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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.

Network192.0.0.0/3
Usable hosts536,870,910
Subnet mask224.0.0.0
Addresses536,870,912
Network address
192.0.0.0
Broadcast address
223.255.255.255
First usable
192.0.0.1
Last usable
223.255.255.254
Usable hosts
536,870,910 (536,870,912 less the network and broadcast addresses)
Subnet mask
224.0.0.0
Wildcard mask
31.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/3
Type
Public public
Old class
C (default /24)
As numbers
Hex C0000000 · Integer 3221225472 to 3758096383
Reverse DNS zones
192.in-addr.arpa
193.in-addr.arpa
194.in-addr.arpa
195.in-addr.arpa
196.in-addr.arpa
197.in-addr.arpa
198.in-addr.arpa
199.in-addr.arpa
200.in-addr.arpa
201.in-addr.arpa
202.in-addr.arpa
203.in-addr.arpa
204.in-addr.arpa
205.in-addr.arpa
206.in-addr.arpa
207.in-addr.arpa
and 16 more
/3 is not on a 8-bit boundary, so it takes 32 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11000000.00000000.00000000.00000000192.0.0.0
Subnet mask11100000.00000000.00000000.00000000224.0.0.0
Network11000000.00000000.00000000.00000000192.0.0.0
Broadcast11011111.11111111.11111111.11111111223.255.255.255
Split into smaller subnets/13
/4 (2)/5 (4)/6 (8)/7 (16)/8 (32)/9 (64)/10 (128)/11 (256)/12 (512)/13 (1,024)/14 (2,048)/15 (4,096)

192.0.0.0/3 makes 1,024 subnets of /13; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1192.0.0.0/13192.0.0.1 to 192.7.255.254192.7.255.255524,286
2192.8.0.0/13192.8.0.1 to 192.15.255.254192.15.255.255524,286
3192.16.0.0/13192.16.0.1 to 192.23.255.254192.23.255.255524,286
4192.24.0.0/13192.24.0.1 to 192.31.255.254192.31.255.255524,286
5192.32.0.0/13192.32.0.1 to 192.39.255.254192.39.255.255524,286
6192.40.0.0/13192.40.0.1 to 192.47.255.254192.47.255.255524,286
7192.48.0.0/13192.48.0.1 to 192.55.255.254192.55.255.255524,286
8192.56.0.0/13192.56.0.1 to 192.63.255.254192.63.255.255524,286
9192.64.0.0/13192.64.0.1 to 192.71.255.254192.71.255.255524,286
10192.72.0.0/13192.72.0.1 to 192.79.255.254192.79.255.255524,286
11192.80.0.0/13192.80.0.1 to 192.87.255.254192.87.255.255524,286
12192.88.0.0/13192.88.0.1 to 192.95.255.254192.95.255.255524,286
13192.96.0.0/13192.96.0.1 to 192.103.255.254192.103.255.255524,286
14192.104.0.0/13192.104.0.1 to 192.111.255.254192.111.255.255524,286
15192.112.0.0/13192.112.0.1 to 192.119.255.254192.119.255.255524,286
16192.120.0.0/13192.120.0.1 to 192.127.255.254192.127.255.255524,286
17192.128.0.0/13192.128.0.1 to 192.135.255.254192.135.255.255524,286
18192.136.0.0/13192.136.0.1 to 192.143.255.254192.143.255.255524,286
19192.144.0.0/13192.144.0.1 to 192.151.255.254192.151.255.255524,286
20192.152.0.0/13192.152.0.1 to 192.159.255.254192.159.255.255524,286
21192.160.0.0/13192.160.0.1 to 192.167.255.254192.167.255.255524,286
22192.168.0.0/13192.168.0.1 to 192.175.255.254192.175.255.255524,286
23192.176.0.0/13192.176.0.1 to 192.183.255.254192.183.255.255524,286
24192.184.0.0/13192.184.0.1 to 192.191.255.254192.191.255.255524,286
25192.192.0.0/13192.192.0.1 to 192.199.255.254192.199.255.255524,286
26192.200.0.0/13192.200.0.1 to 192.207.255.254192.207.255.255524,286
