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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.

Network228.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
228.0.0.0
Broadcast address
228.255.255.255
First usable
228.0.0.1
Last usable
228.255.255.254
Usable hosts
16,777,214 (16,777,216 less the network and broadcast addresses)
Subnet mask
255.0.0.0
Wildcard mask
0.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/8
Type
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E4000000 · Integer 3825205248 to 3841982463
Reverse DNS zone
228.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11100100..00000000.00000000.00000000228.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network11100100..00000000.00000000.00000000228.0.0.0
Broadcast11100100..11111111.11111111.11111111228.255.255.255
Split into smaller subnets/16
/9 (2)/10 (4)/11 (8)/12 (16)/13 (32)/14 (64)/15 (128)/16 (256)/17 (512)/18 (1,024)/19 (2,048)/20 (4,096)

228.0.0.0/8 makes 256 subnets of /16.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1228.0.0.0/16228.0.0.1 to 228.0.255.254228.0.255.25565,534
2228.1.0.0/16228.1.0.1 to 228.1.255.254228.1.255.25565,534
3228.2.0.0/16228.2.0.1 to 228.2.255.254228.2.255.25565,534
4228.3.0.0/16228.3.0.1 to 228.3.255.254228.3.255.25565,534
5228.4.0.0/16228.4.0.1 to 228.4.255.254228.4.255.25565,534
6228.5.0.0/16228.5.0.1 to 228.5.255.254228.5.255.25565,534
7228.6.0.0/16228.6.0.1 to 228.6.255.254228.6.255.25565,534
8228.7.0.0/16228.7.0.1 to 228.7.255.254228.7.255.25565,534
9228.8.0.0/16228.8.0.1 to 228.8.255.254228.8.255.25565,534
10228.9.0.0/16228.9.0.1 to 228.9.255.254228.9.255.25565,534
11228.10.0.0/16228.10.0.1 to 228.10.255.254228.10.255.25565,534
12228.11.0.0/16228.11.0.1 to 228.11.255.254228.11.255.25565,534
13228.12.0.0/16228.12.0.1 to 228.12.255.254228.12.255.25565,534
14228.13.0.0/16228.13.0.1 to 228.13.255.254228.13.255.25565,534
15228.14.0.0/16228.14.0.1 to 228.14.255.254228.14.255.25565,534
16228.15.0.0/16228.15.0.1 to 228.15.255.254228.15.255.25565,534
17228.16.0.0/16228.16.0.1 to 228.16.255.254228.16.255.25565,534
18228.17.0.0/16228.17.0.1 to 228.17.255.254228.17.255.25565,534
19228.18.0.0/16228.18.0.1 to 228.18.255.254228.18.255.25565,534
20228.19.0.0/16228.19.0.1 to 228.19.255.254228.19.255.25565,534
21228.20.0.0/16228.20.0.1 to 228.20.255.254228.20.255.25565,534
22228.21.0.0/16228.21.0.1 to 228.21.255.254228.21.255.25565,534
23228.22.0.0/16228.22.0.1 to 228.22.255.254228.22.255.25565,534
24228.23.0.0/16228.23.0.1 to 228.23.255.254228.23.255.25565,534
25228.24.0.0/16228.24.0.1 to 228.24.255.254228.24.255.25565,534
26228.25.0.0/16228.25.0.1 to 228.25.255.254228.25.255.25565,534
27228.26.0.0/16228.26.0.1 to 228.26.255.254228.26.255.25565,534
28228.27.0.0/16228.27.0.1 to 228.27.255.254228.27.255.25565,534
29228.28.0.0/16228.28.0.1 to 228.28.255.254228.28.255.25565,534
30228.29.0.0/16228.29.0.1 to 228.29.255.254228.29.255.25565,534
31228.30.0.0/16228.30.0.1 to 228.30.255.254228.30.255.25565,534
32228.31.0.0/16228.31.0.1 to 228.31.255.254228.31.255.25565,534
