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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/18
/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 256 subnets of /18.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
145.64.0.0/1845.64.0.1 to 45.64.63.25445.64.63.25516,382
245.64.64.0/1845.64.64.1 to 45.64.127.25445.64.127.25516,382
345.64.128.0/1845.64.128.1 to 45.64.191.25445.64.191.25516,382
445.64.192.0/1845.64.192.1 to 45.64.255.25445.64.255.25516,382
545.65.0.0/1845.65.0.1 to 45.65.63.25445.65.63.25516,382
645.65.64.0/1845.65.64.1 to 45.65.127.25445.65.127.25516,382
745.65.128.0/1845.65.128.1 to 45.65.191.25445.65.191.25516,382
845.65.192.0/1845.65.192.1 to 45.65.255.25445.65.255.25516,382
945.66.0.0/1845.66.0.1 to 45.66.63.25445.66.63.25516,382
1045.66.64.0/1845.66.64.1 to 45.66.127.25445.66.127.25516,382
1145.66.128.0/1845.66.128.1 to 45.66.191.25445.66.191.25516,382
1245.66.192.0/1845.66.192.1 to 45.66.255.25445.66.255.25516,382
1345.67.0.0/1845.67.0.1 to 45.67.63.25445.67.63.25516,382
1445.67.64.0/1845.67.64.1 to 45.67.127.25445.67.127.25516,382
1545.67.128.0/1845.67.128.1 to 45.67.191.25445.67.191.25516,382
1645.67.192.0/1845.67.192.1 to 45.67.255.25445.67.255.25516,382
1745.68.0.0/1845.68.0.1 to 45.68.63.25445.68.63.25516,382
1845.68.64.0/1845.68.64.1 to 45.68.127.25445.68.127.25516,382
1945.68.128.0/1845.68.128.1 to 45.68.191.25445.68.191.25516,382
2045.68.192.0/1845.68.192.1 to 45.68.255.25445.68.255.25516,382
2145.69.0.0/1845.69.0.1 to 45.69.63.25445.69.63.25516,382
2245.69.64.0/1845.69.64.1 to 45.69.127.25445.69.127.25516,382
2345.69.128.0/1845.69.128.1 to 45.69.191.25445.69.191.25516,382
2445.69.192.0/1845.69.192.1 to 45.69.255.25445.69.255.25516,382
2545.70.0.0/1845.70.0.1 to 45.70.63.25445.70.63.25516,382
2645.70.64.0/1845.70.64.1 to 45.70.127.25445.70.127.25516,382
2745.70.128.0/1845.70.128.1 to 45.70.191.25445.70.191.25516,382
2845.70.192.0/1845.70.192.1 to 45.70.255.25445.70.255.25516,382
2945.71.0.0/1845.71.0.1 to 45.71.63.25445.71.63.25516,382
3045.71.64.0/1845.71.64.1 to 45.71.127.25445.71.127.25516,382
3145.71.128.0/1845.71.128.1 to 45.71.191.25445.71.191.25516,382
3245.71.192.0/1845.71.192.1 to 45.71.255.25445.71.255.25516,382
3345.72.0.0/1845.72.0.1 to 45.72.63.25445.72.63.25516,382
3445.72.64.0/1845.72.64.1 to 45.72.127.25445.72.127.25516,382
3545.72.128.0/1845.72.128.1 to 45.72.191.25445.72.191.25516,382
3645.72.192.0/1845.72.192.1 to 45.72.255.25445.72.255.25516,382
3745.73.0.0/1845.73.0.1 to 45.73.63.25445.73.63.25516,382
3845.73.64.0/1845.73.64.1 to 45.73.127.25445.73.127.25516,382
3945.73.128.0/1845.73.128.1 to 45.73.191.25445.73.191.25516,382
4045.73.192.0/1845.73.192.1 to 45.73.255.25445.73.255.25516,382
4145.74.0.0/1845.74.0.1 to 45.74.63.25445.74.63.25516,382
4245.74.64.0/1845.74.64.1 to 45.74.127.25445.74.127.25516,382
4345.74.128.0/1845.74.128.1 to 45.74.191.25445.74.191.25516,382
4445.74.192.0/1845.74.192.1 to 45.74.255.25445.74.255.25516,382
4545.75.0.0/1845.75.0.1 to 45.75.63.25445.75.63.25516,382
4645.75.64.0/1845.75.64.1 to 45.75.127.25445.75.127.25516,382
4745.75.128.0/1845.75.128.1 to 45.75.191.25445.75.191.25516,382
4845.75.192.0/1845.75.192.1 to 45.75.255.25445.75.255.25516,382
4945.76.0.0/1845.76.0.1 to 45.76.63.25445.76.63.25516,382
5045.76.64.0/1845.76.64.1 to 45.76.127.25445.76.127.25516,382
