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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.

Network231.136.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
231.136.0.0
Broadcast address
231.143.255.255
First usable
231.136.0.1
Last usable
231.143.255.254
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
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E7880000 · Integer 3884449792 to 3884974079
Reverse DNS zones
136.231.in-addr.arpa
137.231.in-addr.arpa
138.231.in-addr.arpa
139.231.in-addr.arpa
140.231.in-addr.arpa
141.231.in-addr.arpa
142.231.in-addr.arpa
143.231.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
Address11100111.10001000.00000000.00000000231.136.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network11100111.10001000.00000000.00000000231.136.0.0
Broadcast11100111.10001111.11111111.11111111231.143.255.255
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)

231.136.0.0/13 makes 4,096 subnets of /25; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1231.136.0.0/25231.136.0.1 to 231.136.0.126231.136.0.127126
2231.136.0.128/25231.136.0.129 to 231.136.0.254231.136.0.255126
3231.136.1.0/25231.136.1.1 to 231.136.1.126231.136.1.127126
4231.136.1.128/25231.136.1.129 to 231.136.1.254231.136.1.255126
5231.136.2.0/25231.136.2.1 to 231.136.2.126231.136.2.127126
6231.136.2.128/25231.136.2.129 to 231.136.2.254231.136.2.255126
7231.136.3.0/25231.136.3.1 to 231.136.3.126231.136.3.127126
8231.136.3.128/25231.136.3.129 to 231.136.3.254231.136.3.255126
9231.136.4.0/25231.136.4.1 to 231.136.4.126231.136.4.127126
10231.136.4.128/25231.136.4.129 to 231.136.4.254231.136.4.255126
11231.136.5.0/25231.136.5.1 to 231.136.5.126231.136.5.127126
12231.136.5.128/25231.136.5.129 to 231.136.5.254231.136.5.255126
13231.136.6.0/25231.136.6.1 to 231.136.6.126231.136.6.127126
14231.136.6.128/25231.136.6.129 to 231.136.6.254231.136.6.255126
15231.136.7.0/25231.136.7.1 to 231.136.7.126231.136.7.127126
16231.136.7.128/25231.136.7.129 to 231.136.7.254231.136.7.255126
17231.136.8.0/25231.136.8.1 to 231.136.8.126231.136.8.127126
18231.136.8.128/25231.136.8.129 to 231.136.8.254231.136.8.255126
19231.136.9.0/25231.136.9.1 to 231.136.9.126231.136.9.127126
20231.136.9.128/25231.136.9.129 to 231.136.9.254231.136.9.255126
21231.136.10.0/25231.136.10.1 to 231.136.10.126231.136.10.127126
22231.136.10.128/25231.136.10.129 to 231.136.10.254231.136.10.255126
23231.136.11.0/25231.136.11.1 to 231.136.11.126231.136.11.127126
24231.136.11.128/25231.136.11.129 to 231.136.11.254231.136.11.255126
25231.136.12.0/25231.136.12.1 to 231.136.12.126231.136.12.127126
26231.136.12.128/25231.136.12.129 to 231.136.12.254231.136.12.255126
27231.136.13.0/25231.136.13.1 to 231.136.13.126231.136.13.127126
28231.136.13.128/25231.136.13.129 to 231.136.13.254231.136.13.255126
29231.136.14.0/25231.136.14.1 to 231.136.14.126231.136.14.127126
30231.136.14.128/25231.136.14.129 to 231.136.14.254231.136.14.255126
31231.136.15.0/25231.136.15.1 to 231.136.15.126231.136.15.127126
32231.136.15.128/25231.136.15.129 to 231.136.15.254231.136.15.255126
