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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.

Network102.136.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
102.136.0.0
Broadcast address
102.143.255.255
First usable
102.136.0.1
Last usable
102.143.255.254
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
Public public
Old class
A (default /8)
As numbers
Hex 66880000 · Integer 1720188928 to 1720713215
Reverse DNS zones
136.102.in-addr.arpa
137.102.in-addr.arpa
138.102.in-addr.arpa
139.102.in-addr.arpa
140.102.in-addr.arpa
141.102.in-addr.arpa
142.102.in-addr.arpa
143.102.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
Address01100110.10001000.00000000.00000000102.136.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network01100110.10001000.00000000.00000000102.136.0.0
Broadcast01100110.10001111.11111111.11111111102.143.255.255
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)

102.136.0.0/13 makes 4,096 subnets of /25; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1102.136.0.0/25102.136.0.1 to 102.136.0.126102.136.0.127126
2102.136.0.128/25102.136.0.129 to 102.136.0.254102.136.0.255126
3102.136.1.0/25102.136.1.1 to 102.136.1.126102.136.1.127126
4102.136.1.128/25102.136.1.129 to 102.136.1.254102.136.1.255126
5102.136.2.0/25102.136.2.1 to 102.136.2.126102.136.2.127126
6102.136.2.128/25102.136.2.129 to 102.136.2.254102.136.2.255126
7102.136.3.0/25102.136.3.1 to 102.136.3.126102.136.3.127126
8102.136.3.128/25102.136.3.129 to 102.136.3.254102.136.3.255126
9102.136.4.0/25102.136.4.1 to 102.136.4.126102.136.4.127126
10102.136.4.128/25102.136.4.129 to 102.136.4.254102.136.4.255126
11102.136.5.0/25102.136.5.1 to 102.136.5.126102.136.5.127126
12102.136.5.128/25102.136.5.129 to 102.136.5.254102.136.5.255126
13102.136.6.0/25102.136.6.1 to 102.136.6.126102.136.6.127126
14102.136.6.128/25102.136.6.129 to 102.136.6.254102.136.6.255126
15102.136.7.0/25102.136.7.1 to 102.136.7.126102.136.7.127126
16102.136.7.128/25102.136.7.129 to 102.136.7.254102.136.7.255126
17102.136.8.0/25102.136.8.1 to 102.136.8.126102.136.8.127126
18102.136.8.128/25102.136.8.129 to 102.136.8.254102.136.8.255126
19102.136.9.0/25102.136.9.1 to 102.136.9.126102.136.9.127126
20102.136.9.128/25102.136.9.129 to 102.136.9.254102.136.9.255126
21102.136.10.0/25102.136.10.1 to 102.136.10.126102.136.10.127126
22102.136.10.128/25102.136.10.129 to 102.136.10.254102.136.10.255126
23102.136.11.0/25102.136.11.1 to 102.136.11.126102.136.11.127126
24102.136.11.128/25102.136.11.129 to 102.136.11.254102.136.11.255126
25102.136.12.0/25102.136.12.1 to 102.136.12.126102.136.12.127126
26102.136.12.128/25102.136.12.129 to 102.136.12.254102.136.12.255126
27102.136.13.0/25102.136.13.1 to 102.136.13.126102.136.13.127126
28102.136.13.128/25102.136.13.129 to 102.136.13.254102.136.13.255126
29102.136.14.0/25102.136.14.1 to 102.136.14.126102.136.14.127126
30102.136.14.128/25102.136.14.129 to 102.136.14.254102.136.14.255126
31102.136.15.0/25102.136.15.1 to 102.136.15.126102.136.15.127126
32102.136.15.128/25102.136.15.129 to 102.136.15.254102.136.15.255126