5145.76.128.0/1845.76.128.1 to 45.76.191.25445.76.191.25516,382
5245.76.192.0/1845.76.192.1 to 45.76.255.25445.76.255.25516,382
5345.77.0.0/1845.77.0.1 to 45.77.63.25445.77.63.25516,382
5445.77.64.0/1845.77.64.1 to 45.77.127.25445.77.127.25516,382
5545.77.128.0/1845.77.128.1 to 45.77.191.25445.77.191.25516,382
5645.77.192.0/1845.77.192.1 to 45.77.255.25445.77.255.25516,382
5745.78.0.0/1845.78.0.1 to 45.78.63.25445.78.63.25516,382
5845.78.64.0/1845.78.64.1 to 45.78.127.25445.78.127.25516,382
5945.78.128.0/1845.78.128.1 to 45.78.191.25445.78.191.25516,382
6045.78.192.0/1845.78.192.1 to 45.78.255.25445.78.255.25516,382
6145.79.0.0/1845.79.0.1 to 45.79.63.25445.79.63.25516,382
6245.79.64.0/1845.79.64.1 to 45.79.127.25445.79.127.25516,382
6345.79.128.0/1845.79.128.1 to 45.79.191.25445.79.191.25516,382
6445.79.192.0/1845.79.192.1 to 45.79.255.25445.79.255.25516,382
6545.80.0.0/1845.80.0.1 to 45.80.63.25445.80.63.25516,382
6645.80.64.0/1845.80.64.1 to 45.80.127.25445.80.127.25516,382
6745.80.128.0/1845.80.128.1 to 45.80.191.25445.80.191.25516,382
6845.80.192.0/1845.80.192.1 to 45.80.255.25445.80.255.25516,382
6945.81.0.0/1845.81.0.1 to 45.81.63.25445.81.63.25516,382
7045.81.64.0/1845.81.64.1 to 45.81.127.25445.81.127.25516,382
7145.81.128.0/1845.81.128.1 to 45.81.191.25445.81.191.25516,382
7245.81.192.0/1845.81.192.1 to 45.81.255.25445.81.255.25516,382
7345.82.0.0/1845.82.0.1 to 45.82.63.25445.82.63.25516,382
7445.82.64.0/1845.82.64.1 to 45.82.127.25445.82.127.25516,382
7545.82.128.0/1845.82.128.1 to 45.82.191.25445.82.191.25516,382
7645.82.192.0/1845.82.192.1 to 45.82.255.25445.82.255.25516,382
7745.83.0.0/1845.83.0.1 to 45.83.63.25445.83.63.25516,382
7845.83.64.0/1845.83.64.1 to 45.83.127.25445.83.127.25516,382
7945.83.128.0/1845.83.128.1 to 45.83.191.25445.83.191.25516,382
8045.83.192.0/1845.83.192.1 to 45.83.255.25445.83.255.25516,382
8145.84.0.0/1845.84.0.1 to 45.84.63.25445.84.63.25516,382
8245.84.64.0/1845.84.64.1 to 45.84.127.25445.84.127.25516,382
8345.84.128.0/1845.84.128.1 to 45.84.191.25445.84.191.25516,382
8445.84.192.0/1845.84.192.1 to 45.84.255.25445.84.255.25516,382
8545.85.0.0/1845.85.0.1 to 45.85.63.25445.85.63.25516,382
8645.85.64.0/1845.85.64.1 to 45.85.127.25445.85.127.25516,382
8745.85.128.0/1845.85.128.1 to 45.85.191.25445.85.191.25516,382
8845.85.192.0/1845.85.192.1 to 45.85.255.25445.85.255.25516,382
8945.86.0.0/1845.86.0.1 to 45.86.63.25445.86.63.25516,382
9045.86.64.0/1845.86.64.1 to 45.86.127.25445.86.127.25516,382
9145.86.128.0/1845.86.128.1 to 45.86.191.25445.86.191.25516,382
9245.86.192.0/1845.86.192.1 to 45.86.255.25445.86.255.25516,382
9345.87.0.0/1845.87.0.1 to 45.87.63.25445.87.63.25516,382
9445.87.64.0/1845.87.64.1 to 45.87.127.25445.87.127.25516,382
9545.87.128.0/1845.87.128.1 to 45.87.191.25445.87.191.25516,382
9645.87.192.0/1845.87.192.1 to 45.87.255.25445.87.255.25516,382
9745.88.0.0/1845.88.0.1 to 45.88.63.25445.88.63.25516,382
9845.88.64.0/1845.88.64.1 to 45.88.127.25445.88.127.25516,382
9945.88.128.0/1845.88.128.1 to 45.88.191.25445.88.191.25516,382
10045.88.192.0/1845.88.192.1 to 45.88.255.25445.88.255.25516,382
10145.89.0.0/1845.89.0.1 to 45.89.63.25445.89.63.25516,382
10245.89.64.0/1845.89.64.1 to 45.89.127.25445.89.127.25516,382
10345.89.128.0/1845.89.128.1 to 45.89.191.25445.89.191.25516,382
10445.89.192.0/1845.89.192.1 to 45.89.255.25445.89.255.25516,382
