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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.

Network147.76.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
147.76.0.0
Broadcast address
147.77.255.255
First usable
147.76.0.1
Last usable
147.77.255.254
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 934C0000 · Integer 2471231488 to 2471362559
Reverse DNS zones
76.147.in-addr.arpa
77.147.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
Address10010011.01001100.00000000.00000000147.76.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network10010011.01001100.00000000.00000000147.76.0.0
Broadcast10010011.01001101.11111111.11111111147.77.255.255
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)

147.76.0.0/15 makes 1,024 subnets of /25; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1147.76.0.0/25147.76.0.1 to 147.76.0.126147.76.0.127126
2147.76.0.128/25147.76.0.129 to 147.76.0.254147.76.0.255126
3147.76.1.0/25147.76.1.1 to 147.76.1.126147.76.1.127126
4147.76.1.128/25147.76.1.129 to 147.76.1.254147.76.1.255126
5147.76.2.0/25147.76.2.1 to 147.76.2.126147.76.2.127126
6147.76.2.128/25147.76.2.129 to 147.76.2.254147.76.2.255126
7147.76.3.0/25147.76.3.1 to 147.76.3.126147.76.3.127126
8147.76.3.128/25147.76.3.129 to 147.76.3.254147.76.3.255126
9147.76.4.0/25147.76.4.1 to 147.76.4.126147.76.4.127126
10147.76.4.128/25147.76.4.129 to 147.76.4.254147.76.4.255126
11147.76.5.0/25147.76.5.1 to 147.76.5.126147.76.5.127126
12147.76.5.128/25147.76.5.129 to 147.76.5.254147.76.5.255126
13147.76.6.0/25147.76.6.1 to 147.76.6.126147.76.6.127126
14147.76.6.128/25147.76.6.129 to 147.76.6.254147.76.6.255126
15147.76.7.0/25147.76.7.1 to 147.76.7.126147.76.7.127126
16147.76.7.128/25147.76.7.129 to 147.76.7.254147.76.7.255126
17147.76.8.0/25147.76.8.1 to 147.76.8.126147.76.8.127126
18147.76.8.128/25147.76.8.129 to 147.76.8.254147.76.8.255126
19147.76.9.0/25147.76.9.1 to 147.76.9.126147.76.9.127126
20147.76.9.128/25147.76.9.129 to 147.76.9.254147.76.9.255126
21147.76.10.0/25147.76.10.1 to 147.76.10.126147.76.10.127126
22147.76.10.128/25147.76.10.129 to 147.76.10.254147.76.10.255126
23147.76.11.0/25147.76.11.1 to 147.76.11.126147.76.11.127126
24147.76.11.128/25147.76.11.129 to 147.76.11.254147.76.11.255126
25147.76.12.0/25147.76.12.1 to 147.76.12.126147.76.12.127126
26147.76.12.128/25147.76.12.129 to 147.76.12.254147.76.12.255126
27147.76.13.0/25147.76.13.1 to 147.76.13.126147.76.13.127126
28147.76.13.128/25147.76.13.129 to 147.76.13.254147.76.13.255126
29147.76.14.0/25147.76.14.1 to 147.76.14.126147.76.14.127126
30147.76.14.128/25147.76.14.129 to 147.76.14.254147.76.14.255126
31147.76.15.0/25147.76.15.1 to 147.76.15.126147.76.15.127126
32147.76.15.128/25147.76.15.129 to 147.76.15.254147.76.15.255126
33147.76.16.0/25147.76.16.1 to 147.76.16.126147.76.16.127126
34147.76.16.128/25147.76.16.129 to 147.76.16.254147.76.16.255126
