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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.

Network245.232.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
245.232.0.0
Broadcast address
245.239.255.255
First usable
245.232.0.1
Last usable
245.239.255.254
Usable hosts
524,286 (524,288 less the network and broadcast addresses)
Subnet mask
255.248.0.0
Wildcard mask
0.7.255.255 (Cisco ACLs, OSPF)
Prefix length
/13
Type
Reserved 240.0.0.0/4
Future use; not usable on most systems
Old class
E (reserved)
As numbers
Hex F5E80000 · Integer 4125622272 to 4126146559
Reverse DNS zones
232.245.in-addr.arpa
233.245.in-addr.arpa
234.245.in-addr.arpa
235.245.in-addr.arpa
236.245.in-addr.arpa
237.245.in-addr.arpa
238.245.in-addr.arpa
239.245.in-addr.arpa
/13 is not on a 8-bit boundary, so it takes 8 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11110101.11101000.00000000.00000000245.232.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network11110101.11101000.00000000.00000000245.232.0.0
Broadcast11110101.11101111.11111111.11111111245.239.255.255
Split into smaller subnets/25
/14 (2)/15 (4)/16 (8)/17 (16)/18 (32)/19 (64)/20 (128)/21 (256)/22 (512)/23 (1,024)/24 (2,048)/25 (4,096)

245.232.0.0/13 makes 4,096 subnets of /25; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1245.232.0.0/25245.232.0.1 to 245.232.0.126245.232.0.127126
2245.232.0.128/25245.232.0.129 to 245.232.0.254245.232.0.255126
3245.232.1.0/25245.232.1.1 to 245.232.1.126245.232.1.127126
4245.232.1.128/25245.232.1.129 to 245.232.1.254245.232.1.255126
5245.232.2.0/25245.232.2.1 to 245.232.2.126245.232.2.127126
6245.232.2.128/25245.232.2.129 to 245.232.2.254245.232.2.255126
7245.232.3.0/25245.232.3.1 to 245.232.3.126245.232.3.127126
8245.232.3.128/25245.232.3.129 to 245.232.3.254245.232.3.255126
9245.232.4.0/25245.232.4.1 to 245.232.4.126245.232.4.127126
10245.232.4.128/25245.232.4.129 to 245.232.4.254245.232.4.255126
11245.232.5.0/25245.232.5.1 to 245.232.5.126245.232.5.127126
12245.232.5.128/25245.232.5.129 to 245.232.5.254245.232.5.255126
13245.232.6.0/25245.232.6.1 to 245.232.6.126245.232.6.127126
14245.232.6.128/25245.232.6.129 to 245.232.6.254245.232.6.255126
15245.232.7.0/25245.232.7.1 to 245.232.7.126245.232.7.127126
16245.232.7.128/25245.232.7.129 to 245.232.7.254245.232.7.255126
17245.232.8.0/25245.232.8.1 to 245.232.8.126245.232.8.127126
18245.232.8.128/25245.232.8.129 to 245.232.8.254245.232.8.255126
19245.232.9.0/25245.232.9.1 to 245.232.9.126245.232.9.127126
20245.232.9.128/25245.232.9.129 to 245.232.9.254245.232.9.255126
21245.232.10.0/25245.232.10.1 to 245.232.10.126245.232.10.127126
22245.232.10.128/25245.232.10.129 to 245.232.10.254245.232.10.255126
23245.232.11.0/25245.232.11.1 to 245.232.11.126245.232.11.127126
24245.232.11.128/25245.232.11.129 to 245.232.11.254245.232.11.255126
25245.232.12.0/25245.232.12.1 to 245.232.12.126245.232.12.127126
26245.232.12.128/25245.232.12.129 to 245.232.12.254245.232.12.255126
27245.232.13.0/25245.232.13.1 to 245.232.13.126245.232.13.127126
28245.232.13.128/25245.232.13.129 to 245.232.13.254245.232.13.255126
29245.232.14.0/25245.232.14.1 to 245.232.14.126245.232.14.127126