10545.90.0.0/1845.90.0.1 to 45.90.63.25445.90.63.25516,382
10645.90.64.0/1845.90.64.1 to 45.90.127.25445.90.127.25516,382
10745.90.128.0/1845.90.128.1 to 45.90.191.25445.90.191.25516,382
10845.90.192.0/1845.90.192.1 to 45.90.255.25445.90.255.25516,382
10945.91.0.0/1845.91.0.1 to 45.91.63.25445.91.63.25516,382
11045.91.64.0/1845.91.64.1 to 45.91.127.25445.91.127.25516,382
11145.91.128.0/1845.91.128.1 to 45.91.191.25445.91.191.25516,382
11245.91.192.0/1845.91.192.1 to 45.91.255.25445.91.255.25516,382
11345.92.0.0/1845.92.0.1 to 45.92.63.25445.92.63.25516,382
11445.92.64.0/1845.92.64.1 to 45.92.127.25445.92.127.25516,382
11545.92.128.0/1845.92.128.1 to 45.92.191.25445.92.191.25516,382
11645.92.192.0/1845.92.192.1 to 45.92.255.25445.92.255.25516,382
11745.93.0.0/1845.93.0.1 to 45.93.63.25445.93.63.25516,382
11845.93.64.0/1845.93.64.1 to 45.93.127.25445.93.127.25516,382
11945.93.128.0/1845.93.128.1 to 45.93.191.25445.93.191.25516,382
12045.93.192.0/1845.93.192.1 to 45.93.255.25445.93.255.25516,382
12145.94.0.0/1845.94.0.1 to 45.94.63.25445.94.63.25516,382
12245.94.64.0/1845.94.64.1 to 45.94.127.25445.94.127.25516,382
12345.94.128.0/1845.94.128.1 to 45.94.191.25445.94.191.25516,382
12445.94.192.0/1845.94.192.1 to 45.94.255.25445.94.255.25516,382
12545.95.0.0/1845.95.0.1 to 45.95.63.25445.95.63.25516,382
12645.95.64.0/1845.95.64.1 to 45.95.127.25445.95.127.25516,382
12745.95.128.0/1845.95.128.1 to 45.95.191.25445.95.191.25516,382
12845.95.192.0/1845.95.192.1 to 45.95.255.25445.95.255.25516,382
12945.96.0.0/1845.96.0.1 to 45.96.63.25445.96.63.25516,382
13045.96.64.0/1845.96.64.1 to 45.96.127.25445.96.127.25516,382
13145.96.128.0/1845.96.128.1 to 45.96.191.25445.96.191.25516,382
13245.96.192.0/1845.96.192.1 to 45.96.255.25445.96.255.25516,382
13345.97.0.0/1845.97.0.1 to 45.97.63.25445.97.63.25516,382
13445.97.64.0/1845.97.64.1 to 45.97.127.25445.97.127.25516,382
13545.97.128.0/1845.97.128.1 to 45.97.191.25445.97.191.25516,382
13645.97.192.0/1845.97.192.1 to 45.97.255.25445.97.255.25516,382
13745.98.0.0/1845.98.0.1 to 45.98.63.25445.98.63.25516,382
13845.98.64.0/1845.98.64.1 to 45.98.127.25445.98.127.25516,382
13945.98.128.0/1845.98.128.1 to 45.98.191.25445.98.191.25516,382
14045.98.192.0/1845.98.192.1 to 45.98.255.25445.98.255.25516,382
14145.99.0.0/1845.99.0.1 to 45.99.63.25445.99.63.25516,382
14245.99.64.0/1845.99.64.1 to 45.99.127.25445.99.127.25516,382
14345.99.128.0/1845.99.128.1 to 45.99.191.25445.99.191.25516,382
14445.99.192.0/1845.99.192.1 to 45.99.255.25445.99.255.25516,382
14545.100.0.0/1845.100.0.1 to 45.100.63.25445.100.63.25516,382
14645.100.64.0/1845.100.64.1 to 45.100.127.25445.100.127.25516,382
14745.100.128.0/1845.100.128.1 to 45.100.191.25445.100.191.25516,382
14845.100.192.0/1845.100.192.1 to 45.100.255.25445.100.255.25516,382
14945.101.0.0/1845.101.0.1 to 45.101.63.25445.101.63.25516,382
15045.101.64.0/1845.101.64.1 to 45.101.127.25445.101.127.25516,382
15145.101.128.0/1845.101.128.1 to 45.101.191.25445.101.191.25516,382
15245.101.192.0/1845.101.192.1 to 45.101.255.25445.101.255.25516,382
15345.102.0.0/1845.102.0.1 to 45.102.63.25445.102.63.25516,382
15445.102.64.0/1845.102.64.1 to 45.102.127.25445.102.127.25516,382
15545.102.128.0/1845.102.128.1 to 45.102.191.25445.102.191.25516,382
15645.102.192.0/1845.102.192.1 to 45.102.255.25445.102.255.25516,382
