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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.

Network45.64.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
45.64.0.0
Broadcast address
45.127.255.255
First usable
45.64.0.1
Last usable
45.127.255.254
Usable hosts
4,194,302 (4,194,304 less the network and broadcast addresses)
Subnet mask
255.192.0.0
Wildcard mask
0.63.255.255 (Cisco ACLs, OSPF)
Prefix length
/10
Type
Public public
Old class
A (default /8)
As numbers
Hex 2D400000 · Integer 759169024 to 763363327
Reverse DNS zones
64.45.in-addr.arpa
65.45.in-addr.arpa
66.45.in-addr.arpa
67.45.in-addr.arpa
68.45.in-addr.arpa
69.45.in-addr.arpa
70.45.in-addr.arpa
71.45.in-addr.arpa
72.45.in-addr.arpa
73.45.in-addr.arpa
74.45.in-addr.arpa
75.45.in-addr.arpa
76.45.in-addr.arpa
77.45.in-addr.arpa
78.45.in-addr.arpa
79.45.in-addr.arpa
and 48 more
/10 is not on a 8-bit boundary, so it takes 64 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00101101.01000000.00000000.0000000045.64.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network00101101.01000000.00000000.0000000045.64.0.0
Broadcast00101101.01111111.11111111.1111111145.127.255.255
Split into smaller subnets/19
/11 (2)/12 (4)/13 (8)/14 (16)/15 (32)/16 (64)/17 (128)/18 (256)/19 (512)/20 (1,024)/21 (2,048)/22 (4,096)

45.64.0.0/10 makes 512 subnets of /19; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
145.64.0.0/1945.64.0.1 to 45.64.31.25445.64.31.2558,190
245.64.32.0/1945.64.32.1 to 45.64.63.25445.64.63.2558,190
345.64.64.0/1945.64.64.1 to 45.64.95.25445.64.95.2558,190
445.64.96.0/1945.64.96.1 to 45.64.127.25445.64.127.2558,190
545.64.128.0/1945.64.128.1 to 45.64.159.25445.64.159.2558,190
645.64.160.0/1945.64.160.1 to 45.64.191.25445.64.191.2558,190
745.64.192.0/1945.64.192.1 to 45.64.223.25445.64.223.2558,190
845.64.224.0/1945.64.224.1 to 45.64.255.25445.64.255.2558,190
945.65.0.0/1945.65.0.1 to 45.65.31.25445.65.31.2558,190
1045.65.32.0/1945.65.32.1 to 45.65.63.25445.65.63.2558,190
1145.65.64.0/1945.65.64.1 to 45.65.95.25445.65.95.2558,190
1245.65.96.0/1945.65.96.1 to 45.65.127.25445.65.127.2558,190
1345.65.128.0/1945.65.128.1 to 45.65.159.25445.65.159.2558,190
1445.65.160.0/1945.65.160.1 to 45.65.191.25445.65.191.2558,190
1545.65.192.0/1945.65.192.1 to 45.65.223.25445.65.223.2558,190
1645.65.224.0/1945.65.224.1 to 45.65.255.25445.65.255.2558,190
1745.66.0.0/1945.66.0.1 to 45.66.31.25445.66.31.2558,190
1845.66.32.0/1945.66.32.1 to 45.66.63.25445.66.63.2558,190
1945.66.64.0/1945.66.64.1 to 45.66.95.25445.66.95.2558,190
2045.66.96.0/1945.66.96.1 to 45.66.127.25445.66.127.2558,190
2145.66.128.0/1945.66.128.1 to 45.66.159.25445.66.159.2558,190
2245.66.160.0/1945.66.160.1 to 45.66.191.25445.66.191.2558,190
2345.66.192.0/1945.66.192.1 to 45.66.223.25445.66.223.2558,190
2445.66.224.0/1945.66.224.1 to 45.66.255.25445.66.255.2558,190