33231.136.16.0/25231.136.16.1 to 231.136.16.126231.136.16.127126
34231.136.16.128/25231.136.16.129 to 231.136.16.254231.136.16.255126
35231.136.17.0/25231.136.17.1 to 231.136.17.126231.136.17.127126
36231.136.17.128/25231.136.17.129 to 231.136.17.254231.136.17.255126
37231.136.18.0/25231.136.18.1 to 231.136.18.126231.136.18.127126
38231.136.18.128/25231.136.18.129 to 231.136.18.254231.136.18.255126
39231.136.19.0/25231.136.19.1 to 231.136.19.126231.136.19.127126
40231.136.19.128/25231.136.19.129 to 231.136.19.254231.136.19.255126
41231.136.20.0/25231.136.20.1 to 231.136.20.126231.136.20.127126
42231.136.20.128/25231.136.20.129 to 231.136.20.254231.136.20.255126
43231.136.21.0/25231.136.21.1 to 231.136.21.126231.136.21.127126
44231.136.21.128/25231.136.21.129 to 231.136.21.254231.136.21.255126
45231.136.22.0/25231.136.22.1 to 231.136.22.126231.136.22.127126
46231.136.22.128/25231.136.22.129 to 231.136.22.254231.136.22.255126
47231.136.23.0/25231.136.23.1 to 231.136.23.126231.136.23.127126
48231.136.23.128/25231.136.23.129 to 231.136.23.254231.136.23.255126
49231.136.24.0/25231.136.24.1 to 231.136.24.126231.136.24.127126
50231.136.24.128/25231.136.24.129 to 231.136.24.254231.136.24.255126
51231.136.25.0/25231.136.25.1 to 231.136.25.126231.136.25.127126
52231.136.25.128/25231.136.25.129 to 231.136.25.254231.136.25.255126
53231.136.26.0/25231.136.26.1 to 231.136.26.126231.136.26.127126
54231.136.26.128/25231.136.26.129 to 231.136.26.254231.136.26.255126
55231.136.27.0/25231.136.27.1 to 231.136.27.126231.136.27.127126
56231.136.27.128/25231.136.27.129 to 231.136.27.254231.136.27.255126
57231.136.28.0/25231.136.28.1 to 231.136.28.126231.136.28.127126
58231.136.28.128/25231.136.28.129 to 231.136.28.254231.136.28.255126
59231.136.29.0/25231.136.29.1 to 231.136.29.126231.136.29.127126
60231.136.29.128/25231.136.29.129 to 231.136.29.254231.136.29.255126
61231.136.30.0/25231.136.30.1 to 231.136.30.126231.136.30.127126
62231.136.30.128/25231.136.30.129 to 231.136.30.254231.136.30.255126
63231.136.31.0/25231.136.31.1 to 231.136.31.126231.136.31.127126
64231.136.31.128/25231.136.31.129 to 231.136.31.254231.136.31.255126
65231.136.32.0/25231.136.32.1 to 231.136.32.126231.136.32.127126
66231.136.32.128/25231.136.32.129 to 231.136.32.254231.136.32.255126
67231.136.33.0/25231.136.33.1 to 231.136.33.126231.136.33.127126
68231.136.33.128/25231.136.33.129 to 231.136.33.254231.136.33.255126
69231.136.34.0/25231.136.34.1 to 231.136.34.126231.136.34.127126
70231.136.34.128/25231.136.34.129 to 231.136.34.254231.136.34.255126
71231.136.35.0/25231.136.35.1 to 231.136.35.126231.136.35.127126
72231.136.35.128/25231.136.35.129 to 231.136.35.254231.136.35.255126
73231.136.36.0/25231.136.36.1 to 231.136.36.126231.136.36.127126
74231.136.36.128/25231.136.36.129 to 231.136.36.254231.136.36.255126
75231.136.37.0/25231.136.37.1 to 231.136.37.126231.136.37.127126
76231.136.37.128/25231.136.37.129 to 231.136.37.254231.136.37.255126
77231.136.38.0/25231.136.38.1 to 231.136.38.126231.136.38.127126
78231.136.38.128/25231.136.38.129 to 231.136.38.254231.136.38.255126