15745.103.0.0/1845.103.0.1 to 45.103.63.25445.103.63.25516,382
15845.103.64.0/1845.103.64.1 to 45.103.127.25445.103.127.25516,382
15945.103.128.0/1845.103.128.1 to 45.103.191.25445.103.191.25516,382
16045.103.192.0/1845.103.192.1 to 45.103.255.25445.103.255.25516,382
16145.104.0.0/1845.104.0.1 to 45.104.63.25445.104.63.25516,382
16245.104.64.0/1845.104.64.1 to 45.104.127.25445.104.127.25516,382
16345.104.128.0/1845.104.128.1 to 45.104.191.25445.104.191.25516,382
16445.104.192.0/1845.104.192.1 to 45.104.255.25445.104.255.25516,382
16545.105.0.0/1845.105.0.1 to 45.105.63.25445.105.63.25516,382
16645.105.64.0/1845.105.64.1 to 45.105.127.25445.105.127.25516,382
16745.105.128.0/1845.105.128.1 to 45.105.191.25445.105.191.25516,382
16845.105.192.0/1845.105.192.1 to 45.105.255.25445.105.255.25516,382
16945.106.0.0/1845.106.0.1 to 45.106.63.25445.106.63.25516,382
17045.106.64.0/1845.106.64.1 to 45.106.127.25445.106.127.25516,382
17145.106.128.0/1845.106.128.1 to 45.106.191.25445.106.191.25516,382
17245.106.192.0/1845.106.192.1 to 45.106.255.25445.106.255.25516,382
17345.107.0.0/1845.107.0.1 to 45.107.63.25445.107.63.25516,382
17445.107.64.0/1845.107.64.1 to 45.107.127.25445.107.127.25516,382
17545.107.128.0/1845.107.128.1 to 45.107.191.25445.107.191.25516,382
17645.107.192.0/1845.107.192.1 to 45.107.255.25445.107.255.25516,382
17745.108.0.0/1845.108.0.1 to 45.108.63.25445.108.63.25516,382
17845.108.64.0/1845.108.64.1 to 45.108.127.25445.108.127.25516,382
17945.108.128.0/1845.108.128.1 to 45.108.191.25445.108.191.25516,382
18045.108.192.0/1845.108.192.1 to 45.108.255.25445.108.255.25516,382
18145.109.0.0/1845.109.0.1 to 45.109.63.25445.109.63.25516,382
18245.109.64.0/1845.109.64.1 to 45.109.127.25445.109.127.25516,382
18345.109.128.0/1845.109.128.1 to 45.109.191.25445.109.191.25516,382
18445.109.192.0/1845.109.192.1 to 45.109.255.25445.109.255.25516,382
18545.110.0.0/1845.110.0.1 to 45.110.63.25445.110.63.25516,382
18645.110.64.0/1845.110.64.1 to 45.110.127.25445.110.127.25516,382
18745.110.128.0/1845.110.128.1 to 45.110.191.25445.110.191.25516,382
18845.110.192.0/1845.110.192.1 to 45.110.255.25445.110.255.25516,382
18945.111.0.0/1845.111.0.1 to 45.111.63.25445.111.63.25516,382
19045.111.64.0/1845.111.64.1 to 45.111.127.25445.111.127.25516,382
19145.111.128.0/1845.111.128.1 to 45.111.191.25445.111.191.25516,382
19245.111.192.0/1845.111.192.1 to 45.111.255.25445.111.255.25516,382
19345.112.0.0/1845.112.0.1 to 45.112.63.25445.112.63.25516,382
19445.112.64.0/1845.112.64.1 to 45.112.127.25445.112.127.25516,382
19545.112.128.0/1845.112.128.1 to 45.112.191.25445.112.191.25516,382
19645.112.192.0/1845.112.192.1 to 45.112.255.25445.112.255.25516,382
19745.113.0.0/1845.113.0.1 to 45.113.63.25445.113.63.25516,382
19845.113.64.0/1845.113.64.1 to 45.113.127.25445.113.127.25516,382
19945.113.128.0/1845.113.128.1 to 45.113.191.25445.113.191.25516,382
20045.113.192.0/1845.113.192.1 to 45.113.255.25445.113.255.25516,382
20145.114.0.0/1845.114.0.1 to 45.114.63.25445.114.63.25516,382
20245.114.64.0/1845.114.64.1 to 45.114.127.25445.114.127.25516,382
20345.114.128.0/1845.114.128.1 to 45.114.191.25445.114.191.25516,382
20445.114.192.0/1845.114.192.1 to 45.114.255.25445.114.255.25516,382
20545.115.0.0/1845.115.0.1 to 45.115.63.25445.115.63.25516,382
20645.115.64.0/1845.115.64.1 to 45.115.127.25445.115.127.25516,382
