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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.

Network198.0.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
198.0.0.0
Broadcast address
198.127.255.255
First usable
198.0.0.1
Last usable
198.127.255.254
Usable hosts
8,388,606 (8,388,608 less the network and broadcast addresses)
Subnet mask
255.128.0.0
Wildcard mask
0.127.255.255 (Cisco ACLs, OSPF)
Prefix length
/9
Type
Public public
Old class
C (default /24)
As numbers
Hex C6000000 · Integer 3321888768 to 3330277375
Reverse DNS zones
0.198.in-addr.arpa
1.198.in-addr.arpa
2.198.in-addr.arpa
3.198.in-addr.arpa
4.198.in-addr.arpa
5.198.in-addr.arpa
6.198.in-addr.arpa
7.198.in-addr.arpa
8.198.in-addr.arpa
9.198.in-addr.arpa
10.198.in-addr.arpa
11.198.in-addr.arpa
12.198.in-addr.arpa
13.198.in-addr.arpa
14.198.in-addr.arpa
15.198.in-addr.arpa
and 112 more
/9 is not on a 8-bit boundary, so it takes 128 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11000110.00000000.00000000.00000000198.0.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network11000110.00000000.00000000.00000000198.0.0.0
Broadcast11000110.01111111.11111111.11111111198.127.255.255
Split into smaller subnets/20
/10 (2)/11 (4)/12 (8)/13 (16)/14 (32)/15 (64)/16 (128)/17 (256)/18 (512)/19 (1,024)/20 (2,048)/21 (4,096)

198.0.0.0/9 makes 2,048 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1198.0.0.0/20198.0.0.1 to 198.0.15.254198.0.15.2554,094
2198.0.16.0/20198.0.16.1 to 198.0.31.254198.0.31.2554,094
3198.0.32.0/20198.0.32.1 to 198.0.47.254198.0.47.2554,094
4198.0.48.0/20198.0.48.1 to 198.0.63.254198.0.63.2554,094
5198.0.64.0/20198.0.64.1 to 198.0.79.254198.0.79.2554,094
6198.0.80.0/20198.0.80.1 to 198.0.95.254198.0.95.2554,094
7198.0.96.0/20198.0.96.1 to 198.0.111.254198.0.111.2554,094
8198.0.112.0/20198.0.112.1 to 198.0.127.254198.0.127.2554,094
9198.0.128.0/20198.0.128.1 to 198.0.143.254198.0.143.2554,094
10198.0.144.0/20198.0.144.1 to 198.0.159.254198.0.159.2554,094
11198.0.160.0/20198.0.160.1 to 198.0.175.254198.0.175.2554,094
12198.0.176.0/20198.0.176.1 to 198.0.191.254198.0.191.2554,094
13198.0.192.0/20198.0.192.1 to 198.0.207.254198.0.207.2554,094
14198.0.208.0/20198.0.208.1 to 198.0.223.254198.0.223.2554,094
15198.0.224.0/20198.0.224.1 to 198.0.239.254198.0.239.2554,094
16198.0.240.0/20198.0.240.1 to 198.0.255.254198.0.255.2554,094
17198.1.0.0/20198.1.0.1 to 198.1.15.254198.1.15.2554,094
18198.1.16.0/20198.1.16.1 to 198.1.31.254198.1.31.2554,094
19198.1.32.0/20198.1.32.1 to 198.1.47.254198.1.47.2554,094
20198.1.48.0/20198.1.48.1 to 198.1.63.254198.1.63.2554,094
21198.1.64.0/20198.1.64.1 to 198.1.79.254198.1.79.2554,094
22198.1.80.0/20198.1.80.1 to 198.1.95.254198.1.95.2554,094
23198.1.96.0/20198.1.96.1 to 198.1.111.254198.1.111.2554,094
24198.1.112.0/20198.1.112.1 to 198.1.127.254198.1.127.2554,094
25198.1.128.0/20198.1.128.1 to 198.1.143.254198.1.143.2554,094
26198.1.144.0/20198.1.144.1 to 198.1.159.254198.1.159.2554,094
