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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.

Network228.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
228.0.0.0
Broadcast address
229.255.255.255
First usable
228.0.0.1
Last usable
229.255.255.254
Usable hosts
33,554,430 (33,554,432 less the network and broadcast addresses)
Subnet mask
254.0.0.0
Wildcard mask
1.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/7
Type
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E4000000 · Integer 3825205248 to 3858759679
Reverse DNS zones
228.in-addr.arpa
229.in-addr.arpa
/7 is not on a 8-bit boundary, so it takes 2 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11100100.00000000.00000000.00000000228.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network11100100.00000000.00000000.00000000228.0.0.0
Broadcast11100101.11111111.11111111.11111111229.255.255.255
Split into smaller subnets/18
/8 (2)/9 (4)/10 (8)/11 (16)/12 (32)/13 (64)/14 (128)/15 (256)/16 (512)/17 (1,024)/18 (2,048)/19 (4,096)

228.0.0.0/7 makes 2,048 subnets of /18; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1228.0.0.0/18228.0.0.1 to 228.0.63.254228.0.63.25516,382
2228.0.64.0/18228.0.64.1 to 228.0.127.254228.0.127.25516,382
3228.0.128.0/18228.0.128.1 to 228.0.191.254228.0.191.25516,382
4228.0.192.0/18228.0.192.1 to 228.0.255.254228.0.255.25516,382
5228.1.0.0/18228.1.0.1 to 228.1.63.254228.1.63.25516,382
6228.1.64.0/18228.1.64.1 to 228.1.127.254228.1.127.25516,382
7228.1.128.0/18228.1.128.1 to 228.1.191.254228.1.191.25516,382
8228.1.192.0/18228.1.192.1 to 228.1.255.254228.1.255.25516,382
9228.2.0.0/18228.2.0.1 to 228.2.63.254228.2.63.25516,382
10228.2.64.0/18228.2.64.1 to 228.2.127.254228.2.127.25516,382
11228.2.128.0/18228.2.128.1 to 228.2.191.254228.2.191.25516,382
12228.2.192.0/18228.2.192.1 to 228.2.255.254228.2.255.25516,382
13228.3.0.0/18228.3.0.1 to 228.3.63.254228.3.63.25516,382
14228.3.64.0/18228.3.64.1 to 228.3.127.254228.3.127.25516,382
15228.3.128.0/18228.3.128.1 to 228.3.191.254228.3.191.25516,382
16228.3.192.0/18228.3.192.1 to 228.3.255.254228.3.255.25516,382
17228.4.0.0/18228.4.0.1 to 228.4.63.254228.4.63.25516,382
18228.4.64.0/18228.4.64.1 to 228.4.127.254228.4.127.25516,382
19228.4.128.0/18228.4.128.1 to 228.4.191.254228.4.191.25516,382
20228.4.192.0/18228.4.192.1 to 228.4.255.254228.4.255.25516,382
21228.5.0.0/18228.5.0.1 to 228.5.63.254228.5.63.25516,382
22228.5.64.0/18228.5.64.1 to 228.5.127.254228.5.127.25516,382
23228.5.128.0/18228.5.128.1 to 228.5.191.254228.5.191.25516,382
24228.5.192.0/18228.5.192.1 to 228.5.255.254228.5.255.25516,382
25228.6.0.0/18228.6.0.1 to 228.6.63.254228.6.63.25516,382
26228.6.64.0/18228.6.64.1 to 228.6.127.254228.6.127.25516,382
27228.6.128.0/18228.6.128.1 to 228.6.191.254228.6.191.25516,382
28228.6.192.0/18228.6.192.1 to 228.6.255.254228.6.255.25516,382
29228.7.0.0/18228.7.0.1 to 228.7.63.254228.7.63.25516,382
30228.7.64.0/18228.7.64.1 to 228.7.127.254228.7.127.25516,382
31228.7.128.0/18228.7.128.1 to 228.7.191.254228.7.191.25516,382