35147.76.17.0/25147.76.17.1 to 147.76.17.126147.76.17.127126
36147.76.17.128/25147.76.17.129 to 147.76.17.254147.76.17.255126
37147.76.18.0/25147.76.18.1 to 147.76.18.126147.76.18.127126
38147.76.18.128/25147.76.18.129 to 147.76.18.254147.76.18.255126
39147.76.19.0/25147.76.19.1 to 147.76.19.126147.76.19.127126
40147.76.19.128/25147.76.19.129 to 147.76.19.254147.76.19.255126
41147.76.20.0/25147.76.20.1 to 147.76.20.126147.76.20.127126
42147.76.20.128/25147.76.20.129 to 147.76.20.254147.76.20.255126
43147.76.21.0/25147.76.21.1 to 147.76.21.126147.76.21.127126
44147.76.21.128/25147.76.21.129 to 147.76.21.254147.76.21.255126
45147.76.22.0/25147.76.22.1 to 147.76.22.126147.76.22.127126
46147.76.22.128/25147.76.22.129 to 147.76.22.254147.76.22.255126
47147.76.23.0/25147.76.23.1 to 147.76.23.126147.76.23.127126
48147.76.23.128/25147.76.23.129 to 147.76.23.254147.76.23.255126
49147.76.24.0/25147.76.24.1 to 147.76.24.126147.76.24.127126
50147.76.24.128/25147.76.24.129 to 147.76.24.254147.76.24.255126
51147.76.25.0/25147.76.25.1 to 147.76.25.126147.76.25.127126
52147.76.25.128/25147.76.25.129 to 147.76.25.254147.76.25.255126
53147.76.26.0/25147.76.26.1 to 147.76.26.126147.76.26.127126
54147.76.26.128/25147.76.26.129 to 147.76.26.254147.76.26.255126
55147.76.27.0/25147.76.27.1 to 147.76.27.126147.76.27.127126
56147.76.27.128/25147.76.27.129 to 147.76.27.254147.76.27.255126
57147.76.28.0/25147.76.28.1 to 147.76.28.126147.76.28.127126
58147.76.28.128/25147.76.28.129 to 147.76.28.254147.76.28.255126
59147.76.29.0/25147.76.29.1 to 147.76.29.126147.76.29.127126
60147.76.29.128/25147.76.29.129 to 147.76.29.254147.76.29.255126
61147.76.30.0/25147.76.30.1 to 147.76.30.126147.76.30.127126
62147.76.30.128/25147.76.30.129 to 147.76.30.254147.76.30.255126
63147.76.31.0/25147.76.31.1 to 147.76.31.126147.76.31.127126
64147.76.31.128/25147.76.31.129 to 147.76.31.254147.76.31.255126
65147.76.32.0/25147.76.32.1 to 147.76.32.126147.76.32.127126
66147.76.32.128/25147.76.32.129 to 147.76.32.254147.76.32.255126
67147.76.33.0/25147.76.33.1 to 147.76.33.126147.76.33.127126
68147.76.33.128/25147.76.33.129 to 147.76.33.254147.76.33.255126
69147.76.34.0/25147.76.34.1 to 147.76.34.126147.76.34.127126
70147.76.34.128/25147.76.34.129 to 147.76.34.254147.76.34.255126
71147.76.35.0/25147.76.35.1 to 147.76.35.126147.76.35.127126
72147.76.35.128/25147.76.35.129 to 147.76.35.254147.76.35.255126
73147.76.36.0/25147.76.36.1 to 147.76.36.126147.76.36.127126
74147.76.36.128/25147.76.36.129 to 147.76.36.254147.76.36.255126
75147.76.37.0/25147.76.37.1 to 147.76.37.126147.76.37.127126
76147.76.37.128/25147.76.37.129 to 147.76.37.254147.76.37.255126
77147.76.38.0/25147.76.38.1 to 147.76.38.126147.76.38.127126
78147.76.38.128/25147.76.38.129 to 147.76.38.254147.76.38.255126
79147.76.39.0/25147.76.39.1 to 147.76.39.126147.76.39.127126
80147.76.39.128/25147.76.39.129 to 147.76.39.254147.76.39.255126