27198.1.160.0/20198.1.160.1 to 198.1.175.254198.1.175.2554,094
28198.1.176.0/20198.1.176.1 to 198.1.191.254198.1.191.2554,094
29198.1.192.0/20198.1.192.1 to 198.1.207.254198.1.207.2554,094
30198.1.208.0/20198.1.208.1 to 198.1.223.254198.1.223.2554,094
31198.1.224.0/20198.1.224.1 to 198.1.239.254198.1.239.2554,094
32198.1.240.0/20198.1.240.1 to 198.1.255.254198.1.255.2554,094
33198.2.0.0/20198.2.0.1 to 198.2.15.254198.2.15.2554,094
34198.2.16.0/20198.2.16.1 to 198.2.31.254198.2.31.2554,094
35198.2.32.0/20198.2.32.1 to 198.2.47.254198.2.47.2554,094
36198.2.48.0/20198.2.48.1 to 198.2.63.254198.2.63.2554,094
37198.2.64.0/20198.2.64.1 to 198.2.79.254198.2.79.2554,094
38198.2.80.0/20198.2.80.1 to 198.2.95.254198.2.95.2554,094
39198.2.96.0/20198.2.96.1 to 198.2.111.254198.2.111.2554,094
40198.2.112.0/20198.2.112.1 to 198.2.127.254198.2.127.2554,094
41198.2.128.0/20198.2.128.1 to 198.2.143.254198.2.143.2554,094
42198.2.144.0/20198.2.144.1 to 198.2.159.254198.2.159.2554,094
43198.2.160.0/20198.2.160.1 to 198.2.175.254198.2.175.2554,094
44198.2.176.0/20198.2.176.1 to 198.2.191.254198.2.191.2554,094
45198.2.192.0/20198.2.192.1 to 198.2.207.254198.2.207.2554,094
46198.2.208.0/20198.2.208.1 to 198.2.223.254198.2.223.2554,094
47198.2.224.0/20198.2.224.1 to 198.2.239.254198.2.239.2554,094
48198.2.240.0/20198.2.240.1 to 198.2.255.254198.2.255.2554,094
49198.3.0.0/20198.3.0.1 to 198.3.15.254198.3.15.2554,094
50198.3.16.0/20198.3.16.1 to 198.3.31.254198.3.31.2554,094
51198.3.32.0/20198.3.32.1 to 198.3.47.254198.3.47.2554,094
52198.3.48.0/20198.3.48.1 to 198.3.63.254198.3.63.2554,094
53198.3.64.0/20198.3.64.1 to 198.3.79.254198.3.79.2554,094
54198.3.80.0/20198.3.80.1 to 198.3.95.254198.3.95.2554,094
55198.3.96.0/20198.3.96.1 to 198.3.111.254198.3.111.2554,094
56198.3.112.0/20198.3.112.1 to 198.3.127.254198.3.127.2554,094
57198.3.128.0/20198.3.128.1 to 198.3.143.254198.3.143.2554,094
58198.3.144.0/20198.3.144.1 to 198.3.159.254198.3.159.2554,094
59198.3.160.0/20198.3.160.1 to 198.3.175.254198.3.175.2554,094
60198.3.176.0/20198.3.176.1 to 198.3.191.254198.3.191.2554,094
61198.3.192.0/20198.3.192.1 to 198.3.207.254198.3.207.2554,094
62198.3.208.0/20198.3.208.1 to 198.3.223.254198.3.223.2554,094
63198.3.224.0/20198.3.224.1 to 198.3.239.254198.3.239.2554,094
64198.3.240.0/20198.3.240.1 to 198.3.255.254198.3.255.2554,094
65198.4.0.0/20198.4.0.1 to 198.4.15.254198.4.15.2554,094
66198.4.16.0/20198.4.16.1 to 198.4.31.254198.4.31.2554,094
67198.4.32.0/20198.4.32.1 to 198.4.47.254198.4.47.2554,094
68198.4.48.0/20198.4.48.1 to 198.4.63.254198.4.63.2554,094
69198.4.64.0/20198.4.64.1 to 198.4.79.254198.4.79.2554,094
70198.4.80.0/20198.4.80.1 to 198.4.95.254198.4.95.2554,094
71198.4.96.0/20198.4.96.1 to 198.4.111.254198.4.111.2554,094
72198.4.112.0/20198.4.112.1 to 198.4.127.254198.4.127.2554,094
73198.4.128.0/20198.4.128.1 to 198.4.143.254198.4.143.2554,094
74198.4.144.0/20198.4.144.1 to 198.4.159.254198.4.159.2554,094