33228.32.0.0/16228.32.0.1 to 228.32.255.254228.32.255.25565,534
34228.33.0.0/16228.33.0.1 to 228.33.255.254228.33.255.25565,534
35228.34.0.0/16228.34.0.1 to 228.34.255.254228.34.255.25565,534
36228.35.0.0/16228.35.0.1 to 228.35.255.254228.35.255.25565,534
37228.36.0.0/16228.36.0.1 to 228.36.255.254228.36.255.25565,534
38228.37.0.0/16228.37.0.1 to 228.37.255.254228.37.255.25565,534
39228.38.0.0/16228.38.0.1 to 228.38.255.254228.38.255.25565,534
40228.39.0.0/16228.39.0.1 to 228.39.255.254228.39.255.25565,534
41228.40.0.0/16228.40.0.1 to 228.40.255.254228.40.255.25565,534
42228.41.0.0/16228.41.0.1 to 228.41.255.254228.41.255.25565,534
43228.42.0.0/16228.42.0.1 to 228.42.255.254228.42.255.25565,534
44228.43.0.0/16228.43.0.1 to 228.43.255.254228.43.255.25565,534
45228.44.0.0/16228.44.0.1 to 228.44.255.254228.44.255.25565,534
46228.45.0.0/16228.45.0.1 to 228.45.255.254228.45.255.25565,534
47228.46.0.0/16228.46.0.1 to 228.46.255.254228.46.255.25565,534
48228.47.0.0/16228.47.0.1 to 228.47.255.254228.47.255.25565,534
49228.48.0.0/16228.48.0.1 to 228.48.255.254228.48.255.25565,534
50228.49.0.0/16228.49.0.1 to 228.49.255.254228.49.255.25565,534
51228.50.0.0/16228.50.0.1 to 228.50.255.254228.50.255.25565,534
52228.51.0.0/16228.51.0.1 to 228.51.255.254228.51.255.25565,534
53228.52.0.0/16228.52.0.1 to 228.52.255.254228.52.255.25565,534
54228.53.0.0/16228.53.0.1 to 228.53.255.254228.53.255.25565,534
55228.54.0.0/16228.54.0.1 to 228.54.255.254228.54.255.25565,534
56228.55.0.0/16228.55.0.1 to 228.55.255.254228.55.255.25565,534
57228.56.0.0/16228.56.0.1 to 228.56.255.254228.56.255.25565,534
58228.57.0.0/16228.57.0.1 to 228.57.255.254228.57.255.25565,534
59228.58.0.0/16228.58.0.1 to 228.58.255.254228.58.255.25565,534
60228.59.0.0/16228.59.0.1 to 228.59.255.254228.59.255.25565,534
61228.60.0.0/16228.60.0.1 to 228.60.255.254228.60.255.25565,534
62228.61.0.0/16228.61.0.1 to 228.61.255.254228.61.255.25565,534
63228.62.0.0/16228.62.0.1 to 228.62.255.254228.62.255.25565,534
64228.63.0.0/16228.63.0.1 to 228.63.255.254228.63.255.25565,534
65228.64.0.0/16228.64.0.1 to 228.64.255.254228.64.255.25565,534
66228.65.0.0/16228.65.0.1 to 228.65.255.254228.65.255.25565,534
67228.66.0.0/16228.66.0.1 to 228.66.255.254228.66.255.25565,534
68228.67.0.0/16228.67.0.1 to 228.67.255.254228.67.255.25565,534
69228.68.0.0/16228.68.0.1 to 228.68.255.254228.68.255.25565,534
70228.69.0.0/16228.69.0.1 to 228.69.255.254228.69.255.25565,534
71228.70.0.0/16228.70.0.1 to 228.70.255.254228.70.255.25565,534
72228.71.0.0/16228.71.0.1 to 228.71.255.254228.71.255.25565,534
73228.72.0.0/16228.72.0.1 to 228.72.255.254228.72.255.25565,534
74228.73.0.0/16228.73.0.1 to 228.73.255.254228.73.255.25565,534
75228.74.0.0/16228.74.0.1 to 228.74.255.254228.74.255.25565,534
76228.75.0.0/16228.75.0.1 to 228.75.255.254228.75.255.25565,534
77228.76.0.0/16228.76.0.1 to 228.76.255.254228.76.255.25565,534
78228.77.0.0/16228.77.0.1 to 228.77.255.254228.77.255.25565,534
79228.78.0.0/16228.78.0.1 to 228.78.255.254228.78.255.25565,534
