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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.

Network237.4.0.0/14
Usable hosts262,142
Subnet mask255.252.0.0
Addresses262,144
Network address
237.4.0.0
Broadcast address
237.7.255.255
First usable
237.4.0.1
Last usable
237.7.255.254
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
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex ED040000 · Integer 3976462336 to 3976724479
Reverse DNS zones
4.237.in-addr.arpa
5.237.in-addr.arpa
6.237.in-addr.arpa
7.237.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
Address11101101.00000100.00000000.00000000237.4.0.0
Subnet mask11111111.11111100.00000000.00000000255.252.0.0
Network11101101.00000100.00000000.00000000237.4.0.0
Broadcast11101101.00000111.11111111.11111111237.7.255.255
Split into smaller subnets/25
/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)

237.4.0.0/14 makes 2,048 subnets of /25; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1237.4.0.0/25237.4.0.1 to 237.4.0.126237.4.0.127126
2237.4.0.128/25237.4.0.129 to 237.4.0.254237.4.0.255126
3237.4.1.0/25237.4.1.1 to 237.4.1.126237.4.1.127126
4237.4.1.128/25237.4.1.129 to 237.4.1.254237.4.1.255126
5237.4.2.0/25237.4.2.1 to 237.4.2.126237.4.2.127126
6237.4.2.128/25237.4.2.129 to 237.4.2.254237.4.2.255126
7237.4.3.0/25237.4.3.1 to 237.4.3.126237.4.3.127126
8237.4.3.128/25237.4.3.129 to 237.4.3.254237.4.3.255126
9237.4.4.0/25237.4.4.1 to 237.4.4.126237.4.4.127126
10237.4.4.128/25237.4.4.129 to 237.4.4.254237.4.4.255126
11237.4.5.0/25237.4.5.1 to 237.4.5.126237.4.5.127126
12237.4.5.128/25237.4.5.129 to 237.4.5.254237.4.5.255126
13237.4.6.0/25237.4.6.1 to 237.4.6.126237.4.6.127126
14237.4.6.128/25237.4.6.129 to 237.4.6.254237.4.6.255126
15237.4.7.0/25237.4.7.1 to 237.4.7.126237.4.7.127126
16237.4.7.128/25237.4.7.129 to 237.4.7.254237.4.7.255126
17237.4.8.0/25237.4.8.1 to 237.4.8.126237.4.8.127126
18237.4.8.128/25237.4.8.129 to 237.4.8.254237.4.8.255126
19237.4.9.0/25237.4.9.1 to 237.4.9.126237.4.9.127126
20237.4.9.128/25237.4.9.129 to 237.4.9.254237.4.9.255126
21237.4.10.0/25237.4.10.1 to 237.4.10.126237.4.10.127126
22237.4.10.128/25237.4.10.129 to 237.4.10.254237.4.10.255126
23237.4.11.0/25237.4.11.1 to 237.4.11.126237.4.11.127126
24237.4.11.128/25237.4.11.129 to 237.4.11.254237.4.11.255126
25237.4.12.0/25237.4.12.1 to 237.4.12.126237.4.12.127126
26237.4.12.128/25237.4.12.129 to 237.4.12.254237.4.12.255126
27237.4.13.0/25237.4.13.1 to 237.4.13.126237.4.13.127126
28237.4.13.128/25237.4.13.129 to 237.4.13.254237.4.13.255126
29237.4.14.0/25237.4.14.1 to 237.4.14.126237.4.14.127126
30237.4.14.128/25237.4.14.129 to 237.4.14.254237.4.14.255126
31237.4.15.0/25237.4.15.1 to 237.4.15.126237.4.15.127126
