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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.

Network198.18.192.0/19
Usable hosts8,190
Subnet mask255.255.224.0
Addresses8,192
Network address
198.18.192.0
Broadcast address
198.18.223.255
First usable
198.18.192.1
Last usable
198.18.223.254
Usable hosts
8,190 (8,192 less the network and broadcast addresses)
Subnet mask
255.255.224.0
Wildcard mask
0.0.31.255 (Cisco ACLs, OSPF)
Prefix length
/19
Type
Benchmarking 198.18.0.0/15
Network equipment testing (RFC 2544)
Old class
C (default /24)
As numbers
Hex C612C000 · Integer 3323117568 to 3323125759
Reverse DNS zones
192.18.198.in-addr.arpa
193.18.198.in-addr.arpa
194.18.198.in-addr.arpa
195.18.198.in-addr.arpa
196.18.198.in-addr.arpa
197.18.198.in-addr.arpa
198.18.198.in-addr.arpa
199.18.198.in-addr.arpa
200.18.198.in-addr.arpa
201.18.198.in-addr.arpa
202.18.198.in-addr.arpa
203.18.198.in-addr.arpa
204.18.198.in-addr.arpa
205.18.198.in-addr.arpa
206.18.198.in-addr.arpa
207.18.198.in-addr.arpa
and 16 more
/19 is not on a 8-bit boundary, so it takes 32 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11000110.00010010.11000000.00000000198.18.192.0
Subnet mask11111111.11111111.11100000.00000000255.255.224.0
Network11000110.00010010.11000000.00000000198.18.192.0
Broadcast11000110.00010010.11011111.11111111198.18.223.255
Split into smaller subnets/28
/20 (2)/21 (4)/22 (8)/23 (16)/24 (32)/25 (64)/26 (128)/27 (256)/28 (512)/29 (1,024)/30 (2,048)/31 (4,096)

198.18.192.0/19 makes 512 subnets of /28; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1198.18.192.0/28198.18.192.1 to 198.18.192.14198.18.192.1514
2198.18.192.16/28198.18.192.17 to 198.18.192.30198.18.192.3114
3198.18.192.32/28198.18.192.33 to 198.18.192.46198.18.192.4714
4198.18.192.48/28198.18.192.49 to 198.18.192.62198.18.192.6314
5198.18.192.64/28198.18.192.65 to 198.18.192.78198.18.192.7914
6198.18.192.80/28198.18.192.81 to 198.18.192.94198.18.192.9514
7198.18.192.96/28198.18.192.97 to 198.18.192.110198.18.192.11114
8198.18.192.112/28198.18.192.113 to 198.18.192.126198.18.192.12714
9198.18.192.128/28198.18.192.129 to 198.18.192.142198.18.192.14314
10198.18.192.144/28198.18.192.145 to 198.18.192.158198.18.192.15914
11198.18.192.160/28198.18.192.161 to 198.18.192.174198.18.192.17514
12198.18.192.176/28198.18.192.177 to 198.18.192.190198.18.192.19114
13198.18.192.192/28198.18.192.193 to 198.18.192.206198.18.192.20714
14198.18.192.208/28198.18.192.209 to 198.18.192.222198.18.192.22314
15198.18.192.224/28198.18.192.225 to 198.18.192.238198.18.192.23914
16198.18.192.240/28198.18.192.241 to 198.18.192.254198.18.192.25514
17198.18.193.0/28198.18.193.1 to 198.18.193.14198.18.193.1514
18198.18.193.16/28198.18.193.17 to 198.18.193.30198.18.193.3114
19198.18.193.32/28198.18.193.33 to 198.18.193.46198.18.193.4714
20198.18.193.48/28198.18.193.49 to 198.18.193.62198.18.193.6314
21198.18.193.64/28198.18.193.65 to 198.18.193.78198.18.193.7914
22198.18.193.80/28198.18.193.81 to 198.18.193.94198.18.193.9514
23198.18.193.96/28198.18.193.97 to 198.18.193.110198.18.193.11114
24198.18.193.112/28198.18.193.113 to 198.18.193.126198.18.193.12714