32228.7.192.0/18228.7.192.1 to 228.7.255.254228.7.255.25516,382
33228.8.0.0/18228.8.0.1 to 228.8.63.254228.8.63.25516,382
34228.8.64.0/18228.8.64.1 to 228.8.127.254228.8.127.25516,382
35228.8.128.0/18228.8.128.1 to 228.8.191.254228.8.191.25516,382
36228.8.192.0/18228.8.192.1 to 228.8.255.254228.8.255.25516,382
37228.9.0.0/18228.9.0.1 to 228.9.63.254228.9.63.25516,382
38228.9.64.0/18228.9.64.1 to 228.9.127.254228.9.127.25516,382
39228.9.128.0/18228.9.128.1 to 228.9.191.254228.9.191.25516,382
40228.9.192.0/18228.9.192.1 to 228.9.255.254228.9.255.25516,382
41228.10.0.0/18228.10.0.1 to 228.10.63.254228.10.63.25516,382
42228.10.64.0/18228.10.64.1 to 228.10.127.254228.10.127.25516,382
43228.10.128.0/18228.10.128.1 to 228.10.191.254228.10.191.25516,382
44228.10.192.0/18228.10.192.1 to 228.10.255.254228.10.255.25516,382
45228.11.0.0/18228.11.0.1 to 228.11.63.254228.11.63.25516,382
46228.11.64.0/18228.11.64.1 to 228.11.127.254228.11.127.25516,382
47228.11.128.0/18228.11.128.1 to 228.11.191.254228.11.191.25516,382
48228.11.192.0/18228.11.192.1 to 228.11.255.254228.11.255.25516,382
49228.12.0.0/18228.12.0.1 to 228.12.63.254228.12.63.25516,382
50228.12.64.0/18228.12.64.1 to 228.12.127.254228.12.127.25516,382
51228.12.128.0/18228.12.128.1 to 228.12.191.254228.12.191.25516,382
52228.12.192.0/18228.12.192.1 to 228.12.255.254228.12.255.25516,382
53228.13.0.0/18228.13.0.1 to 228.13.63.254228.13.63.25516,382
54228.13.64.0/18228.13.64.1 to 228.13.127.254228.13.127.25516,382
55228.13.128.0/18228.13.128.1 to 228.13.191.254228.13.191.25516,382
56228.13.192.0/18228.13.192.1 to 228.13.255.254228.13.255.25516,382
57228.14.0.0/18228.14.0.1 to 228.14.63.254228.14.63.25516,382
58228.14.64.0/18228.14.64.1 to 228.14.127.254228.14.127.25516,382
59228.14.128.0/18228.14.128.1 to 228.14.191.254228.14.191.25516,382
60228.14.192.0/18228.14.192.1 to 228.14.255.254228.14.255.25516,382
61228.15.0.0/18228.15.0.1 to 228.15.63.254228.15.63.25516,382
62228.15.64.0/18228.15.64.1 to 228.15.127.254228.15.127.25516,382
63228.15.128.0/18228.15.128.1 to 228.15.191.254228.15.191.25516,382
64228.15.192.0/18228.15.192.1 to 228.15.255.254228.15.255.25516,382
65228.16.0.0/18228.16.0.1 to 228.16.63.254228.16.63.25516,382
66228.16.64.0/18228.16.64.1 to 228.16.127.254228.16.127.25516,382
67228.16.128.0/18228.16.128.1 to 228.16.191.254228.16.191.25516,382
68228.16.192.0/18228.16.192.1 to 228.16.255.254228.16.255.25516,382
69228.17.0.0/18228.17.0.1 to 228.17.63.254228.17.63.25516,382
70228.17.64.0/18228.17.64.1 to 228.17.127.254228.17.127.25516,382
71228.17.128.0/18228.17.128.1 to 228.17.191.254228.17.191.25516,382
72228.17.192.0/18228.17.192.1 to 228.17.255.254228.17.255.25516,382
73228.18.0.0/18228.18.0.1 to 228.18.63.254228.18.63.25516,382
74228.18.64.0/18228.18.64.1 to 228.18.127.254228.18.127.25516,382
75228.18.128.0/18228.18.128.1 to 228.18.191.254228.18.191.25516,382
76228.18.192.0/18228.18.192.1 to 228.18.255.254228.18.255.25516,382
77228.19.0.0/18228.19.0.1 to 228.19.63.254228.19.63.25516,382