79231.136.39.0/25231.136.39.1 to 231.136.39.126231.136.39.127126
80231.136.39.128/25231.136.39.129 to 231.136.39.254231.136.39.255126
81231.136.40.0/25231.136.40.1 to 231.136.40.126231.136.40.127126
82231.136.40.128/25231.136.40.129 to 231.136.40.254231.136.40.255126
83231.136.41.0/25231.136.41.1 to 231.136.41.126231.136.41.127126
84231.136.41.128/25231.136.41.129 to 231.136.41.254231.136.41.255126
85231.136.42.0/25231.136.42.1 to 231.136.42.126231.136.42.127126
86231.136.42.128/25231.136.42.129 to 231.136.42.254231.136.42.255126
87231.136.43.0/25231.136.43.1 to 231.136.43.126231.136.43.127126
88231.136.43.128/25231.136.43.129 to 231.136.43.254231.136.43.255126
89231.136.44.0/25231.136.44.1 to 231.136.44.126231.136.44.127126
90231.136.44.128/25231.136.44.129 to 231.136.44.254231.136.44.255126
91231.136.45.0/25231.136.45.1 to 231.136.45.126231.136.45.127126
92231.136.45.128/25231.136.45.129 to 231.136.45.254231.136.45.255126
93231.136.46.0/25231.136.46.1 to 231.136.46.126231.136.46.127126
94231.136.46.128/25231.136.46.129 to 231.136.46.254231.136.46.255126
95231.136.47.0/25231.136.47.1 to 231.136.47.126231.136.47.127126
96231.136.47.128/25231.136.47.129 to 231.136.47.254231.136.47.255126
97231.136.48.0/25231.136.48.1 to 231.136.48.126231.136.48.127126
98231.136.48.128/25231.136.48.129 to 231.136.48.254231.136.48.255126
99231.136.49.0/25231.136.49.1 to 231.136.49.126231.136.49.127126
100231.136.49.128/25231.136.49.129 to 231.136.49.254231.136.49.255126
101231.136.50.0/25231.136.50.1 to 231.136.50.126231.136.50.127126
102231.136.50.128/25231.136.50.129 to 231.136.50.254231.136.50.255126
103231.136.51.0/25231.136.51.1 to 231.136.51.126231.136.51.127126
104231.136.51.128/25231.136.51.129 to 231.136.51.254231.136.51.255126
105231.136.52.0/25231.136.52.1 to 231.136.52.126231.136.52.127126
106231.136.52.128/25231.136.52.129 to 231.136.52.254231.136.52.255126
107231.136.53.0/25231.136.53.1 to 231.136.53.126231.136.53.127126
108231.136.53.128/25231.136.53.129 to 231.136.53.254231.136.53.255126
109231.136.54.0/25231.136.54.1 to 231.136.54.126231.136.54.127126
110231.136.54.128/25231.136.54.129 to 231.136.54.254231.136.54.255126
111231.136.55.0/25231.136.55.1 to 231.136.55.126231.136.55.127126
112231.136.55.128/25231.136.55.129 to 231.136.55.254231.136.55.255126
113231.136.56.0/25231.136.56.1 to 231.136.56.126231.136.56.127126
114231.136.56.128/25231.136.56.129 to 231.136.56.254231.136.56.255126
115231.136.57.0/25231.136.57.1 to 231.136.57.126231.136.57.127126
116231.136.57.128/25231.136.57.129 to 231.136.57.254231.136.57.255126
117231.136.58.0/25231.136.58.1 to 231.136.58.126231.136.58.127126
118231.136.58.128/25231.136.58.129 to 231.136.58.254231.136.58.255126
119231.136.59.0/25231.136.59.1 to 231.136.59.126231.136.59.127126
120231.136.59.128/25231.136.59.129 to 231.136.59.254231.136.59.255126
121231.136.60.0/25231.136.60.1 to 231.136.60.126231.136.60.127126
122231.136.60.128/25231.136.60.129 to 231.136.60.254231.136.60.255126
123231.136.61.0/25231.136.61.1 to 231.136.61.126231.136.61.127126
124231.136.61.128/25231.136.61.129 to 231.136.61.254231.136.61.255126