75198.4.160.0/20198.4.160.1 to 198.4.175.254198.4.175.2554,094
76198.4.176.0/20198.4.176.1 to 198.4.191.254198.4.191.2554,094
77198.4.192.0/20198.4.192.1 to 198.4.207.254198.4.207.2554,094
78198.4.208.0/20198.4.208.1 to 198.4.223.254198.4.223.2554,094
79198.4.224.0/20198.4.224.1 to 198.4.239.254198.4.239.2554,094
80198.4.240.0/20198.4.240.1 to 198.4.255.254198.4.255.2554,094
81198.5.0.0/20198.5.0.1 to 198.5.15.254198.5.15.2554,094
82198.5.16.0/20198.5.16.1 to 198.5.31.254198.5.31.2554,094
83198.5.32.0/20198.5.32.1 to 198.5.47.254198.5.47.2554,094
84198.5.48.0/20198.5.48.1 to 198.5.63.254198.5.63.2554,094
85198.5.64.0/20198.5.64.1 to 198.5.79.254198.5.79.2554,094
86198.5.80.0/20198.5.80.1 to 198.5.95.254198.5.95.2554,094
87198.5.96.0/20198.5.96.1 to 198.5.111.254198.5.111.2554,094
88198.5.112.0/20198.5.112.1 to 198.5.127.254198.5.127.2554,094
89198.5.128.0/20198.5.128.1 to 198.5.143.254198.5.143.2554,094
90198.5.144.0/20198.5.144.1 to 198.5.159.254198.5.159.2554,094
91198.5.160.0/20198.5.160.1 to 198.5.175.254198.5.175.2554,094
92198.5.176.0/20198.5.176.1 to 198.5.191.254198.5.191.2554,094
93198.5.192.0/20198.5.192.1 to 198.5.207.254198.5.207.2554,094
94198.5.208.0/20198.5.208.1 to 198.5.223.254198.5.223.2554,094
95198.5.224.0/20198.5.224.1 to 198.5.239.254198.5.239.2554,094
96198.5.240.0/20198.5.240.1 to 198.5.255.254198.5.255.2554,094
97198.6.0.0/20198.6.0.1 to 198.6.15.254198.6.15.2554,094
98198.6.16.0/20198.6.16.1 to 198.6.31.254198.6.31.2554,094
99198.6.32.0/20198.6.32.1 to 198.6.47.254198.6.47.2554,094
100198.6.48.0/20198.6.48.1 to 198.6.63.254198.6.63.2554,094
101198.6.64.0/20198.6.64.1 to 198.6.79.254198.6.79.2554,094
102198.6.80.0/20198.6.80.1 to 198.6.95.254198.6.95.2554,094
103198.6.96.0/20198.6.96.1 to 198.6.111.254198.6.111.2554,094
104198.6.112.0/20198.6.112.1 to 198.6.127.254198.6.127.2554,094
105198.6.128.0/20198.6.128.1 to 198.6.143.254198.6.143.2554,094
106198.6.144.0/20198.6.144.1 to 198.6.159.254198.6.159.2554,094
107198.6.160.0/20198.6.160.1 to 198.6.175.254198.6.175.2554,094
108198.6.176.0/20198.6.176.1 to 198.6.191.254198.6.191.2554,094
109198.6.192.0/20198.6.192.1 to 198.6.207.254198.6.207.2554,094
110198.6.208.0/20198.6.208.1 to 198.6.223.254198.6.223.2554,094
111198.6.224.0/20198.6.224.1 to 198.6.239.254198.6.239.2554,094
112198.6.240.0/20198.6.240.1 to 198.6.255.254198.6.255.2554,094
113198.7.0.0/20198.7.0.1 to 198.7.15.254198.7.15.2554,094
114198.7.16.0/20198.7.16.1 to 198.7.31.254198.7.31.2554,094
115198.7.32.0/20198.7.32.1 to 198.7.47.254198.7.47.2554,094
116198.7.48.0/20198.7.48.1 to 198.7.63.254198.7.63.2554,094
117198.7.64.0/20198.7.64.1 to 198.7.79.254198.7.79.2554,094
118198.7.80.0/20198.7.80.1 to 198.7.95.254198.7.95.2554,094
119198.7.96.0/20198.7.96.1 to 198.7.111.254198.7.111.2554,094
120198.7.112.0/20198.7.112.1 to 198.7.127.254198.7.127.2554,094
121198.7.128.0/20198.7.128.1 to 198.7.143.254198.7.143.2554,094