2545.67.0.0/1945.67.0.1 to 45.67.31.25445.67.31.2558,190
2645.67.32.0/1945.67.32.1 to 45.67.63.25445.67.63.2558,190
2745.67.64.0/1945.67.64.1 to 45.67.95.25445.67.95.2558,190
2845.67.96.0/1945.67.96.1 to 45.67.127.25445.67.127.2558,190
2945.67.128.0/1945.67.128.1 to 45.67.159.25445.67.159.2558,190
3045.67.160.0/1945.67.160.1 to 45.67.191.25445.67.191.2558,190
3145.67.192.0/1945.67.192.1 to 45.67.223.25445.67.223.2558,190
3245.67.224.0/1945.67.224.1 to 45.67.255.25445.67.255.2558,190
3345.68.0.0/1945.68.0.1 to 45.68.31.25445.68.31.2558,190
3445.68.32.0/1945.68.32.1 to 45.68.63.25445.68.63.2558,190
3545.68.64.0/1945.68.64.1 to 45.68.95.25445.68.95.2558,190
3645.68.96.0/1945.68.96.1 to 45.68.127.25445.68.127.2558,190
3745.68.128.0/1945.68.128.1 to 45.68.159.25445.68.159.2558,190
3845.68.160.0/1945.68.160.1 to 45.68.191.25445.68.191.2558,190
3945.68.192.0/1945.68.192.1 to 45.68.223.25445.68.223.2558,190
4045.68.224.0/1945.68.224.1 to 45.68.255.25445.68.255.2558,190
4145.69.0.0/1945.69.0.1 to 45.69.31.25445.69.31.2558,190
4245.69.32.0/1945.69.32.1 to 45.69.63.25445.69.63.2558,190
4345.69.64.0/1945.69.64.1 to 45.69.95.25445.69.95.2558,190
4445.69.96.0/1945.69.96.1 to 45.69.127.25445.69.127.2558,190
4545.69.128.0/1945.69.128.1 to 45.69.159.25445.69.159.2558,190
4645.69.160.0/1945.69.160.1 to 45.69.191.25445.69.191.2558,190
4745.69.192.0/1945.69.192.1 to 45.69.223.25445.69.223.2558,190
4845.69.224.0/1945.69.224.1 to 45.69.255.25445.69.255.2558,190
4945.70.0.0/1945.70.0.1 to 45.70.31.25445.70.31.2558,190
5045.70.32.0/1945.70.32.1 to 45.70.63.25445.70.63.2558,190
5145.70.64.0/1945.70.64.1 to 45.70.95.25445.70.95.2558,190
5245.70.96.0/1945.70.96.1 to 45.70.127.25445.70.127.2558,190
5345.70.128.0/1945.70.128.1 to 45.70.159.25445.70.159.2558,190
5445.70.160.0/1945.70.160.1 to 45.70.191.25445.70.191.2558,190
5545.70.192.0/1945.70.192.1 to 45.70.223.25445.70.223.2558,190
5645.70.224.0/1945.70.224.1 to 45.70.255.25445.70.255.2558,190
5745.71.0.0/1945.71.0.1 to 45.71.31.25445.71.31.2558,190
5845.71.32.0/1945.71.32.1 to 45.71.63.25445.71.63.2558,190
5945.71.64.0/1945.71.64.1 to 45.71.95.25445.71.95.2558,190
6045.71.96.0/1945.71.96.1 to 45.71.127.25445.71.127.2558,190
6145.71.128.0/1945.71.128.1 to 45.71.159.25445.71.159.2558,190
6245.71.160.0/1945.71.160.1 to 45.71.191.25445.71.191.2558,190
6345.71.192.0/1945.71.192.1 to 45.71.223.25445.71.223.2558,190
6445.71.224.0/1945.71.224.1 to 45.71.255.25445.71.255.2558,190
6545.72.0.0/1945.72.0.1 to 45.72.31.25445.72.31.2558,190
6645.72.32.0/1945.72.32.1 to 45.72.63.25445.72.63.2558,190
6745.72.64.0/1945.72.64.1 to 45.72.95.25445.72.95.2558,190
6845.72.96.0/1945.72.96.1 to 45.72.127.25445.72.127.2558,190
6945.72.128.0/1945.72.128.1 to 45.72.159.25445.72.159.2558,190
7045.72.160.0/1945.72.160.1 to 45.72.191.25445.72.191.2558,190
7145.72.192.0/1945.72.192.1 to 45.72.223.25445.72.223.2558,190