30245.232.14.128/25245.232.14.129 to 245.232.14.254245.232.14.255126
31245.232.15.0/25245.232.15.1 to 245.232.15.126245.232.15.127126
32245.232.15.128/25245.232.15.129 to 245.232.15.254245.232.15.255126
33245.232.16.0/25245.232.16.1 to 245.232.16.126245.232.16.127126
34245.232.16.128/25245.232.16.129 to 245.232.16.254245.232.16.255126
35245.232.17.0/25245.232.17.1 to 245.232.17.126245.232.17.127126
36245.232.17.128/25245.232.17.129 to 245.232.17.254245.232.17.255126
37245.232.18.0/25245.232.18.1 to 245.232.18.126245.232.18.127126
38245.232.18.128/25245.232.18.129 to 245.232.18.254245.232.18.255126
39245.232.19.0/25245.232.19.1 to 245.232.19.126245.232.19.127126
40245.232.19.128/25245.232.19.129 to 245.232.19.254245.232.19.255126
41245.232.20.0/25245.232.20.1 to 245.232.20.126245.232.20.127126
42245.232.20.128/25245.232.20.129 to 245.232.20.254245.232.20.255126
43245.232.21.0/25245.232.21.1 to 245.232.21.126245.232.21.127126
44245.232.21.128/25245.232.21.129 to 245.232.21.254245.232.21.255126
45245.232.22.0/25245.232.22.1 to 245.232.22.126245.232.22.127126
46245.232.22.128/25245.232.22.129 to 245.232.22.254245.232.22.255126
47245.232.23.0/25245.232.23.1 to 245.232.23.126245.232.23.127126
48245.232.23.128/25245.232.23.129 to 245.232.23.254245.232.23.255126
49245.232.24.0/25245.232.24.1 to 245.232.24.126245.232.24.127126
50245.232.24.128/25245.232.24.129 to 245.232.24.254245.232.24.255126
51245.232.25.0/25245.232.25.1 to 245.232.25.126245.232.25.127126
52245.232.25.128/25245.232.25.129 to 245.232.25.254245.232.25.255126
53245.232.26.0/25245.232.26.1 to 245.232.26.126245.232.26.127126
54245.232.26.128/25245.232.26.129 to 245.232.26.254245.232.26.255126
55245.232.27.0/25245.232.27.1 to 245.232.27.126245.232.27.127126
56245.232.27.128/25245.232.27.129 to 245.232.27.254245.232.27.255126
57245.232.28.0/25245.232.28.1 to 245.232.28.126245.232.28.127126
58245.232.28.128/25245.232.28.129 to 245.232.28.254245.232.28.255126
59245.232.29.0/25245.232.29.1 to 245.232.29.126245.232.29.127126
60245.232.29.128/25245.232.29.129 to 245.232.29.254245.232.29.255126
61245.232.30.0/25245.232.30.1 to 245.232.30.126245.232.30.127126
62245.232.30.128/25245.232.30.129 to 245.232.30.254245.232.30.255126
63245.232.31.0/25245.232.31.1 to 245.232.31.126245.232.31.127126
64245.232.31.128/25245.232.31.129 to 245.232.31.254245.232.31.255126
65245.232.32.0/25245.232.32.1 to 245.232.32.126245.232.32.127126
66245.232.32.128/25245.232.32.129 to 245.232.32.254245.232.32.255126
67245.232.33.0/25245.232.33.1 to 245.232.33.126245.232.33.127126
68245.232.33.128/25245.232.33.129 to 245.232.33.254245.232.33.255126
69245.232.34.0/25245.232.34.1 to 245.232.34.126245.232.34.127126
70245.232.34.128/25245.232.34.129 to 245.232.34.254245.232.34.255126
71245.232.35.0/25245.232.35.1 to 245.232.35.126245.232.35.127126
72245.232.35.128/25245.232.35.129 to 245.232.35.254245.232.35.255126
73245.232.36.0/25245.232.36.1 to 245.232.36.126245.232.36.127126
74245.232.36.128/25245.232.36.129 to 245.232.36.254245.232.36.255126
75245.232.37.0/25245.232.37.1 to 245.232.37.126245.232.37.127126