125231.136.62.0/25231.136.62.1 to 231.136.62.126231.136.62.127126
126231.136.62.128/25231.136.62.129 to 231.136.62.254231.136.62.255126
127231.136.63.0/25231.136.63.1 to 231.136.63.126231.136.63.127126
128231.136.63.128/25231.136.63.129 to 231.136.63.254231.136.63.255126
129231.136.64.0/25231.136.64.1 to 231.136.64.126231.136.64.127126
130231.136.64.128/25231.136.64.129 to 231.136.64.254231.136.64.255126
131231.136.65.0/25231.136.65.1 to 231.136.65.126231.136.65.127126
132231.136.65.128/25231.136.65.129 to 231.136.65.254231.136.65.255126
133231.136.66.0/25231.136.66.1 to 231.136.66.126231.136.66.127126
134231.136.66.128/25231.136.66.129 to 231.136.66.254231.136.66.255126
135231.136.67.0/25231.136.67.1 to 231.136.67.126231.136.67.127126
136231.136.67.128/25231.136.67.129 to 231.136.67.254231.136.67.255126
137231.136.68.0/25231.136.68.1 to 231.136.68.126231.136.68.127126
138231.136.68.128/25231.136.68.129 to 231.136.68.254231.136.68.255126
139231.136.69.0/25231.136.69.1 to 231.136.69.126231.136.69.127126
140231.136.69.128/25231.136.69.129 to 231.136.69.254231.136.69.255126
141231.136.70.0/25231.136.70.1 to 231.136.70.126231.136.70.127126
142231.136.70.128/25231.136.70.129 to 231.136.70.254231.136.70.255126
143231.136.71.0/25231.136.71.1 to 231.136.71.126231.136.71.127126
144231.136.71.128/25231.136.71.129 to 231.136.71.254231.136.71.255126
145231.136.72.0/25231.136.72.1 to 231.136.72.126231.136.72.127126
146231.136.72.128/25231.136.72.129 to 231.136.72.254231.136.72.255126
147231.136.73.0/25231.136.73.1 to 231.136.73.126231.136.73.127126
148231.136.73.128/25231.136.73.129 to 231.136.73.254231.136.73.255126
149231.136.74.0/25231.136.74.1 to 231.136.74.126231.136.74.127126
150231.136.74.128/25231.136.74.129 to 231.136.74.254231.136.74.255126
151231.136.75.0/25231.136.75.1 to 231.136.75.126231.136.75.127126
152231.136.75.128/25231.136.75.129 to 231.136.75.254231.136.75.255126
153231.136.76.0/25231.136.76.1 to 231.136.76.126231.136.76.127126
154231.136.76.128/25231.136.76.129 to 231.136.76.254231.136.76.255126
155231.136.77.0/25231.136.77.1 to 231.136.77.126231.136.77.127126
156231.136.77.128/25231.136.77.129 to 231.136.77.254231.136.77.255126
157231.136.78.0/25231.136.78.1 to 231.136.78.126231.136.78.127126
158231.136.78.128/25231.136.78.129 to 231.136.78.254231.136.78.255126
159231.136.79.0/25231.136.79.1 to 231.136.79.126231.136.79.127126
160231.136.79.128/25231.136.79.129 to 231.136.79.254231.136.79.255126
161231.136.80.0/25231.136.80.1 to 231.136.80.126231.136.80.127126
162231.136.80.128/25231.136.80.129 to 231.136.80.254231.136.80.255126
163231.136.81.0/25231.136.81.1 to 231.136.81.126231.136.81.127126
164231.136.81.128/25231.136.81.129 to 231.136.81.254231.136.81.255126
165231.136.82.0/25231.136.82.1 to 231.136.82.126231.136.82.127126
166231.136.82.128/25231.136.82.129 to 231.136.82.254231.136.82.255126
167231.136.83.0/25231.136.83.1 to 231.136.83.126231.136.83.127126
168231.136.83.128/25231.136.83.129 to 231.136.83.254231.136.83.255126
169231.136.84.0/25231.136.84.1 to 231.136.84.126231.136.84.127126
