74.254178.76.74.255254
76178.76.75.0/24178.76.75.1 to 178.76.75.254178.76.75.255254
77178.76.76.0/24178.76.76.1 to 178.76.76.254178.76.76.255254
78178.76.77.0/24178.76.77.1 to 178.76.77.254178.76.77.255254
79178.76.78.0/24178.76.78.1 to 178.76.78.254178.76.78.255254
80178.76.79.0/24178.76.79.1 to 178.76.79.254178.76.79.255254
81178.76.80.0/24178.76.80.1 to 178.76.80.254178.76.80.255254
82178.76.81.0/24178.76.81.1 to 178.76.81.254178.76.81.255254
83178.76.82.0/24178.76.82.1 to 178.76.82.254178.76.82.255254
84178.76.83.0/24178.76.83.1 to 178.76.83.254178.76.83.255254
85178.76.84.0/24178.76.84.1 to 178.76.84.254178.76.84.255254
86178.76.85.0/24178.76.85.1 to 178.76.85.254178.76.85.255254
87178.76.86.0/24178.76.86.1 to 178.76.86.254178.76.86.255254
88178.76.87.0/24178.76.87.1 to 178.76.87.254178.76.87.255254
89178.76.88.0/24178.76.88.1 to 178.76.88.254178.76.88.255254
90178.76.89.0/24178.76.89.1 to 178.76.89.254178.76.89.255254
91178.76.90.0/24178.76.90.1 to 178.76.90.254178.76.90.255254
92178.76.91.0/24178.76.91.1 to 178.76.91.254178.76.91.255254
93178.76.92.0/24178.76.92.1 to 178.76.92.254178.76.92.255254
94178.76.93.0/24178.76.93.1 to 178.76.93.254178.76.93.255254
95178.76.94.0/24178.76.94.1 to 178.76.94.254178.76.94.255254
96178.76.95.0/24178.76.95.1 to 178.76.95.254178.76.95.255254
97178.76.96.0/24178.76.96.1 to 178.76.96.254178.76.96.255254
98178.76.97.0/24178.76.97.1 to 178.76.97.254178.76.97.255254
99178.76.98.0/24178.76.98.1 to 178.76.98.254178.76.98.255254
100178.76.99.0/24178.76.99.1 to 178.76.99.254178.76.99.255254
101178.76.100.0/24178.76.100.1 to 178.76.100.254178.76.100.255254
102178.76.101.0/24178.76.101.1 to 178.76.101.254178.76.101.255254
103178.76.102.0/24178.76.102.1 to 178.76.102.254178.76.102.255254
104178.76.103.0/24178.76.103.1 to 178.76.103.254178.76.103.255254
105178.76.104.0/24178.76.104.1 to 178.76.104.254178.76.104.255254
106178.76.105.0/24178.76.105.1 to 178.76.105.254178.76.105.255254
107178.76.106.0/24178.76.106.1 to 178.76.106.254178.76.106.255254
108178.76.107.0/24178.76.107.1 to 178.76.107.254178.76.107.255254
109178.76.108.0/24178.76.108.1 to 178.76.108.254178.76.108.255254
110178.76.109.0/24178.76.109.1 to 178.76.109.254178.76.109.255254
111178.76.110.0/24178.76.110.1 to 178.76.110.254178.76.110.255254
112178.76.111.0/24178.76.111.1 to 178.76.111.254178.76.111.255254
113178.76.112.0/24178.76.112.1 to 178.76.112.254178.76.112.255254
114178.76.113.0/24178.76.113.1 to 178.76.113.254178.76.113.255254
115178.76.114.0/24178.76.114.1 to 178.76.114.254178.76.114.255254
116178.76.115.0/24178.76.115.1 to 178.76.115.254178.76.115.255254
117178.76.116.0/24178.76.116.1 to 178.76.116.254178.76.116.255254
118178.76.117.0/24178.76.117.1 to 178.76.117.254178.76.117.255254
119178.76.118.0/24178.76.118.1 to 178.76.118.254178.76.118.255254
120178.76.119.0/24178.76.119.1 to 178.76.119.254178.76.119.255254
121178.76.120.0/24178.76.120.1 to 178.76.120.254178.76.120.255254
122178.76.121.0/24178.76.121.1 to 178.76.121.254178.76.121.255254