27192.208.0.0/13192.208.0.1 to 192.215.255.254192.215.255.255524,286
28192.216.0.0/13192.216.0.1 to 192.223.255.254192.223.255.255524,286
29192.224.0.0/13192.224.0.1 to 192.231.255.254192.231.255.255524,286
30192.232.0.0/13192.232.0.1 to 192.239.255.254192.239.255.255524,286
31192.240.0.0/13192.240.0.1 to 192.247.255.254192.247.255.255524,286
32192.248.0.0/13192.248.0.1 to 192.255.255.254192.255.255.255524,286
33193.0.0.0/13193.0.0.1 to 193.7.255.254193.7.255.255524,286
34193.8.0.0/13193.8.0.1 to 193.15.255.254193.15.255.255524,286
35193.16.0.0/13193.16.0.1 to 193.23.255.254193.23.255.255524,286
36193.24.0.0/13193.24.0.1 to 193.31.255.254193.31.255.255524,286
37193.32.0.0/13193.32.0.1 to 193.39.255.254193.39.255.255524,286
38193.40.0.0/13193.40.0.1 to 193.47.255.254193.47.255.255524,286
39193.48.0.0/13193.48.0.1 to 193.55.255.254193.55.255.255524,286
40193.56.0.0/13193.56.0.1 to 193.63.255.254193.63.255.255524,286
41193.64.0.0/13193.64.0.1 to 193.71.255.254193.71.255.255524,286
42193.72.0.0/13193.72.0.1 to 193.79.255.254193.79.255.255524,286
43193.80.0.0/13193.80.0.1 to 193.87.255.254193.87.255.255524,286
44193.88.0.0/13193.88.0.1 to 193.95.255.254193.95.255.255524,286
45193.96.0.0/13193.96.0.1 to 193.103.255.254193.103.255.255524,286
46193.104.0.0/13193.104.0.1 to 193.111.255.254193.111.255.255524,286
47193.112.0.0/13193.112.0.1 to 193.119.255.254193.119.255.255524,286
48193.120.0.0/13193.120.0.1 to 193.127.255.254193.127.255.255524,286
49193.128.0.0/13193.128.0.1 to 193.135.255.254193.135.255.255524,286
50193.136.0.0/13193.136.0.1 to 193.143.255.254193.143.255.255524,286
51193.144.0.0/13193.144.0.1 to 193.151.255.254193.151.255.255524,286
52193.152.0.0/13193.152.0.1 to 193.159.255.254193.159.255.255524,286
53193.160.0.0/13193.160.0.1 to 193.167.255.254193.167.255.255524,286
54193.168.0.0/13193.168.0.1 to 193.175.255.254193.175.255.255524,286
55193.176.0.0/13193.176.0.1 to 193.183.255.254193.183.255.255524,286
56193.184.0.0/13193.184.0.1 to 193.191.255.254193.191.255.255524,286
57193.192.0.0/13193.192.0.1 to 193.199.255.254193.199.255.255524,286
58193.200.0.0/13193.200.0.1 to 193.207.255.254193.207.255.255524,286
59193.208.0.0/13193.208.0.1 to 193.215.255.254193.215.255.255524,286
60193.216.0.0/13193.216.0.1 to 193.223.255.254193.223.255.255524,286
61193.224.0.0/13193.224.0.1 to 193.231.255.254193.231.255.255524,286
62193.232.0.0/13193.232.0.1 to 193.239.255.254193.239.255.255524,286
63193.240.0.0/13193.240.0.1 to 193.247.255.254193.247.255.255524,286
64193.248.0.0/13193.248.0.1 to 193.255.255.254193.255.255.255524,286
65194.0.0.0/13194.0.0.1 to 194.7.255.254194.7.255.255524,286
66194.8.0.0/13194.8.0.1 to 194.15.255.254194.15.255.255524,286
67194.16.0.0/13194.16.0.1 to 194.23.255.254194.23.255.255524,286
68194.24.0.0/13194.24.0.1 to 194.31.255.254194.31.255.255524,286
69194.32.0.0/13194.32.0.1 to 194.39.255.254194.39.255.255524,286
70194.40.0.0/13194.40.0.1 to 194.47.255.254194.47.255.255524,286
71194.48.0.0/13194.48.0.1 to 194.55.255.254194.55.255.255524,286
72194.56.0.0/13194.56.0.1 to 194.63.255.254194.63.255.255524,286
73194.64.0.0/13194.64.0.1 to 194.71.255.254194.71.255.255524,286