80228.79.0.0/16228.79.0.1 to 228.79.255.254228.79.255.25565,534
81228.80.0.0/16228.80.0.1 to 228.80.255.254228.80.255.25565,534
82228.81.0.0/16228.81.0.1 to 228.81.255.254228.81.255.25565,534
83228.82.0.0/16228.82.0.1 to 228.82.255.254228.82.255.25565,534
84228.83.0.0/16228.83.0.1 to 228.83.255.254228.83.255.25565,534
85228.84.0.0/16228.84.0.1 to 228.84.255.254228.84.255.25565,534
86228.85.0.0/16228.85.0.1 to 228.85.255.254228.85.255.25565,534
87228.86.0.0/16228.86.0.1 to 228.86.255.254228.86.255.25565,534
88228.87.0.0/16228.87.0.1 to 228.87.255.254228.87.255.25565,534
89228.88.0.0/16228.88.0.1 to 228.88.255.254228.88.255.25565,534
90228.89.0.0/16228.89.0.1 to 228.89.255.254228.89.255.25565,534
91228.90.0.0/16228.90.0.1 to 228.90.255.254228.90.255.25565,534
92228.91.0.0/16228.91.0.1 to 228.91.255.254228.91.255.25565,534
93228.92.0.0/16228.92.0.1 to 228.92.255.254228.92.255.25565,534
94228.93.0.0/16228.93.0.1 to 228.93.255.254228.93.255.25565,534
95228.94.0.0/16228.94.0.1 to 228.94.255.254228.94.255.25565,534
96228.95.0.0/16228.95.0.1 to 228.95.255.254228.95.255.25565,534
97228.96.0.0/16228.96.0.1 to 228.96.255.254228.96.255.25565,534
98228.97.0.0/16228.97.0.1 to 228.97.255.254228.97.255.25565,534
99228.98.0.0/16228.98.0.1 to 228.98.255.254228.98.255.25565,534
100228.99.0.0/16228.99.0.1 to 228.99.255.254228.99.255.25565,534
101228.100.0.0/16228.100.0.1 to 228.100.255.254228.100.255.25565,534
102228.101.0.0/16228.101.0.1 to 228.101.255.254228.101.255.25565,534
103228.102.0.0/16228.102.0.1 to 228.102.255.254228.102.255.25565,534
104228.103.0.0/16228.103.0.1 to 228.103.255.254228.103.255.25565,534
105228.104.0.0/16228.104.0.1 to 228.104.255.254228.104.255.25565,534
106228.105.0.0/16228.105.0.1 to 228.105.255.254228.105.255.25565,534
107228.106.0.0/16228.106.0.1 to 228.106.255.254228.106.255.25565,534
108228.107.0.0/16228.107.0.1 to 228.107.255.254228.107.255.25565,534
109228.108.0.0/16228.108.0.1 to 228.108.255.254228.108.255.25565,534
110228.109.0.0/16228.109.0.1 to 228.109.255.254228.109.255.25565,534
111228.110.0.0/16228.110.0.1 to 228.110.255.254228.110.255.25565,534
112228.111.0.0/16228.111.0.1 to 228.111.255.254228.111.255.25565,534
113228.112.0.0/16228.112.0.1 to 228.112.255.254228.112.255.25565,534
114228.113.0.0/16228.113.0.1 to 228.113.255.254228.113.255.25565,534
115228.114.0.0/16228.114.0.1 to 228.114.255.254228.114.255.25565,534
116228.115.0.0/16228.115.0.1 to 228.115.255.254228.115.255.25565,534
117228.116.0.0/16228.116.0.1 to 228.116.255.254228.116.255.25565,534
118228.117.0.0/16228.117.0.1 to 228.117.255.254228.117.255.25565,534
119228.118.0.0/16228.118.0.1 to 228.118.255.254228.118.255.25565,534
120228.119.0.0/16228.119.0.1 to 228.119.255.254228.119.255.25565,534
121228.120.0.0/16228.120.0.1 to 228.120.255.254228.120.255.25565,534
122228.121.0.0/16228.121.0.1 to 228.121.255.254228.121.255.25565,534
123228.122.0.0/16228.122.0.1 to 228.122.255.254228.122.255.25565,534
124228.123.0.0/16228.123.0.1 to 228.123.255.254228.123.255.25565,534
125228.124.0.0/16228.124.0.1 to 228.124.255.254228.124.255.25565,534