32237.4.15.128/25237.4.15.129 to 237.4.15.254237.4.15.255126
33237.4.16.0/25237.4.16.1 to 237.4.16.126237.4.16.127126
34237.4.16.128/25237.4.16.129 to 237.4.16.254237.4.16.255126
35237.4.17.0/25237.4.17.1 to 237.4.17.126237.4.17.127126
36237.4.17.128/25237.4.17.129 to 237.4.17.254237.4.17.255126
37237.4.18.0/25237.4.18.1 to 237.4.18.126237.4.18.127126
38237.4.18.128/25237.4.18.129 to 237.4.18.254237.4.18.255126
39237.4.19.0/25237.4.19.1 to 237.4.19.126237.4.19.127126
40237.4.19.128/25237.4.19.129 to 237.4.19.254237.4.19.255126
41237.4.20.0/25237.4.20.1 to 237.4.20.126237.4.20.127126
42237.4.20.128/25237.4.20.129 to 237.4.20.254237.4.20.255126
43237.4.21.0/25237.4.21.1 to 237.4.21.126237.4.21.127126
44237.4.21.128/25237.4.21.129 to 237.4.21.254237.4.21.255126
45237.4.22.0/25237.4.22.1 to 237.4.22.126237.4.22.127126
46237.4.22.128/25237.4.22.129 to 237.4.22.254237.4.22.255126
47237.4.23.0/25237.4.23.1 to 237.4.23.126237.4.23.127126
48237.4.23.128/25237.4.23.129 to 237.4.23.254237.4.23.255126
49237.4.24.0/25237.4.24.1 to 237.4.24.126237.4.24.127126
50237.4.24.128/25237.4.24.129 to 237.4.24.254237.4.24.255126
51237.4.25.0/25237.4.25.1 to 237.4.25.126237.4.25.127126
52237.4.25.128/25237.4.25.129 to 237.4.25.254237.4.25.255126
53237.4.26.0/25237.4.26.1 to 237.4.26.126237.4.26.127126
54237.4.26.128/25237.4.26.129 to 237.4.26.254237.4.26.255126
55237.4.27.0/25237.4.27.1 to 237.4.27.126237.4.27.127126
56237.4.27.128/25237.4.27.129 to 237.4.27.254237.4.27.255126
57237.4.28.0/25237.4.28.1 to 237.4.28.126237.4.28.127126
58237.4.28.128/25237.4.28.129 to 237.4.28.254237.4.28.255126
59237.4.29.0/25237.4.29.1 to 237.4.29.126237.4.29.127126
60237.4.29.128/25237.4.29.129 to 237.4.29.254237.4.29.255126
61237.4.30.0/25237.4.30.1 to 237.4.30.126237.4.30.127126
62237.4.30.128/25237.4.30.129 to 237.4.30.254237.4.30.255126
63237.4.31.0/25237.4.31.1 to 237.4.31.126237.4.31.127126
64237.4.31.128/25237.4.31.129 to 237.4.31.254237.4.31.255126
65237.4.32.0/25237.4.32.1 to 237.4.32.126237.4.32.127126
66237.4.32.128/25237.4.32.129 to 237.4.32.254237.4.32.255126
67237.4.33.0/25237.4.33.1 to 237.4.33.126237.4.33.127126
68237.4.33.128/25237.4.33.129 to 237.4.33.254237.4.33.255126
69237.4.34.0/25237.4.34.1 to 237.4.34.126237.4.34.127126
70237.4.34.128/25237.4.34.129 to 237.4.34.254237.4.34.255126
71237.4.35.0/25237.4.35.1 to 237.4.35.126237.4.35.127126
72237.4.35.128/25237.4.35.129 to 237.4.35.254237.4.35.255126
73237.4.36.0/25237.4.36.1 to 237.4.36.126237.4.36.127126
74237.4.36.128/25237.4.36.129 to 237.4.36.254237.4.36.255126
75237.4.37.0/25237.4.37.1 to 237.4.37.126237.4.37.127126
76237.4.37.128/25237.4.37.129 to 237.4.37.254237.4.37.255126
77237.4.38.0/25237.4.38.1 to 237.4.38.126237.4.38.127126
78237.4.38.128/25237.4.38.129 to 237.4.38.254237.4.38.255126