81147.76.40.0/25147.76.40.1 to 147.76.40.126147.76.40.127126
82147.76.40.128/25147.76.40.129 to 147.76.40.254147.76.40.255126
83147.76.41.0/25147.76.41.1 to 147.76.41.126147.76.41.127126
84147.76.41.128/25147.76.41.129 to 147.76.41.254147.76.41.255126
85147.76.42.0/25147.76.42.1 to 147.76.42.126147.76.42.127126
86147.76.42.128/25147.76.42.129 to 147.76.42.254147.76.42.255126
87147.76.43.0/25147.76.43.1 to 147.76.43.126147.76.43.127126
88147.76.43.128/25147.76.43.129 to 147.76.43.254147.76.43.255126
89147.76.44.0/25147.76.44.1 to 147.76.44.126147.76.44.127126
90147.76.44.128/25147.76.44.129 to 147.76.44.254147.76.44.255126
91147.76.45.0/25147.76.45.1 to 147.76.45.126147.76.45.127126
92147.76.45.128/25147.76.45.129 to 147.76.45.254147.76.45.255126
93147.76.46.0/25147.76.46.1 to 147.76.46.126147.76.46.127126
94147.76.46.128/25147.76.46.129 to 147.76.46.254147.76.46.255126
95147.76.47.0/25147.76.47.1 to 147.76.47.126147.76.47.127126
96147.76.47.128/25147.76.47.129 to 147.76.47.254147.76.47.255126
97147.76.48.0/25147.76.48.1 to 147.76.48.126147.76.48.127126
98147.76.48.128/25147.76.48.129 to 147.76.48.254147.76.48.255126
99147.76.49.0/25147.76.49.1 to 147.76.49.126147.76.49.127126
100147.76.49.128/25147.76.49.129 to 147.76.49.254147.76.49.255126
101147.76.50.0/25147.76.50.1 to 147.76.50.126147.76.50.127126
102147.76.50.128/25147.76.50.129 to 147.76.50.254147.76.50.255126
103147.76.51.0/25147.76.51.1 to 147.76.51.126147.76.51.127126
104147.76.51.128/25147.76.51.129 to 147.76.51.254147.76.51.255126
105147.76.52.0/25147.76.52.1 to 147.76.52.126147.76.52.127126
106147.76.52.128/25147.76.52.129 to 147.76.52.254147.76.52.255126
107147.76.53.0/25147.76.53.1 to 147.76.53.126147.76.53.127126
108147.76.53.128/25147.76.53.129 to 147.76.53.254147.76.53.255126
109147.76.54.0/25147.76.54.1 to 147.76.54.126147.76.54.127126
110147.76.54.128/25147.76.54.129 to 147.76.54.254147.76.54.255126
111147.76.55.0/25147.76.55.1 to 147.76.55.126147.76.55.127126
112147.76.55.128/25147.76.55.129 to 147.76.55.254147.76.55.255126
113147.76.56.0/25147.76.56.1 to 147.76.56.126147.76.56.127126
114147.76.56.128/25147.76.56.129 to 147.76.56.254147.76.56.255126
115147.76.57.0/25147.76.57.1 to 147.76.57.126147.76.57.127126
116147.76.57.128/25147.76.57.129 to 147.76.57.254147.76.57.255126
117147.76.58.0/25147.76.58.1 to 147.76.58.126147.76.58.127126
118147.76.58.128/25147.76.58.129 to 147.76.58.254147.76.58.255126
119147.76.59.0/25147.76.59.1 to 147.76.59.126147.76.59.127126
120147.76.59.128/25147.76.59.129 to 147.76.59.254147.76.59.255126
121147.76.60.0/25147.76.60.1 to 147.76.60.126147.76.60.127126
122147.76.60.128/25147.76.60.129 to 147.76.60.254147.76.60.255126
123147.76.61.0/25147.76.61.1 to 147.76.61.126147.76.61.127126
124147.76.61.128/25147.76.61.129 to 147.76.61.254147.76.61.255126
125147.76.62.0/25147.76.62.1 to 147.76.62.126147.76.62.127126