122198.7.144.0/20198.7.144.1 to 198.7.159.254198.7.159.2554,094
123198.7.160.0/20198.7.160.1 to 198.7.175.254198.7.175.2554,094
124198.7.176.0/20198.7.176.1 to 198.7.191.254198.7.191.2554,094
125198.7.192.0/20198.7.192.1 to 198.7.207.254198.7.207.2554,094
126198.7.208.0/20198.7.208.1 to 198.7.223.254198.7.223.2554,094
127198.7.224.0/20198.7.224.1 to 198.7.239.254198.7.239.2554,094
128198.7.240.0/20198.7.240.1 to 198.7.255.254198.7.255.2554,094
129198.8.0.0/20198.8.0.1 to 198.8.15.254198.8.15.2554,094
130198.8.16.0/20198.8.16.1 to 198.8.31.254198.8.31.2554,094
131198.8.32.0/20198.8.32.1 to 198.8.47.254198.8.47.2554,094
132198.8.48.0/20198.8.48.1 to 198.8.63.254198.8.63.2554,094
133198.8.64.0/20198.8.64.1 to 198.8.79.254198.8.79.2554,094
134198.8.80.0/20198.8.80.1 to 198.8.95.254198.8.95.2554,094
135198.8.96.0/20198.8.96.1 to 198.8.111.254198.8.111.2554,094
136198.8.112.0/20198.8.112.1 to 198.8.127.254198.8.127.2554,094
137198.8.128.0/20198.8.128.1 to 198.8.143.254198.8.143.2554,094
138198.8.144.0/20198.8.144.1 to 198.8.159.254198.8.159.2554,094
139198.8.160.0/20198.8.160.1 to 198.8.175.254198.8.175.2554,094
140198.8.176.0/20198.8.176.1 to 198.8.191.254198.8.191.2554,094
141198.8.192.0/20198.8.192.1 to 198.8.207.254198.8.207.2554,094
142198.8.208.0/20198.8.208.1 to 198.8.223.254198.8.223.2554,094
143198.8.224.0/20198.8.224.1 to 198.8.239.254198.8.239.2554,094
144198.8.240.0/20198.8.240.1 to 198.8.255.254198.8.255.2554,094
145198.9.0.0/20198.9.0.1 to 198.9.15.254198.9.15.2554,094
146198.9.16.0/20198.9.16.1 to 198.9.31.254198.9.31.2554,094
147198.9.32.0/20198.9.32.1 to 198.9.47.254198.9.47.2554,094
148198.9.48.0/20198.9.48.1 to 198.9.63.254198.9.63.2554,094
149198.9.64.0/20198.9.64.1 to 198.9.79.254198.9.79.2554,094
150198.9.80.0/20198.9.80.1 to 198.9.95.254198.9.95.2554,094
151198.9.96.0/20198.9.96.1 to 198.9.111.254198.9.111.2554,094
152198.9.112.0/20198.9.112.1 to 198.9.127.254198.9.127.2554,094
153198.9.128.0/20198.9.128.1 to 198.9.143.254198.9.143.2554,094
154198.9.144.0/20198.9.144.1 to 198.9.159.254198.9.159.2554,094
155198.9.160.0/20198.9.160.1 to 198.9.175.254198.9.175.2554,094
156198.9.176.0/20198.9.176.1 to 198.9.191.254198.9.191.2554,094
157198.9.192.0/20198.9.192.1 to 198.9.207.254198.9.207.2554,094
158198.9.208.0/20198.9.208.1 to 198.9.223.254198.9.223.2554,094
159198.9.224.0/20198.9.224.1 to 198.9.239.254198.9.239.2554,094
160198.9.240.0/20198.9.240.1 to 198.9.255.254198.9.255.2554,094
161198.10.0.0/20198.10.0.1 to 198.10.15.254198.10.15.2554,094
162198.10.16.0/20198.10.16.1 to 198.10.31.254198.10.31.2554,094
163198.10.32.0/20198.10.32.1 to 198.10.47.254198.10.47.2554,094
164198.10.48.0/20198.10.48.1 to 198.10.63.254198.10.63.2554,094
165198.10.64.0/20198.10.64.1 to 198.10.79.254198.10.79.2554,094
166198.10.80.0/20198.10.80.1 to 198.10.95.254198.10.95.2554,094
167198.10.96.0/20198.10.96.1 to 198.10.111.254198.10.111.2554,094
168198.10.112.0/20198.10.112.1 to 198.10.127.254198.10.127.2554,094
