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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.

Network253.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
253.0.0.0
Broadcast address
253.255.255.255
First usable
253.0.0.1
Last usable
253.255.255.254
Usable hosts
16,777,214 (16,777,216 less the network and broadcast addresses)
Subnet mask
255.0.0.0
Wildcard mask
0.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/8
Type
Reserved 240.0.0.0/4
Future use; not usable on most systems
Old class
E (reserved)
As numbers
Hex FD000000 · Integer 4244635648 to 4261412863
Reverse DNS zone
253.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11111101..00000000.00000000.00000000253.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network11111101..00000000.00000000.00000000253.0.0.0
Broadcast11111101..11111111.11111111.11111111253.255.255.255
Split into smaller subnets/17
/9 (2)/10 (4)/11 (8)/12 (16)/13 (32)/14 (64)/15 (128)/16 (256)/17 (512)/18 (1,024)/19 (2,048)/20 (4,096)

253.0.0.0/8 makes 512 subnets of /17; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1253.0.0.0/17253.0.0.1 to 253.0.127.254253.0.127.25532,766
2253.0.128.0/17253.0.128.1 to 253.0.255.254253.0.255.25532,766
3253.1.0.0/17253.1.0.1 to 253.1.127.254253.1.127.25532,766
4253.1.128.0/17253.1.128.1 to 253.1.255.254253.1.255.25532,766
5253.2.0.0/17253.2.0.1 to 253.2.127.254253.2.127.25532,766
6253.2.128.0/17253.2.128.1 to 253.2.255.254253.2.255.25532,766
7253.3.0.0/17253.3.0.1 to 253.3.127.254253.3.127.25532,766
8253.3.128.0/17253.3.128.1 to 253.3.255.254253.3.255.25532,766
9253.4.0.0/17253.4.0.1 to 253.4.127.254253.4.127.25532,766
10253.4.128.0/17253.4.128.1 to 253.4.255.254253.4.255.25532,766
11253.5.0.0/17253.5.0.1 to 253.5.127.254253.5.127.25532,766
12253.5.128.0/17253.5.128.1 to 253.5.255.254253.5.255.25532,766
13253.6.0.0/17253.6.0.1 to 253.6.127.254253.6.127.25532,766
14253.6.128.0/17253.6.128.1 to 253.6.255.254253.6.255.25532,766
15253.7.0.0/17253.7.0.1 to 253.7.127.254253.7.127.25532,766
16253.7.128.0/17253.7.128.1 to 253.7.255.254253.7.255.25532,766
17253.8.0.0/17253.8.0.1 to 253.8.127.254253.8.127.25532,766
18253.8.128.0/17253.8.128.1 to 253.8.255.254253.8.255.25532,766
19253.9.0.0/17253.9.0.1 to 253.9.127.254253.9.127.25532,766
20253.9.128.0/17253.9.128.1 to 253.9.255.254253.9.255.25532,766
21253.10.0.0/17253.10.0.1 to 253.10.127.254253.10.127.25532,766
22253.10.128.0/17253.10.128.1 to 253.10.255.254253.10.255.25532,766
23253.11.0.0/17253.11.0.1 to 253.11.127.254253.11.127.25532,766
24253.11.128.0/17253.11.128.1 to 253.11.255.254253.11.255.25532,766
25253.12.0.0/17253.12.0.1 to 253.12.127.254253.12.127.25532,766
26253.12.128.0/17253.12.128.1 to 253.12.255.254253.12.255.25532,766
27253.13.0.0/17253.13.0.1 to 253.13.127.254253.13.127.25532,766
28253.13.128.0/17253.13.128.1 to 253.13.255.254253.13.255.25532,766
29253.14.0.0/17253.14.0.1 to 253.14.127.254253.14.127.25532,766
30253.14.128.0/17253.14.128.1 to 253.14.255.254253.14.255.25532,766
31253.15.0.0/17253.15.0.1 to 253.15.127.254253.15.127.25532,766