25198.18.193.128/28198.18.193.129 to 198.18.193.142198.18.193.14314
26198.18.193.144/28198.18.193.145 to 198.18.193.158198.18.193.15914
27198.18.193.160/28198.18.193.161 to 198.18.193.174198.18.193.17514
28198.18.193.176/28198.18.193.177 to 198.18.193.190198.18.193.19114
29198.18.193.192/28198.18.193.193 to 198.18.193.206198.18.193.20714
30198.18.193.208/28198.18.193.209 to 198.18.193.222198.18.193.22314
31198.18.193.224/28198.18.193.225 to 198.18.193.238198.18.193.23914
32198.18.193.240/28198.18.193.241 to 198.18.193.254198.18.193.25514
33198.18.194.0/28198.18.194.1 to 198.18.194.14198.18.194.1514
34198.18.194.16/28198.18.194.17 to 198.18.194.30198.18.194.3114
35198.18.194.32/28198.18.194.33 to 198.18.194.46198.18.194.4714
36198.18.194.48/28198.18.194.49 to 198.18.194.62198.18.194.6314
37198.18.194.64/28198.18.194.65 to 198.18.194.78198.18.194.7914
38198.18.194.80/28198.18.194.81 to 198.18.194.94198.18.194.9514
39198.18.194.96/28198.18.194.97 to 198.18.194.110198.18.194.11114
40198.18.194.112/28198.18.194.113 to 198.18.194.126198.18.194.12714
41198.18.194.128/28198.18.194.129 to 198.18.194.142198.18.194.14314
42198.18.194.144/28198.18.194.145 to 198.18.194.158198.18.194.15914
43198.18.194.160/28198.18.194.161 to 198.18.194.174198.18.194.17514
44198.18.194.176/28198.18.194.177 to 198.18.194.190198.18.194.19114
45198.18.194.192/28198.18.194.193 to 198.18.194.206198.18.194.20714
46198.18.194.208/28198.18.194.209 to 198.18.194.222198.18.194.22314
47198.18.194.224/28198.18.194.225 to 198.18.194.238198.18.194.23914
48198.18.194.240/28198.18.194.241 to 198.18.194.254198.18.194.25514
49198.18.195.0/28198.18.195.1 to 198.18.195.14198.18.195.1514
50198.18.195.16/28198.18.195.17 to 198.18.195.30198.18.195.3114
51198.18.195.32/28198.18.195.33 to 198.18.195.46198.18.195.4714
52198.18.195.48/28198.18.195.49 to 198.18.195.62198.18.195.6314
53198.18.195.64/28198.18.195.65 to 198.18.195.78198.18.195.7914
54198.18.195.80/28198.18.195.81 to 198.18.195.94198.18.195.9514
55198.18.195.96/28198.18.195.97 to 198.18.195.110198.18.195.11114
56198.18.195.112/28198.18.195.113 to 198.18.195.126198.18.195.12714
57198.18.195.128/28198.18.195.129 to 198.18.195.142198.18.195.14314
58198.18.195.144/28198.18.195.145 to 198.18.195.158198.18.195.15914
59198.18.195.160/28198.18.195.161 to 198.18.195.174198.18.195.17514
60198.18.195.176/28198.18.195.177 to 198.18.195.190198.18.195.19114
61198.18.195.192/28198.18.195.193 to 198.18.195.206198.18.195.20714
62198.18.195.208/28198.18.195.209 to 198.18.195.222198.18.195.22314
63198.18.195.224/28198.18.195.225 to 198.18.195.238198.18.195.23914
64198.18.195.240/28198.18.195.241 to 198.18.195.254198.18.195.25514
65198.18.196.0/28198.18.196.1 to 198.18.196.14198.18.196.1514
66198.18.196.16/28198.18.196.17 to 198.18.196.30198.18.196.3114
67198.18.196.32/28198.18.196.33 to 198.18.196.46198.18.196.4714
68198.18.196.48/28198.18.196.49 to 198.18.196.62198.18.196.6314
69198.18.196.64/28198.18.196.65 to 198.18.196.78198.18.196.7914
70198.18.196.80/28198.18.196.81 to 198.18.196.94198.18.196.9514
71198.18.196.96/28198.18.196.97 to 198.18.196.110198.18.196.11114