74194.72.0.0/13194.72.0.1 to 194.79.255.254194.79.255.255524,286
75194.80.0.0/13194.80.0.1 to 194.87.255.254194.87.255.255524,286
76194.88.0.0/13194.88.0.1 to 194.95.255.254194.95.255.255524,286
77194.96.0.0/13194.96.0.1 to 194.103.255.254194.103.255.255524,286
78194.104.0.0/13194.104.0.1 to 194.111.255.254194.111.255.255524,286
79194.112.0.0/13194.112.0.1 to 194.119.255.254194.119.255.255524,286
80194.120.0.0/13194.120.0.1 to 194.127.255.254194.127.255.255524,286
81194.128.0.0/13194.128.0.1 to 194.135.255.254194.135.255.255524,286
82194.136.0.0/13194.136.0.1 to 194.143.255.254194.143.255.255524,286
83194.144.0.0/13194.144.0.1 to 194.151.255.254194.151.255.255524,286
84194.152.0.0/13194.152.0.1 to 194.159.255.254194.159.255.255524,286
85194.160.0.0/13194.160.0.1 to 194.167.255.254194.167.255.255524,286
86194.168.0.0/13194.168.0.1 to 194.175.255.254194.175.255.255524,286
87194.176.0.0/13194.176.0.1 to 194.183.255.254194.183.255.255524,286
88194.184.0.0/13194.184.0.1 to 194.191.255.254194.191.255.255524,286
89194.192.0.0/13194.192.0.1 to 194.199.255.254194.199.255.255524,286
90194.200.0.0/13194.200.0.1 to 194.207.255.254194.207.255.255524,286
91194.208.0.0/13194.208.0.1 to 194.215.255.254194.215.255.255524,286
92194.216.0.0/13194.216.0.1 to 194.223.255.254194.223.255.255524,286
93194.224.0.0/13194.224.0.1 to 194.231.255.254194.231.255.255524,286
94194.232.0.0/13194.232.0.1 to 194.239.255.254194.239.255.255524,286
95194.240.0.0/13194.240.0.1 to 194.247.255.254194.247.255.255524,286
96194.248.0.0/13194.248.0.1 to 194.255.255.254194.255.255.255524,286
97195.0.0.0/13195.0.0.1 to 195.7.255.254195.7.255.255524,286
98195.8.0.0/13195.8.0.1 to 195.15.255.254195.15.255.255524,286
99195.16.0.0/13195.16.0.1 to 195.23.255.254195.23.255.255524,286
100195.24.0.0/13195.24.0.1 to 195.31.255.254195.31.255.255524,286
101195.32.0.0/13195.32.0.1 to 195.39.255.254195.39.255.255524,286
102195.40.0.0/13195.40.0.1 to 195.47.255.254195.47.255.255524,286
103195.48.0.0/13195.48.0.1 to 195.55.255.254195.55.255.255524,286
104195.56.0.0/13195.56.0.1 to 195.63.255.254195.63.255.255524,286
105195.64.0.0/13195.64.0.1 to 195.71.255.254195.71.255.255524,286
106195.72.0.0/13195.72.0.1 to 195.79.255.254195.79.255.255524,286
107195.80.0.0/13195.80.0.1 to 195.87.255.254195.87.255.255524,286
108195.88.0.0/13195.88.0.1 to 195.95.255.254195.95.255.255524,286
109195.96.0.0/13195.96.0.1 to 195.103.255.254195.103.255.255524,286
110195.104.0.0/13195.104.0.1 to 195.111.255.254195.111.255.255524,286
111195.112.0.0/13195.112.0.1 to 195.119.255.254195.119.255.255524,286
112195.120.0.0/13195.120.0.1 to 195.127.255.254195.127.255.255524,286
113195.128.0.0/13195.128.0.1 to 195.135.255.254195.135.255.255524,286
114195.136.0.0/13195.136.0.1 to 195.143.255.254195.143.255.255524,286
115195.144.0.0/13195.144.0.1 to 195.151.255.254195.151.255.255524,286
116195.152.0.0/13195.152.0.1 to 195.159.255.254195.159.255.255524,286
117195.160.0.0/13195.160.0.1 to 195.167.255.254195.167.255.255524,286
118195.168.0.0/13195.168.0.1 to 195.175.255.254195.175.255.255524,286
119195.176.0.0/13195.176.0.1 to 195.183.255.254195.183.255.255524,286