33102.136.16.0/25102.136.16.1 to 102.136.16.126102.136.16.127126
34102.136.16.128/25102.136.16.129 to 102.136.16.254102.136.16.255126
35102.136.17.0/25102.136.17.1 to 102.136.17.126102.136.17.127126
36102.136.17.128/25102.136.17.129 to 102.136.17.254102.136.17.255126
37102.136.18.0/25102.136.18.1 to 102.136.18.126102.136.18.127126
38102.136.18.128/25102.136.18.129 to 102.136.18.254102.136.18.255126
39102.136.19.0/25102.136.19.1 to 102.136.19.126102.136.19.127126
40102.136.19.128/25102.136.19.129 to 102.136.19.254102.136.19.255126
41102.136.20.0/25102.136.20.1 to 102.136.20.126102.136.20.127126
42102.136.20.128/25102.136.20.129 to 102.136.20.254102.136.20.255126
43102.136.21.0/25102.136.21.1 to 102.136.21.126102.136.21.127126
44102.136.21.128/25102.136.21.129 to 102.136.21.254102.136.21.255126
45102.136.22.0/25102.136.22.1 to 102.136.22.126102.136.22.127126
46102.136.22.128/25102.136.22.129 to 102.136.22.254102.136.22.255126
47102.136.23.0/25102.136.23.1 to 102.136.23.126102.136.23.127126
48102.136.23.128/25102.136.23.129 to 102.136.23.254102.136.23.255126
49102.136.24.0/25102.136.24.1 to 102.136.24.126102.136.24.127126
50102.136.24.128/25102.136.24.129 to 102.136.24.254102.136.24.255126
51102.136.25.0/25102.136.25.1 to 102.136.25.126102.136.25.127126
52102.136.25.128/25102.136.25.129 to 102.136.25.254102.136.25.255126
53102.136.26.0/25102.136.26.1 to 102.136.26.126102.136.26.127126
54102.136.26.128/25102.136.26.129 to 102.136.26.254102.136.26.255126
55102.136.27.0/25102.136.27.1 to 102.136.27.126102.136.27.127126
56102.136.27.128/25102.136.27.129 to 102.136.27.254102.136.27.255126
57102.136.28.0/25102.136.28.1 to 102.136.28.126102.136.28.127126
58102.136.28.128/25102.136.28.129 to 102.136.28.254102.136.28.255126
59102.136.29.0/25102.136.29.1 to 102.136.29.126102.136.29.127126
60102.136.29.128/25102.136.29.129 to 102.136.29.254102.136.29.255126
61102.136.30.0/25102.136.30.1 to 102.136.30.126102.136.30.127126
62102.136.30.128/25102.136.30.129 to 102.136.30.254102.136.30.255126
63102.136.31.0/25102.136.31.1 to 102.136.31.126102.136.31.127126
64102.136.31.128/25102.136.31.129 to 102.136.31.254102.136.31.255126
65102.136.32.0/25102.136.32.1 to 102.136.32.126102.136.32.127126
66102.136.32.128/25102.136.32.129 to 102.136.32.254102.136.32.255126
67102.136.33.0/25102.136.33.1 to 102.136.33.126102.136.33.127126
68102.136.33.128/25102.136.33.129 to 102.136.33.254102.136.33.255126
69102.136.34.0/25102.136.34.1 to 102.136.34.126102.136.34.127126
70102.136.34.128/25102.136.34.129 to 102.136.34.254102.136.34.255126
71102.136.35.0/25102.136.35.1 to 102.136.35.126102.136.35.127126
72102.136.35.128/25102.136.35.129 to 102.136.35.254102.136.35.255126
73102.136.36.0/25102.136.36.1 to 102.136.36.126102.136.36.127126
74102.136.36.128/25102.136.36.129 to 102.136.36.254102.136.36.255126
75102.136.37.0/25102.136.37.1 to 102.136.37.126102.136.37.127126
76102.136.37.128/25102.136.37.129 to 102.136.37.254102.136.37.255126
77102.136.38.0/25102.136.38.1 to 102.136.38.126102.136.38.127126
78102.136.38.128/25102.136.38.129 to 102.136.38.254102.136.38.255126
