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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.

Network227.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
227.0.0.0
Broadcast address
227.255.255.255
First usable
227.0.0.1
Last usable
227.255.255.254
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 E3000000 · Integer 3808428032 to 3825205247
Reverse DNS zone
227.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11100011..00000000.00000000.00000000227.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network11100011..00000000.00000000.00000000227.0.0.0
Broadcast11100011..11111111.11111111.11111111227.255.255.255
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)

227.0.0.0/8 makes 256 subnets of /16.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1227.0.0.0/16227.0.0.1 to 227.0.255.254227.0.255.25565,534
2227.1.0.0/16227.1.0.1 to 227.1.255.254227.1.255.25565,534
3227.2.0.0/16227.2.0.1 to 227.2.255.254227.2.255.25565,534
4227.3.0.0/16227.3.0.1 to 227.3.255.254227.3.255.25565,534
5227.4.0.0/16227.4.0.1 to 227.4.255.254227.4.255.25565,534
6227.5.0.0/16227.5.0.1 to 227.5.255.254227.5.255.25565,534
7227.6.0.0/16227.6.0.1 to 227.6.255.254227.6.255.25565,534
8227.7.0.0/16227.7.0.1 to 227.7.255.254227.7.255.25565,534
9227.8.0.0/16227.8.0.1 to 227.8.255.254227.8.255.25565,534
10227.9.0.0/16227.9.0.1 to 227.9.255.254227.9.255.25565,534
11227.10.0.0/16227.10.0.1 to 227.10.255.254227.10.255.25565,534
12227.11.0.0/16227.11.0.1 to 227.11.255.254227.11.255.25565,534
13227.12.0.0/16227.12.0.1 to 227.12.255.254227.12.255.25565,534
14227.13.0.0/16227.13.0.1 to 227.13.255.254227.13.255.25565,534
15227.14.0.0/16227.14.0.1 to 227.14.255.254227.14.255.25565,534
16227.15.0.0/16227.15.0.1 to 227.15.255.254227.15.255.25565,534
17227.16.0.0/16227.16.0.1 to 227.16.255.254227.16.255.25565,534
18227.17.0.0/16227.17.0.1 to 227.17.255.254227.17.255.25565,534
19227.18.0.0/16227.18.0.1 to 227.18.255.254227.18.255.25565,534
20227.19.0.0/16227.19.0.1 to 227.19.255.254227.19.255.25565,534
21227.20.0.0/16227.20.0.1 to 227.20.255.254227.20.255.25565,534
22227.21.0.0/16227.21.0.1 to 227.21.255.254227.21.255.25565,534
23227.22.0.0/16227.22.0.1 to 227.22.255.254227.22.255.25565,534
24227.23.0.0/16227.23.0.1 to 227.23.255.254227.23.255.25565,534
25227.24.0.0/16227.24.0.1 to 227.24.255.254227.24.255.25565,534
26227.25.0.0/16227.25.0.1 to 227.25.255.254227.25.255.25565,534
27227.26.0.0/16227.26.0.1 to 227.26.255.254227.26.255.25565,534
28227.27.0.0/16227.27.0.1 to 227.27.255.254227.27.255.25565,534
29227.28.0.0/16227.28.0.1 to 227.28.255.254227.28.255.25565,534
30227.29.0.0/16227.29.0.1 to 227.29.255.254227.29.255.25565,534
31227.30.0.0/16227.30.0.1 to 227.30.255.254227.30.255.25565,534
32227.31.0.0/16227.31.0.1 to 227.31.255.254227.31.255.25565,534
33227.32.0.0/16227.32.0.1 to 227.32.255.254227.32.255.25565,534
34227.33.0.0/16227.33.0.1 to 227.33.255.254227.33.255.25565,534
35227.34.0.0/16227.34.0.1 to 227.34.255.254227.34.255.25565,534
