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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.

Network154.158.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
154.158.0.0
Broadcast address
154.159.255.255
First usable
154.158.0.1
Last usable
154.159.255.254
Usable hosts
131,070 (131,072 less the network and broadcast addresses)
Subnet mask
255.254.0.0
Wildcard mask
0.1.255.255 (Cisco ACLs, OSPF)
Prefix length
/15
Type
Public public
Old class
B (default /16)
As numbers
Hex 9A9E0000 · Integer 2594045952 to 2594177023
Reverse DNS zones
158.154.in-addr.arpa
159.154.in-addr.arpa
/15 is not on a 8-bit boundary, so it takes 2 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10011010.10011110.00000000.00000000154.158.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network10011010.10011110.00000000.00000000154.158.0.0
Broadcast10011010.10011111.11111111.11111111154.159.255.255
Split into smaller subnets/25
/16 (2)/17 (4)/18 (8)/19 (16)/20 (32)/21 (64)/22 (128)/23 (256)/24 (512)/25 (1,024)/26 (2,048)/27 (4,096)

154.158.0.0/15 makes 1,024 subnets of /25; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1154.158.0.0/25154.158.0.1 to 154.158.0.126154.158.0.127126
2154.158.0.128/25154.158.0.129 to 154.158.0.254154.158.0.255126
3154.158.1.0/25154.158.1.1 to 154.158.1.126154.158.1.127126
4154.158.1.128/25154.158.1.129 to 154.158.1.254154.158.1.255126
5154.158.2.0/25154.158.2.1 to 154.158.2.126154.158.2.127126
6154.158.2.128/25154.158.2.129 to 154.158.2.254154.158.2.255126
7154.158.3.0/25154.158.3.1 to 154.158.3.126154.158.3.127126
8154.158.3.128/25154.158.3.129 to 154.158.3.254154.158.3.255126
9154.158.4.0/25154.158.4.1 to 154.158.4.126154.158.4.127126
10154.158.4.128/25154.158.4.129 to 154.158.4.254154.158.4.255126
11154.158.5.0/25154.158.5.1 to 154.158.5.126154.158.5.127126
12154.158.5.128/25154.158.5.129 to 154.158.5.254154.158.5.255126
13154.158.6.0/25154.158.6.1 to 154.158.6.126154.158.6.127126
14154.158.6.128/25154.158.6.129 to 154.158.6.254154.158.6.255126
15154.158.7.0/25154.158.7.1 to 154.158.7.126154.158.7.127126
16154.158.7.128/25154.158.7.129 to 154.158.7.254154.158.7.255126
17154.158.8.0/25154.158.8.1 to 154.158.8.126154.158.8.127126
18154.158.8.128/25154.158.8.129 to 154.158.8.254154.158.8.255126
19154.158.9.0/25154.158.9.1 to 154.158.9.126154.158.9.127126
20154.158.9.128/25154.158.9.129 to 154.158.9.254154.158.9.255126
21154.158.10.0/25154.158.10.1 to 154.158.10.126154.158.10.127126
22154.158.10.128/25154.158.10.129 to 154.158.10.254154.158.10.255126
23154.158.11.0/25154.158.11.1 to 154.158.11.126154.158.11.127126
24154.158.11.128/25154.158.11.129 to 154.158.11.254154.158.11.255126
25154.158.12.0/25154.158.12.1 to 154.158.12.126154.158.12.127126
26154.158.12.128/25154.158.12.129 to 154.158.12.254154.158.12.255126
27154.158.13.0/25154.158.13.1 to 154.158.13.126154.158.13.127126
28154.158.13.128/25154.158.13.129 to 154.158.13.254154.158.13.255126
29154.158.14.0/25154.158.14.1 to 154.158.14.126154.158.14.127126
30154.158.14.128/25154.158.14.129 to 154.158.14.254154.158.14.255126
31154.158.15.0/25154.158.15.1 to 154.158.15.126154.158.15.127126