79102.136.39.0/25102.136.39.1 to 102.136.39.126102.136.39.127126
80102.136.39.128/25102.136.39.129 to 102.136.39.254102.136.39.255126
81102.136.40.0/25102.136.40.1 to 102.136.40.126102.136.40.127126
82102.136.40.128/25102.136.40.129 to 102.136.40.254102.136.40.255126
83102.136.41.0/25102.136.41.1 to 102.136.41.126102.136.41.127126
84102.136.41.128/25102.136.41.129 to 102.136.41.254102.136.41.255126
85102.136.42.0/25102.136.42.1 to 102.136.42.126102.136.42.127126
86102.136.42.128/25102.136.42.129 to 102.136.42.254102.136.42.255126
87102.136.43.0/25102.136.43.1 to 102.136.43.126102.136.43.127126
88102.136.43.128/25102.136.43.129 to 102.136.43.254102.136.43.255126
89102.136.44.0/25102.136.44.1 to 102.136.44.126102.136.44.127126
90102.136.44.128/25102.136.44.129 to 102.136.44.254102.136.44.255126
91102.136.45.0/25102.136.45.1 to 102.136.45.126102.136.45.127126
92102.136.45.128/25102.136.45.129 to 102.136.45.254102.136.45.255126
93102.136.46.0/25102.136.46.1 to 102.136.46.126102.136.46.127126
94102.136.46.128/25102.136.46.129 to 102.136.46.254102.136.46.255126
95102.136.47.0/25102.136.47.1 to 102.136.47.126102.136.47.127126
96102.136.47.128/25102.136.47.129 to 102.136.47.254102.136.47.255126
97102.136.48.0/25102.136.48.1 to 102.136.48.126102.136.48.127126
98102.136.48.128/25102.136.48.129 to 102.136.48.254102.136.48.255126
99102.136.49.0/25102.136.49.1 to 102.136.49.126102.136.49.127126
100102.136.49.128/25102.136.49.129 to 102.136.49.254102.136.49.255126
101102.136.50.0/25102.136.50.1 to 102.136.50.126102.136.50.127126
102102.136.50.128/25102.136.50.129 to 102.136.50.254102.136.50.255126
103102.136.51.0/25102.136.51.1 to 102.136.51.126102.136.51.127126
104102.136.51.128/25102.136.51.129 to 102.136.51.254102.136.51.255126
105102.136.52.0/25102.136.52.1 to 102.136.52.126102.136.52.127126
106102.136.52.128/25102.136.52.129 to 102.136.52.254102.136.52.255126
107102.136.53.0/25102.136.53.1 to 102.136.53.126102.136.53.127126
108102.136.53.128/25102.136.53.129 to 102.136.53.254102.136.53.255126
109102.136.54.0/25102.136.54.1 to 102.136.54.126102.136.54.127126
110102.136.54.128/25102.136.54.129 to 102.136.54.254102.136.54.255126
111102.136.55.0/25102.136.55.1 to 102.136.55.126102.136.55.127126
112102.136.55.128/25102.136.55.129 to 102.136.55.254102.136.55.255126
113102.136.56.0/25102.136.56.1 to 102.136.56.126102.136.56.127126
114102.136.56.128/25102.136.56.129 to 102.136.56.254102.136.56.255126
115102.136.57.0/25102.136.57.1 to 102.136.57.126102.136.57.127126
116102.136.57.128/25102.136.57.129 to 102.136.57.254102.136.57.255126
117102.136.58.0/25102.136.58.1 to 102.136.58.126102.136.58.127126
118102.136.58.128/25102.136.58.129 to 102.136.58.254102.136.58.255126
119102.136.59.0/25102.136.59.1 to 102.136.59.126102.136.59.127126
120102.136.59.128/25102.136.59.129 to 102.136.59.254102.136.59.255126
121102.136.60.0/25102.136.60.1 to 102.136.60.126102.136.60.127126
122102.136.60.128/25102.136.60.129 to 102.136.60.254102.136.60.255126
123102.136.61.0/25102.136.61.1 to 102.136.61.126102.136.61.127126
124102.136.61.128/25102.136.61.129 to 102.136.61.254102.136.61.255126