36227.35.0.0/16227.35.0.1 to 227.35.255.254227.35.255.25565,534
37227.36.0.0/16227.36.0.1 to 227.36.255.254227.36.255.25565,534
38227.37.0.0/16227.37.0.1 to 227.37.255.254227.37.255.25565,534
39227.38.0.0/16227.38.0.1 to 227.38.255.254227.38.255.25565,534
40227.39.0.0/16227.39.0.1 to 227.39.255.254227.39.255.25565,534
41227.40.0.0/16227.40.0.1 to 227.40.255.254227.40.255.25565,534
42227.41.0.0/16227.41.0.1 to 227.41.255.254227.41.255.25565,534
43227.42.0.0/16227.42.0.1 to 227.42.255.254227.42.255.25565,534
44227.43.0.0/16227.43.0.1 to 227.43.255.254227.43.255.25565,534
45227.44.0.0/16227.44.0.1 to 227.44.255.254227.44.255.25565,534
46227.45.0.0/16227.45.0.1 to 227.45.255.254227.45.255.25565,534
47227.46.0.0/16227.46.0.1 to 227.46.255.254227.46.255.25565,534
48227.47.0.0/16227.47.0.1 to 227.47.255.254227.47.255.25565,534
49227.48.0.0/16227.48.0.1 to 227.48.255.254227.48.255.25565,534
50227.49.0.0/16227.49.0.1 to 227.49.255.254227.49.255.25565,534
51227.50.0.0/16227.50.0.1 to 227.50.255.254227.50.255.25565,534
52227.51.0.0/16227.51.0.1 to 227.51.255.254227.51.255.25565,534
53227.52.0.0/16227.52.0.1 to 227.52.255.254227.52.255.25565,534
54227.53.0.0/16227.53.0.1 to 227.53.255.254227.53.255.25565,534
55227.54.0.0/16227.54.0.1 to 227.54.255.254227.54.255.25565,534
56227.55.0.0/16227.55.0.1 to 227.55.255.254227.55.255.25565,534
57227.56.0.0/16227.56.0.1 to 227.56.255.254227.56.255.25565,534
58227.57.0.0/16227.57.0.1 to 227.57.255.254227.57.255.25565,534
59227.58.0.0/16227.58.0.1 to 227.58.255.254227.58.255.25565,534
60227.59.0.0/16227.59.0.1 to 227.59.255.254227.59.255.25565,534
61227.60.0.0/16227.60.0.1 to 227.60.255.254227.60.255.25565,534
62227.61.0.0/16227.61.0.1 to 227.61.255.254227.61.255.25565,534
63227.62.0.0/16227.62.0.1 to 227.62.255.254227.62.255.25565,534
64227.63.0.0/16227.63.0.1 to 227.63.255.254227.63.255.25565,534
65227.64.0.0/16227.64.0.1 to 227.64.255.254227.64.255.25565,534
66227.65.0.0/16227.65.0.1 to 227.65.255.254227.65.255.25565,534
67227.66.0.0/16227.66.0.1 to 227.66.255.254227.66.255.25565,534
68227.67.0.0/16227.67.0.1 to 227.67.255.254227.67.255.25565,534
69227.68.0.0/16227.68.0.1 to 227.68.255.254227.68.255.25565,534
70227.69.0.0/16227.69.0.1 to 227.69.255.254227.69.255.25565,534
71227.70.0.0/16227.70.0.1 to 227.70.255.254227.70.255.25565,534
72227.71.0.0/16227.71.0.1 to 227.71.255.254227.71.255.25565,534
73227.72.0.0/16227.72.0.1 to 227.72.255.254227.72.255.25565,534
74227.73.0.0/16227.73.0.1 to 227.73.255.254227.73.255.25565,534
75227.74.0.0/16227.74.0.1 to 227.74.255.254227.74.255.25565,534
76227.75.0.0/16227.75.0.1 to 227.75.255.254227.75.255.25565,534
77227.76.0.0/16227.76.0.1 to 227.76.255.254227.76.255.25565,534
78227.77.0.0/16227.77.0.1 to 227.77.255.254227.77.255.25565,534
79227.78.0.0/16227.78.0.1 to 227.78.255.254227.78.255.25565,534
80227.79.0.0/16227.79.0.1 to 227.79.255.254227.79.255.25565,534
81227.80.0.0/16227.80.0.1 to 227.80.255.254227.80.255.25565,534
82227.81.0.0/16227.81.0.1 to 227.81.255.254227.81.255.25565,534