32154.158.15.128/25154.158.15.129 to 154.158.15.254154.158.15.255126
33154.158.16.0/25154.158.16.1 to 154.158.16.126154.158.16.127126
34154.158.16.128/25154.158.16.129 to 154.158.16.254154.158.16.255126
35154.158.17.0/25154.158.17.1 to 154.158.17.126154.158.17.127126
36154.158.17.128/25154.158.17.129 to 154.158.17.254154.158.17.255126
37154.158.18.0/25154.158.18.1 to 154.158.18.126154.158.18.127126
38154.158.18.128/25154.158.18.129 to 154.158.18.254154.158.18.255126
39154.158.19.0/25154.158.19.1 to 154.158.19.126154.158.19.127126
40154.158.19.128/25154.158.19.129 to 154.158.19.254154.158.19.255126
41154.158.20.0/25154.158.20.1 to 154.158.20.126154.158.20.127126
42154.158.20.128/25154.158.20.129 to 154.158.20.254154.158.20.255126
43154.158.21.0/25154.158.21.1 to 154.158.21.126154.158.21.127126
44154.158.21.128/25154.158.21.129 to 154.158.21.254154.158.21.255126
45154.158.22.0/25154.158.22.1 to 154.158.22.126154.158.22.127126
46154.158.22.128/25154.158.22.129 to 154.158.22.254154.158.22.255126
47154.158.23.0/25154.158.23.1 to 154.158.23.126154.158.23.127126
48154.158.23.128/25154.158.23.129 to 154.158.23.254154.158.23.255126
49154.158.24.0/25154.158.24.1 to 154.158.24.126154.158.24.127126
50154.158.24.128/25154.158.24.129 to 154.158.24.254154.158.24.255126
51154.158.25.0/25154.158.25.1 to 154.158.25.126154.158.25.127126
52154.158.25.128/25154.158.25.129 to 154.158.25.254154.158.25.255126
53154.158.26.0/25154.158.26.1 to 154.158.26.126154.158.26.127126
54154.158.26.128/25154.158.26.129 to 154.158.26.254154.158.26.255126
55154.158.27.0/25154.158.27.1 to 154.158.27.126154.158.27.127126
56154.158.27.128/25154.158.27.129 to 154.158.27.254154.158.27.255126
57154.158.28.0/25154.158.28.1 to 154.158.28.126154.158.28.127126
58154.158.28.128/25154.158.28.129 to 154.158.28.254154.158.28.255126
59154.158.29.0/25154.158.29.1 to 154.158.29.126154.158.29.127126
60154.158.29.128/25154.158.29.129 to 154.158.29.254154.158.29.255126
61154.158.30.0/25154.158.30.1 to 154.158.30.126154.158.30.127126
62154.158.30.128/25154.158.30.129 to 154.158.30.254154.158.30.255126
63154.158.31.0/25154.158.31.1 to 154.158.31.126154.158.31.127126
64154.158.31.128/25154.158.31.129 to 154.158.31.254154.158.31.255126
65154.158.32.0/25154.158.32.1 to 154.158.32.126154.158.32.127126
66154.158.32.128/25154.158.32.129 to 154.158.32.254154.158.32.255126
67154.158.33.0/25154.158.33.1 to 154.158.33.126154.158.33.127126
68154.158.33.128/25154.158.33.129 to 154.158.33.254154.158.33.255126
69154.158.34.0/25154.158.34.1 to 154.158.34.126154.158.34.127126
70154.158.34.128/25154.158.34.129 to 154.158.34.254154.158.34.255126
71154.158.35.0/25154.158.35.1 to 154.158.35.126154.158.35.127126
72154.158.35.128/25154.158.35.129 to 154.158.35.254154.158.35.255126
73154.158.36.0/25154.158.36.1 to 154.158.36.126154.158.36.127126
74154.158.36.128/25154.158.36.129 to 154.158.36.254154.158.36.255126
75154.158.37.0/25154.158.37.1 to 154.158.37.126154.158.37.127126
76154.158.37.128/25154.158.37.129 to 154.158.37.254154.158.37.255126
77154.158.38.0/25154.158.38.1 to 154.158.38.126154.158.38.127126