126228.125.0.0/16228.125.0.1 to 228.125.255.254228.125.255.25565,534
127228.126.0.0/16228.126.0.1 to 228.126.255.254228.126.255.25565,534
128228.127.0.0/16228.127.0.1 to 228.127.255.254228.127.255.25565,534
129228.128.0.0/16228.128.0.1 to 228.128.255.254228.128.255.25565,534
130228.129.0.0/16228.129.0.1 to 228.129.255.254228.129.255.25565,534
131228.130.0.0/16228.130.0.1 to 228.130.255.254228.130.255.25565,534
132228.131.0.0/16228.131.0.1 to 228.131.255.254228.131.255.25565,534
133228.132.0.0/16228.132.0.1 to 228.132.255.254228.132.255.25565,534
134228.133.0.0/16228.133.0.1 to 228.133.255.254228.133.255.25565,534
135228.134.0.0/16228.134.0.1 to 228.134.255.254228.134.255.25565,534
136228.135.0.0/16228.135.0.1 to 228.135.255.254228.135.255.25565,534
137228.136.0.0/16228.136.0.1 to 228.136.255.254228.136.255.25565,534
138228.137.0.0/16228.137.0.1 to 228.137.255.254228.137.255.25565,534
139228.138.0.0/16228.138.0.1 to 228.138.255.254228.138.255.25565,534
140228.139.0.0/16228.139.0.1 to 228.139.255.254228.139.255.25565,534
141228.140.0.0/16228.140.0.1 to 228.140.255.254228.140.255.25565,534
142228.141.0.0/16228.141.0.1 to 228.141.255.254228.141.255.25565,534
143228.142.0.0/16228.142.0.1 to 228.142.255.254228.142.255.25565,534
144228.143.0.0/16228.143.0.1 to 228.143.255.254228.143.255.25565,534
145228.144.0.0/16228.144.0.1 to 228.144.255.254228.144.255.25565,534
146228.145.0.0/16228.145.0.1 to 228.145.255.254228.145.255.25565,534
147228.146.0.0/16228.146.0.1 to 228.146.255.254228.146.255.25565,534
148228.147.0.0/16228.147.0.1 to 228.147.255.254228.147.255.25565,534
149228.148.0.0/16228.148.0.1 to 228.148.255.254228.148.255.25565,534
150228.149.0.0/16228.149.0.1 to 228.149.255.254228.149.255.25565,534
151228.150.0.0/16228.150.0.1 to 228.150.255.254228.150.255.25565,534
152228.151.0.0/16228.151.0.1 to 228.151.255.254228.151.255.25565,534
153228.152.0.0/16228.152.0.1 to 228.152.255.254228.152.255.25565,534
154228.153.0.0/16228.153.0.1 to 228.153.255.254228.153.255.25565,534
155228.154.0.0/16228.154.0.1 to 228.154.255.254228.154.255.25565,534
156228.155.0.0/16228.155.0.1 to 228.155.255.254228.155.255.25565,534
157228.156.0.0/16228.156.0.1 to 228.156.255.254228.156.255.25565,534
158228.157.0.0/16228.157.0.1 to 228.157.255.254228.157.255.25565,534
159228.158.0.0/16228.158.0.1 to 228.158.255.254228.158.255.25565,534
160228.159.0.0/16228.159.0.1 to 228.159.255.254228.159.255.25565,534
161228.160.0.0/16228.160.0.1 to 228.160.255.254228.160.255.25565,534
162228.161.0.0/16228.161.0.1 to 228.161.255.254228.161.255.25565,534
163228.162.0.0/16228.162.0.1 to 228.162.255.254228.162.255.25565,534
164228.163.0.0/16228.163.0.1 to 228.163.255.254228.163.255.25565,534
165228.164.0.0/16228.164.0.1 to 228.164.255.254228.164.255.25565,534
166228.165.0.0/16228.165.0.1 to 228.165.255.254228.165.255.25565,534
167228.166.0.0/16228.166.0.1 to 228.166.255.254228.166.255.25565,534
168228.167.0.0/16228.167.0.1 to 228.167.255.254228.167.255.25565,534
169228.168.0.0/16228.168.0.1 to 228.168.255.254228.168.255.25565,534
