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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.

Network44.64.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
44.64.0.0
Broadcast address
44.127.255.255
First usable
44.64.0.1
Last usable
44.127.255.254
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 2C400000 · Integer 742391808 to 746586111
Reverse DNS zones
64.44.in-addr.arpa
65.44.in-addr.arpa
66.44.in-addr.arpa
67.44.in-addr.arpa
68.44.in-addr.arpa
69.44.in-addr.arpa
70.44.in-addr.arpa
71.44.in-addr.arpa
72.44.in-addr.arpa
73.44.in-addr.arpa
74.44.in-addr.arpa
75.44.in-addr.arpa
76.44.in-addr.arpa
77.44.in-addr.arpa
78.44.in-addr.arpa
79.44.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
Address00101100.01000000.00000000.0000000044.64.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network00101100.01000000.00000000.0000000044.64.0.0
Broadcast00101100.01111111.11111111.1111111144.127.255.255
Split into smaller subnets/20
/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)

44.64.0.0/10 makes 1,024 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
144.64.0.0/2044.64.0.1 to 44.64.15.25444.64.15.2554,094
244.64.16.0/2044.64.16.1 to 44.64.31.25444.64.31.2554,094
344.64.32.0/2044.64.32.1 to 44.64.47.25444.64.47.2554,094
444.64.48.0/2044.64.48.1 to 44.64.63.25444.64.63.2554,094
544.64.64.0/2044.64.64.1 to 44.64.79.25444.64.79.2554,094
644.64.80.0/2044.64.80.1 to 44.64.95.25444.64.95.2554,094
744.64.96.0/2044.64.96.1 to 44.64.111.25444.64.111.2554,094
844.64.112.0/2044.64.112.1 to 44.64.127.25444.64.127.2554,094
944.64.128.0/2044.64.128.1 to 44.64.143.25444.64.143.2554,094
1044.64.144.0/2044.64.144.1 to 44.64.159.25444.64.159.2554,094
1144.64.160.0/2044.64.160.1 to 44.64.175.25444.64.175.2554,094
1244.64.176.0/2044.64.176.1 to 44.64.191.25444.64.191.2554,094
1344.64.192.0/2044.64.192.1 to 44.64.207.25444.64.207.2554,094
1444.64.208.0/2044.64.208.1 to 44.64.223.25444.64.223.2554,094
1544.64.224.0/2044.64.224.1 to 44.64.239.25444.64.239.2554,094
1644.64.240.0/2044.64.240.1 to 44.64.255.25444.64.255.2554,094
1744.65.0.0/2044.65.0.1 to 44.65.15.25444.65.15.2554,094
1844.65.16.0/2044.65.16.1 to 44.65.31.25444.65.31.2554,094
1944.65.32.0/2044.65.32.1 to 44.65.47.25444.65.47.2554,094
2044.65.48.0/2044.65.48.1 to 44.65.63.25444.65.63.2554,094
2144.65.64.0/2044.65.64.1 to 44.65.79.25444.65.79.2554,094
2244.65.80.0/2044.65.80.1 to 44.65.95.25444.65.95.2554,094
2344.65.96.0/2044.65.96.1 to 44.65.111.25444.65.111.2554,094
2444.65.112.0/2044.65.112.1 to 44.65.127.25444.65.127.2554,094
2544.65.128.0/2044.65.128.1 to 44.65.143.25444.65.143.2554,094
2644.65.144.0/2044.65.144.1 to 44.65.159.25444.65.159.2554,094
2744.65.160.0/2044.65.160.1 to 44.65.175.25444.65.175.2554,094