78228.19.64.0/18228.19.64.1 to 228.19.127.254228.19.127.25516,382
79228.19.128.0/18228.19.128.1 to 228.19.191.254228.19.191.25516,382
80228.19.192.0/18228.19.192.1 to 228.19.255.254228.19.255.25516,382
81228.20.0.0/18228.20.0.1 to 228.20.63.254228.20.63.25516,382
82228.20.64.0/18228.20.64.1 to 228.20.127.254228.20.127.25516,382
83228.20.128.0/18228.20.128.1 to 228.20.191.254228.20.191.25516,382
84228.20.192.0/18228.20.192.1 to 228.20.255.254228.20.255.25516,382
85228.21.0.0/18228.21.0.1 to 228.21.63.254228.21.63.25516,382
86228.21.64.0/18228.21.64.1 to 228.21.127.254228.21.127.25516,382
87228.21.128.0/18228.21.128.1 to 228.21.191.254228.21.191.25516,382
88228.21.192.0/18228.21.192.1 to 228.21.255.254228.21.255.25516,382
89228.22.0.0/18228.22.0.1 to 228.22.63.254228.22.63.25516,382
90228.22.64.0/18228.22.64.1 to 228.22.127.254228.22.127.25516,382
91228.22.128.0/18228.22.128.1 to 228.22.191.254228.22.191.25516,382
92228.22.192.0/18228.22.192.1 to 228.22.255.254228.22.255.25516,382
93228.23.0.0/18228.23.0.1 to 228.23.63.254228.23.63.25516,382
94228.23.64.0/18228.23.64.1 to 228.23.127.254228.23.127.25516,382
95228.23.128.0/18228.23.128.1 to 228.23.191.254228.23.191.25516,382
96228.23.192.0/18228.23.192.1 to 228.23.255.254228.23.255.25516,382
97228.24.0.0/18228.24.0.1 to 228.24.63.254228.24.63.25516,382
98228.24.64.0/18228.24.64.1 to 228.24.127.254228.24.127.25516,382
99228.24.128.0/18228.24.128.1 to 228.24.191.254228.24.191.25516,382
100228.24.192.0/18228.24.192.1 to 228.24.255.254228.24.255.25516,382
101228.25.0.0/18228.25.0.1 to 228.25.63.254228.25.63.25516,382
102228.25.64.0/18228.25.64.1 to 228.25.127.254228.25.127.25516,382
103228.25.128.0/18228.25.128.1 to 228.25.191.254228.25.191.25516,382
104228.25.192.0/18228.25.192.1 to 228.25.255.254228.25.255.25516,382
105228.26.0.0/18228.26.0.1 to 228.26.63.254228.26.63.25516,382
106228.26.64.0/18228.26.64.1 to 228.26.127.254228.26.127.25516,382
107228.26.128.0/18228.26.128.1 to 228.26.191.254228.26.191.25516,382
108228.26.192.0/18228.26.192.1 to 228.26.255.254228.26.255.25516,382
109228.27.0.0/18228.27.0.1 to 228.27.63.254228.27.63.25516,382
110228.27.64.0/18228.27.64.1 to 228.27.127.254228.27.127.25516,382
111228.27.128.0/18228.27.128.1 to 228.27.191.254228.27.191.25516,382
112228.27.192.0/18228.27.192.1 to 228.27.255.254228.27.255.25516,382
113228.28.0.0/18228.28.0.1 to 228.28.63.254228.28.63.25516,382
114228.28.64.0/18228.28.64.1 to 228.28.127.254228.28.127.25516,382
115228.28.128.0/18228.28.128.1 to 228.28.191.254228.28.191.25516,382
116228.28.192.0/18228.28.192.1 to 228.28.255.254228.28.255.25516,382
117228.29.0.0/18228.29.0.1 to 228.29.63.254228.29.63.25516,382
118228.29.64.0/18228.29.64.1 to 228.29.127.254228.29.127.25516,382
119228.29.128.0/18228.29.128.1 to 228.29.191.254228.29.191.25516,382
120228.29.192.0/18228.29.192.1 to 228.29.255.254228.29.255.25516,382
121228.30.0.0/18228.30.0.1 to 228.30.63.254228.30.63.25516,382
122228.30.64.0/18228.30.64.1 to 228.30.127.254228.30.127.25516,382