32253.15.128.0/17253.15.128.1 to 253.15.255.254253.15.255.25532,766
33253.16.0.0/17253.16.0.1 to 253.16.127.254253.16.127.25532,766
34253.16.128.0/17253.16.128.1 to 253.16.255.254253.16.255.25532,766
35253.17.0.0/17253.17.0.1 to 253.17.127.254253.17.127.25532,766
36253.17.128.0/17253.17.128.1 to 253.17.255.254253.17.255.25532,766
37253.18.0.0/17253.18.0.1 to 253.18.127.254253.18.127.25532,766
38253.18.128.0/17253.18.128.1 to 253.18.255.254253.18.255.25532,766
39253.19.0.0/17253.19.0.1 to 253.19.127.254253.19.127.25532,766
40253.19.128.0/17253.19.128.1 to 253.19.255.254253.19.255.25532,766
41253.20.0.0/17253.20.0.1 to 253.20.127.254253.20.127.25532,766
42253.20.128.0/17253.20.128.1 to 253.20.255.254253.20.255.25532,766
43253.21.0.0/17253.21.0.1 to 253.21.127.254253.21.127.25532,766
44253.21.128.0/17253.21.128.1 to 253.21.255.254253.21.255.25532,766
45253.22.0.0/17253.22.0.1 to 253.22.127.254253.22.127.25532,766
46253.22.128.0/17253.22.128.1 to 253.22.255.254253.22.255.25532,766
47253.23.0.0/17253.23.0.1 to 253.23.127.254253.23.127.25532,766
48253.23.128.0/17253.23.128.1 to 253.23.255.254253.23.255.25532,766
49253.24.0.0/17253.24.0.1 to 253.24.127.254253.24.127.25532,766
50253.24.128.0/17253.24.128.1 to 253.24.255.254253.24.255.25532,766
51253.25.0.0/17253.25.0.1 to 253.25.127.254253.25.127.25532,766
52253.25.128.0/17253.25.128.1 to 253.25.255.254253.25.255.25532,766
53253.26.0.0/17253.26.0.1 to 253.26.127.254253.26.127.25532,766
54253.26.128.0/17253.26.128.1 to 253.26.255.254253.26.255.25532,766
55253.27.0.0/17253.27.0.1 to 253.27.127.254253.27.127.25532,766
56253.27.128.0/17253.27.128.1 to 253.27.255.254253.27.255.25532,766
57253.28.0.0/17253.28.0.1 to 253.28.127.254253.28.127.25532,766
58253.28.128.0/17253.28.128.1 to 253.28.255.254253.28.255.25532,766
59253.29.0.0/17253.29.0.1 to 253.29.127.254253.29.127.25532,766
60253.29.128.0/17253.29.128.1 to 253.29.255.254253.29.255.25532,766
61253.30.0.0/17253.30.0.1 to 253.30.127.254253.30.127.25532,766
62253.30.128.0/17253.30.128.1 to 253.30.255.254253.30.255.25532,766
63253.31.0.0/17253.31.0.1 to 253.31.127.254253.31.127.25532,766
64253.31.128.0/17253.31.128.1 to 253.31.255.254253.31.255.25532,766
65253.32.0.0/17253.32.0.1 to 253.32.127.254253.32.127.25532,766
66253.32.128.0/17253.32.128.1 to 253.32.255.254253.32.255.25532,766
67253.33.0.0/17253.33.0.1 to 253.33.127.254253.33.127.25532,766
68253.33.128.0/17253.33.128.1 to 253.33.255.254253.33.255.25532,766
69253.34.0.0/17253.34.0.1 to 253.34.127.254253.34.127.25532,766
70253.34.128.0/17253.34.128.1 to 253.34.255.254253.34.255.25532,766
71253.35.0.0/17253.35.0.1 to 253.35.127.254253.35.127.25532,766
72253.35.128.0/17253.35.128.1 to 253.35.255.254253.35.255.25532,766
73253.36.0.0/17253.36.0.1 to 253.36.127.254253.36.127.25532,766
74253.36.128.0/17253.36.128.1 to 253.36.255.254253.36.255.25532,766
75253.37.0.0/17253.37.0.1 to 253.37.127.254253.37.127.25532,766
76253.37.128.0/17253.37.128.1 to 253.37.255.254253.37.255.25532,766
77253.38.0.0/17253.38.0.1 to 253.38.127.254253.38.127.25532,766