170231.136.84.128/25231.136.84.129 to 231.136.84.254231.136.84.255126
171231.136.85.0/25231.136.85.1 to 231.136.85.126231.136.85.127126
172231.136.85.128/25231.136.85.129 to 231.136.85.254231.136.85.255126
173231.136.86.0/25231.136.86.1 to 231.136.86.126231.136.86.127126
174231.136.86.128/25231.136.86.129 to 231.136.86.254231.136.86.255126
175231.136.87.0/25231.136.87.1 to 231.136.87.126231.136.87.127126
176231.136.87.128/25231.136.87.129 to 231.136.87.254231.136.87.255126
177231.136.88.0/25231.136.88.1 to 231.136.88.126231.136.88.127126
178231.136.88.128/25231.136.88.129 to 231.136.88.254231.136.88.255126
179231.136.89.0/25231.136.89.1 to 231.136.89.126231.136.89.127126
180231.136.89.128/25231.136.89.129 to 231.136.89.254231.136.89.255126
181231.136.90.0/25231.136.90.1 to 231.136.90.126231.136.90.127126
182231.136.90.128/25231.136.90.129 to 231.136.90.254231.136.90.255126
183231.136.91.0/25231.136.91.1 to 231.136.91.126231.136.91.127126
184231.136.91.128/25231.136.91.129 to 231.136.91.254231.136.91.255126
185231.136.92.0/25231.136.92.1 to 231.136.92.126231.136.92.127126
186231.136.92.128/25231.136.92.129 to 231.136.92.254231.136.92.255126
187231.136.93.0/25231.136.93.1 to 231.136.93.126231.136.93.127126
188231.136.93.128/25231.136.93.129 to 231.136.93.254231.136.93.255126
189231.136.94.0/25231.136.94.1 to 231.136.94.126231.136.94.127126
190231.136.94.128/25231.136.94.129 to 231.136.94.254231.136.94.255126
191231.136.95.0/25231.136.95.1 to 231.136.95.126231.136.95.127126
192231.136.95.128/25231.136.95.129 to 231.136.95.254231.136.95.255126
193231.136.96.0/25231.136.96.1 to 231.136.96.126231.136.96.127126
194231.136.96.128/25231.136.96.129 to 231.136.96.254231.136.96.255126
195231.136.97.0/25231.136.97.1 to 231.136.97.126231.136.97.127126
196231.136.97.128/25231.136.97.129 to 231.136.97.254231.136.97.255126
197231.136.98.0/25231.136.98.1 to 231.136.98.126231.136.98.127126
198231.136.98.128/25231.136.98.129 to 231.136.98.254231.136.98.255126
199231.136.99.0/25231.136.99.1 to 231.136.99.126231.136.99.127126
200231.136.99.128/25231.136.99.129 to 231.136.99.254231.136.99.255126
201231.136.100.0/25231.136.100.1 to 231.136.100.126231.136.100.127126
202231.136.100.128/25231.136.100.129 to 231.136.100.254231.136.100.255126
203231.136.101.0/25231.136.101.1 to 231.136.101.126231.136.101.127126
204231.136.101.128/25231.136.101.129 to 231.136.101.254231.136.101.255126
205231.136.102.0/25231.136.102.1 to 231.136.102.126231.136.102.127126
206231.136.102.128/25231.136.102.129 to 231.136.102.254231.136.102.255126
207231.136.103.0/25231.136.103.1 to 231.136.103.126231.136.103.127126
208231.136.103.128/25231.136.103.129 to 231.136.103.254231.136.103.255126
209231.136.104.0/25231.136.104.1 to 231.136.104.126231.136.104.127126
210231.136.104.128/25231.136.104.129 to 231.136.104.254231.136.104.255126
211231.136.105.0/25231.136.105.1 to 231.136.105.126231.136.105.127126
212231.136.105.128/25231.136.105.129 to 231.136.105.254231.136.105.255126
213231.136.106.0/25231.136.106.1 to 231.136.106.126231.136.106.127126
214231.136.106.128/25231.136.106.129 to 231.136.106.254231.136.106.255126