79237.4.39.0/25237.4.39.1 to 237.4.39.126237.4.39.127126
80237.4.39.128/25237.4.39.129 to 237.4.39.254237.4.39.255126
81237.4.40.0/25237.4.40.1 to 237.4.40.126237.4.40.127126
82237.4.40.128/25237.4.40.129 to 237.4.40.254237.4.40.255126
83237.4.41.0/25237.4.41.1 to 237.4.41.126237.4.41.127126
84237.4.41.128/25237.4.41.129 to 237.4.41.254237.4.41.255126
85237.4.42.0/25237.4.42.1 to 237.4.42.126237.4.42.127126
86237.4.42.128/25237.4.42.129 to 237.4.42.254237.4.42.255126
87237.4.43.0/25237.4.43.1 to 237.4.43.126237.4.43.127126
88237.4.43.128/25237.4.43.129 to 237.4.43.254237.4.43.255126
89237.4.44.0/25237.4.44.1 to 237.4.44.126237.4.44.127126
90237.4.44.128/25237.4.44.129 to 237.4.44.254237.4.44.255126
91237.4.45.0/25237.4.45.1 to 237.4.45.126237.4.45.127126
92237.4.45.128/25237.4.45.129 to 237.4.45.254237.4.45.255126
93237.4.46.0/25237.4.46.1 to 237.4.46.126237.4.46.127126
94237.4.46.128/25237.4.46.129 to 237.4.46.254237.4.46.255126
95237.4.47.0/25237.4.47.1 to 237.4.47.126237.4.47.127126
96237.4.47.128/25237.4.47.129 to 237.4.47.254237.4.47.255126
97237.4.48.0/25237.4.48.1 to 237.4.48.126237.4.48.127126
98237.4.48.128/25237.4.48.129 to 237.4.48.254237.4.48.255126
99237.4.49.0/25237.4.49.1 to 237.4.49.126237.4.49.127126
100237.4.49.128/25237.4.49.129 to 237.4.49.254237.4.49.255126
101237.4.50.0/25237.4.50.1 to 237.4.50.126237.4.50.127126
102237.4.50.128/25237.4.50.129 to 237.4.50.254237.4.50.255126
103237.4.51.0/25237.4.51.1 to 237.4.51.126237.4.51.127126
104237.4.51.128/25237.4.51.129 to 237.4.51.254237.4.51.255126
105237.4.52.0/25237.4.52.1 to 237.4.52.126237.4.52.127126
106237.4.52.128/25237.4.52.129 to 237.4.52.254237.4.52.255126
107237.4.53.0/25237.4.53.1 to 237.4.53.126237.4.53.127126
108237.4.53.128/25237.4.53.129 to 237.4.53.254237.4.53.255126
109237.4.54.0/25237.4.54.1 to 237.4.54.126237.4.54.127126
110237.4.54.128/25237.4.54.129 to 237.4.54.254237.4.54.255126
111237.4.55.0/25237.4.55.1 to 237.4.55.126237.4.55.127126
112237.4.55.128/25237.4.55.129 to 237.4.55.254237.4.55.255126
113237.4.56.0/25237.4.56.1 to 237.4.56.126237.4.56.127126
114237.4.56.128/25237.4.56.129 to 237.4.56.254237.4.56.255126
115237.4.57.0/25237.4.57.1 to 237.4.57.126237.4.57.127126
116237.4.57.128/25237.4.57.129 to 237.4.57.254237.4.57.255126
117237.4.58.0/25237.4.58.1 to 237.4.58.126237.4.58.127126
118237.4.58.128/25237.4.58.129 to 237.4.58.254237.4.58.255126
119237.4.59.0/25237.4.59.1 to 237.4.59.126237.4.59.127126
120237.4.59.128/25237.4.59.129 to 237.4.59.254237.4.59.255126
121237.4.60.0/25237.4.60.1 to 237.4.60.126237.4.60.127126
122237.4.60.128/25237.4.60.129 to 237.4.60.254237.4.60.255126
123237.4.61.0/25237.4.61.1 to 237.4.61.126237.4.61.127126
124237.4.61.128/25237.4.61.129 to 237.4.61.254237.4.61.255126