78154.158.38.128/25154.158.38.129 to 154.158.38.254154.158.38.255126
79154.158.39.0/25154.158.39.1 to 154.158.39.126154.158.39.127126
80154.158.39.128/25154.158.39.129 to 154.158.39.254154.158.39.255126
81154.158.40.0/25154.158.40.1 to 154.158.40.126154.158.40.127126
82154.158.40.128/25154.158.40.129 to 154.158.40.254154.158.40.255126
83154.158.41.0/25154.158.41.1 to 154.158.41.126154.158.41.127126
84154.158.41.128/25154.158.41.129 to 154.158.41.254154.158.41.255126
85154.158.42.0/25154.158.42.1 to 154.158.42.126154.158.42.127126
86154.158.42.128/25154.158.42.129 to 154.158.42.254154.158.42.255126
87154.158.43.0/25154.158.43.1 to 154.158.43.126154.158.43.127126
88154.158.43.128/25154.158.43.129 to 154.158.43.254154.158.43.255126
89154.158.44.0/25154.158.44.1 to 154.158.44.126154.158.44.127126
90154.158.44.128/25154.158.44.129 to 154.158.44.254154.158.44.255126
91154.158.45.0/25154.158.45.1 to 154.158.45.126154.158.45.127126
92154.158.45.128/25154.158.45.129 to 154.158.45.254154.158.45.255126
93154.158.46.0/25154.158.46.1 to 154.158.46.126154.158.46.127126
94154.158.46.128/25154.158.46.129 to 154.158.46.254154.158.46.255126
95154.158.47.0/25154.158.47.1 to 154.158.47.126154.158.47.127126
96154.158.47.128/25154.158.47.129 to 154.158.47.254154.158.47.255126
97154.158.48.0/25154.158.48.1 to 154.158.48.126154.158.48.127126
98154.158.48.128/25154.158.48.129 to 154.158.48.254154.158.48.255126
99154.158.49.0/25154.158.49.1 to 154.158.49.126154.158.49.127126
100154.158.49.128/25154.158.49.129 to 154.158.49.254154.158.49.255126
101154.158.50.0/25154.158.50.1 to 154.158.50.126154.158.50.127126
102154.158.50.128/25154.158.50.129 to 154.158.50.254154.158.50.255126
103154.158.51.0/25154.158.51.1 to 154.158.51.126154.158.51.127126
104154.158.51.128/25154.158.51.129 to 154.158.51.254154.158.51.255126
105154.158.52.0/25154.158.52.1 to 154.158.52.126154.158.52.127126
106154.158.52.128/25154.158.52.129 to 154.158.52.254154.158.52.255126
107154.158.53.0/25154.158.53.1 to 154.158.53.126154.158.53.127126
108154.158.53.128/25154.158.53.129 to 154.158.53.254154.158.53.255126
109154.158.54.0/25154.158.54.1 to 154.158.54.126154.158.54.127126
110154.158.54.128/25154.158.54.129 to 154.158.54.254154.158.54.255126
111154.158.55.0/25154.158.55.1 to 154.158.55.126154.158.55.127126
112154.158.55.128/25154.158.55.129 to 154.158.55.254154.158.55.255126
113154.158.56.0/25154.158.56.1 to 154.158.56.126154.158.56.127126
114154.158.56.128/25154.158.56.129 to 154.158.56.254154.158.56.255126
115154.158.57.0/25154.158.57.1 to 154.158.57.126154.158.57.127126
116154.158.57.128/25154.158.57.129 to 154.158.57.254154.158.57.255126
117154.158.58.0/25154.158.58.1 to 154.158.58.126154.158.58.127126
118154.158.58.128/25154.158.58.129 to 154.158.58.254154.158.58.255126
119154.158.59.0/25154.158.59.1 to 154.158.59.126154.158.59.127126
120154.158.59.128/25154.158.59.129 to 154.158.59.254154.158.59.255126
121154.158.60.0/25154.158.60.1 to 154.158.60.126154.158.60.127126
122154.158.60.128/25154.158.60.129 to 154.158.60.254154.158.60.255126
123154.158.61.0/25154.158.61.1 to 154.158.61.126154.158.61.127126