76245.232.37.128/25245.232.37.129 to 245.232.37.254245.232.37.255126
77245.232.38.0/25245.232.38.1 to 245.232.38.126245.232.38.127126
78245.232.38.128/25245.232.38.129 to 245.232.38.254245.232.38.255126
79245.232.39.0/25245.232.39.1 to 245.232.39.126245.232.39.127126
80245.232.39.128/25245.232.39.129 to 245.232.39.254245.232.39.255126
81245.232.40.0/25245.232.40.1 to 245.232.40.126245.232.40.127126
82245.232.40.128/25245.232.40.129 to 245.232.40.254245.232.40.255126
83245.232.41.0/25245.232.41.1 to 245.232.41.126245.232.41.127126
84245.232.41.128/25245.232.41.129 to 245.232.41.254245.232.41.255126
85245.232.42.0/25245.232.42.1 to 245.232.42.126245.232.42.127126
86245.232.42.128/25245.232.42.129 to 245.232.42.254245.232.42.255126
87245.232.43.0/25245.232.43.1 to 245.232.43.126245.232.43.127126
88245.232.43.128/25245.232.43.129 to 245.232.43.254245.232.43.255126
89245.232.44.0/25245.232.44.1 to 245.232.44.126245.232.44.127126
90245.232.44.128/25245.232.44.129 to 245.232.44.254245.232.44.255126
91245.232.45.0/25245.232.45.1 to 245.232.45.126245.232.45.127126
92245.232.45.128/25245.232.45.129 to 245.232.45.254245.232.45.255126
93245.232.46.0/25245.232.46.1 to 245.232.46.126245.232.46.127126
94245.232.46.128/25245.232.46.129 to 245.232.46.254245.232.46.255126
95245.232.47.0/25245.232.47.1 to 245.232.47.126245.232.47.127126
96245.232.47.128/25245.232.47.129 to 245.232.47.254245.232.47.255126
97245.232.48.0/25245.232.48.1 to 245.232.48.126245.232.48.127126
98245.232.48.128/25245.232.48.129 to 245.232.48.254245.232.48.255126
99245.232.49.0/25245.232.49.1 to 245.232.49.126245.232.49.127126
100245.232.49.128/25245.232.49.129 to 245.232.49.254245.232.49.255126
101245.232.50.0/25245.232.50.1 to 245.232.50.126245.232.50.127126
102245.232.50.128/25245.232.50.129 to 245.232.50.254245.232.50.255126
103245.232.51.0/25245.232.51.1 to 245.232.51.126245.232.51.127126
104245.232.51.128/25245.232.51.129 to 245.232.51.254245.232.51.255126
105245.232.52.0/25245.232.52.1 to 245.232.52.126245.232.52.127126
106245.232.52.128/25245.232.52.129 to 245.232.52.254245.232.52.255126
107245.232.53.0/25245.232.53.1 to 245.232.53.126245.232.53.127126
108245.232.53.128/25245.232.53.129 to 245.232.53.254245.232.53.255126
109245.232.54.0/25245.232.54.1 to 245.232.54.126245.232.54.127126
110245.232.54.128/25245.232.54.129 to 245.232.54.254245.232.54.255126
111245.232.55.0/25245.232.55.1 to 245.232.55.126245.232.55.127126
112245.232.55.128/25245.232.55.129 to 245.232.55.254245.232.55.255126
113245.232.56.0/25245.232.56.1 to 245.232.56.126245.232.56.127126
114245.232.56.128/25245.232.56.129 to 245.232.56.254245.232.56.255126
115245.232.57.0/25245.232.57.1 to 245.232.57.126245.232.57.127126
116245.232.57.128/25245.232.57.129 to 245.232.57.254245.232.57.255126
117245.232.58.0/25245.232.58.1 to 245.232.58.126245.232.58.127126
118245.232.58.128/25245.232.58.129 to 245.232.58.254245.232.58.255126
119245.232.59.0/25245.232.59.1 to 245.232.59.126245.232.59.127126
120245.232.59.128/25245.232.59.129 to 245.232.59.254245.232.59.255126
121245.232.60.0/25245.232.60.1 to 245.232.60.126245.232.60.127126
122245.232.60.128/25245.232.60.129 to 245.232.60.254245.232.60.255126