78253.38.128.0/17253.38.128.1 to 253.38.255.254253.38.255.25532,766
79253.39.0.0/17253.39.0.1 to 253.39.127.254253.39.127.25532,766
80253.39.128.0/17253.39.128.1 to 253.39.255.254253.39.255.25532,766
81253.40.0.0/17253.40.0.1 to 253.40.127.254253.40.127.25532,766
82253.40.128.0/17253.40.128.1 to 253.40.255.254253.40.255.25532,766
83253.41.0.0/17253.41.0.1 to 253.41.127.254253.41.127.25532,766
84253.41.128.0/17253.41.128.1 to 253.41.255.254253.41.255.25532,766
85253.42.0.0/17253.42.0.1 to 253.42.127.254253.42.127.25532,766
86253.42.128.0/17253.42.128.1 to 253.42.255.254253.42.255.25532,766
87253.43.0.0/17253.43.0.1 to 253.43.127.254253.43.127.25532,766
88253.43.128.0/17253.43.128.1 to 253.43.255.254253.43.255.25532,766
89253.44.0.0/17253.44.0.1 to 253.44.127.254253.44.127.25532,766
90253.44.128.0/17253.44.128.1 to 253.44.255.254253.44.255.25532,766
91253.45.0.0/17253.45.0.1 to 253.45.127.254253.45.127.25532,766
92253.45.128.0/17253.45.128.1 to 253.45.255.254253.45.255.25532,766
93253.46.0.0/17253.46.0.1 to 253.46.127.254253.46.127.25532,766
94253.46.128.0/17253.46.128.1 to 253.46.255.254253.46.255.25532,766
95253.47.0.0/17253.47.0.1 to 253.47.127.254253.47.127.25532,766
96253.47.128.0/17253.47.128.1 to 253.47.255.254253.47.255.25532,766
97253.48.0.0/17253.48.0.1 to 253.48.127.254253.48.127.25532,766
98253.48.128.0/17253.48.128.1 to 253.48.255.254253.48.255.25532,766
99253.49.0.0/17253.49.0.1 to 253.49.127.254253.49.127.25532,766
100253.49.128.0/17253.49.128.1 to 253.49.255.254253.49.255.25532,766
101253.50.0.0/17253.50.0.1 to 253.50.127.254253.50.127.25532,766
102253.50.128.0/17253.50.128.1 to 253.50.255.254253.50.255.25532,766
103253.51.0.0/17253.51.0.1 to 253.51.127.254253.51.127.25532,766
104253.51.128.0/17253.51.128.1 to 253.51.255.254253.51.255.25532,766
105253.52.0.0/17253.52.0.1 to 253.52.127.254253.52.127.25532,766
106253.52.128.0/17253.52.128.1 to 253.52.255.254253.52.255.25532,766
107253.53.0.0/17253.53.0.1 to 253.53.127.254253.53.127.25532,766
108253.53.128.0/17253.53.128.1 to 253.53.255.254253.53.255.25532,766
109253.54.0.0/17253.54.0.1 to 253.54.127.254253.54.127.25532,766
110253.54.128.0/17253.54.128.1 to 253.54.255.254253.54.255.25532,766
111253.55.0.0/17253.55.0.1 to 253.55.127.254253.55.127.25532,766
112253.55.128.0/17253.55.128.1 to 253.55.255.254253.55.255.25532,766
113253.56.0.0/17253.56.0.1 to 253.56.127.254253.56.127.25532,766
114253.56.128.0/17253.56.128.1 to 253.56.255.254253.56.255.25532,766
115253.57.0.0/17253.57.0.1 to 253.57.127.254253.57.127.25532,766
116253.57.128.0/17253.57.128.1 to 253.57.255.254253.57.255.25532,766
117253.58.0.0/17253.58.0.1 to 253.58.127.254253.58.127.25532,766
118253.58.128.0/17253.58.128.1 to 253.58.255.254253.58.255.25532,766
119253.59.0.0/17253.59.0.1 to 253.59.127.254253.59.127.25532,766
120253.59.128.0/17253.59.128.1 to 253.59.255.254253.59.255.25532,766
121253.60.0.0/17253.60.0.1 to 253.60.127.254253.60.127.25532,766
122253.60.128.0/17253.60.128.1 to 253.60.255.254253.60.255.25532,766
123253.61.0.0/17253.61.0.1 to 253.61.127.254253.61.127.25532,766