123178.76.122.0/24178.76.122.1 to 178.76.122.254178.76.122.255254
124178.76.123.0/24178.76.123.1 to 178.76.123.254178.76.123.255254
125178.76.124.0/24178.76.124.1 to 178.76.124.254178.76.124.255254
126178.76.125.0/24178.76.125.1 to 178.76.125.254178.76.125.255254
127178.76.126.0/24178.76.126.1 to 178.76.126.254178.76.126.255254
128178.76.127.0/24178.76.127.1 to 178.76.127.254178.76.127.255254
129178.76.128.0/24178.76.128.1 to 178.76.128.254178.76.128.255254
130178.76.129.0/24178.76.129.1 to 178.76.129.254178.76.129.255254
131178.76.130.0/24178.76.130.1 to 178.76.130.254178.76.130.255254
132178.76.131.0/24178.76.131.1 to 178.76.131.254178.76.131.255254
133178.76.132.0/24178.76.132.1 to 178.76.132.254178.76.132.255254
134178.76.133.0/24178.76.133.1 to 178.76.133.254178.76.133.255254
135178.76.134.0/24178.76.134.1 to 178.76.134.254178.76.134.255254
136178.76.135.0/24178.76.135.1 to 178.76.135.254178.76.135.255254
137178.76.136.0/24178.76.136.1 to 178.76.136.254178.76.136.255254
138178.76.137.0/24178.76.137.1 to 178.76.137.254178.76.137.255254
139178.76.138.0/24178.76.138.1 to 178.76.138.254178.76.138.255254
140178.76.139.0/24178.76.139.1 to 178.76.139.254178.76.139.255254
141178.76.140.0/24178.76.140.1 to 178.76.140.254178.76.140.255254
142178.76.141.0/24178.76.141.1 to 178.76.141.254178.76.141.255254
143178.76.142.0/24178.76.142.1 to 178.76.142.254178.76.142.255254
144178.76.143.0/24178.76.143.1 to 178.76.143.254178.76.143.255254
145178.76.144.0/24178.76.144.1 to 178.76.144.254178.76.144.255254
146178.76.145.0/24178.76.145.1 to 178.76.145.254178.76.145.255254
147178.76.146.0/24178.76.146.1 to 178.76.146.254178.76.146.255254
148178.76.147.0/24178.76.147.1 to 178.76.147.254178.76.147.255254
149178.76.148.0/24178.76.148.1 to 178.76.148.254178.76.148.255254
150178.76.149.0/24178.76.149.1 to 178.76.149.254178.76.149.255254
151178.76.150.0/24178.76.150.1 to 178.76.150.254178.76.150.255254
152178.76.151.0/24178.76.151.1 to 178.76.151.254178.76.151.255254
153178.76.152.0/24178.76.152.1 to 178.76.152.254178.76.152.255254
154178.76.153.0/24178.76.153.1 to 178.76.153.254178.76.153.255254
155178.76.154.0/24178.76.154.1 to 178.76.154.254178.76.154.255254
156178.76.155.0/24178.76.155.1 to 178.76.155.254178.76.155.255254
157178.76.156.0/24178.76.156.1 to 178.76.156.254178.76.156.255254
158178.76.157.0/24178.76.157.1 to 178.76.157.254178.76.157.255254
159178.76.158.0/24178.76.158.1 to 178.76.158.254178.76.158.255254
160178.76.159.0/24178.76.159.1 to 178.76.159.254178.76.159.255254
161178.76.160.0/24178.76.160.1 to 178.76.160.254178.76.160.255254
162178.76.161.0/24178.76.161.1 to 178.76.161.254178.76.161.255254
163178.76.162.0/24178.76.162.1 to 178.76.162.254178.76.162.255254
164178.76.163.0/24178.76.163.1 to 178.76.163.254178.76.163.255254
165178.76.164.0/24178.76.164.1 to 178.76.164.254178.76.164.255254
166178.76.165.0/24178.76.165.1 to 178.76.165.254178.76.165.255254
167178.76.166.0/24178.76.166.1 to 178.76.166.254178.76.166.255254