20745.115.128.0/1845.115.128.1 to 45.115.191.25445.115.191.25516,382
20845.115.192.0/1845.115.192.1 to 45.115.255.25445.115.255.25516,382
20945.116.0.0/1845.116.0.1 to 45.116.63.25445.116.63.25516,382
21045.116.64.0/1845.116.64.1 to 45.116.127.25445.116.127.25516,382
21145.116.128.0/1845.116.128.1 to 45.116.191.25445.116.191.25516,382
21245.116.192.0/1845.116.192.1 to 45.116.255.25445.116.255.25516,382
21345.117.0.0/1845.117.0.1 to 45.117.63.25445.117.63.25516,382
21445.117.64.0/1845.117.64.1 to 45.117.127.25445.117.127.25516,382
21545.117.128.0/1845.117.128.1 to 45.117.191.25445.117.191.25516,382
21645.117.192.0/1845.117.192.1 to 45.117.255.25445.117.255.25516,382
21745.118.0.0/1845.118.0.1 to 45.118.63.25445.118.63.25516,382
21845.118.64.0/1845.118.64.1 to 45.118.127.25445.118.127.25516,382
21945.118.128.0/1845.118.128.1 to 45.118.191.25445.118.191.25516,382
22045.118.192.0/1845.118.192.1 to 45.118.255.25445.118.255.25516,382
22145.119.0.0/1845.119.0.1 to 45.119.63.25445.119.63.25516,382
22245.119.64.0/1845.119.64.1 to 45.119.127.25445.119.127.25516,382
22345.119.128.0/1845.119.128.1 to 45.119.191.25445.119.191.25516,382
22445.119.192.0/1845.119.192.1 to 45.119.255.25445.119.255.25516,382
22545.120.0.0/1845.120.0.1 to 45.120.63.25445.120.63.25516,382
22645.120.64.0/1845.120.64.1 to 45.120.127.25445.120.127.25516,382
22745.120.128.0/1845.120.128.1 to 45.120.191.25445.120.191.25516,382
22845.120.192.0/1845.120.192.1 to 45.120.255.25445.120.255.25516,382
22945.121.0.0/1845.121.0.1 to 45.121.63.25445.121.63.25516,382
23045.121.64.0/1845.121.64.1 to 45.121.127.25445.121.127.25516,382
23145.121.128.0/1845.121.128.1 to 45.121.191.25445.121.191.25516,382
23245.121.192.0/1845.121.192.1 to 45.121.255.25445.121.255.25516,382
23345.122.0.0/1845.122.0.1 to 45.122.63.25445.122.63.25516,382
23445.122.64.0/1845.122.64.1 to 45.122.127.25445.122.127.25516,382
23545.122.128.0/1845.122.128.1 to 45.122.191.25445.122.191.25516,382
23645.122.192.0/1845.122.192.1 to 45.122.255.25445.122.255.25516,382
23745.123.0.0/1845.123.0.1 to 45.123.63.25445.123.63.25516,382
23845.123.64.0/1845.123.64.1 to 45.123.127.25445.123.127.25516,382
23945.123.128.0/1845.123.128.1 to 45.123.191.25445.123.191.25516,382
24045.123.192.0/1845.123.192.1 to 45.123.255.25445.123.255.25516,382
24145.124.0.0/1845.124.0.1 to 45.124.63.25445.124.63.25516,382
24245.124.64.0/1845.124.64.1 to 45.124.127.25445.124.127.25516,382
24345.124.128.0/1845.124.128.1 to 45.124.191.25445.124.191.25516,382
24445.124.192.0/1845.124.192.1 to 45.124.255.25445.124.255.25516,382
24545.125.0.0/1845.125.0.1 to 45.125.63.25445.125.63.25516,382
24645.125.64.0/1845.125.64.1 to 45.125.127.25445.125.127.25516,382
24745.125.128.0/1845.125.128.1 to 45.125.191.25445.125.191.25516,382
24845.125.192.0/1845.125.192.1 to 45.125.255.25445.125.255.25516,382
24945.126.0.0/1845.126.0.1 to 45.126.63.25445.126.63.25516,382
25045.126.64.0/1845.126.64.1 to 45.126.127.25445.126.127.25516,382
25145.126.128.0/1845.126.128.1 to 45.126.191.25445.126.191.25516,382
25245.126.192.0/1845.126.192.1 to 45.126.255.25445.126.255.25516,382
25345.127.0.0/1845.127.0.1 to 45.127.63.25445.127.63.25516,382
25445.127.64.0/1845.127.64.1 to 45.127.127.25445.127.127.25516,382
25545.127.128.0/1845.127.128.1 to 45.127.191.25445.127.191.25516,382
25645.127.192.0/1845.127.192.1 to 45.127.255.25445.127.255.25516,382