83227.82.0.0/16227.82.0.1 to 227.82.255.254227.82.255.25565,534
84227.83.0.0/16227.83.0.1 to 227.83.255.254227.83.255.25565,534
85227.84.0.0/16227.84.0.1 to 227.84.255.254227.84.255.25565,534
86227.85.0.0/16227.85.0.1 to 227.85.255.254227.85.255.25565,534
87227.86.0.0/16227.86.0.1 to 227.86.255.254227.86.255.25565,534
88227.87.0.0/16227.87.0.1 to 227.87.255.254227.87.255.25565,534
89227.88.0.0/16227.88.0.1 to 227.88.255.254227.88.255.25565,534
90227.89.0.0/16227.89.0.1 to 227.89.255.254227.89.255.25565,534
91227.90.0.0/16227.90.0.1 to 227.90.255.254227.90.255.25565,534
92227.91.0.0/16227.91.0.1 to 227.91.255.254227.91.255.25565,534
93227.92.0.0/16227.92.0.1 to 227.92.255.254227.92.255.25565,534
94227.93.0.0/16227.93.0.1 to 227.93.255.254227.93.255.25565,534
95227.94.0.0/16227.94.0.1 to 227.94.255.254227.94.255.25565,534
96227.95.0.0/16227.95.0.1 to 227.95.255.254227.95.255.25565,534
97227.96.0.0/16227.96.0.1 to 227.96.255.254227.96.255.25565,534
98227.97.0.0/16227.97.0.1 to 227.97.255.254227.97.255.25565,534
99227.98.0.0/16227.98.0.1 to 227.98.255.254227.98.255.25565,534
100227.99.0.0/16227.99.0.1 to 227.99.255.254227.99.255.25565,534
101227.100.0.0/16227.100.0.1 to 227.100.255.254227.100.255.25565,534
102227.101.0.0/16227.101.0.1 to 227.101.255.254227.101.255.25565,534
103227.102.0.0/16227.102.0.1 to 227.102.255.254227.102.255.25565,534
104227.103.0.0/16227.103.0.1 to 227.103.255.254227.103.255.25565,534
105227.104.0.0/16227.104.0.1 to 227.104.255.254227.104.255.25565,534
106227.105.0.0/16227.105.0.1 to 227.105.255.254227.105.255.25565,534
107227.106.0.0/16227.106.0.1 to 227.106.255.254227.106.255.25565,534
108227.107.0.0/16227.107.0.1 to 227.107.255.254227.107.255.25565,534
109227.108.0.0/16227.108.0.1 to 227.108.255.254227.108.255.25565,534
110227.109.0.0/16227.109.0.1 to 227.109.255.254227.109.255.25565,534
111227.110.0.0/16227.110.0.1 to 227.110.255.254227.110.255.25565,534
112227.111.0.0/16227.111.0.1 to 227.111.255.254227.111.255.25565,534
113227.112.0.0/16227.112.0.1 to 227.112.255.254227.112.255.25565,534
114227.113.0.0/16227.113.0.1 to 227.113.255.254227.113.255.25565,534
115227.114.0.0/16227.114.0.1 to 227.114.255.254227.114.255.25565,534
116227.115.0.0/16227.115.0.1 to 227.115.255.254227.115.255.25565,534
117227.116.0.0/16227.116.0.1 to 227.116.255.254227.116.255.25565,534
118227.117.0.0/16227.117.0.1 to 227.117.255.254227.117.255.25565,534
119227.118.0.0/16227.118.0.1 to 227.118.255.254227.118.255.25565,534
120227.119.0.0/16227.119.0.1 to 227.119.255.254227.119.255.25565,534
121227.120.0.0/16227.120.0.1 to 227.120.255.254227.120.255.25565,534
122227.121.0.0/16227.121.0.1 to 227.121.255.254227.121.255.25565,534
123227.122.0.0/16227.122.0.1 to 227.122.255.254227.122.255.25565,534
124227.123.0.0/16227.123.0.1 to 227.123.255.254227.123.255.25565,534
125227.124.0.0/16227.124.0.1 to 227.124.255.254227.124.255.25565,534
126227.125.0.0/16227.125.0.1 to 227.125.255.254227.125.255.25565,534
127227.126.0.0/16227.126.0.1 to 227.126.255.254227.126.255.25565,534