123228.30.128.0/18228.30.128.1 to 228.30.191.254228.30.191.25516,382
124228.30.192.0/18228.30.192.1 to 228.30.255.254228.30.255.25516,382
125228.31.0.0/18228.31.0.1 to 228.31.63.254228.31.63.25516,382
126228.31.64.0/18228.31.64.1 to 228.31.127.254228.31.127.25516,382
127228.31.128.0/18228.31.128.1 to 228.31.191.254228.31.191.25516,382
128228.31.192.0/18228.31.192.1 to 228.31.255.254228.31.255.25516,382
129228.32.0.0/18228.32.0.1 to 228.32.63.254228.32.63.25516,382
130228.32.64.0/18228.32.64.1 to 228.32.127.254228.32.127.25516,382
131228.32.128.0/18228.32.128.1 to 228.32.191.254228.32.191.25516,382
132228.32.192.0/18228.32.192.1 to 228.32.255.254228.32.255.25516,382
133228.33.0.0/18228.33.0.1 to 228.33.63.254228.33.63.25516,382
134228.33.64.0/18228.33.64.1 to 228.33.127.254228.33.127.25516,382
135228.33.128.0/18228.33.128.1 to 228.33.191.254228.33.191.25516,382
136228.33.192.0/18228.33.192.1 to 228.33.255.254228.33.255.25516,382
137228.34.0.0/18228.34.0.1 to 228.34.63.254228.34.63.25516,382
138228.34.64.0/18228.34.64.1 to 228.34.127.254228.34.127.25516,382
139228.34.128.0/18228.34.128.1 to 228.34.191.254228.34.191.25516,382
140228.34.192.0/18228.34.192.1 to 228.34.255.254228.34.255.25516,382
141228.35.0.0/18228.35.0.1 to 228.35.63.254228.35.63.25516,382
142228.35.64.0/18228.35.64.1 to 228.35.127.254228.35.127.25516,382
143228.35.128.0/18228.35.128.1 to 228.35.191.254228.35.191.25516,382
144228.35.192.0/18228.35.192.1 to 228.35.255.254228.35.255.25516,382
145228.36.0.0/18228.36.0.1 to 228.36.63.254228.36.63.25516,382
146228.36.64.0/18228.36.64.1 to 228.36.127.254228.36.127.25516,382
147228.36.128.0/18228.36.128.1 to 228.36.191.254228.36.191.25516,382
148228.36.192.0/18228.36.192.1 to 228.36.255.254228.36.255.25516,382
149228.37.0.0/18228.37.0.1 to 228.37.63.254228.37.63.25516,382
150228.37.64.0/18228.37.64.1 to 228.37.127.254228.37.127.25516,382
151228.37.128.0/18228.37.128.1 to 228.37.191.254228.37.191.25516,382
152228.37.192.0/18228.37.192.1 to 228.37.255.254228.37.255.25516,382
153228.38.0.0/18228.38.0.1 to 228.38.63.254228.38.63.25516,382
154228.38.64.0/18228.38.64.1 to 228.38.127.254228.38.127.25516,382
155228.38.128.0/18228.38.128.1 to 228.38.191.254228.38.191.25516,382
156228.38.192.0/18228.38.192.1 to 228.38.255.254228.38.255.25516,382
157228.39.0.0/18228.39.0.1 to 228.39.63.254228.39.63.25516,382
158228.39.64.0/18228.39.64.1 to 228.39.127.254228.39.127.25516,382
159228.39.128.0/18228.39.128.1 to 228.39.191.254228.39.191.25516,382
160228.39.192.0/18228.39.192.1 to 228.39.255.254228.39.255.25516,382
161228.40.0.0/18228.40.0.1 to 228.40.63.254228.40.63.25516,382
162228.40.64.0/18228.40.64.1 to 228.40.127.254228.40.127.25516,382
163228.40.128.0/18228.40.128.1 to 228.40.191.254228.40.191.25516,382
164228.40.192.0/18228.40.192.1 to 228.40.255.254228.40.255.25516,382
165228.41.0.0/18228.41.0.1 to 228.41.63.254228.41.63.25516,382
166228.41.64.0/18228.41.64.1 to 228.41.127.254228.41.127.25516,382
167228.41.128.0/18228.41.128.1 to 228.41.191.254228.41.191.25516,382