169198.10.128.0/20198.10.128.1 to 198.10.143.254198.10.143.2554,094
170198.10.144.0/20198.10.144.1 to 198.10.159.254198.10.159.2554,094
171198.10.160.0/20198.10.160.1 to 198.10.175.254198.10.175.2554,094
172198.10.176.0/20198.10.176.1 to 198.10.191.254198.10.191.2554,094
173198.10.192.0/20198.10.192.1 to 198.10.207.254198.10.207.2554,094
174198.10.208.0/20198.10.208.1 to 198.10.223.254198.10.223.2554,094
175198.10.224.0/20198.10.224.1 to 198.10.239.254198.10.239.2554,094
176198.10.240.0/20198.10.240.1 to 198.10.255.254198.10.255.2554,094
177198.11.0.0/20198.11.0.1 to 198.11.15.254198.11.15.2554,094
178198.11.16.0/20198.11.16.1 to 198.11.31.254198.11.31.2554,094
179198.11.32.0/20198.11.32.1 to 198.11.47.254198.11.47.2554,094
180198.11.48.0/20198.11.48.1 to 198.11.63.254198.11.63.2554,094
181198.11.64.0/20198.11.64.1 to 198.11.79.254198.11.79.2554,094
182198.11.80.0/20198.11.80.1 to 198.11.95.254198.11.95.2554,094
183198.11.96.0/20198.11.96.1 to 198.11.111.254198.11.111.2554,094
184198.11.112.0/20198.11.112.1 to 198.11.127.254198.11.127.2554,094
185198.11.128.0/20198.11.128.1 to 198.11.143.254198.11.143.2554,094
186198.11.144.0/20198.11.144.1 to 198.11.159.254198.11.159.2554,094
187198.11.160.0/20198.11.160.1 to 198.11.175.254198.11.175.2554,094
188198.11.176.0/20198.11.176.1 to 198.11.191.254198.11.191.2554,094
189198.11.192.0/20198.11.192.1 to 198.11.207.254198.11.207.2554,094
190198.11.208.0/20198.11.208.1 to 198.11.223.254198.11.223.2554,094
191198.11.224.0/20198.11.224.1 to 198.11.239.254198.11.239.2554,094
192198.11.240.0/20198.11.240.1 to 198.11.255.254198.11.255.2554,094
193198.12.0.0/20198.12.0.1 to 198.12.15.254198.12.15.2554,094
194198.12.16.0/20198.12.16.1 to 198.12.31.254198.12.31.2554,094
195198.12.32.0/20198.12.32.1 to 198.12.47.254198.12.47.2554,094
196198.12.48.0/20198.12.48.1 to 198.12.63.254198.12.63.2554,094
197198.12.64.0/20198.12.64.1 to 198.12.79.254198.12.79.2554,094
198198.12.80.0/20198.12.80.1 to 198.12.95.254198.12.95.2554,094
199198.12.96.0/20198.12.96.1 to 198.12.111.254198.12.111.2554,094
200198.12.112.0/20198.12.112.1 to 198.12.127.254198.12.127.2554,094
201198.12.128.0/20198.12.128.1 to 198.12.143.254198.12.143.2554,094
202198.12.144.0/20198.12.144.1 to 198.12.159.254198.12.159.2554,094
203198.12.160.0/20198.12.160.1 to 198.12.175.254198.12.175.2554,094
204198.12.176.0/20198.12.176.1 to 198.12.191.254198.12.191.2554,094
205198.12.192.0/20198.12.192.1 to 198.12.207.254198.12.207.2554,094
206198.12.208.0/20198.12.208.1 to 198.12.223.254198.12.223.2554,094
207198.12.224.0/20198.12.224.1 to 198.12.239.254198.12.239.2554,094
208198.12.240.0/20198.12.240.1 to 198.12.255.254198.12.255.2554,094
209198.13.0.0/20198.13.0.1 to 198.13.15.254198.13.15.2554,094
210198.13.16.0/20198.13.16.1 to 198.13.31.254198.13.31.2554,094
211198.13.32.0/20198.13.32.1 to 198.13.47.254198.13.47.2554,094
212198.13.48.0/20198.13.48.1 to 198.13.63.254198.13.63.2554,094
213198.13.64.0/20198.13.64.1 to 198.13.79.254198.13.79.2554,094