170228.169.0.0/16228.169.0.1 to 228.169.255.254228.169.255.25565,534
171228.170.0.0/16228.170.0.1 to 228.170.255.254228.170.255.25565,534
172228.171.0.0/16228.171.0.1 to 228.171.255.254228.171.255.25565,534
173228.172.0.0/16228.172.0.1 to 228.172.255.254228.172.255.25565,534
174228.173.0.0/16228.173.0.1 to 228.173.255.254228.173.255.25565,534
175228.174.0.0/16228.174.0.1 to 228.174.255.254228.174.255.25565,534
176228.175.0.0/16228.175.0.1 to 228.175.255.254228.175.255.25565,534
177228.176.0.0/16228.176.0.1 to 228.176.255.254228.176.255.25565,534
178228.177.0.0/16228.177.0.1 to 228.177.255.254228.177.255.25565,534
179228.178.0.0/16228.178.0.1 to 228.178.255.254228.178.255.25565,534
180228.179.0.0/16228.179.0.1 to 228.179.255.254228.179.255.25565,534
181228.180.0.0/16228.180.0.1 to 228.180.255.254228.180.255.25565,534
182228.181.0.0/16228.181.0.1 to 228.181.255.254228.181.255.25565,534
183228.182.0.0/16228.182.0.1 to 228.182.255.254228.182.255.25565,534
184228.183.0.0/16228.183.0.1 to 228.183.255.254228.183.255.25565,534
185228.184.0.0/16228.184.0.1 to 228.184.255.254228.184.255.25565,534
186228.185.0.0/16228.185.0.1 to 228.185.255.254228.185.255.25565,534
187228.186.0.0/16228.186.0.1 to 228.186.255.254228.186.255.25565,534
188228.187.0.0/16228.187.0.1 to 228.187.255.254228.187.255.25565,534
189228.188.0.0/16228.188.0.1 to 228.188.255.254228.188.255.25565,534
190228.189.0.0/16228.189.0.1 to 228.189.255.254228.189.255.25565,534
191228.190.0.0/16228.190.0.1 to 228.190.255.254228.190.255.25565,534
192228.191.0.0/16228.191.0.1 to 228.191.255.254228.191.255.25565,534
193228.192.0.0/16228.192.0.1 to 228.192.255.254228.192.255.25565,534
194228.193.0.0/16228.193.0.1 to 228.193.255.254228.193.255.25565,534
195228.194.0.0/16228.194.0.1 to 228.194.255.254228.194.255.25565,534
196228.195.0.0/16228.195.0.1 to 228.195.255.254228.195.255.25565,534
197228.196.0.0/16228.196.0.1 to 228.196.255.254228.196.255.25565,534
198228.197.0.0/16228.197.0.1 to 228.197.255.254228.197.255.25565,534
199228.198.0.0/16228.198.0.1 to 228.198.255.254228.198.255.25565,534
200228.199.0.0/16228.199.0.1 to 228.199.255.254228.199.255.25565,534
201228.200.0.0/16228.200.0.1 to 228.200.255.254228.200.255.25565,534
202228.201.0.0/16228.201.0.1 to 228.201.255.254228.201.255.25565,534
203228.202.0.0/16228.202.0.1 to 228.202.255.254228.202.255.25565,534
204228.203.0.0/16228.203.0.1 to 228.203.255.254228.203.255.25565,534
205228.204.0.0/16228.204.0.1 to 228.204.255.254228.204.255.25565,534
206228.205.0.0/16228.205.0.1 to 228.205.255.254228.205.255.25565,534
207228.206.0.0/16228.206.0.1 to 228.206.255.254228.206.255.25565,534
208228.207.0.0/16228.207.0.1 to 228.207.255.254228.207.255.25565,534
209228.208.0.0/16228.208.0.1 to 228.208.255.254228.208.255.25565,534
210228.209.0.0/16228.209.0.1 to 228.209.255.254228.209.255.25565,534
211228.210.0.0/16228.210.0.1 to 228.210.255.254228.210.255.25565,534
212228.211.0.0/16228.211.0.1 to 228.211.255.254228.211.255.25565,534
213228.212.0.0/16228.212.0.1 to 228.212.255.254228.212.255.25565,534