126147.76.62.128/25147.76.62.129 to 147.76.62.254147.76.62.255126
127147.76.63.0/25147.76.63.1 to 147.76.63.126147.76.63.127126
128147.76.63.128/25147.76.63.129 to 147.76.63.254147.76.63.255126
129147.76.64.0/25147.76.64.1 to 147.76.64.126147.76.64.127126
130147.76.64.128/25147.76.64.129 to 147.76.64.254147.76.64.255126
131147.76.65.0/25147.76.65.1 to 147.76.65.126147.76.65.127126
132147.76.65.128/25147.76.65.129 to 147.76.65.254147.76.65.255126
133147.76.66.0/25147.76.66.1 to 147.76.66.126147.76.66.127126
134147.76.66.128/25147.76.66.129 to 147.76.66.254147.76.66.255126
135147.76.67.0/25147.76.67.1 to 147.76.67.126147.76.67.127126
136147.76.67.128/25147.76.67.129 to 147.76.67.254147.76.67.255126
137147.76.68.0/25147.76.68.1 to 147.76.68.126147.76.68.127126
138147.76.68.128/25147.76.68.129 to 147.76.68.254147.76.68.255126
139147.76.69.0/25147.76.69.1 to 147.76.69.126147.76.69.127126
140147.76.69.128/25147.76.69.129 to 147.76.69.254147.76.69.255126
141147.76.70.0/25147.76.70.1 to 147.76.70.126147.76.70.127126
142147.76.70.128/25147.76.70.129 to 147.76.70.254147.76.70.255126
143147.76.71.0/25147.76.71.1 to 147.76.71.126147.76.71.127126
144147.76.71.128/25147.76.71.129 to 147.76.71.254147.76.71.255126
145147.76.72.0/25147.76.72.1 to 147.76.72.126147.76.72.127126
146147.76.72.128/25147.76.72.129 to 147.76.72.254147.76.72.255126
147147.76.73.0/25147.76.73.1 to 147.76.73.126147.76.73.127126
148147.76.73.128/25147.76.73.129 to 147.76.73.254147.76.73.255126
149147.76.74.0/25147.76.74.1 to 147.76.74.126147.76.74.127126
150147.76.74.128/25147.76.74.129 to 147.76.74.254147.76.74.255126
151147.76.75.0/25147.76.75.1 to 147.76.75.126147.76.75.127126
152147.76.75.128/25147.76.75.129 to 147.76.75.254147.76.75.255126
153147.76.76.0/25147.76.76.1 to 147.76.76.126147.76.76.127126
154147.76.76.128/25147.76.76.129 to 147.76.76.254147.76.76.255126
155147.76.77.0/25147.76.77.1 to 147.76.77.126147.76.77.127126
156147.76.77.128/25147.76.77.129 to 147.76.77.254147.76.77.255126
157147.76.78.0/25147.76.78.1 to 147.76.78.126147.76.78.127126
158147.76.78.128/25147.76.78.129 to 147.76.78.254147.76.78.255126
159147.76.79.0/25147.76.79.1 to 147.76.79.126147.76.79.127126
160147.76.79.128/25147.76.79.129 to 147.76.79.254147.76.79.255126
161147.76.80.0/25147.76.80.1 to 147.76.80.126147.76.80.127126
162147.76.80.128/25147.76.80.129 to 147.76.80.254147.76.80.255126
163147.76.81.0/25147.76.81.1 to 147.76.81.126147.76.81.127126
164147.76.81.128/25147.76.81.129 to 147.76.81.254147.76.81.255126
165147.76.82.0/25147.76.82.1 to 147.76.82.126147.76.82.127126
166147.76.82.128/25147.76.82.129 to 147.76.82.254147.76.82.255126
167147.76.83.0/25147.76.83.1 to 147.76.83.126147.76.83.127126
168147.76.83.128/25147.76.83.129 to 147.76.83.254147.76.83.255126
169147.76.84.0/25147.76.84.1 to 147.76.84.126147.76.84.127126
170147.76.84.128/25147.76.84.129 to 147.76.84.254147.76.84.255126