7245.72.224.0/1945.72.224.1 to 45.72.255.25445.72.255.2558,190
7345.73.0.0/1945.73.0.1 to 45.73.31.25445.73.31.2558,190
7445.73.32.0/1945.73.32.1 to 45.73.63.25445.73.63.2558,190
7545.73.64.0/1945.73.64.1 to 45.73.95.25445.73.95.2558,190
7645.73.96.0/1945.73.96.1 to 45.73.127.25445.73.127.2558,190
7745.73.128.0/1945.73.128.1 to 45.73.159.25445.73.159.2558,190
7845.73.160.0/1945.73.160.1 to 45.73.191.25445.73.191.2558,190
7945.73.192.0/1945.73.192.1 to 45.73.223.25445.73.223.2558,190
8045.73.224.0/1945.73.224.1 to 45.73.255.25445.73.255.2558,190
8145.74.0.0/1945.74.0.1 to 45.74.31.25445.74.31.2558,190
8245.74.32.0/1945.74.32.1 to 45.74.63.25445.74.63.2558,190
8345.74.64.0/1945.74.64.1 to 45.74.95.25445.74.95.2558,190
8445.74.96.0/1945.74.96.1 to 45.74.127.25445.74.127.2558,190
8545.74.128.0/1945.74.128.1 to 45.74.159.25445.74.159.2558,190
8645.74.160.0/1945.74.160.1 to 45.74.191.25445.74.191.2558,190
8745.74.192.0/1945.74.192.1 to 45.74.223.25445.74.223.2558,190
8845.74.224.0/1945.74.224.1 to 45.74.255.25445.74.255.2558,190
8945.75.0.0/1945.75.0.1 to 45.75.31.25445.75.31.2558,190
9045.75.32.0/1945.75.32.1 to 45.75.63.25445.75.63.2558,190
9145.75.64.0/1945.75.64.1 to 45.75.95.25445.75.95.2558,190
9245.75.96.0/1945.75.96.1 to 45.75.127.25445.75.127.2558,190
9345.75.128.0/1945.75.128.1 to 45.75.159.25445.75.159.2558,190
9445.75.160.0/1945.75.160.1 to 45.75.191.25445.75.191.2558,190
9545.75.192.0/1945.75.192.1 to 45.75.223.25445.75.223.2558,190
9645.75.224.0/1945.75.224.1 to 45.75.255.25445.75.255.2558,190
9745.76.0.0/1945.76.0.1 to 45.76.31.25445.76.31.2558,190
9845.76.32.0/1945.76.32.1 to 45.76.63.25445.76.63.2558,190
9945.76.64.0/1945.76.64.1 to 45.76.95.25445.76.95.2558,190
10045.76.96.0/1945.76.96.1 to 45.76.127.25445.76.127.2558,190
10145.76.128.0/1945.76.128.1 to 45.76.159.25445.76.159.2558,190
10245.76.160.0/1945.76.160.1 to 45.76.191.25445.76.191.2558,190
10345.76.192.0/1945.76.192.1 to 45.76.223.25445.76.223.2558,190
10445.76.224.0/1945.76.224.1 to 45.76.255.25445.76.255.2558,190
10545.77.0.0/1945.77.0.1 to 45.77.31.25445.77.31.2558,190
10645.77.32.0/1945.77.32.1 to 45.77.63.25445.77.63.2558,190
10745.77.64.0/1945.77.64.1 to 45.77.95.25445.77.95.2558,190
10845.77.96.0/1945.77.96.1 to 45.77.127.25445.77.127.2558,190
10945.77.128.0/1945.77.128.1 to 45.77.159.25445.77.159.2558,190
11045.77.160.0/1945.77.160.1 to 45.77.191.25445.77.191.2558,190
11145.77.192.0/1945.77.192.1 to 45.77.223.25445.77.223.2558,190
11245.77.224.0/1945.77.224.1 to 45.77.255.25445.77.255.2558,190
11345.78.0.0/1945.78.0.1 to 45.78.31.25445.78.31.2558,190
11445.78.32.0/1945.78.32.1 to 45.78.63.25445.78.63.2558,190
11545.78.64.0/1945.78.64.1 to 45.78.95.25445.78.95.2558,190
11645.78.96.0/1945.78.96.1 to 45.78.127.25445.78.127.2558,190
11745.78.128.0/1945.78.128.1 to 45.78.159.25445.78.159.2558,190
11845.78.160.0/1945.78.160.1 to 45.78.191.25445.78.191.2558,190