124253.61.128.0/17253.61.128.1 to 253.61.255.254253.61.255.25532,766
125253.62.0.0/17253.62.0.1 to 253.62.127.254253.62.127.25532,766
126253.62.128.0/17253.62.128.1 to 253.62.255.254253.62.255.25532,766
127253.63.0.0/17253.63.0.1 to 253.63.127.254253.63.127.25532,766
128253.63.128.0/17253.63.128.1 to 253.63.255.254253.63.255.25532,766
129253.64.0.0/17253.64.0.1 to 253.64.127.254253.64.127.25532,766
130253.64.128.0/17253.64.128.1 to 253.64.255.254253.64.255.25532,766
131253.65.0.0/17253.65.0.1 to 253.65.127.254253.65.127.25532,766
132253.65.128.0/17253.65.128.1 to 253.65.255.254253.65.255.25532,766
133253.66.0.0/17253.66.0.1 to 253.66.127.254253.66.127.25532,766
134253.66.128.0/17253.66.128.1 to 253.66.255.254253.66.255.25532,766
135253.67.0.0/17253.67.0.1 to 253.67.127.254253.67.127.25532,766
136253.67.128.0/17253.67.128.1 to 253.67.255.254253.67.255.25532,766
137253.68.0.0/17253.68.0.1 to 253.68.127.254253.68.127.25532,766
138253.68.128.0/17253.68.128.1 to 253.68.255.254253.68.255.25532,766
139253.69.0.0/17253.69.0.1 to 253.69.127.254253.69.127.25532,766
140253.69.128.0/17253.69.128.1 to 253.69.255.254253.69.255.25532,766
141253.70.0.0/17253.70.0.1 to 253.70.127.254253.70.127.25532,766
142253.70.128.0/17253.70.128.1 to 253.70.255.254253.70.255.25532,766
143253.71.0.0/17253.71.0.1 to 253.71.127.254253.71.127.25532,766
144253.71.128.0/17253.71.128.1 to 253.71.255.254253.71.255.25532,766
145253.72.0.0/17253.72.0.1 to 253.72.127.254253.72.127.25532,766
146253.72.128.0/17253.72.128.1 to 253.72.255.254253.72.255.25532,766
147253.73.0.0/17253.73.0.1 to 253.73.127.254253.73.127.25532,766
148253.73.128.0/17253.73.128.1 to 253.73.255.254253.73.255.25532,766
149253.74.0.0/17253.74.0.1 to 253.74.127.254253.74.127.25532,766
150253.74.128.0/17253.74.128.1 to 253.74.255.254253.74.255.25532,766
151253.75.0.0/17253.75.0.1 to 253.75.127.254253.75.127.25532,766
152253.75.128.0/17253.75.128.1 to 253.75.255.254253.75.255.25532,766
153253.76.0.0/17253.76.0.1 to 253.76.127.254253.76.127.25532,766
154253.76.128.0/17253.76.128.1 to 253.76.255.254253.76.255.25532,766
155253.77.0.0/17253.77.0.1 to 253.77.127.254253.77.127.25532,766
156253.77.128.0/17253.77.128.1 to 253.77.255.254253.77.255.25532,766
157253.78.0.0/17253.78.0.1 to 253.78.127.254253.78.127.25532,766
158253.78.128.0/17253.78.128.1 to 253.78.255.254253.78.255.25532,766
159253.79.0.0/17253.79.0.1 to 253.79.127.254253.79.127.25532,766
160253.79.128.0/17253.79.128.1 to 253.79.255.254253.79.255.25532,766
161253.80.0.0/17253.80.0.1 to 253.80.127.254253.80.127.25532,766
162253.80.128.0/17253.80.128.1 to 253.80.255.254253.80.255.25532,766
163253.81.0.0/17253.81.0.1 to 253.81.127.254253.81.127.25532,766
164253.81.128.0/17253.81.128.1 to 253.81.255.254253.81.255.25532,766
165253.82.0.0/17253.82.0.1 to 253.82.127.254253.82.127.25532,766
166253.82.128.0/17253.82.128.1 to 253.82.255.254253.82.255.25532,766
167253.83.0.0/17253.83.0.1 to 253.83.127.254253.83.127.25532,766
168253.83.128.0/17253.83.128.1 to 253.83.255.254253.83.255.25532,766
169253.84.0.0/17253.84.0.1 to 253.84.127.254253.84.127.25532,766