124154.158.61.128/25154.158.61.129 to 154.158.61.254154.158.61.255126
125154.158.62.0/25154.158.62.1 to 154.158.62.126154.158.62.127126
126154.158.62.128/25154.158.62.129 to 154.158.62.254154.158.62.255126
127154.158.63.0/25154.158.63.1 to 154.158.63.126154.158.63.127126
128154.158.63.128/25154.158.63.129 to 154.158.63.254154.158.63.255126
129154.158.64.0/25154.158.64.1 to 154.158.64.126154.158.64.127126
130154.158.64.128/25154.158.64.129 to 154.158.64.254154.158.64.255126
131154.158.65.0/25154.158.65.1 to 154.158.65.126154.158.65.127126
132154.158.65.128/25154.158.65.129 to 154.158.65.254154.158.65.255126
133154.158.66.0/25154.158.66.1 to 154.158.66.126154.158.66.127126
134154.158.66.128/25154.158.66.129 to 154.158.66.254154.158.66.255126
135154.158.67.0/25154.158.67.1 to 154.158.67.126154.158.67.127126
136154.158.67.128/25154.158.67.129 to 154.158.67.254154.158.67.255126
137154.158.68.0/25154.158.68.1 to 154.158.68.126154.158.68.127126
138154.158.68.128/25154.158.68.129 to 154.158.68.254154.158.68.255126
139154.158.69.0/25154.158.69.1 to 154.158.69.126154.158.69.127126
140154.158.69.128/25154.158.69.129 to 154.158.69.254154.158.69.255126
141154.158.70.0/25154.158.70.1 to 154.158.70.126154.158.70.127126
142154.158.70.128/25154.158.70.129 to 154.158.70.254154.158.70.255126
143154.158.71.0/25154.158.71.1 to 154.158.71.126154.158.71.127126
144154.158.71.128/25154.158.71.129 to 154.158.71.254154.158.71.255126
145154.158.72.0/25154.158.72.1 to 154.158.72.126154.158.72.127126
146154.158.72.128/25154.158.72.129 to 154.158.72.254154.158.72.255126
147154.158.73.0/25154.158.73.1 to 154.158.73.126154.158.73.127126
148154.158.73.128/25154.158.73.129 to 154.158.73.254154.158.73.255126
149154.158.74.0/25154.158.74.1 to 154.158.74.126154.158.74.127126
150154.158.74.128/25154.158.74.129 to 154.158.74.254154.158.74.255126
151154.158.75.0/25154.158.75.1 to 154.158.75.126154.158.75.127126
152154.158.75.128/25154.158.75.129 to 154.158.75.254154.158.75.255126
153154.158.76.0/25154.158.76.1 to 154.158.76.126154.158.76.127126
154154.158.76.128/25154.158.76.129 to 154.158.76.254154.158.76.255126
155154.158.77.0/25154.158.77.1 to 154.158.77.126154.158.77.127126
156154.158.77.128/25154.158.77.129 to 154.158.77.254154.158.77.255126
157154.158.78.0/25154.158.78.1 to 154.158.78.126154.158.78.127126
158154.158.78.128/25154.158.78.129 to 154.158.78.254154.158.78.255126
159154.158.79.0/25154.158.79.1 to 154.158.79.126154.158.79.127126
160154.158.79.128/25154.158.79.129 to 154.158.79.254154.158.79.255126
161154.158.80.0/25154.158.80.1 to 154.158.80.126154.158.80.127126
162154.158.80.128/25154.158.80.129 to 154.158.80.254154.158.80.255126
163154.158.81.0/25154.158.81.1 to 154.158.81.126154.158.81.127126
164154.158.81.128/25154.158.81.129 to 154.158.81.254154.158.81.255126
165154.158.82.0/25154.158.82.1 to 154.158.82.126154.158.82.127126
166154.158.82.128/25154.158.82.129 to 154.158.82.254154.158.82.255126
167154.158.83.0/25154.158.83.1 to 154.158.83.126154.158.83.127126
168154.158.83.128/25154.158.83.129 to 154.158.83.254154.158.83.255126
169154.158.84.0/25154.158.84.1 to 154.158.84.126154.158.84.127126