IPv4 CIDR reference (/0 to /32)

IPv4 prefix lengths
PrefixSubnet maskWildcardAddressesUsable hostsSizeTypical use
/00.0.0.0255.255.255.2554,294,967,2964,294,967,29416,777,216 × /24
/1128.0.0.0127.255.255.2552,147,483,6482,147,483,6468,388,608 × /24
/2192.0.0.063.255.255.2551,073,741,8241,073,741,8224,194,304 × /24
/3224.0.0.031.255.255.255536,870,912536,870,9102,097,152 × /24
/4240.0.0.015.255.255.255268,435,456268,435,4541,048,576 × /24
/5248.0.0.07.255.255.255134,217,728134,217,726524,288 × /24
/6252.0.0.03.255.255.25567,108,86467,108,862262,144 × /24
/7254.0.0.01.255.255.25533,554,43233,554,430131,072 × /24
/8255.0.0.00.255.255.25516,777,21616,777,21465,536 × /24Old class A; 10.0.0.0/8
/9255.128.0.00.127.255.2558,388,6088,388,60632,768 × /24
/10255.192.0.00.63.255.2554,194,3044,194,30216,384 × /24
/11255.224.0.00.31.255.2552,097,1522,097,1508,192 × /24
/12255.240.0.00.15.255.2551,048,5761,048,5744,096 × /24172.16.0.0/12
/13255.248.0.00.7.255.255524,288524,2862,048 × /24
/14255.252.0.00.3.255.255262,144262,1421,024 × /24
/15255.254.0.00.1.255.255131,072131,070512 × /24
/16255.255.0.00.0.255.25565,53665,534256 × /24Old class B; 192.168.0.0/16
/17255.255.128.00.0.127.25532,76832,766128 × /24
/18255.255.192.00.0.63.25516,38416,38264 × /24
/19255.255.224.00.0.31.2558,1928,19032 × /24
/20255.255.240.00.0.15.2554,0964,09416 × /24
/21255.255.248.00.0.7.2552,0482,0468 × /24
/22255.255.252.00.0.3.2551,0241,0224 × /24Large office or guest Wi-Fi (1,022 hosts)
/23255.255.254.00.0.1.2555125102 × /24Larger office LAN (510 hosts)
/24255.255.255.00.0.0.2552562541 × /24Typical office LAN (old class C)
/25255.255.255.1280.0.0.1271281261/2 of a /24Smaller LAN or VLAN
/26255.255.255.1920.0.0.6364621/4 of a /24Smaller LAN or VLAN
/27255.255.255.2240.0.0.3132301/8 of a /24Small VLAN, phones, cameras
/28255.255.255.2400.0.0.1516141/16 of a /24Small VLAN, phones, cameras
/29255.255.255.2480.0.0.7861/32 of a /24Small fixed public block (5 usable)
/30255.255.255.2520.0.0.3421/64 of a /24Point-to-point (old style)
/31255.255.255.2540.0.0.1221/128 of a /24Point-to-point link (RFC 3021)
/32255.255.255.2550.0.0.0111/256 of a /24One host