171147.76.85.0/25147.76.85.1 to 147.76.85.126147.76.85.127126
172147.76.85.128/25147.76.85.129 to 147.76.85.254147.76.85.255126
173147.76.86.0/25147.76.86.1 to 147.76.86.126147.76.86.127126
174147.76.86.128/25147.76.86.129 to 147.76.86.254147.76.86.255126
175147.76.87.0/25147.76.87.1 to 147.76.87.126147.76.87.127126
176147.76.87.128/25147.76.87.129 to 147.76.87.254147.76.87.255126
177147.76.88.0/25147.76.88.1 to 147.76.88.126147.76.88.127126
178147.76.88.128/25147.76.88.129 to 147.76.88.254147.76.88.255126
179147.76.89.0/25147.76.89.1 to 147.76.89.126147.76.89.127126
180147.76.89.128/25147.76.89.129 to 147.76.89.254147.76.89.255126
181147.76.90.0/25147.76.90.1 to 147.76.90.126147.76.90.127126
182147.76.90.128/25147.76.90.129 to 147.76.90.254147.76.90.255126
183147.76.91.0/25147.76.91.1 to 147.76.91.126147.76.91.127126
184147.76.91.128/25147.76.91.129 to 147.76.91.254147.76.91.255126
185147.76.92.0/25147.76.92.1 to 147.76.92.126147.76.92.127126
186147.76.92.128/25147.76.92.129 to 147.76.92.254147.76.92.255126
187147.76.93.0/25147.76.93.1 to 147.76.93.126147.76.93.127126
188147.76.93.128/25147.76.93.129 to 147.76.93.254147.76.93.255126
189147.76.94.0/25147.76.94.1 to 147.76.94.126147.76.94.127126
190147.76.94.128/25147.76.94.129 to 147.76.94.254147.76.94.255126
191147.76.95.0/25147.76.95.1 to 147.76.95.126147.76.95.127126
192147.76.95.128/25147.76.95.129 to 147.76.95.254147.76.95.255126
193147.76.96.0/25147.76.96.1 to 147.76.96.126147.76.96.127126
194147.76.96.128/25147.76.96.129 to 147.76.96.254147.76.96.255126
195147.76.97.0/25147.76.97.1 to 147.76.97.126147.76.97.127126
196147.76.97.128/25147.76.97.129 to 147.76.97.254147.76.97.255126
197147.76.98.0/25147.76.98.1 to 147.76.98.126147.76.98.127126
198147.76.98.128/25147.76.98.129 to 147.76.98.254147.76.98.255126
199147.76.99.0/25147.76.99.1 to 147.76.99.126147.76.99.127126
200147.76.99.128/25147.76.99.129 to 147.76.99.254147.76.99.255126
201147.76.100.0/25147.76.100.1 to 147.76.100.126147.76.100.127126
202147.76.100.128/25147.76.100.129 to 147.76.100.254147.76.100.255126
203147.76.101.0/25147.76.101.1 to 147.76.101.126147.76.101.127126
204147.76.101.128/25147.76.101.129 to 147.76.101.254147.76.101.255126
205147.76.102.0/25147.76.102.1 to 147.76.102.126147.76.102.127126
206147.76.102.128/25147.76.102.129 to 147.76.102.254147.76.102.255126
207147.76.103.0/25147.76.103.1 to 147.76.103.126147.76.103.127126
208147.76.103.128/25147.76.103.129 to 147.76.103.254147.76.103.255126
209147.76.104.0/25147.76.104.1 to 147.76.104.126147.76.104.127126
210147.76.104.128/25147.76.104.129 to 147.76.104.254147.76.104.255126
211147.76.105.0/25147.76.105.1 to 147.76.105.126147.76.105.127126
212147.76.105.128/25147.76.105.129 to 147.76.105.254147.76.105.255126
213147.76.106.0/25147.76.106.1 to 147.76.106.126147.76.106.127126
214147.76.106.128/25147.76.106.129 to 147.76.106.254147.76.106.255126