123245.232.61.0/25245.232.61.1 to 245.232.61.126245.232.61.127126
124245.232.61.128/25245.232.61.129 to 245.232.61.254245.232.61.255126
125245.232.62.0/25245.232.62.1 to 245.232.62.126245.232.62.127126
126245.232.62.128/25245.232.62.129 to 245.232.62.254245.232.62.255126
127245.232.63.0/25245.232.63.1 to 245.232.63.126245.232.63.127126
128245.232.63.128/25245.232.63.129 to 245.232.63.254245.232.63.255126
129245.232.64.0/25245.232.64.1 to 245.232.64.126245.232.64.127126
130245.232.64.128/25245.232.64.129 to 245.232.64.254245.232.64.255126
131245.232.65.0/25245.232.65.1 to 245.232.65.126245.232.65.127126
132245.232.65.128/25245.232.65.129 to 245.232.65.254245.232.65.255126
133245.232.66.0/25245.232.66.1 to 245.232.66.126245.232.66.127126
134245.232.66.128/25245.232.66.129 to 245.232.66.254245.232.66.255126
135245.232.67.0/25245.232.67.1 to 245.232.67.126245.232.67.127126
136245.232.67.128/25245.232.67.129 to 245.232.67.254245.232.67.255126
137245.232.68.0/25245.232.68.1 to 245.232.68.126245.232.68.127126
138245.232.68.128/25245.232.68.129 to 245.232.68.254245.232.68.255126
139245.232.69.0/25245.232.69.1 to 245.232.69.126245.232.69.127126
140245.232.69.128/25245.232.69.129 to 245.232.69.254245.232.69.255126
141245.232.70.0/25245.232.70.1 to 245.232.70.126245.232.70.127126
142245.232.70.128/25245.232.70.129 to 245.232.70.254245.232.70.255126
143245.232.71.0/25245.232.71.1 to 245.232.71.126245.232.71.127126
144245.232.71.128/25245.232.71.129 to 245.232.71.254245.232.71.255126
145245.232.72.0/25245.232.72.1 to 245.232.72.126245.232.72.127126
146245.232.72.128/25245.232.72.129 to 245.232.72.254245.232.72.255126
147245.232.73.0/25245.232.73.1 to 245.232.73.126245.232.73.127126
148245.232.73.128/25245.232.73.129 to 245.232.73.254245.232.73.255126
149245.232.74.0/25245.232.74.1 to 245.232.74.126245.232.74.127126
150245.232.74.128/25245.232.74.129 to 245.232.74.254245.232.74.255126
151245.232.75.0/25245.232.75.1 to 245.232.75.126245.232.75.127126
152245.232.75.128/25245.232.75.129 to 245.232.75.254245.232.75.255126
153245.232.76.0/25245.232.76.1 to 245.232.76.126245.232.76.127126
154245.232.76.128/25245.232.76.129 to 245.232.76.254245.232.76.255126
155245.232.77.0/25245.232.77.1 to 245.232.77.126245.232.77.127126
156245.232.77.128/25245.232.77.129 to 245.232.77.254245.232.77.255126
157245.232.78.0/25245.232.78.1 to 245.232.78.126245.232.78.127126
158245.232.78.128/25245.232.78.129 to 245.232.78.254245.232.78.255126
159245.232.79.0/25245.232.79.1 to 245.232.79.126245.232.79.127126
160245.232.79.128/25245.232.79.129 to 245.232.79.254245.232.79.255126
161245.232.80.0/25245.232.80.1 to 245.232.80.126245.232.80.127126
162245.232.80.128/25245.232.80.129 to 245.232.80.254245.232.80.255126
163245.232.81.0/25245.232.81.1 to 245.232.81.126245.232.81.127126
164245.232.81.128/25245.232.81.129 to 245.232.81.254245.232.81.255126
165245.232.82.0/25245.232.82.1 to 245.232.82.126245.232.82.127126
166245.232.82.128/25245.232.82.129 to 245.232.82.254245.232.82.255126
167245.232.83.0/25245.232.83.1 to 245.232.83.126245.232.83.127126
168245.232.83.128/25245.232.83.129 to 245.232.83.254245.232.83.255126