168178.76.167.0/24178.76.167.1 to 178.76.167.254178.76.167.255254
169178.76.168.0/24178.76.168.1 to 178.76.168.254178.76.168.255254
170178.76.169.0/24178.76.169.1 to 178.76.169.254178.76.169.255254
171178.76.170.0/24178.76.170.1 to 178.76.170.254178.76.170.255254
172178.76.171.0/24178.76.171.1 to 178.76.171.254178.76.171.255254
173178.76.172.0/24178.76.172.1 to 178.76.172.254178.76.172.255254
174178.76.173.0/24178.76.173.1 to 178.76.173.254178.76.173.255254
175178.76.174.0/24178.76.174.1 to 178.76.174.254178.76.174.255254
176178.76.175.0/24178.76.175.1 to 178.76.175.254178.76.175.255254
177178.76.176.0/24178.76.176.1 to 178.76.176.254178.76.176.255254
178178.76.177.0/24178.76.177.1 to 178.76.177.254178.76.177.255254
179178.76.178.0/24178.76.178.1 to 178.76.178.254178.76.178.255254
180178.76.179.0/24178.76.179.1 to 178.76.179.254178.76.179.255254
181178.76.180.0/24178.76.180.1 to 178.76.180.254178.76.180.255254
182178.76.181.0/24178.76.181.1 to 178.76.181.254178.76.181.255254
183178.76.182.0/24178.76.182.1 to 178.76.182.254178.76.182.255254
184178.76.183.0/24178.76.183.1 to 178.76.183.254178.76.183.255254
185178.76.184.0/24178.76.184.1 to 178.76.184.254178.76.184.255254
186178.76.185.0/24178.76.185.1 to 178.76.185.254178.76.185.255254
187178.76.186.0/24178.76.186.1 to 178.76.186.254178.76.186.255254
188178.76.187.0/24178.76.187.1 to 178.76.187.254178.76.187.255254
189178.76.188.0/24178.76.188.1 to 178.76.188.254178.76.188.255254
190178.76.189.0/24178.76.189.1 to 178.76.189.254178.76.189.255254
191178.76.190.0/24178.76.190.1 to 178.76.190.254178.76.190.255254
192178.76.191.0/24178.76.191.1 to 178.76.191.254178.76.191.255254
193178.76.192.0/24178.76.192.1 to 178.76.192.254178.76.192.255254
194178.76.193.0/24178.76.193.1 to 178.76.193.254178.76.193.255254
195178.76.194.0/24178.76.194.1 to 178.76.194.254178.76.194.255254
196178.76.195.0/24178.76.195.1 to 178.76.195.254178.76.195.255254
197178.76.196.0/24178.76.196.1 to 178.76.196.254178.76.196.255254
198178.76.197.0/24178.76.197.1 to 178.76.197.254178.76.197.255254
199178.76.198.0/24178.76.198.1 to 178.76.198.254178.76.198.255254
200178.76.199.0/24178.76.199.1 to 178.76.199.254178.76.199.255254
201178.76.200.0/24178.76.200.1 to 178.76.200.254178.76.200.255254
202178.76.201.0/24178.76.201.1 to 178.76.201.254178.76.201.255254
203178.76.202.0/24178.76.202.1 to 178.76.202.254178.76.202.255254
204178.76.203.0/24178.76.203.1 to 178.76.203.254178.76.203.255254
205178.76.204.0/24178.76.204.1 to 178.76.204.254178.76.204.255254
206178.76.205.0/24178.76.205.1 to 178.76.205.254178.76.205.255254
207178.76.206.0/24178.76.206.1 to 178.76.206.254178.76.206.255254
208178.76.207.0/24178.76.207.1 to 178.76.207.254178.76.207.255254
209178.76.208.0/24178.76.208.1 to 178.76.208.254178.76.208.255254
210178.76.209.0/24178.76.209.1 to 178.76.209.254178.76.209.255254
211178.76.210.0/24178.76.210.1 to 178.76.210.254178.76.210.255254
212178.76.211.0/24178.76.211.1 to 178.76.211.254178.76.211.255254