120195.184.0.0/13195.184.0.1 to 195.191.255.254195.191.255.255524,286
121195.192.0.0/13195.192.0.1 to 195.199.255.254195.199.255.255524,286
122195.200.0.0/13195.200.0.1 to 195.207.255.254195.207.255.255524,286
123195.208.0.0/13195.208.0.1 to 195.215.255.254195.215.255.255524,286
124195.216.0.0/13195.216.0.1 to 195.223.255.254195.223.255.255524,286
125195.224.0.0/13195.224.0.1 to 195.231.255.254195.231.255.255524,286
126195.232.0.0/13195.232.0.1 to 195.239.255.254195.239.255.255524,286
127195.240.0.0/13195.240.0.1 to 195.247.255.254195.247.255.255524,286
128195.248.0.0/13195.248.0.1 to 195.255.255.254195.255.255.255524,286
129196.0.0.0/13196.0.0.1 to 196.7.255.254196.7.255.255524,286
130196.8.0.0/13196.8.0.1 to 196.15.255.254196.15.255.255524,286
131196.16.0.0/13196.16.0.1 to 196.23.255.254196.23.255.255524,286
132196.24.0.0/13196.24.0.1 to 196.31.255.254196.31.255.255524,286
133196.32.0.0/13196.32.0.1 to 196.39.255.254196.39.255.255524,286
134196.40.0.0/13196.40.0.1 to 196.47.255.254196.47.255.255524,286
135196.48.0.0/13196.48.0.1 to 196.55.255.254196.55.255.255524,286
136196.56.0.0/13196.56.0.1 to 196.63.255.254196.63.255.255524,286
137196.64.0.0/13196.64.0.1 to 196.71.255.254196.71.255.255524,286
138196.72.0.0/13196.72.0.1 to 196.79.255.254196.79.255.255524,286
139196.80.0.0/13196.80.0.1 to 196.87.255.254196.87.255.255524,286
140196.88.0.0/13196.88.0.1 to 196.95.255.254196.95.255.255524,286
141196.96.0.0/13196.96.0.1 to 196.103.255.254196.103.255.255524,286
142196.104.0.0/13196.104.0.1 to 196.111.255.254196.111.255.255524,286
143196.112.0.0/13196.112.0.1 to 196.119.255.254196.119.255.255524,286
144196.120.0.0/13196.120.0.1 to 196.127.255.254196.127.255.255524,286
145196.128.0.0/13196.128.0.1 to 196.135.255.254196.135.255.255524,286
146196.136.0.0/13196.136.0.1 to 196.143.255.254196.143.255.255524,286
147196.144.0.0/13196.144.0.1 to 196.151.255.254196.151.255.255524,286
148196.152.0.0/13196.152.0.1 to 196.159.255.254196.159.255.255524,286
149196.160.0.0/13196.160.0.1 to 196.167.255.254196.167.255.255524,286
150196.168.0.0/13196.168.0.1 to 196.175.255.254196.175.255.255524,286
151196.176.0.0/13196.176.0.1 to 196.183.255.254196.183.255.255524,286
152196.184.0.0/13196.184.0.1 to 196.191.255.254196.191.255.255524,286
153196.192.0.0/13196.192.0.1 to 196.199.255.254196.199.255.255524,286
154196.200.0.0/13196.200.0.1 to 196.207.255.254196.207.255.255524,286
155196.208.0.0/13196.208.0.1 to 196.215.255.254196.215.255.255524,286
156196.216.0.0/13196.216.0.1 to 196.223.255.254196.223.255.255524,286
157196.224.0.0/13196.224.0.1 to 196.231.255.254196.231.255.255524,286
158196.232.0.0/13196.232.0.1 to 196.239.255.254196.239.255.255524,286
159196.240.0.0/13196.240.0.1 to 196.247.255.254196.247.255.255524,286
160196.248.0.0/13196.248.0.1 to 196.255.255.254196.255.255.255524,286
161197.0.0.0/13197.0.0.1 to 197.7.255.254197.7.255.255524,286
162197.8.0.0/13197.8.0.1 to 197.15.255.254197.15.255.255524,286
163197.16.0.0/13197.16.0.1 to 197.23.255.254197.23.255.255524,286
164197.24.0.0/13197.24.0.1 to 197.31.255.254197.31.255.255524,286
165197.32.0.0/13197.32.0.1 to 197.39.255.254197.39.255.255524,286