IPv6 prefix reference

IPv6 prefix lengths
PrefixAddresses/64 LANs/48 sitesNibbleTypical use
/342,535,295,865,117,307,932,921,825,928,971,026,432 (2^125)2,305,843,009,213,693,95235,184,372,088,832NoAll global unicast (2000::/3)
/165,192,296,858,534,827,628,530,496,329,220,096 (2^112)281,474,976,710,6564,294,967,296Yes
/20324,518,553,658,426,726,783,156,020,576,256 (2^108)17,592,186,044,416268,435,456YesLarge provider allocation (RIPE minimum for some)
/29633,825,300,114,114,700,748,351,602,688 (2^99)34,359,738,368524,288NoRIPE allocation to a provider (often)
/3279,228,162,514,264,337,593,543,950,336 (2^96)4,294,967,29665,536YesProvider allocation (RIPE default)
/364,951,760,157,141,521,099,596,496,896 (2^92)268,435,4564,096Yes
/40309,485,009,821,345,068,724,781,056 (2^88)16,777,216256Yes
/4419,342,813,113,834,066,795,298,816 (2^84)1,048,57616Yes
/481,208,925,819,614,629,174,706,176 (2^80)65,5361YesOne site or organisation (RIPE PI / assignment)
/5275,557,863,725,914,323,419,136 (2^76)4,096Yes
/564,722,366,482,869,645,213,696 (2^72)256YesSmall site or home (common provider assignment)
/60295,147,905,179,352,825,856 (2^68)16YesSome home broadband (16 LANs)
/6418,446,744,073,709,551,616 (2^64)1YesOne LAN or VLAN (needed for SLAAC)
/7272,057,594,037,927,936 (2^56)1/256 of a /64Yes
/80281,474,976,710,656 (2^48)1/65,536 of a /64Yes
/964,294,967,2961/4,294,967,296 of a /64YesEmbeds an IPv4 address (NAT64)
/11265,5361/281,474,976,710,656 of a /64Yes
/1202561/72,057,594,037,927,936 of a /64Yes
/124161/1,152,921,504,606,846,976 of a /64Yes
/12641/4,611,686,018,427,387,904 of a /64No
/12721/9,223,372,036,854,775,808 of a /64NoPoint-to-point link (RFC 6164)
/12811/18,446,744,073,709,551,616 of a /64YesOne host or loopback