213178.76.212.0/24178.76.212.1 to 178.76.212.254178.76.212.255254
214178.76.213.0/24178.76.213.1 to 178.76.213.254178.76.213.255254
215178.76.214.0/24178.76.214.1 to 178.76.214.254178.76.214.255254
216178.76.215.0/24178.76.215.1 to 178.76.215.254178.76.215.255254
217178.76.216.0/24178.76.216.1 to 178.76.216.254178.76.216.255254
218178.76.217.0/24178.76.217.1 to 178.76.217.254178.76.217.255254
219178.76.218.0/24178.76.218.1 to 178.76.218.254178.76.218.255254
220178.76.219.0/24178.76.219.1 to 178.76.219.254178.76.219.255254
221178.76.220.0/24178.76.220.1 to 178.76.220.254178.76.220.255254
222178.76.221.0/24178.76.221.1 to 178.76.221.254178.76.221.255254
223178.76.222.0/24178.76.222.1 to 178.76.222.254178.76.222.255254
224178.76.223.0/24178.76.223.1 to 178.76.223.254178.76.223.255254
225178.76.224.0/24178.76.224.1 to 178.76.224.254178.76.224.255254
226178.76.225.0/24178.76.225.1 to 178.76.225.254178.76.225.255254
227178.76.226.0/24178.76.226.1 to 178.76.226.254178.76.226.255254
228178.76.227.0/24178.76.227.1 to 178.76.227.254178.76.227.255254
229178.76.228.0/24178.76.228.1 to 178.76.228.254178.76.228.255254
230178.76.229.0/24178.76.229.1 to 178.76.229.254178.76.229.255254
231178.76.230.0/24178.76.230.1 to 178.76.230.254178.76.230.255254
232178.76.231.0/24178.76.231.1 to 178.76.231.254178.76.231.255254
233178.76.232.0/24178.76.232.1 to 178.76.232.254178.76.232.255254
234178.76.233.0/24178.76.233.1 to 178.76.233.254178.76.233.255254
235178.76.234.0/24178.76.234.1 to 178.76.234.254178.76.234.255254
236178.76.235.0/24178.76.235.1 to 178.76.235.254178.76.235.255254
237178.76.236.0/24178.76.236.1 to 178.76.236.254178.76.236.255254
238178.76.237.0/24178.76.237.1 to 178.76.237.254178.76.237.255254
239178.76.238.0/24178.76.238.1 to 178.76.238.254178.76.238.255254
240178.76.239.0/24178.76.239.1 to 178.76.239.254178.76.239.255254
241178.76.240.0/24178.76.240.1 to 178.76.240.254178.76.240.255254
242178.76.241.0/24178.76.241.1 to 178.76.241.254178.76.241.255254
243178.76.242.0/24178.76.242.1 to 178.76.242.254178.76.242.255254
244178.76.243.0/24178.76.243.1 to 178.76.243.254178.76.243.255254
245178.76.244.0/24178.76.244.1 to 178.76.244.254178.76.244.255254
246178.76.245.0/24178.76.245.1 to 178.76.245.254178.76.245.255254
247178.76.246.0/24178.76.246.1 to 178.76.246.254178.76.246.255254
248178.76.247.0/24178.76.247.1 to 178.76.247.254178.76.247.255254
249178.76.248.0/24178.76.248.1 to 178.76.248.254178.76.248.255254
250178.76.249.0/24178.76.249.1 to 178.76.249.254178.76.249.255254
251178.76.250.0/24178.76.250.1 to 178.76.250.254178.76.250.255254
252178.76.251.0/24178.76.251.1 to 178.76.251.254178.76.251.255254
253178.76.252.0/24178.76.252.1 to 178.76.252.254178.76.252.255254
254178.76.253.0/24178.76.253.1 to 178.76.253.254178.76.253.255254
255178.76.254.0/24178.76.254.1 to 178.76.254.254178.76.254.255254
256178.76.255.0/24178.76.255.1 to 178.76.255.254178.76.255.255254

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.