170253.84.128.0/17253.84.128.1 to 253.84.255.254253.84.255.25532,766
171253.85.0.0/17253.85.0.1 to 253.85.127.254253.85.127.25532,766
172253.85.128.0/17253.85.128.1 to 253.85.255.254253.85.255.25532,766
173253.86.0.0/17253.86.0.1 to 253.86.127.254253.86.127.25532,766
174253.86.128.0/17253.86.128.1 to 253.86.255.254253.86.255.25532,766
175253.87.0.0/17253.87.0.1 to 253.87.127.254253.87.127.25532,766
176253.87.128.0/17253.87.128.1 to 253.87.255.254253.87.255.25532,766
177253.88.0.0/17253.88.0.1 to 253.88.127.254253.88.127.25532,766
178253.88.128.0/17253.88.128.1 to 253.88.255.254253.88.255.25532,766
179253.89.0.0/17253.89.0.1 to 253.89.127.254253.89.127.25532,766
180253.89.128.0/17253.89.128.1 to 253.89.255.254253.89.255.25532,766
181253.90.0.0/17253.90.0.1 to 253.90.127.254253.90.127.25532,766
182253.90.128.0/17253.90.128.1 to 253.90.255.254253.90.255.25532,766
183253.91.0.0/17253.91.0.1 to 253.91.127.254253.91.127.25532,766
184253.91.128.0/17253.91.128.1 to 253.91.255.254253.91.255.25532,766
185253.92.0.0/17253.92.0.1 to 253.92.127.254253.92.127.25532,766
186253.92.128.0/17253.92.128.1 to 253.92.255.254253.92.255.25532,766
187253.93.0.0/17253.93.0.1 to 253.93.127.254253.93.127.25532,766
188253.93.128.0/17253.93.128.1 to 253.93.255.254253.93.255.25532,766
189253.94.0.0/17253.94.0.1 to 253.94.127.254253.94.127.25532,766
190253.94.128.0/17253.94.128.1 to 253.94.255.254253.94.255.25532,766
191253.95.0.0/17253.95.0.1 to 253.95.127.254253.95.127.25532,766
192253.95.128.0/17253.95.128.1 to 253.95.255.254253.95.255.25532,766
193253.96.0.0/17253.96.0.1 to 253.96.127.254253.96.127.25532,766
194253.96.128.0/17253.96.128.1 to 253.96.255.254253.96.255.25532,766
195253.97.0.0/17253.97.0.1 to 253.97.127.254253.97.127.25532,766
196253.97.128.0/17253.97.128.1 to 253.97.255.254253.97.255.25532,766
197253.98.0.0/17253.98.0.1 to 253.98.127.254253.98.127.25532,766
198253.98.128.0/17253.98.128.1 to 253.98.255.254253.98.255.25532,766
199253.99.0.0/17253.99.0.1 to 253.99.127.254253.99.127.25532,766
200253.99.128.0/17253.99.128.1 to 253.99.255.254253.99.255.25532,766
201253.100.0.0/17253.100.0.1 to 253.100.127.254253.100.127.25532,766
202253.100.128.0/17253.100.128.1 to 253.100.255.254253.100.255.25532,766
203253.101.0.0/17253.101.0.1 to 253.101.127.254253.101.127.25532,766
204253.101.128.0/17253.101.128.1 to 253.101.255.254253.101.255.25532,766
205253.102.0.0/17253.102.0.1 to 253.102.127.254253.102.127.25532,766
206253.102.128.0/17253.102.128.1 to 253.102.255.254253.102.255.25532,766
207253.103.0.0/17253.103.0.1 to 253.103.127.254253.103.127.25532,766
208253.103.128.0/17253.103.128.1 to 253.103.255.254253.103.255.25532,766
209253.104.0.0/17253.104.0.1 to 253.104.127.254253.104.127.25532,766
210253.104.128.0/17253.104.128.1 to 253.104.255.254253.104.255.25532,766
211253.105.0.0/17253.105.0.1 to 253.105.127.254253.105.127.25532,766
212253.105.128.0/17253.105.128.1 to 253.105.255.254253.105.255.25532,766
213253.106.0.0/17253.106.0.1 to 253.106.127.254253.106.127.25532,766
214253.106.128.0/17253.106.128.1 to 253.106.255.254253.106.255.25532,766