72198.18.196.112/28198.18.196.113 to 198.18.196.126198.18.196.12714
73198.18.196.128/28198.18.196.129 to 198.18.196.142198.18.196.14314
74198.18.196.144/28198.18.196.145 to 198.18.196.158198.18.196.15914
75198.18.196.160/28198.18.196.161 to 198.18.196.174198.18.196.17514
76198.18.196.176/28198.18.196.177 to 198.18.196.190198.18.196.19114
77198.18.196.192/28198.18.196.193 to 198.18.196.206198.18.196.20714
78198.18.196.208/28198.18.196.209 to 198.18.196.222198.18.196.22314
79198.18.196.224/28198.18.196.225 to 198.18.196.238198.18.196.23914
80198.18.196.240/28198.18.196.241 to 198.18.196.254198.18.196.25514
81198.18.197.0/28198.18.197.1 to 198.18.197.14198.18.197.1514
82198.18.197.16/28198.18.197.17 to 198.18.197.30198.18.197.3114
83198.18.197.32/28198.18.197.33 to 198.18.197.46198.18.197.4714
84198.18.197.48/28198.18.197.49 to 198.18.197.62198.18.197.6314
85198.18.197.64/28198.18.197.65 to 198.18.197.78198.18.197.7914
86198.18.197.80/28198.18.197.81 to 198.18.197.94198.18.197.9514
87198.18.197.96/28198.18.197.97 to 198.18.197.110198.18.197.11114
88198.18.197.112/28198.18.197.113 to 198.18.197.126198.18.197.12714
89198.18.197.128/28198.18.197.129 to 198.18.197.142198.18.197.14314
90198.18.197.144/28198.18.197.145 to 198.18.197.158198.18.197.15914
91198.18.197.160/28198.18.197.161 to 198.18.197.174198.18.197.17514
92198.18.197.176/28198.18.197.177 to 198.18.197.190198.18.197.19114
93198.18.197.192/28198.18.197.193 to 198.18.197.206198.18.197.20714
94198.18.197.208/28198.18.197.209 to 198.18.197.222198.18.197.22314
95198.18.197.224/28198.18.197.225 to 198.18.197.238198.18.197.23914
96198.18.197.240/28198.18.197.241 to 198.18.197.254198.18.197.25514
97198.18.198.0/28198.18.198.1 to 198.18.198.14198.18.198.1514
98198.18.198.16/28198.18.198.17 to 198.18.198.30198.18.198.3114
99198.18.198.32/28198.18.198.33 to 198.18.198.46198.18.198.4714
100198.18.198.48/28198.18.198.49 to 198.18.198.62198.18.198.6314
101198.18.198.64/28198.18.198.65 to 198.18.198.78198.18.198.7914
102198.18.198.80/28198.18.198.81 to 198.18.198.94198.18.198.9514
103198.18.198.96/28198.18.198.97 to 198.18.198.110198.18.198.11114
104198.18.198.112/28198.18.198.113 to 198.18.198.126198.18.198.12714
105198.18.198.128/28198.18.198.129 to 198.18.198.142198.18.198.14314
106198.18.198.144/28198.18.198.145 to 198.18.198.158198.18.198.15914
107198.18.198.160/28198.18.198.161 to 198.18.198.174198.18.198.17514
108198.18.198.176/28198.18.198.177 to 198.18.198.190198.18.198.19114
109198.18.198.192/28198.18.198.193 to 198.18.198.206198.18.198.20714
110198.18.198.208/28198.18.198.209 to 198.18.198.222198.18.198.22314
111198.18.198.224/28198.18.198.225 to 198.18.198.238198.18.198.23914
112198.18.198.240/28198.18.198.241 to 198.18.198.254198.18.198.25514
113198.18.199.0/28198.18.199.1 to 198.18.199.14198.18.199.1514
114198.18.199.16/28198.18.199.17 to 198.18.199.30198.18.199.3114
115198.18.199.32/28198.18.199.33 to 198.18.199.46198.18.199.4714
116198.18.199.48/28198.18.199.49 to 198.18.199.62198.18.199.6314
117198.18.199.64/28198.18.199.65 to 198.18.199.78198.18.199.7914
118198.18.199.80/28198.18.199.81 to 198.18.199.94198.18.199.9514