11945.78.192.0/1945.78.192.1 to 45.78.223.25445.78.223.2558,190
12045.78.224.0/1945.78.224.1 to 45.78.255.25445.78.255.2558,190
12145.79.0.0/1945.79.0.1 to 45.79.31.25445.79.31.2558,190
12245.79.32.0/1945.79.32.1 to 45.79.63.25445.79.63.2558,190
12345.79.64.0/1945.79.64.1 to 45.79.95.25445.79.95.2558,190
12445.79.96.0/1945.79.96.1 to 45.79.127.25445.79.127.2558,190
12545.79.128.0/1945.79.128.1 to 45.79.159.25445.79.159.2558,190
12645.79.160.0/1945.79.160.1 to 45.79.191.25445.79.191.2558,190
12745.79.192.0/1945.79.192.1 to 45.79.223.25445.79.223.2558,190
12845.79.224.0/1945.79.224.1 to 45.79.255.25445.79.255.2558,190
12945.80.0.0/1945.80.0.1 to 45.80.31.25445.80.31.2558,190
13045.80.32.0/1945.80.32.1 to 45.80.63.25445.80.63.2558,190
13145.80.64.0/1945.80.64.1 to 45.80.95.25445.80.95.2558,190
13245.80.96.0/1945.80.96.1 to 45.80.127.25445.80.127.2558,190
13345.80.128.0/1945.80.128.1 to 45.80.159.25445.80.159.2558,190
13445.80.160.0/1945.80.160.1 to 45.80.191.25445.80.191.2558,190
13545.80.192.0/1945.80.192.1 to 45.80.223.25445.80.223.2558,190
13645.80.224.0/1945.80.224.1 to 45.80.255.25445.80.255.2558,190
13745.81.0.0/1945.81.0.1 to 45.81.31.25445.81.31.2558,190
13845.81.32.0/1945.81.32.1 to 45.81.63.25445.81.63.2558,190
13945.81.64.0/1945.81.64.1 to 45.81.95.25445.81.95.2558,190
14045.81.96.0/1945.81.96.1 to 45.81.127.25445.81.127.2558,190
14145.81.128.0/1945.81.128.1 to 45.81.159.25445.81.159.2558,190
14245.81.160.0/1945.81.160.1 to 45.81.191.25445.81.191.2558,190
14345.81.192.0/1945.81.192.1 to 45.81.223.25445.81.223.2558,190
14445.81.224.0/1945.81.224.1 to 45.81.255.25445.81.255.2558,190
14545.82.0.0/1945.82.0.1 to 45.82.31.25445.82.31.2558,190
14645.82.32.0/1945.82.32.1 to 45.82.63.25445.82.63.2558,190
14745.82.64.0/1945.82.64.1 to 45.82.95.25445.82.95.2558,190
14845.82.96.0/1945.82.96.1 to 45.82.127.25445.82.127.2558,190
14945.82.128.0/1945.82.128.1 to 45.82.159.25445.82.159.2558,190
15045.82.160.0/1945.82.160.1 to 45.82.191.25445.82.191.2558,190
15145.82.192.0/1945.82.192.1 to 45.82.223.25445.82.223.2558,190
15245.82.224.0/1945.82.224.1 to 45.82.255.25445.82.255.2558,190
15345.83.0.0/1945.83.0.1 to 45.83.31.25445.83.31.2558,190
15445.83.32.0/1945.83.32.1 to 45.83.63.25445.83.63.2558,190
15545.83.64.0/1945.83.64.1 to 45.83.95.25445.83.95.2558,190
15645.83.96.0/1945.83.96.1 to 45.83.127.25445.83.127.2558,190
15745.83.128.0/1945.83.128.1 to 45.83.159.25445.83.159.2558,190
15845.83.160.0/1945.83.160.1 to 45.83.191.25445.83.191.2558,190
15945.83.192.0/1945.83.192.1 to 45.83.223.25445.83.223.2558,190
16045.83.224.0/1945.83.224.1 to 45.83.255.25445.83.255.2558,190
16145.84.0.0/1945.84.0.1 to 45.84.31.25445.84.31.2558,190
16245.84.32.0/1945.84.32.1 to 45.84.63.25445.84.63.2558,190
16345.84.64.0/1945.84.64.1 to 45.84.95.25445.84.95.2558,190
16445.84.96.0/1945.84.96.1 to 45.84.127.25445.84.127.2558,190