Private and special ranges

IPv4

Special-purpose ranges
RangeNameWhat it is
255.255.255.255/32Limited broadcastEvery host on the local network
0.0.0.0/8This networkNot routed; 0.0.0.0 means "any address" in settings
10.0.0.0/8Private (RFC 1918)Office and home networks; not routed on the internet
100.64.0.0/10Shared address space (CGNAT)Used by providers behind carrier-grade NAT (RFC 6598)
127.0.0.0/8LoopbackThis computer
169.254.0.0/16Link-local (APIPA)Self-assigned when no DHCP server answers
172.16.0.0/12Private (RFC 1918)Office and home networks; not routed on the internet
192.0.0.0/24IETF protocol assignmentsSpecial uses such as DS-Lite
192.0.2.0/24Documentation (TEST-NET-1)For examples; never used on a network
192.88.99.0/246to4 relay (deprecated)Formerly anycast for 6to4
192.168.0.0/16Private (RFC 1918)Office and home networks; not routed on the internet
198.18.0.0/15BenchmarkingNetwork equipment testing (RFC 2544)
198.51.100.0/24Documentation (TEST-NET-2)For examples; never used on a network
203.0.113.0/24Documentation (TEST-NET-3)For examples; never used on a network
224.0.0.0/4MulticastOne-to-many traffic, such as IPTV and routing protocols
240.0.0.0/4ReservedFuture use; not usable on most systems

IPv6

Special-purpose ranges
RangeNameWhat it is
::/128UnspecifiedNo address; :: means "any address" in settings
::1/128LoopbackThis computer
::ffff:0:0/96IPv4-mappedAn IPv4 address written as IPv6
64:ff9b::/96NAT64IPv4 addresses reached through a NAT64 gateway
100::/64Discard onlyTraffic sent here is dropped (RFC 6666)
2001:db8::/32DocumentationFor examples; never used on a network
2001::/32TeredoIPv6 tunnelled over IPv4 UDP
2002::/166to4IPv6 tunnelled over IPv4 (largely retired)
3fff::/20DocumentationFor examples (RFC 9637)
fc00::/7Unique local (ULA)Private IPv6, like RFC 1918; usually fd00::/8
fe80::/10Link-localEvery IPv6 interface has one; not routed
ff00::/8MulticastOne-to-many traffic; replaces broadcast
2000::/3Global unicastPublic internet addresses

About this tool

A network is written as an address and a prefix length, such as 192.168.1.0/24: the first 24 bits name the network and the rest number the devices on it. The calculator works out where the network starts and ends, how many devices it holds, its subnet and wildcard masks, and the reverse DNS zone to ask your provider for.

It also splits a network into equal smaller ones (one per VLAN or site), turns a range of addresses into the fewest CIDR blocks for a firewall rule, and lists every IPv4 prefix length and the common IPv6 ones in reference tables.

Common questions

Why are two addresses lost in every IPv4 subnet?

The first address names the network and the last is the broadcast address, so a /24 has 256 addresses but 254 for devices. A /31 (a link between two routers) and a /32 (one host) are the exceptions.

What size of IPv6 network should a LAN use?

Always /64. Devices pick their own address within it (SLAAC), which needs the full 64 bits. A site usually gets a /48 or /56 from its provider, which holds 65,536 or 256 LANs.

What is a wildcard mask?

The subnet mask turned inside out: 255.255.255.0 becomes 0.0.0.255. Cisco access lists and OSPF use it to say which bits must match.

Which ranges can I use inside an office?

IPv4: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. IPv6: unique local addresses from fd00::/8, though most networks use the public prefix from their provider.