119198.18.199.96/28198.18.199.97 to 198.18.199.110198.18.199.11114
120198.18.199.112/28198.18.199.113 to 198.18.199.126198.18.199.12714
121198.18.199.128/28198.18.199.129 to 198.18.199.142198.18.199.14314
122198.18.199.144/28198.18.199.145 to 198.18.199.158198.18.199.15914
123198.18.199.160/28198.18.199.161 to 198.18.199.174198.18.199.17514
124198.18.199.176/28198.18.199.177 to 198.18.199.190198.18.199.19114
125198.18.199.192/28198.18.199.193 to 198.18.199.206198.18.199.20714
126198.18.199.208/28198.18.199.209 to 198.18.199.222198.18.199.22314
127198.18.199.224/28198.18.199.225 to 198.18.199.238198.18.199.23914
128198.18.199.240/28198.18.199.241 to 198.18.199.254198.18.199.25514
129198.18.200.0/28198.18.200.1 to 198.18.200.14198.18.200.1514
130198.18.200.16/28198.18.200.17 to 198.18.200.30198.18.200.3114
131198.18.200.32/28198.18.200.33 to 198.18.200.46198.18.200.4714
132198.18.200.48/28198.18.200.49 to 198.18.200.62198.18.200.6314
133198.18.200.64/28198.18.200.65 to 198.18.200.78198.18.200.7914
134198.18.200.80/28198.18.200.81 to 198.18.200.94198.18.200.9514
135198.18.200.96/28198.18.200.97 to 198.18.200.110198.18.200.11114
136198.18.200.112/28198.18.200.113 to 198.18.200.126198.18.200.12714
137198.18.200.128/28198.18.200.129 to 198.18.200.142198.18.200.14314
138198.18.200.144/28198.18.200.145 to 198.18.200.158198.18.200.15914
139198.18.200.160/28198.18.200.161 to 198.18.200.174198.18.200.17514
140198.18.200.176/28198.18.200.177 to 198.18.200.190198.18.200.19114
141198.18.200.192/28198.18.200.193 to 198.18.200.206198.18.200.20714
142198.18.200.208/28198.18.200.209 to 198.18.200.222198.18.200.22314
143198.18.200.224/28198.18.200.225 to 198.18.200.238198.18.200.23914
144198.18.200.240/28198.18.200.241 to 198.18.200.254198.18.200.25514
145198.18.201.0/28198.18.201.1 to 198.18.201.14198.18.201.1514
146198.18.201.16/28198.18.201.17 to 198.18.201.30198.18.201.3114
147198.18.201.32/28198.18.201.33 to 198.18.201.46198.18.201.4714
148198.18.201.48/28198.18.201.49 to 198.18.201.62198.18.201.6314
149198.18.201.64/28198.18.201.65 to 198.18.201.78198.18.201.7914
150198.18.201.80/28198.18.201.81 to 198.18.201.94198.18.201.9514
151198.18.201.96/28198.18.201.97 to 198.18.201.110198.18.201.11114
152198.18.201.112/28198.18.201.113 to 198.18.201.126198.18.201.12714
153198.18.201.128/28198.18.201.129 to 198.18.201.142198.18.201.14314
154198.18.201.144/28198.18.201.145 to 198.18.201.158198.18.201.15914
155198.18.201.160/28198.18.201.161 to 198.18.201.174198.18.201.17514
156198.18.201.176/28198.18.201.177 to 198.18.201.190198.18.201.19114
157198.18.201.192/28198.18.201.193 to 198.18.201.206198.18.201.20714
158198.18.201.208/28198.18.201.209 to 198.18.201.222198.18.201.22314
159198.18.201.224/28198.18.201.225 to 198.18.201.238198.18.201.23914
160198.18.201.240/28198.18.201.241 to 198.18.201.254198.18.201.25514
161198.18.202.0/28198.18.202.1 to 198.18.202.14198.18.202.1514
162198.18.202.16/28198.18.202.17 to 198.18.202.30198.18.202.3114
163198.18.202.32/28198.18.202.33 to 198.18.202.46198.18.202.4714
164198.18.202.48/28198.18.202.49 to 198.18.202.62198.18.202.6314