169245.232.84.0/25245.232.84.1 to 245.232.84.126245.232.84.127126
170245.232.84.128/25245.232.84.129 to 245.232.84.254245.232.84.255126
171245.232.85.0/25245.232.85.1 to 245.232.85.126245.232.85.127126
172245.232.85.128/25245.232.85.129 to 245.232.85.254245.232.85.255126
173245.232.86.0/25245.232.86.1 to 245.232.86.126245.232.86.127126
174245.232.86.128/25245.232.86.129 to 245.232.86.254245.232.86.255126
175245.232.87.0/25245.232.87.1 to 245.232.87.126245.232.87.127126
176245.232.87.128/25245.232.87.129 to 245.232.87.254245.232.87.255126
177245.232.88.0/25245.232.88.1 to 245.232.88.126245.232.88.127126
178245.232.88.128/25245.232.88.129 to 245.232.88.254245.232.88.255126
179245.232.89.0/25245.232.89.1 to 245.232.89.126245.232.89.127126
180245.232.89.128/25245.232.89.129 to 245.232.89.254245.232.89.255126
181245.232.90.0/25245.232.90.1 to 245.232.90.126245.232.90.127126
182245.232.90.128/25245.232.90.129 to 245.232.90.254245.232.90.255126
183245.232.91.0/25245.232.91.1 to 245.232.91.126245.232.91.127126
184245.232.91.128/25245.232.91.129 to 245.232.91.254245.232.91.255126
185245.232.92.0/25245.232.92.1 to 245.232.92.126245.232.92.127126
186245.232.92.128/25245.232.92.129 to 245.232.92.254245.232.92.255126
187245.232.93.0/25245.232.93.1 to 245.232.93.126245.232.93.127126
188245.232.93.128/25245.232.93.129 to 245.232.93.254245.232.93.255126
189245.232.94.0/25245.232.94.1 to 245.232.94.126245.232.94.127126
190245.232.94.128/25245.232.94.129 to 245.232.94.254245.232.94.255126
191245.232.95.0/25245.232.95.1 to 245.232.95.126245.232.95.127126
192245.232.95.128/25245.232.95.129 to 245.232.95.254245.232.95.255126
193245.232.96.0/25245.232.96.1 to 245.232.96.126245.232.96.127126
194245.232.96.128/25245.232.96.129 to 245.232.96.254245.232.96.255126
195245.232.97.0/25245.232.97.1 to 245.232.97.126245.232.97.127126
196245.232.97.128/25245.232.97.129 to 245.232.97.254245.232.97.255126
197245.232.98.0/25245.232.98.1 to 245.232.98.126245.232.98.127126
198245.232.98.128/25245.232.98.129 to 245.232.98.254245.232.98.255126
199245.232.99.0/25245.232.99.1 to 245.232.99.126245.232.99.127126
200245.232.99.128/25245.232.99.129 to 245.232.99.254245.232.99.255126
201245.232.100.0/25245.232.100.1 to 245.232.100.126245.232.100.127126
202245.232.100.128/25245.232.100.129 to 245.232.100.254245.232.100.255126
203245.232.101.0/25245.232.101.1 to 245.232.101.126245.232.101.127126
204245.232.101.128/25245.232.101.129 to 245.232.101.254245.232.101.255126
205245.232.102.0/25245.232.102.1 to 245.232.102.126245.232.102.127126
206245.232.102.128/25245.232.102.129 to 245.232.102.254245.232.102.255126
207245.232.103.0/25245.232.103.1 to 245.232.103.126245.232.103.127126
208245.232.103.128/25245.232.103.129 to 245.232.103.254245.232.103.255126
209245.232.104.0/25245.232.104.1 to 245.232.104.126245.232.104.127126
210245.232.104.128/25245.232.104.129 to 245.232.104.254245.232.104.255126
211245.232.105.0/25245.232.105.1 to 245.232.105.126245.232.105.127126
212245.232.105.128/25245.232.105.129 to 245.232.105.254245.232.105.255126
213245.232.106.0/25245.232.106.1 to 245.232.106.126245.232.106.127126