16545.84.128.0/1945.84.128.1 to 45.84.159.25445.84.159.2558,190
16645.84.160.0/1945.84.160.1 to 45.84.191.25445.84.191.2558,190
16745.84.192.0/1945.84.192.1 to 45.84.223.25445.84.223.2558,190
16845.84.224.0/1945.84.224.1 to 45.84.255.25445.84.255.2558,190
16945.85.0.0/1945.85.0.1 to 45.85.31.25445.85.31.2558,190
17045.85.32.0/1945.85.32.1 to 45.85.63.25445.85.63.2558,190
17145.85.64.0/1945.85.64.1 to 45.85.95.25445.85.95.2558,190
17245.85.96.0/1945.85.96.1 to 45.85.127.25445.85.127.2558,190
17345.85.128.0/1945.85.128.1 to 45.85.159.25445.85.159.2558,190
17445.85.160.0/1945.85.160.1 to 45.85.191.25445.85.191.2558,190
17545.85.192.0/1945.85.192.1 to 45.85.223.25445.85.223.2558,190
17645.85.224.0/1945.85.224.1 to 45.85.255.25445.85.255.2558,190
17745.86.0.0/1945.86.0.1 to 45.86.31.25445.86.31.2558,190
17845.86.32.0/1945.86.32.1 to 45.86.63.25445.86.63.2558,190
17945.86.64.0/1945.86.64.1 to 45.86.95.25445.86.95.2558,190
18045.86.96.0/1945.86.96.1 to 45.86.127.25445.86.127.2558,190
18145.86.128.0/1945.86.128.1 to 45.86.159.25445.86.159.2558,190
18245.86.160.0/1945.86.160.1 to 45.86.191.25445.86.191.2558,190
18345.86.192.0/1945.86.192.1 to 45.86.223.25445.86.223.2558,190
18445.86.224.0/1945.86.224.1 to 45.86.255.25445.86.255.2558,190
18545.87.0.0/1945.87.0.1 to 45.87.31.25445.87.31.2558,190
18645.87.32.0/1945.87.32.1 to 45.87.63.25445.87.63.2558,190
18745.87.64.0/1945.87.64.1 to 45.87.95.25445.87.95.2558,190
18845.87.96.0/1945.87.96.1 to 45.87.127.25445.87.127.2558,190
18945.87.128.0/1945.87.128.1 to 45.87.159.25445.87.159.2558,190
19045.87.160.0/1945.87.160.1 to 45.87.191.25445.87.191.2558,190
19145.87.192.0/1945.87.192.1 to 45.87.223.25445.87.223.2558,190
19245.87.224.0/1945.87.224.1 to 45.87.255.25445.87.255.2558,190
19345.88.0.0/1945.88.0.1 to 45.88.31.25445.88.31.2558,190
19445.88.32.0/1945.88.32.1 to 45.88.63.25445.88.63.2558,190
19545.88.64.0/1945.88.64.1 to 45.88.95.25445.88.95.2558,190
19645.88.96.0/1945.88.96.1 to 45.88.127.25445.88.127.2558,190
19745.88.128.0/1945.88.128.1 to 45.88.159.25445.88.159.2558,190
19845.88.160.0/1945.88.160.1 to 45.88.191.25445.88.191.2558,190
19945.88.192.0/1945.88.192.1 to 45.88.223.25445.88.223.2558,190
20045.88.224.0/1945.88.224.1 to 45.88.255.25445.88.255.2558,190
20145.89.0.0/1945.89.0.1 to 45.89.31.25445.89.31.2558,190
20245.89.32.0/1945.89.32.1 to 45.89.63.25445.89.63.2558,190
20345.89.64.0/1945.89.64.1 to 45.89.95.25445.89.95.2558,190
20445.89.96.0/1945.89.96.1 to 45.89.127.25445.89.127.2558,190
20545.89.128.0/1945.89.128.1 to 45.89.159.25445.89.159.2558,190
20645.89.160.0/1945.89.160.1 to 45.89.191.25445.89.191.2558,190
20745.89.192.0/1945.89.192.1 to 45.89.223.25445.89.223.2558,190
20845.89.224.0/1945.89.224.1 to 45.89.255.25445.89.255.2558,190
20945.90.0.0/1945.90.0.1 to 45.90.31.25445.90.31.2558,190
21045.90.32.0/1945.90.32.1 to 45.90.63.25445.90.63.2558,190
21145.90.64.0/1945.90.64.1 to 45.90.95.25445.90.95.2558,190