215147.76.107.0/25147.76.107.1 to 147.76.107.126147.76.107.127126
216147.76.107.128/25147.76.107.129 to 147.76.107.254147.76.107.255126
217147.76.108.0/25147.76.108.1 to 147.76.108.126147.76.108.127126
218147.76.108.128/25147.76.108.129 to 147.76.108.254147.76.108.255126
219147.76.109.0/25147.76.109.1 to 147.76.109.126147.76.109.127126
220147.76.109.128/25147.76.109.129 to 147.76.109.254147.76.109.255126
221147.76.110.0/25147.76.110.1 to 147.76.110.126147.76.110.127126
222147.76.110.128/25147.76.110.129 to 147.76.110.254147.76.110.255126
223147.76.111.0/25147.76.111.1 to 147.76.111.126147.76.111.127126
224147.76.111.128/25147.76.111.129 to 147.76.111.254147.76.111.255126
225147.76.112.0/25147.76.112.1 to 147.76.112.126147.76.112.127126
226147.76.112.128/25147.76.112.129 to 147.76.112.254147.76.112.255126
227147.76.113.0/25147.76.113.1 to 147.76.113.126147.76.113.127126
228147.76.113.128/25147.76.113.129 to 147.76.113.254147.76.113.255126
229147.76.114.0/25147.76.114.1 to 147.76.114.126147.76.114.127126
230147.76.114.128/25147.76.114.129 to 147.76.114.254147.76.114.255126
231147.76.115.0/25147.76.115.1 to 147.76.115.126147.76.115.127126
232147.76.115.128/25147.76.115.129 to 147.76.115.254147.76.115.255126
233147.76.116.0/25147.76.116.1 to 147.76.116.126147.76.116.127126
234147.76.116.128/25147.76.116.129 to 147.76.116.254147.76.116.255126
235147.76.117.0/25147.76.117.1 to 147.76.117.126147.76.117.127126
236147.76.117.128/25147.76.117.129 to 147.76.117.254147.76.117.255126
237147.76.118.0/25147.76.118.1 to 147.76.118.126147.76.118.127126
238147.76.118.128/25147.76.118.129 to 147.76.118.254147.76.118.255126
239147.76.119.0/25147.76.119.1 to 147.76.119.126147.76.119.127126
240147.76.119.128/25147.76.119.129 to 147.76.119.254147.76.119.255126
241147.76.120.0/25147.76.120.1 to 147.76.120.126147.76.120.127126
242147.76.120.128/25147.76.120.129 to 147.76.120.254147.76.120.255126
243147.76.121.0/25147.76.121.1 to 147.76.121.126147.76.121.127126
244147.76.121.128/25147.76.121.129 to 147.76.121.254147.76.121.255126
245147.76.122.0/25147.76.122.1 to 147.76.122.126147.76.122.127126
246147.76.122.128/25147.76.122.129 to 147.76.122.254147.76.122.255126
247147.76.123.0/25147.76.123.1 to 147.76.123.126147.76.123.127126
248147.76.123.128/25147.76.123.129 to 147.76.123.254147.76.123.255126
249147.76.124.0/25147.76.124.1 to 147.76.124.126147.76.124.127126
250147.76.124.128/25147.76.124.129 to 147.76.124.254147.76.124.255126
251147.76.125.0/25147.76.125.1 to 147.76.125.126147.76.125.127126
252147.76.125.128/25147.76.125.129 to 147.76.125.254147.76.125.255126
253147.76.126.0/25147.76.126.1 to 147.76.126.126147.76.126.127126
254147.76.126.128/25147.76.126.129 to 147.76.126.254147.76.126.255126
255147.76.127.0/25147.76.127.1 to 147.76.127.126147.76.127.127126
256147.76.127.128/25147.76.127.129 to 147.76.127.254147.76.127.255126

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.