125102.136.62.0/25102.136.62.1 to 102.136.62.126102.136.62.127126
126102.136.62.128/25102.136.62.129 to 102.136.62.254102.136.62.255126
127102.136.63.0/25102.136.63.1 to 102.136.63.126102.136.63.127126
128102.136.63.128/25102.136.63.129 to 102.136.63.254102.136.63.255126
129102.136.64.0/25102.136.64.1 to 102.136.64.126102.136.64.127126
130102.136.64.128/25102.136.64.129 to 102.136.64.254102.136.64.255126
131102.136.65.0/25102.136.65.1 to 102.136.65.126102.136.65.127126
132102.136.65.128/25102.136.65.129 to 102.136.65.254102.136.65.255126
133102.136.66.0/25102.136.66.1 to 102.136.66.126102.136.66.127126
134102.136.66.128/25102.136.66.129 to 102.136.66.254102.136.66.255126
135102.136.67.0/25102.136.67.1 to 102.136.67.126102.136.67.127126
136102.136.67.128/25102.136.67.129 to 102.136.67.254102.136.67.255126
137102.136.68.0/25102.136.68.1 to 102.136.68.126102.136.68.127126
138102.136.68.128/25102.136.68.129 to 102.136.68.254102.136.68.255126
139102.136.69.0/25102.136.69.1 to 102.136.69.126102.136.69.127126
140102.136.69.128/25102.136.69.129 to 102.136.69.254102.136.69.255126
141102.136.70.0/25102.136.70.1 to 102.136.70.126102.136.70.127126
142102.136.70.128/25102.136.70.129 to 102.136.70.254102.136.70.255126
143102.136.71.0/25102.136.71.1 to 102.136.71.126102.136.71.127126
144102.136.71.128/25102.136.71.129 to 102.136.71.254102.136.71.255126
145102.136.72.0/25102.136.72.1 to 102.136.72.126102.136.72.127126
146102.136.72.128/25102.136.72.129 to 102.136.72.254102.136.72.255126
147102.136.73.0/25102.136.73.1 to 102.136.73.126102.136.73.127126
148102.136.73.128/25102.136.73.129 to 102.136.73.254102.136.73.255126
149102.136.74.0/25102.136.74.1 to 102.136.74.126102.136.74.127126
150102.136.74.128/25102.136.74.129 to 102.136.74.254102.136.74.255126
151102.136.75.0/25102.136.75.1 to 102.136.75.126102.136.75.127126
152102.136.75.128/25102.136.75.129 to 102.136.75.254102.136.75.255126
153102.136.76.0/25102.136.76.1 to 102.136.76.126102.136.76.127126
154102.136.76.128/25102.136.76.129 to 102.136.76.254102.136.76.255126
155102.136.77.0/25102.136.77.1 to 102.136.77.126102.136.77.127126
156102.136.77.128/25102.136.77.129 to 102.136.77.254102.136.77.255126
157102.136.78.0/25102.136.78.1 to 102.136.78.126102.136.78.127126
158102.136.78.128/25102.136.78.129 to 102.136.78.254102.136.78.255126
159102.136.79.0/25102.136.79.1 to 102.136.79.126102.136.79.127126
160102.136.79.128/25102.136.79.129 to 102.136.79.254102.136.79.255126
161102.136.80.0/25102.136.80.1 to 102.136.80.126102.136.80.127126
162102.136.80.128/25102.136.80.129 to 102.136.80.254102.136.80.255126
163102.136.81.0/25102.136.81.1 to 102.136.81.126102.136.81.127126
164102.136.81.128/25102.136.81.129 to 102.136.81.254102.136.81.255126
165102.136.82.0/25102.136.82.1 to 102.136.82.126102.136.82.127126
166102.136.82.128/25102.136.82.129 to 102.136.82.254102.136.82.255126
167102.136.83.0/25102.136.83.1 to 102.136.83.126102.136.83.127126
168102.136.83.128/25102.136.83.129 to 102.136.83.254102.136.83.255126
169102.136.84.0/25102.136.84.1 to 102.136.84.126102.136.84.127126