168228.41.192.0/18228.41.192.1 to 228.41.255.254228.41.255.25516,382
169228.42.0.0/18228.42.0.1 to 228.42.63.254228.42.63.25516,382
170228.42.64.0/18228.42.64.1 to 228.42.127.254228.42.127.25516,382
171228.42.128.0/18228.42.128.1 to 228.42.191.254228.42.191.25516,382
172228.42.192.0/18228.42.192.1 to 228.42.255.254228.42.255.25516,382
173228.43.0.0/18228.43.0.1 to 228.43.63.254228.43.63.25516,382
174228.43.64.0/18228.43.64.1 to 228.43.127.254228.43.127.25516,382
175228.43.128.0/18228.43.128.1 to 228.43.191.254228.43.191.25516,382
176228.43.192.0/18228.43.192.1 to 228.43.255.254228.43.255.25516,382
177228.44.0.0/18228.44.0.1 to 228.44.63.254228.44.63.25516,382
178228.44.64.0/18228.44.64.1 to 228.44.127.254228.44.127.25516,382
179228.44.128.0/18228.44.128.1 to 228.44.191.254228.44.191.25516,382
180228.44.192.0/18228.44.192.1 to 228.44.255.254228.44.255.25516,382
181228.45.0.0/18228.45.0.1 to 228.45.63.254228.45.63.25516,382
182228.45.64.0/18228.45.64.1 to 228.45.127.254228.45.127.25516,382
183228.45.128.0/18228.45.128.1 to 228.45.191.254228.45.191.25516,382
184228.45.192.0/18228.45.192.1 to 228.45.255.254228.45.255.25516,382
185228.46.0.0/18228.46.0.1 to 228.46.63.254228.46.63.25516,382
186228.46.64.0/18228.46.64.1 to 228.46.127.254228.46.127.25516,382
187228.46.128.0/18228.46.128.1 to 228.46.191.254228.46.191.25516,382
188228.46.192.0/18228.46.192.1 to 228.46.255.254228.46.255.25516,382
189228.47.0.0/18228.47.0.1 to 228.47.63.254228.47.63.25516,382
190228.47.64.0/18228.47.64.1 to 228.47.127.254228.47.127.25516,382
191228.47.128.0/18228.47.128.1 to 228.47.191.254228.47.191.25516,382
192228.47.192.0/18228.47.192.1 to 228.47.255.254228.47.255.25516,382
193228.48.0.0/18228.48.0.1 to 228.48.63.254228.48.63.25516,382
194228.48.64.0/18228.48.64.1 to 228.48.127.254228.48.127.25516,382
195228.48.128.0/18228.48.128.1 to 228.48.191.254228.48.191.25516,382
196228.48.192.0/18228.48.192.1 to 228.48.255.254228.48.255.25516,382
197228.49.0.0/18228.49.0.1 to 228.49.63.254228.49.63.25516,382
198228.49.64.0/18228.49.64.1 to 228.49.127.254228.49.127.25516,382
199228.49.128.0/18228.49.128.1 to 228.49.191.254228.49.191.25516,382
200228.49.192.0/18228.49.192.1 to 228.49.255.254228.49.255.25516,382
201228.50.0.0/18228.50.0.1 to 228.50.63.254228.50.63.25516,382
202228.50.64.0/18228.50.64.1 to 228.50.127.254228.50.127.25516,382
203228.50.128.0/18228.50.128.1 to 228.50.191.254228.50.191.25516,382
204228.50.192.0/18228.50.192.1 to 228.50.255.254228.50.255.25516,382
205228.51.0.0/18228.51.0.1 to 228.51.63.254228.51.63.25516,382
206228.51.64.0/18228.51.64.1 to 228.51.127.254228.51.127.25516,382
207228.51.128.0/18228.51.128.1 to 228.51.191.254228.51.191.25516,382
208228.51.192.0/18228.51.192.1 to 228.51.255.254228.51.255.25516,382
209228.52.0.0/18228.52.0.1 to 228.52.63.254228.52.63.25516,382
210228.52.64.0/18228.52.64.1 to 228.52.127.254228.52.127.25516,382
211228.52.128.0/18228.52.128.1 to 228.52.191.254228.52.191.25516,382
212228.52.192.0/18228.52.192.1 to 228.52.255.254228.52.255.25516,382