125237.4.62.0/25237.4.62.1 to 237.4.62.126237.4.62.127126
126237.4.62.128/25237.4.62.129 to 237.4.62.254237.4.62.255126
127237.4.63.0/25237.4.63.1 to 237.4.63.126237.4.63.127126
128237.4.63.128/25237.4.63.129 to 237.4.63.254237.4.63.255126
129237.4.64.0/25237.4.64.1 to 237.4.64.126237.4.64.127126
130237.4.64.128/25237.4.64.129 to 237.4.64.254237.4.64.255126
131237.4.65.0/25237.4.65.1 to 237.4.65.126237.4.65.127126
132237.4.65.128/25237.4.65.129 to 237.4.65.254237.4.65.255126
133237.4.66.0/25237.4.66.1 to 237.4.66.126237.4.66.127126
134237.4.66.128/25237.4.66.129 to 237.4.66.254237.4.66.255126
135237.4.67.0/25237.4.67.1 to 237.4.67.126237.4.67.127126
136237.4.67.128/25237.4.67.129 to 237.4.67.254237.4.67.255126
137237.4.68.0/25237.4.68.1 to 237.4.68.126237.4.68.127126
138237.4.68.128/25237.4.68.129 to 237.4.68.254237.4.68.255126
139237.4.69.0/25237.4.69.1 to 237.4.69.126237.4.69.127126
140237.4.69.128/25237.4.69.129 to 237.4.69.254237.4.69.255126
141237.4.70.0/25237.4.70.1 to 237.4.70.126237.4.70.127126
142237.4.70.128/25237.4.70.129 to 237.4.70.254237.4.70.255126
143237.4.71.0/25237.4.71.1 to 237.4.71.126237.4.71.127126
144237.4.71.128/25237.4.71.129 to 237.4.71.254237.4.71.255126
145237.4.72.0/25237.4.72.1 to 237.4.72.126237.4.72.127126
146237.4.72.128/25237.4.72.129 to 237.4.72.254237.4.72.255126
147237.4.73.0/25237.4.73.1 to 237.4.73.126237.4.73.127126
148237.4.73.128/25237.4.73.129 to 237.4.73.254237.4.73.255126
149237.4.74.0/25237.4.74.1 to 237.4.74.126237.4.74.127126
150237.4.74.128/25237.4.74.129 to 237.4.74.254237.4.74.255126
151237.4.75.0/25237.4.75.1 to 237.4.75.126237.4.75.127126
152237.4.75.128/25237.4.75.129 to 237.4.75.254237.4.75.255126
153237.4.76.0/25237.4.76.1 to 237.4.76.126237.4.76.127126
154237.4.76.128/25237.4.76.129 to 237.4.76.254237.4.76.255126
155237.4.77.0/25237.4.77.1 to 237.4.77.126237.4.77.127126
156237.4.77.128/25237.4.77.129 to 237.4.77.254237.4.77.255126
157237.4.78.0/25237.4.78.1 to 237.4.78.126237.4.78.127126
158237.4.78.128/25237.4.78.129 to 237.4.78.254237.4.78.255126
159237.4.79.0/25237.4.79.1 to 237.4.79.126237.4.79.127126
160237.4.79.128/25237.4.79.129 to 237.4.79.254237.4.79.255126
161237.4.80.0/25237.4.80.1 to 237.4.80.126237.4.80.127126
162237.4.80.128/25237.4.80.129 to 237.4.80.254237.4.80.255126
163237.4.81.0/25237.4.81.1 to 237.4.81.126237.4.81.127126
164237.4.81.128/25237.4.81.129 to 237.4.81.254237.4.81.255126
165237.4.82.0/25237.4.82.1 to 237.4.82.126237.4.82.127126
166237.4.82.128/25237.4.82.129 to 237.4.82.254237.4.82.255126
167237.4.83.0/25237.4.83.1 to 237.4.83.126237.4.83.127126
168237.4.83.128/25237.4.83.129 to 237.4.83.254237.4.83.255126
169237.4.84.0/25237.4.84.1 to 237.4.84.126237.4.84.127126