170102.136.84.128/25102.136.84.129 to 102.136.84.254102.136.84.255126
171102.136.85.0/25102.136.85.1 to 102.136.85.126102.136.85.127126
172102.136.85.128/25102.136.85.129 to 102.136.85.254102.136.85.255126
173102.136.86.0/25102.136.86.1 to 102.136.86.126102.136.86.127126
174102.136.86.128/25102.136.86.129 to 102.136.86.254102.136.86.255126
175102.136.87.0/25102.136.87.1 to 102.136.87.126102.136.87.127126
176102.136.87.128/25102.136.87.129 to 102.136.87.254102.136.87.255126
177102.136.88.0/25102.136.88.1 to 102.136.88.126102.136.88.127126
178102.136.88.128/25102.136.88.129 to 102.136.88.254102.136.88.255126
179102.136.89.0/25102.136.89.1 to 102.136.89.126102.136.89.127126
180102.136.89.128/25102.136.89.129 to 102.136.89.254102.136.89.255126
181102.136.90.0/25102.136.90.1 to 102.136.90.126102.136.90.127126
182102.136.90.128/25102.136.90.129 to 102.136.90.254102.136.90.255126
183102.136.91.0/25102.136.91.1 to 102.136.91.126102.136.91.127126
184102.136.91.128/25102.136.91.129 to 102.136.91.254102.136.91.255126
185102.136.92.0/25102.136.92.1 to 102.136.92.126102.136.92.127126
186102.136.92.128/25102.136.92.129 to 102.136.92.254102.136.92.255126
187102.136.93.0/25102.136.93.1 to 102.136.93.126102.136.93.127126
188102.136.93.128/25102.136.93.129 to 102.136.93.254102.136.93.255126
189102.136.94.0/25102.136.94.1 to 102.136.94.126102.136.94.127126
190102.136.94.128/25102.136.94.129 to 102.136.94.254102.136.94.255126
191102.136.95.0/25102.136.95.1 to 102.136.95.126102.136.95.127126
192102.136.95.128/25102.136.95.129 to 102.136.95.254102.136.95.255126
193102.136.96.0/25102.136.96.1 to 102.136.96.126102.136.96.127126
194102.136.96.128/25102.136.96.129 to 102.136.96.254102.136.96.255126
195102.136.97.0/25102.136.97.1 to 102.136.97.126102.136.97.127126
196102.136.97.128/25102.136.97.129 to 102.136.97.254102.136.97.255126
197102.136.98.0/25102.136.98.1 to 102.136.98.126102.136.98.127126
198102.136.98.128/25102.136.98.129 to 102.136.98.254102.136.98.255126
199102.136.99.0/25102.136.99.1 to 102.136.99.126102.136.99.127126
200102.136.99.128/25102.136.99.129 to 102.136.99.254102.136.99.255126
201102.136.100.0/25102.136.100.1 to 102.136.100.126102.136.100.127126
202102.136.100.128/25102.136.100.129 to 102.136.100.254102.136.100.255126
203102.136.101.0/25102.136.101.1 to 102.136.101.126102.136.101.127126
204102.136.101.128/25102.136.101.129 to 102.136.101.254102.136.101.255126
205102.136.102.0/25102.136.102.1 to 102.136.102.126102.136.102.127126
206102.136.102.128/25102.136.102.129 to 102.136.102.254102.136.102.255126
207102.136.103.0/25102.136.103.1 to 102.136.103.126102.136.103.127126
208102.136.103.128/25102.136.103.129 to 102.136.103.254102.136.103.255126
209102.136.104.0/25102.136.104.1 to 102.136.104.126102.136.104.127126
210102.136.104.128/25102.136.104.129 to 102.136.104.254102.136.104.255126
211102.136.105.0/25102.136.105.1 to 102.136.105.126102.136.105.127126
212102.136.105.128/25102.136.105.129 to 102.136.105.254102.136.105.255126
213102.136.106.0/25102.136.106.1 to 102.136.106.126102.136.106.127126
214102.136.106.128/25102.136.106.129 to 102.136.106.254102.136.106.255126