170154.158.84.128/25154.158.84.129 to 154.158.84.254154.158.84.255126
171154.158.85.0/25154.158.85.1 to 154.158.85.126154.158.85.127126
172154.158.85.128/25154.158.85.129 to 154.158.85.254154.158.85.255126
173154.158.86.0/25154.158.86.1 to 154.158.86.126154.158.86.127126
174154.158.86.128/25154.158.86.129 to 154.158.86.254154.158.86.255126
175154.158.87.0/25154.158.87.1 to 154.158.87.126154.158.87.127126
176154.158.87.128/25154.158.87.129 to 154.158.87.254154.158.87.255126
177154.158.88.0/25154.158.88.1 to 154.158.88.126154.158.88.127126
178154.158.88.128/25154.158.88.129 to 154.158.88.254154.158.88.255126
179154.158.89.0/25154.158.89.1 to 154.158.89.126154.158.89.127126
180154.158.89.128/25154.158.89.129 to 154.158.89.254154.158.89.255126
181154.158.90.0/25154.158.90.1 to 154.158.90.126154.158.90.127126
182154.158.90.128/25154.158.90.129 to 154.158.90.254154.158.90.255126
183154.158.91.0/25154.158.91.1 to 154.158.91.126154.158.91.127126
184154.158.91.128/25154.158.91.129 to 154.158.91.254154.158.91.255126
185154.158.92.0/25154.158.92.1 to 154.158.92.126154.158.92.127126
186154.158.92.128/25154.158.92.129 to 154.158.92.254154.158.92.255126
187154.158.93.0/25154.158.93.1 to 154.158.93.126154.158.93.127126
188154.158.93.128/25154.158.93.129 to 154.158.93.254154.158.93.255126
189154.158.94.0/25154.158.94.1 to 154.158.94.126154.158.94.127126
190154.158.94.128/25154.158.94.129 to 154.158.94.254154.158.94.255126
191154.158.95.0/25154.158.95.1 to 154.158.95.126154.158.95.127126
192154.158.95.128/25154.158.95.129 to 154.158.95.254154.158.95.255126
193154.158.96.0/25154.158.96.1 to 154.158.96.126154.158.96.127126
194154.158.96.128/25154.158.96.129 to 154.158.96.254154.158.96.255126
195154.158.97.0/25154.158.97.1 to 154.158.97.126154.158.97.127126
196154.158.97.128/25154.158.97.129 to 154.158.97.254154.158.97.255126
197154.158.98.0/25154.158.98.1 to 154.158.98.126154.158.98.127126
198154.158.98.128/25154.158.98.129 to 154.158.98.254154.158.98.255126
199154.158.99.0/25154.158.99.1 to 154.158.99.126154.158.99.127126
200154.158.99.128/25154.158.99.129 to 154.158.99.254154.158.99.255126
201154.158.100.0/25154.158.100.1 to 154.158.100.126154.158.100.127126
202154.158.100.128/25154.158.100.129 to 154.158.100.254154.158.100.255126
203154.158.101.0/25154.158.101.1 to 154.158.101.126154.158.101.127126
204154.158.101.128/25154.158.101.129 to 154.158.101.254154.158.101.255126
205154.158.102.0/25154.158.102.1 to 154.158.102.126154.158.102.127126
206154.158.102.128/25154.158.102.129 to 154.158.102.254154.158.102.255126
207154.158.103.0/25154.158.103.1 to 154.158.103.126154.158.103.127126
208154.158.103.128/25154.158.103.129 to 154.158.103.254154.158.103.255126
209154.158.104.0/25154.158.104.1 to 154.158.104.126154.158.104.127126
210154.158.104.128/25154.158.104.129 to 154.158.104.254154.158.104.255126
211154.158.105.0/25154.158.105.1 to 154.158.105.126154.158.105.127126
212154.158.105.128/25154.158.105.129 to 154.158.105.254154.158.105.255126
213154.158.106.0/25154.158.106.1 to 154.158.106.126154.158.106.127126
214154.158.106.128/25154.158.106.129 to 154.158.106.254154.158.106.255126