170237.4.84.128/25237.4.84.129 to 237.4.84.254237.4.84.255126
171237.4.85.0/25237.4.85.1 to 237.4.85.126237.4.85.127126
172237.4.85.128/25237.4.85.129 to 237.4.85.254237.4.85.255126
173237.4.86.0/25237.4.86.1 to 237.4.86.126237.4.86.127126
174237.4.86.128/25237.4.86.129 to 237.4.86.254237.4.86.255126
175237.4.87.0/25237.4.87.1 to 237.4.87.126237.4.87.127126
176237.4.87.128/25237.4.87.129 to 237.4.87.254237.4.87.255126
177237.4.88.0/25237.4.88.1 to 237.4.88.126237.4.88.127126
178237.4.88.128/25237.4.88.129 to 237.4.88.254237.4.88.255126
179237.4.89.0/25237.4.89.1 to 237.4.89.126237.4.89.127126
180237.4.89.128/25237.4.89.129 to 237.4.89.254237.4.89.255126
181237.4.90.0/25237.4.90.1 to 237.4.90.126237.4.90.127126
182237.4.90.128/25237.4.90.129 to 237.4.90.254237.4.90.255126
183237.4.91.0/25237.4.91.1 to 237.4.91.126237.4.91.127126
184237.4.91.128/25237.4.91.129 to 237.4.91.254237.4.91.255126
185237.4.92.0/25237.4.92.1 to 237.4.92.126237.4.92.127126
186237.4.92.128/25237.4.92.129 to 237.4.92.254237.4.92.255126
187237.4.93.0/25237.4.93.1 to 237.4.93.126237.4.93.127126
188237.4.93.128/25237.4.93.129 to 237.4.93.254237.4.93.255126
189237.4.94.0/25237.4.94.1 to 237.4.94.126237.4.94.127126
190237.4.94.128/25237.4.94.129 to 237.4.94.254237.4.94.255126
191237.4.95.0/25237.4.95.1 to 237.4.95.126237.4.95.127126
192237.4.95.128/25237.4.95.129 to 237.4.95.254237.4.95.255126
193237.4.96.0/25237.4.96.1 to 237.4.96.126237.4.96.127126
194237.4.96.128/25237.4.96.129 to 237.4.96.254237.4.96.255126
195237.4.97.0/25237.4.97.1 to 237.4.97.126237.4.97.127126
196237.4.97.128/25237.4.97.129 to 237.4.97.254237.4.97.255126
197237.4.98.0/25237.4.98.1 to 237.4.98.126237.4.98.127126
198237.4.98.128/25237.4.98.129 to 237.4.98.254237.4.98.255126
199237.4.99.0/25237.4.99.1 to 237.4.99.126237.4.99.127126
200237.4.99.128/25237.4.99.129 to 237.4.99.254237.4.99.255126
201237.4.100.0/25237.4.100.1 to 237.4.100.126237.4.100.127126
202237.4.100.128/25237.4.100.129 to 237.4.100.254237.4.100.255126
203237.4.101.0/25237.4.101.1 to 237.4.101.126237.4.101.127126
204237.4.101.128/25237.4.101.129 to 237.4.101.254237.4.101.255126
205237.4.102.0/25237.4.102.1 to 237.4.102.126237.4.102.127126
206237.4.102.128/25237.4.102.129 to 237.4.102.254237.4.102.255126
207237.4.103.0/25237.4.103.1 to 237.4.103.126237.4.103.127126
208237.4.103.128/25237.4.103.129 to 237.4.103.254237.4.103.255126
209237.4.104.0/25237.4.104.1 to 237.4.104.126237.4.104.127126
210237.4.104.128/25237.4.104.129 to 237.4.104.254237.4.104.255126
211237.4.105.0/25237.4.105.1 to 237.4.105.126237.4.105.127126
212237.4.105.128/25237.4.105.129 to 237.4.105.254237.4.105.255126
213237.4.106.0/25237.4.106.1 to 237.4.106.126237.4.106.127126
214237.4.106.128/25237.4.106.129 to 237.4.106.254237.4.106.255126