215102.136.107.0/25102.136.107.1 to 102.136.107.126102.136.107.127126
216102.136.107.128/25102.136.107.129 to 102.136.107.254102.136.107.255126
217102.136.108.0/25102.136.108.1 to 102.136.108.126102.136.108.127126
218102.136.108.128/25102.136.108.129 to 102.136.108.254102.136.108.255126
219102.136.109.0/25102.136.109.1 to 102.136.109.126102.136.109.127126
220102.136.109.128/25102.136.109.129 to 102.136.109.254102.136.109.255126
221102.136.110.0/25102.136.110.1 to 102.136.110.126102.136.110.127126
222102.136.110.128/25102.136.110.129 to 102.136.110.254102.136.110.255126
223102.136.111.0/25102.136.111.1 to 102.136.111.126102.136.111.127126
224102.136.111.128/25102.136.111.129 to 102.136.111.254102.136.111.255126
225102.136.112.0/25102.136.112.1 to 102.136.112.126102.136.112.127126
226102.136.112.128/25102.136.112.129 to 102.136.112.254102.136.112.255126
227102.136.113.0/25102.136.113.1 to 102.136.113.126102.136.113.127126
228102.136.113.128/25102.136.113.129 to 102.136.113.254102.136.113.255126
229102.136.114.0/25102.136.114.1 to 102.136.114.126102.136.114.127126
230102.136.114.128/25102.136.114.129 to 102.136.114.254102.136.114.255126
231102.136.115.0/25102.136.115.1 to 102.136.115.126102.136.115.127126
232102.136.115.128/25102.136.115.129 to 102.136.115.254102.136.115.255126
233102.136.116.0/25102.136.116.1 to 102.136.116.126102.136.116.127126
234102.136.116.128/25102.136.116.129 to 102.136.116.254102.136.116.255126
235102.136.117.0/25102.136.117.1 to 102.136.117.126102.136.117.127126
236102.136.117.128/25102.136.117.129 to 102.136.117.254102.136.117.255126
237102.136.118.0/25102.136.118.1 to 102.136.118.126102.136.118.127126
238102.136.118.128/25102.136.118.129 to 102.136.118.254102.136.118.255126
239102.136.119.0/25102.136.119.1 to 102.136.119.126102.136.119.127126
240102.136.119.128/25102.136.119.129 to 102.136.119.254102.136.119.255126
241102.136.120.0/25102.136.120.1 to 102.136.120.126102.136.120.127126
242102.136.120.128/25102.136.120.129 to 102.136.120.254102.136.120.255126
243102.136.121.0/25102.136.121.1 to 102.136.121.126102.136.121.127126
244102.136.121.128/25102.136.121.129 to 102.136.121.254102.136.121.255126
245102.136.122.0/25102.136.122.1 to 102.136.122.126102.136.122.127126
246102.136.122.128/25102.136.122.129 to 102.136.122.254102.136.122.255126
247102.136.123.0/25102.136.123.1 to 102.136.123.126102.136.123.127126
248102.136.123.128/25102.136.123.129 to 102.136.123.254102.136.123.255126
249102.136.124.0/25102.136.124.1 to 102.136.124.126102.136.124.127126
250102.136.124.128/25102.136.124.129 to 102.136.124.254102.136.124.255126
251102.136.125.0/25102.136.125.1 to 102.136.125.126102.136.125.127126
252102.136.125.128/25102.136.125.129 to 102.136.125.254102.136.125.255126
253102.136.126.0/25102.136.126.1 to 102.136.126.126102.136.126.127126
254102.136.126.128/25102.136.126.129 to 102.136.126.254102.136.126.255126
255102.136.127.0/25102.136.127.1 to 102.136.127.126102.136.127.127126
256102.136.127.128/25102.136.127.129 to 102.136.127.254102.136.127.255126

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.