215154.158.107.0/25154.158.107.1 to 154.158.107.126154.158.107.127126
216154.158.107.128/25154.158.107.129 to 154.158.107.254154.158.107.255126
217154.158.108.0/25154.158.108.1 to 154.158.108.126154.158.108.127126
218154.158.108.128/25154.158.108.129 to 154.158.108.254154.158.108.255126
219154.158.109.0/25154.158.109.1 to 154.158.109.126154.158.109.127126
220154.158.109.128/25154.158.109.129 to 154.158.109.254154.158.109.255126
221154.158.110.0/25154.158.110.1 to 154.158.110.126154.158.110.127126
222154.158.110.128/25154.158.110.129 to 154.158.110.254154.158.110.255126
223154.158.111.0/25154.158.111.1 to 154.158.111.126154.158.111.127126
224154.158.111.128/25154.158.111.129 to 154.158.111.254154.158.111.255126
225154.158.112.0/25154.158.112.1 to 154.158.112.126154.158.112.127126
226154.158.112.128/25154.158.112.129 to 154.158.112.254154.158.112.255126
227154.158.113.0/25154.158.113.1 to 154.158.113.126154.158.113.127126
228154.158.113.128/25154.158.113.129 to 154.158.113.254154.158.113.255126
229154.158.114.0/25154.158.114.1 to 154.158.114.126154.158.114.127126
230154.158.114.128/25154.158.114.129 to 154.158.114.254154.158.114.255126
231154.158.115.0/25154.158.115.1 to 154.158.115.126154.158.115.127126
232154.158.115.128/25154.158.115.129 to 154.158.115.254154.158.115.255126
233154.158.116.0/25154.158.116.1 to 154.158.116.126154.158.116.127126
234154.158.116.128/25154.158.116.129 to 154.158.116.254154.158.116.255126
235154.158.117.0/25154.158.117.1 to 154.158.117.126154.158.117.127126
236154.158.117.128/25154.158.117.129 to 154.158.117.254154.158.117.255126
237154.158.118.0/25154.158.118.1 to 154.158.118.126154.158.118.127126
238154.158.118.128/25154.158.118.129 to 154.158.118.254154.158.118.255126
239154.158.119.0/25154.158.119.1 to 154.158.119.126154.158.119.127126
240154.158.119.128/25154.158.119.129 to 154.158.119.254154.158.119.255126
241154.158.120.0/25154.158.120.1 to 154.158.120.126154.158.120.127126
242154.158.120.128/25154.158.120.129 to 154.158.120.254154.158.120.255126
243154.158.121.0/25154.158.121.1 to 154.158.121.126154.158.121.127126
244154.158.121.128/25154.158.121.129 to 154.158.121.254154.158.121.255126
245154.158.122.0/25154.158.122.1 to 154.158.122.126154.158.122.127126
246154.158.122.128/25154.158.122.129 to 154.158.122.254154.158.122.255126
247154.158.123.0/25154.158.123.1 to 154.158.123.126154.158.123.127126
248154.158.123.128/25154.158.123.129 to 154.158.123.254154.158.123.255126
249154.158.124.0/25154.158.124.1 to 154.158.124.126154.158.124.127126
250154.158.124.128/25154.158.124.129 to 154.158.124.254154.158.124.255126
251154.158.125.0/25154.158.125.1 to 154.158.125.126154.158.125.127126
252154.158.125.128/25154.158.125.129 to 154.158.125.254154.158.125.255126
253154.158.126.0/25154.158.126.1 to 154.158.126.126154.158.126.127126
254154.158.126.128/25154.158.126.129 to 154.158.126.254154.158.126.255126
255154.158.127.0/25154.158.127.1 to 154.158.127.126154.158.127.127126
256154.158.127.128/25154.158.127.129 to 154.158.127.254154.158.127.255126

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.