215231.136.107.0/25231.136.107.1 to 231.136.107.126231.136.107.127126
216231.136.107.128/25231.136.107.129 to 231.136.107.254231.136.107.255126
217231.136.108.0/25231.136.108.1 to 231.136.108.126231.136.108.127126
218231.136.108.128/25231.136.108.129 to 231.136.108.254231.136.108.255126
219231.136.109.0/25231.136.109.1 to 231.136.109.126231.136.109.127126
220231.136.109.128/25231.136.109.129 to 231.136.109.254231.136.109.255126
221231.136.110.0/25231.136.110.1 to 231.136.110.126231.136.110.127126
222231.136.110.128/25231.136.110.129 to 231.136.110.254231.136.110.255126
223231.136.111.0/25231.136.111.1 to 231.136.111.126231.136.111.127126
224231.136.111.128/25231.136.111.129 to 231.136.111.254231.136.111.255126
225231.136.112.0/25231.136.112.1 to 231.136.112.126231.136.112.127126
226231.136.112.128/25231.136.112.129 to 231.136.112.254231.136.112.255126
227231.136.113.0/25231.136.113.1 to 231.136.113.126231.136.113.127126
228231.136.113.128/25231.136.113.129 to 231.136.113.254231.136.113.255126
229231.136.114.0/25231.136.114.1 to 231.136.114.126231.136.114.127126
230231.136.114.128/25231.136.114.129 to 231.136.114.254231.136.114.255126
231231.136.115.0/25231.136.115.1 to 231.136.115.126231.136.115.127126
232231.136.115.128/25231.136.115.129 to 231.136.115.254231.136.115.255126
233231.136.116.0/25231.136.116.1 to 231.136.116.126231.136.116.127126
234231.136.116.128/25231.136.116.129 to 231.136.116.254231.136.116.255126
235231.136.117.0/25231.136.117.1 to 231.136.117.126231.136.117.127126
236231.136.117.128/25231.136.117.129 to 231.136.117.254231.136.117.255126
237231.136.118.0/25231.136.118.1 to 231.136.118.126231.136.118.127126
238231.136.118.128/25231.136.118.129 to 231.136.118.254231.136.118.255126
239231.136.119.0/25231.136.119.1 to 231.136.119.126231.136.119.127126
240231.136.119.128/25231.136.119.129 to 231.136.119.254231.136.119.255126
241231.136.120.0/25231.136.120.1 to 231.136.120.126231.136.120.127126
242231.136.120.128/25231.136.120.129 to 231.136.120.254231.136.120.255126
243231.136.121.0/25231.136.121.1 to 231.136.121.126231.136.121.127126
244231.136.121.128/25231.136.121.129 to 231.136.121.254231.136.121.255126
245231.136.122.0/25231.136.122.1 to 231.136.122.126231.136.122.127126
246231.136.122.128/25231.136.122.129 to 231.136.122.254231.136.122.255126
247231.136.123.0/25231.136.123.1 to 231.136.123.126231.136.123.127126
248231.136.123.128/25231.136.123.129 to 231.136.123.254231.136.123.255126
249231.136.124.0/25231.136.124.1 to 231.136.124.126231.136.124.127126
250231.136.124.128/25231.136.124.129 to 231.136.124.254231.136.124.255126
251231.136.125.0/25231.136.125.1 to 231.136.125.126231.136.125.127126
252231.136.125.128/25231.136.125.129 to 231.136.125.254231.136.125.255126
253231.136.126.0/25231.136.126.1 to 231.136.126.126231.136.126.127126
254231.136.126.128/25231.136.126.129 to 231.136.126.254231.136.126.255126
255231.136.127.0/25231.136.127.1 to 231.136.127.126231.136.127.127126
256231.136.127.128/25231.136.127.129 to 231.136.127.254231.136.127.255126

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.