214228.213.0.0/16228.213.0.1 to 228.213.255.254228.213.255.25565,534
215228.214.0.0/16228.214.0.1 to 228.214.255.254228.214.255.25565,534
216228.215.0.0/16228.215.0.1 to 228.215.255.254228.215.255.25565,534
217228.216.0.0/16228.216.0.1 to 228.216.255.254228.216.255.25565,534
218228.217.0.0/16228.217.0.1 to 228.217.255.254228.217.255.25565,534
219228.218.0.0/16228.218.0.1 to 228.218.255.254228.218.255.25565,534
220228.219.0.0/16228.219.0.1 to 228.219.255.254228.219.255.25565,534
221228.220.0.0/16228.220.0.1 to 228.220.255.254228.220.255.25565,534
222228.221.0.0/16228.221.0.1 to 228.221.255.254228.221.255.25565,534
223228.222.0.0/16228.222.0.1 to 228.222.255.254228.222.255.25565,534
224228.223.0.0/16228.223.0.1 to 228.223.255.254228.223.255.25565,534
225228.224.0.0/16228.224.0.1 to 228.224.255.254228.224.255.25565,534
226228.225.0.0/16228.225.0.1 to 228.225.255.254228.225.255.25565,534
227228.226.0.0/16228.226.0.1 to 228.226.255.254228.226.255.25565,534
228228.227.0.0/16228.227.0.1 to 228.227.255.254228.227.255.25565,534
229228.228.0.0/16228.228.0.1 to 228.228.255.254228.228.255.25565,534
230228.229.0.0/16228.229.0.1 to 228.229.255.254228.229.255.25565,534
231228.230.0.0/16228.230.0.1 to 228.230.255.254228.230.255.25565,534
232228.231.0.0/16228.231.0.1 to 228.231.255.254228.231.255.25565,534
233228.232.0.0/16228.232.0.1 to 228.232.255.254228.232.255.25565,534
234228.233.0.0/16228.233.0.1 to 228.233.255.254228.233.255.25565,534
235228.234.0.0/16228.234.0.1 to 228.234.255.254228.234.255.25565,534
236228.235.0.0/16228.235.0.1 to 228.235.255.254228.235.255.25565,534
237228.236.0.0/16228.236.0.1 to 228.236.255.254228.236.255.25565,534
238228.237.0.0/16228.237.0.1 to 228.237.255.254228.237.255.25565,534
239228.238.0.0/16228.238.0.1 to 228.238.255.254228.238.255.25565,534
240228.239.0.0/16228.239.0.1 to 228.239.255.254228.239.255.25565,534
241228.240.0.0/16228.240.0.1 to 228.240.255.254228.240.255.25565,534
242228.241.0.0/16228.241.0.1 to 228.241.255.254228.241.255.25565,534
243228.242.0.0/16228.242.0.1 to 228.242.255.254228.242.255.25565,534
244228.243.0.0/16228.243.0.1 to 228.243.255.254228.243.255.25565,534
245228.244.0.0/16228.244.0.1 to 228.244.255.254228.244.255.25565,534
246228.245.0.0/16228.245.0.1 to 228.245.255.254228.245.255.25565,534
247228.246.0.0/16228.246.0.1 to 228.246.255.254228.246.255.25565,534
248228.247.0.0/16228.247.0.1 to 228.247.255.254228.247.255.25565,534
249228.248.0.0/16228.248.0.1 to 228.248.255.254228.248.255.25565,534
250228.249.0.0/16228.249.0.1 to 228.249.255.254228.249.255.25565,534
251228.250.0.0/16228.250.0.1 to 228.250.255.254228.250.255.25565,534
252228.251.0.0/16228.251.0.1 to 228.251.255.254228.251.255.25565,534
253228.252.0.0/16228.252.0.1 to 228.252.255.254228.252.255.25565,534
254228.253.0.0/16228.253.0.1 to 228.253.255.254228.253.255.25565,534
255228.254.0.0/16228.254.0.1 to 228.254.255.254228.254.255.25565,534
256228.255.0.0/16228.255.0.1 to 228.255.255.254228.255.255.25565,534

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.