128227.127.0.0/16227.127.0.1 to 227.127.255.254227.127.255.25565,534
129227.128.0.0/16227.128.0.1 to 227.128.255.254227.128.255.25565,534
130227.129.0.0/16227.129.0.1 to 227.129.255.254227.129.255.25565,534
131227.130.0.0/16227.130.0.1 to 227.130.255.254227.130.255.25565,534
132227.131.0.0/16227.131.0.1 to 227.131.255.254227.131.255.25565,534
133227.132.0.0/16227.132.0.1 to 227.132.255.254227.132.255.25565,534
134227.133.0.0/16227.133.0.1 to 227.133.255.254227.133.255.25565,534
135227.134.0.0/16227.134.0.1 to 227.134.255.254227.134.255.25565,534
136227.135.0.0/16227.135.0.1 to 227.135.255.254227.135.255.25565,534
137227.136.0.0/16227.136.0.1 to 227.136.255.254227.136.255.25565,534
138227.137.0.0/16227.137.0.1 to 227.137.255.254227.137.255.25565,534
139227.138.0.0/16227.138.0.1 to 227.138.255.254227.138.255.25565,534
140227.139.0.0/16227.139.0.1 to 227.139.255.254227.139.255.25565,534
141227.140.0.0/16227.140.0.1 to 227.140.255.254227.140.255.25565,534
142227.141.0.0/16227.141.0.1 to 227.141.255.254227.141.255.25565,534
143227.142.0.0/16227.142.0.1 to 227.142.255.254227.142.255.25565,534
144227.143.0.0/16227.143.0.1 to 227.143.255.254227.143.255.25565,534
145227.144.0.0/16227.144.0.1 to 227.144.255.254227.144.255.25565,534
146227.145.0.0/16227.145.0.1 to 227.145.255.254227.145.255.25565,534
147227.146.0.0/16227.146.0.1 to 227.146.255.254227.146.255.25565,534
148227.147.0.0/16227.147.0.1 to 227.147.255.254227.147.255.25565,534
149227.148.0.0/16227.148.0.1 to 227.148.255.254227.148.255.25565,534
150227.149.0.0/16227.149.0.1 to 227.149.255.254227.149.255.25565,534
151227.150.0.0/16227.150.0.1 to 227.150.255.254227.150.255.25565,534
152227.151.0.0/16227.151.0.1 to 227.151.255.254227.151.255.25565,534
153227.152.0.0/16227.152.0.1 to 227.152.255.254227.152.255.25565,534
154227.153.0.0/16227.153.0.1 to 227.153.255.254227.153.255.25565,534
155227.154.0.0/16227.154.0.1 to 227.154.255.254227.154.255.25565,534
156227.155.0.0/16227.155.0.1 to 227.155.255.254227.155.255.25565,534
157227.156.0.0/16227.156.0.1 to 227.156.255.254227.156.255.25565,534
158227.157.0.0/16227.157.0.1 to 227.157.255.254227.157.255.25565,534
159227.158.0.0/16227.158.0.1 to 227.158.255.254227.158.255.25565,534
160227.159.0.0/16227.159.0.1 to 227.159.255.254227.159.255.25565,534
161227.160.0.0/16227.160.0.1 to 227.160.255.254227.160.255.25565,534
162227.161.0.0/16227.161.0.1 to 227.161.255.254227.161.255.25565,534
163227.162.0.0/16227.162.0.1 to 227.162.255.254227.162.255.25565,534
164227.163.0.0/16227.163.0.1 to 227.163.255.254227.163.255.25565,534
165227.164.0.0/16227.164.0.1 to 227.164.255.254227.164.255.25565,534
166227.165.0.0/16227.165.0.1 to 227.165.255.254227.165.255.25565,534
167227.166.0.0/16227.166.0.1 to 227.166.255.254227.166.255.25565,534
168227.167.0.0/16227.167.0.1 to 227.167.255.254227.167.255.25565,534
169227.168.0.0/16227.168.0.1 to 227.168.255.254227.168.255.25565,534
170227.169.0.0/16227.169.0.1 to 227.169.255.254227.169.255.25565,534