214245.232.106.128/25245.232.106.129 to 245.232.106.254245.232.106.255126
215245.232.107.0/25245.232.107.1 to 245.232.107.126245.232.107.127126
216245.232.107.128/25245.232.107.129 to 245.232.107.254245.232.107.255126
217245.232.108.0/25245.232.108.1 to 245.232.108.126245.232.108.127126
218245.232.108.128/25245.232.108.129 to 245.232.108.254245.232.108.255126
219245.232.109.0/25245.232.109.1 to 245.232.109.126245.232.109.127126
220245.232.109.128/25245.232.109.129 to 245.232.109.254245.232.109.255126
221245.232.110.0/25245.232.110.1 to 245.232.110.126245.232.110.127126
222245.232.110.128/25245.232.110.129 to 245.232.110.254245.232.110.255126
223245.232.111.0/25245.232.111.1 to 245.232.111.126245.232.111.127126
224245.232.111.128/25245.232.111.129 to 245.232.111.254245.232.111.255126
225245.232.112.0/25245.232.112.1 to 245.232.112.126245.232.112.127126
226245.232.112.128/25245.232.112.129 to 245.232.112.254245.232.112.255126
227245.232.113.0/25245.232.113.1 to 245.232.113.126245.232.113.127126
228245.232.113.128/25245.232.113.129 to 245.232.113.254245.232.113.255126
229245.232.114.0/25245.232.114.1 to 245.232.114.126245.232.114.127126
230245.232.114.128/25245.232.114.129 to 245.232.114.254245.232.114.255126
231245.232.115.0/25245.232.115.1 to 245.232.115.126245.232.115.127126
232245.232.115.128/25245.232.115.129 to 245.232.115.254245.232.115.255126
233245.232.116.0/25245.232.116.1 to 245.232.116.126245.232.116.127126
234245.232.116.128/25245.232.116.129 to 245.232.116.254245.232.116.255126
235245.232.117.0/25245.232.117.1 to 245.232.117.126245.232.117.127126
236245.232.117.128/25245.232.117.129 to 245.232.117.254245.232.117.255126
237245.232.118.0/25245.232.118.1 to 245.232.118.126245.232.118.127126
238245.232.118.128/25245.232.118.129 to 245.232.118.254245.232.118.255126
239245.232.119.0/25245.232.119.1 to 245.232.119.126245.232.119.127126
240245.232.119.128/25245.232.119.129 to 245.232.119.254245.232.119.255126
241245.232.120.0/25245.232.120.1 to 245.232.120.126245.232.120.127126
242245.232.120.128/25245.232.120.129 to 245.232.120.254245.232.120.255126
243245.232.121.0/25245.232.121.1 to 245.232.121.126245.232.121.127126
244245.232.121.128/25245.232.121.129 to 245.232.121.254245.232.121.255126
245245.232.122.0/25245.232.122.1 to 245.232.122.126245.232.122.127126
246245.232.122.128/25245.232.122.129 to 245.232.122.254245.232.122.255126
247245.232.123.0/25245.232.123.1 to 245.232.123.126245.232.123.127126
248245.232.123.128/25245.232.123.129 to 245.232.123.254245.232.123.255126
249245.232.124.0/25245.232.124.1 to 245.232.124.126245.232.124.127126
250245.232.124.128/25245.232.124.129 to 245.232.124.254245.232.124.255126
251245.232.125.0/25245.232.125.1 to 245.232.125.126245.232.125.127126
252245.232.125.128/25245.232.125.129 to 245.232.125.254245.232.125.255126
253245.232.126.0/25245.232.126.1 to 245.232.126.126245.232.126.127126
254245.232.126.128/25245.232.126.129 to 245.232.126.254245.232.126.255126
255245.232.127.0/25245.232.127.1 to 245.232.127.126245.232.127.127126
256245.232.127.128/25245.232.127.129 to 245.232.127.254245.232.127.255126

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.