215253.107.0.0/17253.107.0.1 to 253.107.127.254253.107.127.25532,766
216253.107.128.0/17253.107.128.1 to 253.107.255.254253.107.255.25532,766
217253.108.0.0/17253.108.0.1 to 253.108.127.254253.108.127.25532,766
218253.108.128.0/17253.108.128.1 to 253.108.255.254253.108.255.25532,766
219253.109.0.0/17253.109.0.1 to 253.109.127.254253.109.127.25532,766
220253.109.128.0/17253.109.128.1 to 253.109.255.254253.109.255.25532,766
221253.110.0.0/17253.110.0.1 to 253.110.127.254253.110.127.25532,766
222253.110.128.0/17253.110.128.1 to 253.110.255.254253.110.255.25532,766
223253.111.0.0/17253.111.0.1 to 253.111.127.254253.111.127.25532,766
224253.111.128.0/17253.111.128.1 to 253.111.255.254253.111.255.25532,766
225253.112.0.0/17253.112.0.1 to 253.112.127.254253.112.127.25532,766
226253.112.128.0/17253.112.128.1 to 253.112.255.254253.112.255.25532,766
227253.113.0.0/17253.113.0.1 to 253.113.127.254253.113.127.25532,766
228253.113.128.0/17253.113.128.1 to 253.113.255.254253.113.255.25532,766
229253.114.0.0/17253.114.0.1 to 253.114.127.254253.114.127.25532,766
230253.114.128.0/17253.114.128.1 to 253.114.255.254253.114.255.25532,766
231253.115.0.0/17253.115.0.1 to 253.115.127.254253.115.127.25532,766
232253.115.128.0/17253.115.128.1 to 253.115.255.254253.115.255.25532,766
233253.116.0.0/17253.116.0.1 to 253.116.127.254253.116.127.25532,766
234253.116.128.0/17253.116.128.1 to 253.116.255.254253.116.255.25532,766
235253.117.0.0/17253.117.0.1 to 253.117.127.254253.117.127.25532,766
236253.117.128.0/17253.117.128.1 to 253.117.255.254253.117.255.25532,766
237253.118.0.0/17253.118.0.1 to 253.118.127.254253.118.127.25532,766
238253.118.128.0/17253.118.128.1 to 253.118.255.254253.118.255.25532,766
239253.119.0.0/17253.119.0.1 to 253.119.127.254253.119.127.25532,766
240253.119.128.0/17253.119.128.1 to 253.119.255.254253.119.255.25532,766
241253.120.0.0/17253.120.0.1 to 253.120.127.254253.120.127.25532,766
242253.120.128.0/17253.120.128.1 to 253.120.255.254253.120.255.25532,766
243253.121.0.0/17253.121.0.1 to 253.121.127.254253.121.127.25532,766
244253.121.128.0/17253.121.128.1 to 253.121.255.254253.121.255.25532,766
245253.122.0.0/17253.122.0.1 to 253.122.127.254253.122.127.25532,766
246253.122.128.0/17253.122.128.1 to 253.122.255.254253.122.255.25532,766
247253.123.0.0/17253.123.0.1 to 253.123.127.254253.123.127.25532,766
248253.123.128.0/17253.123.128.1 to 253.123.255.254253.123.255.25532,766
249253.124.0.0/17253.124.0.1 to 253.124.127.254253.124.127.25532,766
250253.124.128.0/17253.124.128.1 to 253.124.255.254253.124.255.25532,766
251253.125.0.0/17253.125.0.1 to 253.125.127.254253.125.127.25532,766
252253.125.128.0/17253.125.128.1 to 253.125.255.254253.125.255.25532,766
253253.126.0.0/17253.126.0.1 to 253.126.127.254253.126.127.25532,766
254253.126.128.0/17253.126.128.1 to 253.126.255.254253.126.255.25532,766
255253.127.0.0/17253.127.0.1 to 253.127.127.254253.127.127.25532,766
256253.127.128.0/17253.127.128.1 to 253.127.255.254253.127.255.25532,766

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.