165198.18.202.64/28198.18.202.65 to 198.18.202.78198.18.202.7914
166198.18.202.80/28198.18.202.81 to 198.18.202.94198.18.202.9514
167198.18.202.96/28198.18.202.97 to 198.18.202.110198.18.202.11114
168198.18.202.112/28198.18.202.113 to 198.18.202.126198.18.202.12714
169198.18.202.128/28198.18.202.129 to 198.18.202.142198.18.202.14314
170198.18.202.144/28198.18.202.145 to 198.18.202.158198.18.202.15914
171198.18.202.160/28198.18.202.161 to 198.18.202.174198.18.202.17514
172198.18.202.176/28198.18.202.177 to 198.18.202.190198.18.202.19114
173198.18.202.192/28198.18.202.193 to 198.18.202.206198.18.202.20714
174198.18.202.208/28198.18.202.209 to 198.18.202.222198.18.202.22314
175198.18.202.224/28198.18.202.225 to 198.18.202.238198.18.202.23914
176198.18.202.240/28198.18.202.241 to 198.18.202.254198.18.202.25514
177198.18.203.0/28198.18.203.1 to 198.18.203.14198.18.203.1514
178198.18.203.16/28198.18.203.17 to 198.18.203.30198.18.203.3114
179198.18.203.32/28198.18.203.33 to 198.18.203.46198.18.203.4714
180198.18.203.48/28198.18.203.49 to 198.18.203.62198.18.203.6314
181198.18.203.64/28198.18.203.65 to 198.18.203.78198.18.203.7914
182198.18.203.80/28198.18.203.81 to 198.18.203.94198.18.203.9514
183198.18.203.96/28198.18.203.97 to 198.18.203.110198.18.203.11114
184198.18.203.112/28198.18.203.113 to 198.18.203.126198.18.203.12714
185198.18.203.128/28198.18.203.129 to 198.18.203.142198.18.203.14314
186198.18.203.144/28198.18.203.145 to 198.18.203.158198.18.203.15914
187198.18.203.160/28198.18.203.161 to 198.18.203.174198.18.203.17514
188198.18.203.176/28198.18.203.177 to 198.18.203.190198.18.203.19114
189198.18.203.192/28198.18.203.193 to 198.18.203.206198.18.203.20714
190198.18.203.208/28198.18.203.209 to 198.18.203.222198.18.203.22314
191198.18.203.224/28198.18.203.225 to 198.18.203.238198.18.203.23914
192198.18.203.240/28198.18.203.241 to 198.18.203.254198.18.203.25514
193198.18.204.0/28198.18.204.1 to 198.18.204.14198.18.204.1514
194198.18.204.16/28198.18.204.17 to 198.18.204.30198.18.204.3114
195198.18.204.32/28198.18.204.33 to 198.18.204.46198.18.204.4714
196198.18.204.48/28198.18.204.49 to 198.18.204.62198.18.204.6314
197198.18.204.64/28198.18.204.65 to 198.18.204.78198.18.204.7914
198198.18.204.80/28198.18.204.81 to 198.18.204.94198.18.204.9514
199198.18.204.96/28198.18.204.97 to 198.18.204.110198.18.204.11114
200198.18.204.112/28198.18.204.113 to 198.18.204.126198.18.204.12714
201198.18.204.128/28198.18.204.129 to 198.18.204.142198.18.204.14314
202198.18.204.144/28198.18.204.145 to 198.18.204.158198.18.204.15914
203198.18.204.160/28198.18.204.161 to 198.18.204.174198.18.204.17514
204198.18.204.176/28198.18.204.177 to 198.18.204.190198.18.204.19114
205198.18.204.192/28198.18.204.193 to 198.18.204.206198.18.204.20714
206198.18.204.208/28198.18.204.209 to 198.18.204.222198.18.204.22314
207198.18.204.224/28198.18.204.225 to 198.18.204.238198.18.204.23914
208198.18.204.240/28198.18.204.241 to 198.18.204.254198.18.204.25514
209198.18.205.0/28198.18.205.1 to 198.18.205.14198.18.205.1514
210198.18.205.16/28198.18.205.17 to 198.18.205.30198.18.205.3114