171227.170.0.0/16227.170.0.1 to 227.170.255.254227.170.255.25565,534
172227.171.0.0/16227.171.0.1 to 227.171.255.254227.171.255.25565,534
173227.172.0.0/16227.172.0.1 to 227.172.255.254227.172.255.25565,534
174227.173.0.0/16227.173.0.1 to 227.173.255.254227.173.255.25565,534
175227.174.0.0/16227.174.0.1 to 227.174.255.254227.174.255.25565,534
176227.175.0.0/16227.175.0.1 to 227.175.255.254227.175.255.25565,534
177227.176.0.0/16227.176.0.1 to 227.176.255.254227.176.255.25565,534
178227.177.0.0/16227.177.0.1 to 227.177.255.254227.177.255.25565,534
179227.178.0.0/16227.178.0.1 to 227.178.255.254227.178.255.25565,534
180227.179.0.0/16227.179.0.1 to 227.179.255.254227.179.255.25565,534
181227.180.0.0/16227.180.0.1 to 227.180.255.254227.180.255.25565,534
182227.181.0.0/16227.181.0.1 to 227.181.255.254227.181.255.25565,534
183227.182.0.0/16227.182.0.1 to 227.182.255.254227.182.255.25565,534
184227.183.0.0/16227.183.0.1 to 227.183.255.254227.183.255.25565,534
185227.184.0.0/16227.184.0.1 to 227.184.255.254227.184.255.25565,534
186227.185.0.0/16227.185.0.1 to 227.185.255.254227.185.255.25565,534
187227.186.0.0/16227.186.0.1 to 227.186.255.254227.186.255.25565,534
188227.187.0.0/16227.187.0.1 to 227.187.255.254227.187.255.25565,534
189227.188.0.0/16227.188.0.1 to 227.188.255.254227.188.255.25565,534
190227.189.0.0/16227.189.0.1 to 227.189.255.254227.189.255.25565,534
191227.190.0.0/16227.190.0.1 to 227.190.255.254227.190.255.25565,534
192227.191.0.0/16227.191.0.1 to 227.191.255.254227.191.255.25565,534
193227.192.0.0/16227.192.0.1 to 227.192.255.254227.192.255.25565,534
194227.193.0.0/16227.193.0.1 to 227.193.255.254227.193.255.25565,534
195227.194.0.0/16227.194.0.1 to 227.194.255.254227.194.255.25565,534
196227.195.0.0/16227.195.0.1 to 227.195.255.254227.195.255.25565,534
197227.196.0.0/16227.196.0.1 to 227.196.255.254227.196.255.25565,534
198227.197.0.0/16227.197.0.1 to 227.197.255.254227.197.255.25565,534
199227.198.0.0/16227.198.0.1 to 227.198.255.254227.198.255.25565,534
200227.199.0.0/16227.199.0.1 to 227.199.255.254227.199.255.25565,534
201227.200.0.0/16227.200.0.1 to 227.200.255.254227.200.255.25565,534
202227.201.0.0/16227.201.0.1 to 227.201.255.254227.201.255.25565,534
203227.202.0.0/16227.202.0.1 to 227.202.255.254227.202.255.25565,534
204227.203.0.0/16227.203.0.1 to 227.203.255.254227.203.255.25565,534
205227.204.0.0/16227.204.0.1 to 227.204.255.254227.204.255.25565,534
206227.205.0.0/16227.205.0.1 to 227.205.255.254227.205.255.25565,534
207227.206.0.0/16227.206.0.1 to 227.206.255.254227.206.255.25565,534
208227.207.0.0/16227.207.0.1 to 227.207.255.254227.207.255.25565,534
209227.208.0.0/16227.208.0.1 to 227.208.255.254227.208.255.25565,534
210227.209.0.0/16227.209.0.1 to 227.209.255.254227.209.255.25565,534
211227.210.0.0/16227.210.0.1 to 227.210.255.254227.210.255.25565,534
212227.211.0.0/16227.211.0.1 to 227.211.255.254227.211.255.25565,534
213227.212.0.0/16227.212.0.1 to 227.212.255.254227.212.255.25565,534