214198.13.80.0/20198.13.80.1 to 198.13.95.254198.13.95.2554,094
215198.13.96.0/20198.13.96.1 to 198.13.111.254198.13.111.2554,094
216198.13.112.0/20198.13.112.1 to 198.13.127.254198.13.127.2554,094
217198.13.128.0/20198.13.128.1 to 198.13.143.254198.13.143.2554,094
218198.13.144.0/20198.13.144.1 to 198.13.159.254198.13.159.2554,094
219198.13.160.0/20198.13.160.1 to 198.13.175.254198.13.175.2554,094
220198.13.176.0/20198.13.176.1 to 198.13.191.254198.13.191.2554,094
221198.13.192.0/20198.13.192.1 to 198.13.207.254198.13.207.2554,094
222198.13.208.0/20198.13.208.1 to 198.13.223.254198.13.223.2554,094
223198.13.224.0/20198.13.224.1 to 198.13.239.254198.13.239.2554,094
224198.13.240.0/20198.13.240.1 to 198.13.255.254198.13.255.2554,094
225198.14.0.0/20198.14.0.1 to 198.14.15.254198.14.15.2554,094
226198.14.16.0/20198.14.16.1 to 198.14.31.254198.14.31.2554,094
227198.14.32.0/20198.14.32.1 to 198.14.47.254198.14.47.2554,094
228198.14.48.0/20198.14.48.1 to 198.14.63.254198.14.63.2554,094
229198.14.64.0/20198.14.64.1 to 198.14.79.254198.14.79.2554,094
230198.14.80.0/20198.14.80.1 to 198.14.95.254198.14.95.2554,094
231198.14.96.0/20198.14.96.1 to 198.14.111.254198.14.111.2554,094
232198.14.112.0/20198.14.112.1 to 198.14.127.254198.14.127.2554,094
233198.14.128.0/20198.14.128.1 to 198.14.143.254198.14.143.2554,094
234198.14.144.0/20198.14.144.1 to 198.14.159.254198.14.159.2554,094
235198.14.160.0/20198.14.160.1 to 198.14.175.254198.14.175.2554,094
236198.14.176.0/20198.14.176.1 to 198.14.191.254198.14.191.2554,094
237198.14.192.0/20198.14.192.1 to 198.14.207.254198.14.207.2554,094
238198.14.208.0/20198.14.208.1 to 198.14.223.254198.14.223.2554,094
239198.14.224.0/20198.14.224.1 to 198.14.239.254198.14.239.2554,094
240198.14.240.0/20198.14.240.1 to 198.14.255.254198.14.255.2554,094
241198.15.0.0/20198.15.0.1 to 198.15.15.254198.15.15.2554,094
242198.15.16.0/20198.15.16.1 to 198.15.31.254198.15.31.2554,094
243198.15.32.0/20198.15.32.1 to 198.15.47.254198.15.47.2554,094
244198.15.48.0/20198.15.48.1 to 198.15.63.254198.15.63.2554,094
245198.15.64.0/20198.15.64.1 to 198.15.79.254198.15.79.2554,094
246198.15.80.0/20198.15.80.1 to 198.15.95.254198.15.95.2554,094
247198.15.96.0/20198.15.96.1 to 198.15.111.254198.15.111.2554,094
248198.15.112.0/20198.15.112.1 to 198.15.127.254198.15.127.2554,094
249198.15.128.0/20198.15.128.1 to 198.15.143.254198.15.143.2554,094
250198.15.144.0/20198.15.144.1 to 198.15.159.254198.15.159.2554,094
251198.15.160.0/20198.15.160.1 to 198.15.175.254198.15.175.2554,094
252198.15.176.0/20198.15.176.1 to 198.15.191.254198.15.191.2554,094
253198.15.192.0/20198.15.192.1 to 198.15.207.254198.15.207.2554,094
254198.15.208.0/20198.15.208.1 to 198.15.223.254198.15.223.2554,094
255198.15.224.0/20198.15.224.1 to 198.15.239.254198.15.239.2554,094
256198.15.240.0/20198.15.240.1 to 198.15.255.254198.15.255.2554,094

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.