215237.4.107.0/25237.4.107.1 to 237.4.107.126237.4.107.127126
216237.4.107.128/25237.4.107.129 to 237.4.107.254237.4.107.255126
217237.4.108.0/25237.4.108.1 to 237.4.108.126237.4.108.127126
218237.4.108.128/25237.4.108.129 to 237.4.108.254237.4.108.255126
219237.4.109.0/25237.4.109.1 to 237.4.109.126237.4.109.127126
220237.4.109.128/25237.4.109.129 to 237.4.109.254237.4.109.255126
221237.4.110.0/25237.4.110.1 to 237.4.110.126237.4.110.127126
222237.4.110.128/25237.4.110.129 to 237.4.110.254237.4.110.255126
223237.4.111.0/25237.4.111.1 to 237.4.111.126237.4.111.127126
224237.4.111.128/25237.4.111.129 to 237.4.111.254237.4.111.255126
225237.4.112.0/25237.4.112.1 to 237.4.112.126237.4.112.127126
226237.4.112.128/25237.4.112.129 to 237.4.112.254237.4.112.255126
227237.4.113.0/25237.4.113.1 to 237.4.113.126237.4.113.127126
228237.4.113.128/25237.4.113.129 to 237.4.113.254237.4.113.255126
229237.4.114.0/25237.4.114.1 to 237.4.114.126237.4.114.127126
230237.4.114.128/25237.4.114.129 to 237.4.114.254237.4.114.255126
231237.4.115.0/25237.4.115.1 to 237.4.115.126237.4.115.127126
232237.4.115.128/25237.4.115.129 to 237.4.115.254237.4.115.255126
233237.4.116.0/25237.4.116.1 to 237.4.116.126237.4.116.127126
234237.4.116.128/25237.4.116.129 to 237.4.116.254237.4.116.255126
235237.4.117.0/25237.4.117.1 to 237.4.117.126237.4.117.127126
236237.4.117.128/25237.4.117.129 to 237.4.117.254237.4.117.255126
237237.4.118.0/25237.4.118.1 to 237.4.118.126237.4.118.127126
238237.4.118.128/25237.4.118.129 to 237.4.118.254237.4.118.255126
239237.4.119.0/25237.4.119.1 to 237.4.119.126237.4.119.127126
240237.4.119.128/25237.4.119.129 to 237.4.119.254237.4.119.255126
241237.4.120.0/25237.4.120.1 to 237.4.120.126237.4.120.127126
242237.4.120.128/25237.4.120.129 to 237.4.120.254237.4.120.255126
243237.4.121.0/25237.4.121.1 to 237.4.121.126237.4.121.127126
244237.4.121.128/25237.4.121.129 to 237.4.121.254237.4.121.255126
245237.4.122.0/25237.4.122.1 to 237.4.122.126237.4.122.127126
246237.4.122.128/25237.4.122.129 to 237.4.122.254237.4.122.255126
247237.4.123.0/25237.4.123.1 to 237.4.123.126237.4.123.127126
248237.4.123.128/25237.4.123.129 to 237.4.123.254237.4.123.255126
249237.4.124.0/25237.4.124.1 to 237.4.124.126237.4.124.127126
250237.4.124.128/25237.4.124.129 to 237.4.124.254237.4.124.255126
251237.4.125.0/25237.4.125.1 to 237.4.125.126237.4.125.127126
252237.4.125.128/25237.4.125.129 to 237.4.125.254237.4.125.255126
253237.4.126.0/25237.4.126.1 to 237.4.126.126237.4.126.127126
254237.4.126.128/25237.4.126.129 to 237.4.126.254237.4.126.255126
255237.4.127.0/25237.4.127.1 to 237.4.127.126237.4.127.127126
256237.4.127.128/25237.4.127.129 to 237.4.127.254237.4.127.255126

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.