214227.213.0.0/16227.213.0.1 to 227.213.255.254227.213.255.25565,534
215227.214.0.0/16227.214.0.1 to 227.214.255.254227.214.255.25565,534
216227.215.0.0/16227.215.0.1 to 227.215.255.254227.215.255.25565,534
217227.216.0.0/16227.216.0.1 to 227.216.255.254227.216.255.25565,534
218227.217.0.0/16227.217.0.1 to 227.217.255.254227.217.255.25565,534
219227.218.0.0/16227.218.0.1 to 227.218.255.254227.218.255.25565,534
220227.219.0.0/16227.219.0.1 to 227.219.255.254227.219.255.25565,534
221227.220.0.0/16227.220.0.1 to 227.220.255.254227.220.255.25565,534
222227.221.0.0/16227.221.0.1 to 227.221.255.254227.221.255.25565,534
223227.222.0.0/16227.222.0.1 to 227.222.255.254227.222.255.25565,534
224227.223.0.0/16227.223.0.1 to 227.223.255.254227.223.255.25565,534
225227.224.0.0/16227.224.0.1 to 227.224.255.254227.224.255.25565,534
226227.225.0.0/16227.225.0.1 to 227.225.255.254227.225.255.25565,534
227227.226.0.0/16227.226.0.1 to 227.226.255.254227.226.255.25565,534
228227.227.0.0/16227.227.0.1 to 227.227.255.254227.227.255.25565,534
229227.228.0.0/16227.228.0.1 to 227.228.255.254227.228.255.25565,534
230227.229.0.0/16227.229.0.1 to 227.229.255.254227.229.255.25565,534
231227.230.0.0/16227.230.0.1 to 227.230.255.254227.230.255.25565,534
232227.231.0.0/16227.231.0.1 to 227.231.255.254227.231.255.25565,534
233227.232.0.0/16227.232.0.1 to 227.232.255.254227.232.255.25565,534
234227.233.0.0/16227.233.0.1 to 227.233.255.254227.233.255.25565,534
235227.234.0.0/16227.234.0.1 to 227.234.255.254227.234.255.25565,534
236227.235.0.0/16227.235.0.1 to 227.235.255.254227.235.255.25565,534
237227.236.0.0/16227.236.0.1 to 227.236.255.254227.236.255.25565,534
238227.237.0.0/16227.237.0.1 to 227.237.255.254227.237.255.25565,534
239227.238.0.0/16227.238.0.1 to 227.238.255.254227.238.255.25565,534
240227.239.0.0/16227.239.0.1 to 227.239.255.254227.239.255.25565,534
241227.240.0.0/16227.240.0.1 to 227.240.255.254227.240.255.25565,534
242227.241.0.0/16227.241.0.1 to 227.241.255.254227.241.255.25565,534
243227.242.0.0/16227.242.0.1 to 227.242.255.254227.242.255.25565,534
244227.243.0.0/16227.243.0.1 to 227.243.255.254227.243.255.25565,534
245227.244.0.0/16227.244.0.1 to 227.244.255.254227.244.255.25565,534
246227.245.0.0/16227.245.0.1 to 227.245.255.254227.245.255.25565,534
247227.246.0.0/16227.246.0.1 to 227.246.255.254227.246.255.25565,534
248227.247.0.0/16227.247.0.1 to 227.247.255.254227.247.255.25565,534
249227.248.0.0/16227.248.0.1 to 227.248.255.254227.248.255.25565,534
250227.249.0.0/16227.249.0.1 to 227.249.255.254227.249.255.25565,534
251227.250.0.0/16227.250.0.1 to 227.250.255.254227.250.255.25565,534
252227.251.0.0/16227.251.0.1 to 227.251.255.254227.251.255.25565,534
253227.252.0.0/16227.252.0.1 to 227.252.255.254227.252.255.25565,534
254227.253.0.0/16227.253.0.1 to 227.253.255.254227.253.255.25565,534
255227.254.0.0/16227.254.0.1 to 227.254.255.254227.254.255.25565,534
256227.255.0.0/16227.255.0.1 to 227.255.255.254227.255.255.25565,534

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.