2844.65.176.0/2044.65.176.1 to 44.65.191.25444.65.191.2554,094
2944.65.192.0/2044.65.192.1 to 44.65.207.25444.65.207.2554,094
3044.65.208.0/2044.65.208.1 to 44.65.223.25444.65.223.2554,094
3144.65.224.0/2044.65.224.1 to 44.65.239.25444.65.239.2554,094
3244.65.240.0/2044.65.240.1 to 44.65.255.25444.65.255.2554,094
3344.66.0.0/2044.66.0.1 to 44.66.15.25444.66.15.2554,094
3444.66.16.0/2044.66.16.1 to 44.66.31.25444.66.31.2554,094
3544.66.32.0/2044.66.32.1 to 44.66.47.25444.66.47.2554,094
3644.66.48.0/2044.66.48.1 to 44.66.63.25444.66.63.2554,094
3744.66.64.0/2044.66.64.1 to 44.66.79.25444.66.79.2554,094
3844.66.80.0/2044.66.80.1 to 44.66.95.25444.66.95.2554,094
3944.66.96.0/2044.66.96.1 to 44.66.111.25444.66.111.2554,094
4044.66.112.0/2044.66.112.1 to 44.66.127.25444.66.127.2554,094
4144.66.128.0/2044.66.128.1 to 44.66.143.25444.66.143.2554,094
4244.66.144.0/2044.66.144.1 to 44.66.159.25444.66.159.2554,094
4344.66.160.0/2044.66.160.1 to 44.66.175.25444.66.175.2554,094
4444.66.176.0/2044.66.176.1 to 44.66.191.25444.66.191.2554,094
4544.66.192.0/2044.66.192.1 to 44.66.207.25444.66.207.2554,094
4644.66.208.0/2044.66.208.1 to 44.66.223.25444.66.223.2554,094
4744.66.224.0/2044.66.224.1 to 44.66.239.25444.66.239.2554,094
4844.66.240.0/2044.66.240.1 to 44.66.255.25444.66.255.2554,094
4944.67.0.0/2044.67.0.1 to 44.67.15.25444.67.15.2554,094
5044.67.16.0/2044.67.16.1 to 44.67.31.25444.67.31.2554,094
5144.67.32.0/2044.67.32.1 to 44.67.47.25444.67.47.2554,094
5244.67.48.0/2044.67.48.1 to 44.67.63.25444.67.63.2554,094
5344.67.64.0/2044.67.64.1 to 44.67.79.25444.67.79.2554,094
5444.67.80.0/2044.67.80.1 to 44.67.95.25444.67.95.2554,094
5544.67.96.0/2044.67.96.1 to 44.67.111.25444.67.111.2554,094
5644.67.112.0/2044.67.112.1 to 44.67.127.25444.67.127.2554,094
5744.67.128.0/2044.67.128.1 to 44.67.143.25444.67.143.2554,094
5844.67.144.0/2044.67.144.1 to 44.67.159.25444.67.159.2554,094
5944.67.160.0/2044.67.160.1 to 44.67.175.25444.67.175.2554,094
6044.67.176.0/2044.67.176.1 to 44.67.191.25444.67.191.2554,094
6144.67.192.0/2044.67.192.1 to 44.67.207.25444.67.207.2554,094
6244.67.208.0/2044.67.208.1 to 44.67.223.25444.67.223.2554,094
6344.67.224.0/2044.67.224.1 to 44.67.239.25444.67.239.2554,094
6444.67.240.0/2044.67.240.1 to 44.67.255.25444.67.255.2554,094
6544.68.0.0/2044.68.0.1 to 44.68.15.25444.68.15.2554,094
6644.68.16.0/2044.68.16.1 to 44.68.31.25444.68.31.2554,094
6744.68.32.0/2044.68.32.1 to 44.68.47.25444.68.47.2554,094
6844.68.48.0/2044.68.48.1 to 44.68.63.25444.68.63.2554,094
6944.68.64.0/2044.68.64.1 to 44.68.79.25444.68.79.2554,094
7044.68.80.0/2044.68.80.1 to 44.68.95.25444.68.95.2554,094
7144.68.96.0/2044.68.96.1 to 44.68.111.25444.68.111.2554,094
7244.68.112.0/2044.68.112.1 to 44.68.127.25444.68.127.2554,094