166197.40.0.0/13197.40.0.1 to 197.47.255.254197.47.255.255524,286
167197.48.0.0/13197.48.0.1 to 197.55.255.254197.55.255.255524,286
168197.56.0.0/13197.56.0.1 to 197.63.255.254197.63.255.255524,286
169197.64.0.0/13197.64.0.1 to 197.71.255.254197.71.255.255524,286
170197.72.0.0/13197.72.0.1 to 197.79.255.254197.79.255.255524,286
171197.80.0.0/13197.80.0.1 to 197.87.255.254197.87.255.255524,286
172197.88.0.0/13197.88.0.1 to 197.95.255.254197.95.255.255524,286
173197.96.0.0/13197.96.0.1 to 197.103.255.254197.103.255.255524,286
174197.104.0.0/13197.104.0.1 to 197.111.255.254197.111.255.255524,286
175197.112.0.0/13197.112.0.1 to 197.119.255.254197.119.255.255524,286
176197.120.0.0/13197.120.0.1 to 197.127.255.254197.127.255.255524,286
177197.128.0.0/13197.128.0.1 to 197.135.255.254197.135.255.255524,286
178197.136.0.0/13197.136.0.1 to 197.143.255.254197.143.255.255524,286
179197.144.0.0/13197.144.0.1 to 197.151.255.254197.151.255.255524,286
180197.152.0.0/13197.152.0.1 to 197.159.255.254197.159.255.255524,286
181197.160.0.0/13197.160.0.1 to 197.167.255.254197.167.255.255524,286
182197.168.0.0/13197.168.0.1 to 197.175.255.254197.175.255.255524,286
183197.176.0.0/13197.176.0.1 to 197.183.255.254197.183.255.255524,286
184197.184.0.0/13197.184.0.1 to 197.191.255.254197.191.255.255524,286
185197.192.0.0/13197.192.0.1 to 197.199.255.254197.199.255.255524,286
186197.200.0.0/13197.200.0.1 to 197.207.255.254197.207.255.255524,286
187197.208.0.0/13197.208.0.1 to 197.215.255.254197.215.255.255524,286
188197.216.0.0/13197.216.0.1 to 197.223.255.254197.223.255.255524,286
189197.224.0.0/13197.224.0.1 to 197.231.255.254197.231.255.255524,286
190197.232.0.0/13197.232.0.1 to 197.239.255.254197.239.255.255524,286
191197.240.0.0/13197.240.0.1 to 197.247.255.254197.247.255.255524,286
192197.248.0.0/13197.248.0.1 to 197.255.255.254197.255.255.255524,286
193198.0.0.0/13198.0.0.1 to 198.7.255.254198.7.255.255524,286
194198.8.0.0/13198.8.0.1 to 198.15.255.254198.15.255.255524,286
195198.16.0.0/13198.16.0.1 to 198.23.255.254198.23.255.255524,286
196198.24.0.0/13198.24.0.1 to 198.31.255.254198.31.255.255524,286
197198.32.0.0/13198.32.0.1 to 198.39.255.254198.39.255.255524,286
198198.40.0.0/13198.40.0.1 to 198.47.255.254198.47.255.255524,286
199198.48.0.0/13198.48.0.1 to 198.55.255.254198.55.255.255524,286
200198.56.0.0/13198.56.0.1 to 198.63.255.254198.63.255.255524,286
201198.64.0.0/13198.64.0.1 to 198.71.255.254198.71.255.255524,286
202198.72.0.0/13198.72.0.1 to 198.79.255.254198.79.255.255524,286
203198.80.0.0/13198.80.0.1 to 198.87.255.254198.87.255.255524,286
204198.88.0.0/13198.88.0.1 to 198.95.255.254198.95.255.255524,286
205198.96.0.0/13198.96.0.1 to 198.103.255.254198.103.255.255524,286
206198.104.0.0/13198.104.0.1 to 198.111.255.254198.111.255.255524,286
207198.112.0.0/13198.112.0.1 to 198.119.255.254198.119.255.255524,286
208198.120.0.0/13198.120.0.1 to 198.127.255.254198.127.255.255524,286
209198.128.0.0/13198.128.0.1 to 198.135.255.254198.135.255.255524,286
210198.136.0.0/13198.136.0.1 to 198.143.255.254198.143.255.255524,286
211198.144.0.0/13198.144.0.1 to 198.151.255.254198.151.255.255524,286