21245.90.96.0/1945.90.96.1 to 45.90.127.25445.90.127.2558,190
21345.90.128.0/1945.90.128.1 to 45.90.159.25445.90.159.2558,190
21445.90.160.0/1945.90.160.1 to 45.90.191.25445.90.191.2558,190
21545.90.192.0/1945.90.192.1 to 45.90.223.25445.90.223.2558,190
21645.90.224.0/1945.90.224.1 to 45.90.255.25445.90.255.2558,190
21745.91.0.0/1945.91.0.1 to 45.91.31.25445.91.31.2558,190
21845.91.32.0/1945.91.32.1 to 45.91.63.25445.91.63.2558,190
21945.91.64.0/1945.91.64.1 to 45.91.95.25445.91.95.2558,190
22045.91.96.0/1945.91.96.1 to 45.91.127.25445.91.127.2558,190
22145.91.128.0/1945.91.128.1 to 45.91.159.25445.91.159.2558,190
22245.91.160.0/1945.91.160.1 to 45.91.191.25445.91.191.2558,190
22345.91.192.0/1945.91.192.1 to 45.91.223.25445.91.223.2558,190
22445.91.224.0/1945.91.224.1 to 45.91.255.25445.91.255.2558,190
22545.92.0.0/1945.92.0.1 to 45.92.31.25445.92.31.2558,190
22645.92.32.0/1945.92.32.1 to 45.92.63.25445.92.63.2558,190
22745.92.64.0/1945.92.64.1 to 45.92.95.25445.92.95.2558,190
22845.92.96.0/1945.92.96.1 to 45.92.127.25445.92.127.2558,190
22945.92.128.0/1945.92.128.1 to 45.92.159.25445.92.159.2558,190
23045.92.160.0/1945.92.160.1 to 45.92.191.25445.92.191.2558,190
23145.92.192.0/1945.92.192.1 to 45.92.223.25445.92.223.2558,190
23245.92.224.0/1945.92.224.1 to 45.92.255.25445.92.255.2558,190
23345.93.0.0/1945.93.0.1 to 45.93.31.25445.93.31.2558,190
23445.93.32.0/1945.93.32.1 to 45.93.63.25445.93.63.2558,190
23545.93.64.0/1945.93.64.1 to 45.93.95.25445.93.95.2558,190
23645.93.96.0/1945.93.96.1 to 45.93.127.25445.93.127.2558,190
23745.93.128.0/1945.93.128.1 to 45.93.159.25445.93.159.2558,190
23845.93.160.0/1945.93.160.1 to 45.93.191.25445.93.191.2558,190
23945.93.192.0/1945.93.192.1 to 45.93.223.25445.93.223.2558,190
24045.93.224.0/1945.93.224.1 to 45.93.255.25445.93.255.2558,190
24145.94.0.0/1945.94.0.1 to 45.94.31.25445.94.31.2558,190
24245.94.32.0/1945.94.32.1 to 45.94.63.25445.94.63.2558,190
24345.94.64.0/1945.94.64.1 to 45.94.95.25445.94.95.2558,190
24445.94.96.0/1945.94.96.1 to 45.94.127.25445.94.127.2558,190
24545.94.128.0/1945.94.128.1 to 45.94.159.25445.94.159.2558,190
24645.94.160.0/1945.94.160.1 to 45.94.191.25445.94.191.2558,190
24745.94.192.0/1945.94.192.1 to 45.94.223.25445.94.223.2558,190
24845.94.224.0/1945.94.224.1 to 45.94.255.25445.94.255.2558,190
24945.95.0.0/1945.95.0.1 to 45.95.31.25445.95.31.2558,190
25045.95.32.0/1945.95.32.1 to 45.95.63.25445.95.63.2558,190
25145.95.64.0/1945.95.64.1 to 45.95.95.25445.95.95.2558,190
25245.95.96.0/1945.95.96.1 to 45.95.127.25445.95.127.2558,190
25345.95.128.0/1945.95.128.1 to 45.95.159.25445.95.159.2558,190
25445.95.160.0/1945.95.160.1 to 45.95.191.25445.95.191.2558,190
25545.95.192.0/1945.95.192.1 to 45.95.223.25445.95.223.2558,190
25645.95.224.0/1945.95.224.1 to 45.95.255.25445.95.255.2558,190

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.