211198.18.205.32/28198.18.205.33 to 198.18.205.46198.18.205.4714
212198.18.205.48/28198.18.205.49 to 198.18.205.62198.18.205.6314
213198.18.205.64/28198.18.205.65 to 198.18.205.78198.18.205.7914
214198.18.205.80/28198.18.205.81 to 198.18.205.94198.18.205.9514
215198.18.205.96/28198.18.205.97 to 198.18.205.110198.18.205.11114
216198.18.205.112/28198.18.205.113 to 198.18.205.126198.18.205.12714
217198.18.205.128/28198.18.205.129 to 198.18.205.142198.18.205.14314
218198.18.205.144/28198.18.205.145 to 198.18.205.158198.18.205.15914
219198.18.205.160/28198.18.205.161 to 198.18.205.174198.18.205.17514
220198.18.205.176/28198.18.205.177 to 198.18.205.190198.18.205.19114
221198.18.205.192/28198.18.205.193 to 198.18.205.206198.18.205.20714
222198.18.205.208/28198.18.205.209 to 198.18.205.222198.18.205.22314
223198.18.205.224/28198.18.205.225 to 198.18.205.238198.18.205.23914
224198.18.205.240/28198.18.205.241 to 198.18.205.254198.18.205.25514
225198.18.206.0/28198.18.206.1 to 198.18.206.14198.18.206.1514
226198.18.206.16/28198.18.206.17 to 198.18.206.30198.18.206.3114
227198.18.206.32/28198.18.206.33 to 198.18.206.46198.18.206.4714
228198.18.206.48/28198.18.206.49 to 198.18.206.62198.18.206.6314
229198.18.206.64/28198.18.206.65 to 198.18.206.78198.18.206.7914
230198.18.206.80/28198.18.206.81 to 198.18.206.94198.18.206.9514
231198.18.206.96/28198.18.206.97 to 198.18.206.110198.18.206.11114
232198.18.206.112/28198.18.206.113 to 198.18.206.126198.18.206.12714
233198.18.206.128/28198.18.206.129 to 198.18.206.142198.18.206.14314
234198.18.206.144/28198.18.206.145 to 198.18.206.158198.18.206.15914
235198.18.206.160/28198.18.206.161 to 198.18.206.174198.18.206.17514
236198.18.206.176/28198.18.206.177 to 198.18.206.190198.18.206.19114
237198.18.206.192/28198.18.206.193 to 198.18.206.206198.18.206.20714
238198.18.206.208/28198.18.206.209 to 198.18.206.222198.18.206.22314
239198.18.206.224/28198.18.206.225 to 198.18.206.238198.18.206.23914
240198.18.206.240/28198.18.206.241 to 198.18.206.254198.18.206.25514
241198.18.207.0/28198.18.207.1 to 198.18.207.14198.18.207.1514
242198.18.207.16/28198.18.207.17 to 198.18.207.30198.18.207.3114
243198.18.207.32/28198.18.207.33 to 198.18.207.46198.18.207.4714
244198.18.207.48/28198.18.207.49 to 198.18.207.62198.18.207.6314
245198.18.207.64/28198.18.207.65 to 198.18.207.78198.18.207.7914
246198.18.207.80/28198.18.207.81 to 198.18.207.94198.18.207.9514
247198.18.207.96/28198.18.207.97 to 198.18.207.110198.18.207.11114
248198.18.207.112/28198.18.207.113 to 198.18.207.126198.18.207.12714
249198.18.207.128/28198.18.207.129 to 198.18.207.142198.18.207.14314
250198.18.207.144/28198.18.207.145 to 198.18.207.158198.18.207.15914
251198.18.207.160/28198.18.207.161 to 198.18.207.174198.18.207.17514
252198.18.207.176/28198.18.207.177 to 198.18.207.190198.18.207.19114
253198.18.207.192/28198.18.207.193 to 198.18.207.206198.18.207.20714
254198.18.207.208/28198.18.207.209 to 198.18.207.222198.18.207.22314
255198.18.207.224/28198.18.207.225 to 198.18.207.238198.18.207.23914
256198.18.207.240/28198.18.207.241 to 198.18.207.254198.18.207.25514

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.