213228.53.0.0/18228.53.0.1 to 228.53.63.254228.53.63.25516,382
214228.53.64.0/18228.53.64.1 to 228.53.127.254228.53.127.25516,382
215228.53.128.0/18228.53.128.1 to 228.53.191.254228.53.191.25516,382
216228.53.192.0/18228.53.192.1 to 228.53.255.254228.53.255.25516,382
217228.54.0.0/18228.54.0.1 to 228.54.63.254228.54.63.25516,382
218228.54.64.0/18228.54.64.1 to 228.54.127.254228.54.127.25516,382
219228.54.128.0/18228.54.128.1 to 228.54.191.254228.54.191.25516,382
220228.54.192.0/18228.54.192.1 to 228.54.255.254228.54.255.25516,382
221228.55.0.0/18228.55.0.1 to 228.55.63.254228.55.63.25516,382
222228.55.64.0/18228.55.64.1 to 228.55.127.254228.55.127.25516,382
223228.55.128.0/18228.55.128.1 to 228.55.191.254228.55.191.25516,382
224228.55.192.0/18228.55.192.1 to 228.55.255.254228.55.255.25516,382
225228.56.0.0/18228.56.0.1 to 228.56.63.254228.56.63.25516,382
226228.56.64.0/18228.56.64.1 to 228.56.127.254228.56.127.25516,382
227228.56.128.0/18228.56.128.1 to 228.56.191.254228.56.191.25516,382
228228.56.192.0/18228.56.192.1 to 228.56.255.254228.56.255.25516,382
229228.57.0.0/18228.57.0.1 to 228.57.63.254228.57.63.25516,382
230228.57.64.0/18228.57.64.1 to 228.57.127.254228.57.127.25516,382
231228.57.128.0/18228.57.128.1 to 228.57.191.254228.57.191.25516,382
232228.57.192.0/18228.57.192.1 to 228.57.255.254228.57.255.25516,382
233228.58.0.0/18228.58.0.1 to 228.58.63.254228.58.63.25516,382
234228.58.64.0/18228.58.64.1 to 228.58.127.254228.58.127.25516,382
235228.58.128.0/18228.58.128.1 to 228.58.191.254228.58.191.25516,382
236228.58.192.0/18228.58.192.1 to 228.58.255.254228.58.255.25516,382
237228.59.0.0/18228.59.0.1 to 228.59.63.254228.59.63.25516,382
238228.59.64.0/18228.59.64.1 to 228.59.127.254228.59.127.25516,382
239228.59.128.0/18228.59.128.1 to 228.59.191.254228.59.191.25516,382
240228.59.192.0/18228.59.192.1 to 228.59.255.254228.59.255.25516,382
241228.60.0.0/18228.60.0.1 to 228.60.63.254228.60.63.25516,382
242228.60.64.0/18228.60.64.1 to 228.60.127.254228.60.127.25516,382
243228.60.128.0/18228.60.128.1 to 228.60.191.254228.60.191.25516,382
244228.60.192.0/18228.60.192.1 to 228.60.255.254228.60.255.25516,382
245228.61.0.0/18228.61.0.1 to 228.61.63.254228.61.63.25516,382
246228.61.64.0/18228.61.64.1 to 228.61.127.254228.61.127.25516,382
247228.61.128.0/18228.61.128.1 to 228.61.191.254228.61.191.25516,382
248228.61.192.0/18228.61.192.1 to 228.61.255.254228.61.255.25516,382
249228.62.0.0/18228.62.0.1 to 228.62.63.254228.62.63.25516,382
250228.62.64.0/18228.62.64.1 to 228.62.127.254228.62.127.25516,382
251228.62.128.0/18228.62.128.1 to 228.62.191.254228.62.191.25516,382
252228.62.192.0/18228.62.192.1 to 228.62.255.254228.62.255.25516,382
253228.63.0.0/18228.63.0.1 to 228.63.63.254228.63.63.25516,382
254228.63.64.0/18228.63.64.1 to 228.63.127.254228.63.127.25516,382
255228.63.128.0/18228.63.128.1 to 228.63.191.254228.63.191.25516,382
256228.63.192.0/18228.63.192.1 to 228.63.255.254228.63.255.25516,382

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.