212198.152.0.0/13198.152.0.1 to 198.159.255.254198.159.255.255524,286
213198.160.0.0/13198.160.0.1 to 198.167.255.254198.167.255.255524,286
214198.168.0.0/13198.168.0.1 to 198.175.255.254198.175.255.255524,286
215198.176.0.0/13198.176.0.1 to 198.183.255.254198.183.255.255524,286
216198.184.0.0/13198.184.0.1 to 198.191.255.254198.191.255.255524,286
217198.192.0.0/13198.192.0.1 to 198.199.255.254198.199.255.255524,286
218198.200.0.0/13198.200.0.1 to 198.207.255.254198.207.255.255524,286
219198.208.0.0/13198.208.0.1 to 198.215.255.254198.215.255.255524,286
220198.216.0.0/13198.216.0.1 to 198.223.255.254198.223.255.255524,286
221198.224.0.0/13198.224.0.1 to 198.231.255.254198.231.255.255524,286
222198.232.0.0/13198.232.0.1 to 198.239.255.254198.239.255.255524,286
223198.240.0.0/13198.240.0.1 to 198.247.255.254198.247.255.255524,286
224198.248.0.0/13198.248.0.1 to 198.255.255.254198.255.255.255524,286
225199.0.0.0/13199.0.0.1 to 199.7.255.254199.7.255.255524,286
226199.8.0.0/13199.8.0.1 to 199.15.255.254199.15.255.255524,286
227199.16.0.0/13199.16.0.1 to 199.23.255.254199.23.255.255524,286
228199.24.0.0/13199.24.0.1 to 199.31.255.254199.31.255.255524,286
229199.32.0.0/13199.32.0.1 to 199.39.255.254199.39.255.255524,286
230199.40.0.0/13199.40.0.1 to 199.47.255.254199.47.255.255524,286
231199.48.0.0/13199.48.0.1 to 199.55.255.254199.55.255.255524,286
232199.56.0.0/13199.56.0.1 to 199.63.255.254199.63.255.255524,286
233199.64.0.0/13199.64.0.1 to 199.71.255.254199.71.255.255524,286
234199.72.0.0/13199.72.0.1 to 199.79.255.254199.79.255.255524,286
235199.80.0.0/13199.80.0.1 to 199.87.255.254199.87.255.255524,286
236199.88.0.0/13199.88.0.1 to 199.95.255.254199.95.255.255524,286
237199.96.0.0/13199.96.0.1 to 199.103.255.254199.103.255.255524,286
238199.104.0.0/13199.104.0.1 to 199.111.255.254199.111.255.255524,286
239199.112.0.0/13199.112.0.1 to 199.119.255.254199.119.255.255524,286
240199.120.0.0/13199.120.0.1 to 199.127.255.254199.127.255.255524,286
241199.128.0.0/13199.128.0.1 to 199.135.255.254199.135.255.255524,286
242199.136.0.0/13199.136.0.1 to 199.143.255.254199.143.255.255524,286
243199.144.0.0/13199.144.0.1 to 199.151.255.254199.151.255.255524,286
244199.152.0.0/13199.152.0.1 to 199.159.255.254199.159.255.255524,286
245199.160.0.0/13199.160.0.1 to 199.167.255.254199.167.255.255524,286
246199.168.0.0/13199.168.0.1 to 199.175.255.254199.175.255.255524,286
247199.176.0.0/13199.176.0.1 to 199.183.255.254199.183.255.255524,286
248199.184.0.0/13199.184.0.1 to 199.191.255.254199.191.255.255524,286
249199.192.0.0/13199.192.0.1 to 199.199.255.254199.199.255.255524,286
250199.200.0.0/13199.200.0.1 to 199.207.255.254199.207.255.255524,286
251199.208.0.0/13199.208.0.1 to 199.215.255.254199.215.255.255524,286
252199.216.0.0/13199.216.0.1 to 199.223.255.254199.223.255.255524,286
253199.224.0.0/13199.224.0.1 to 199.231.255.254199.231.255.255524,286
254199.232.0.0/13199.232.0.1 to 199.239.255.254199.239.255.255524,286
255199.240.0.0/13199.240.0.1 to 199.247.255.254199.247.255.255524,286
256199.248.0.0/13199.248.0.1 to 199.255.255.254199.255.255.255524,286

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.