7344.68.128.0/2044.68.128.1 to 44.68.143.25444.68.143.2554,094
7444.68.144.0/2044.68.144.1 to 44.68.159.25444.68.159.2554,094
7544.68.160.0/2044.68.160.1 to 44.68.175.25444.68.175.2554,094
7644.68.176.0/2044.68.176.1 to 44.68.191.25444.68.191.2554,094
7744.68.192.0/2044.68.192.1 to 44.68.207.25444.68.207.2554,094
7844.68.208.0/2044.68.208.1 to 44.68.223.25444.68.223.2554,094
7944.68.224.0/2044.68.224.1 to 44.68.239.25444.68.239.2554,094
8044.68.240.0/2044.68.240.1 to 44.68.255.25444.68.255.2554,094
8144.69.0.0/2044.69.0.1 to 44.69.15.25444.69.15.2554,094
8244.69.16.0/2044.69.16.1 to 44.69.31.25444.69.31.2554,094
8344.69.32.0/2044.69.32.1 to 44.69.47.25444.69.47.2554,094
8444.69.48.0/2044.69.48.1 to 44.69.63.25444.69.63.2554,094
8544.69.64.0/2044.69.64.1 to 44.69.79.25444.69.79.2554,094
8644.69.80.0/2044.69.80.1 to 44.69.95.25444.69.95.2554,094
8744.69.96.0/2044.69.96.1 to 44.69.111.25444.69.111.2554,094
8844.69.112.0/2044.69.112.1 to 44.69.127.25444.69.127.2554,094
8944.69.128.0/2044.69.128.1 to 44.69.143.25444.69.143.2554,094
9044.69.144.0/2044.69.144.1 to 44.69.159.25444.69.159.2554,094
9144.69.160.0/2044.69.160.1 to 44.69.175.25444.69.175.2554,094
9244.69.176.0/2044.69.176.1 to 44.69.191.25444.69.191.2554,094
9344.69.192.0/2044.69.192.1 to 44.69.207.25444.69.207.2554,094
9444.69.208.0/2044.69.208.1 to 44.69.223.25444.69.223.2554,094
9544.69.224.0/2044.69.224.1 to 44.69.239.25444.69.239.2554,094
9644.69.240.0/2044.69.240.1 to 44.69.255.25444.69.255.2554,094
9744.70.0.0/2044.70.0.1 to 44.70.15.25444.70.15.2554,094
9844.70.16.0/2044.70.16.1 to 44.70.31.25444.70.31.2554,094
9944.70.32.0/2044.70.32.1 to 44.70.47.25444.70.47.2554,094
10044.70.48.0/2044.70.48.1 to 44.70.63.25444.70.63.2554,094
10144.70.64.0/2044.70.64.1 to 44.70.79.25444.70.79.2554,094
10244.70.80.0/2044.70.80.1 to 44.70.95.25444.70.95.2554,094
10344.70.96.0/2044.70.96.1 to 44.70.111.25444.70.111.2554,094
10444.70.112.0/2044.70.112.1 to 44.70.127.25444.70.127.2554,094
10544.70.128.0/2044.70.128.1 to 44.70.143.25444.70.143.2554,094
10644.70.144.0/2044.70.144.1 to 44.70.159.25444.70.159.2554,094
10744.70.160.0/2044.70.160.1 to 44.70.175.25444.70.175.2554,094
10844.70.176.0/2044.70.176.1 to 44.70.191.25444.70.191.2554,094
10944.70.192.0/2044.70.192.1 to 44.70.207.25444.70.207.2554,094
11044.70.208.0/2044.70.208.1 to 44.70.223.25444.70.223.2554,094
11144.70.224.0/2044.70.224.1 to 44.70.239.25444.70.239.2554,094
11244.70.240.0/2044.70.240.1 to 44.70.255.25444.70.255.2554,094
11344.71.0.0/2044.71.0.1 to 44.71.15.25444.71.15.2554,094
11444.71.16.0/2044.71.16.1 to 44.71.31.25444.71.31.2554,094
11544.71.32.0/2044.71.32.1 to 44.71.47.25444.71.47.2554,094
11644.71.48.0/2044.71.48.1 to 44.71.63.25444.71.63.2554,094
11744.71.64.0/2044.71.64.1 to 44.71.79.25444.71.79.2554,094
11844.71.80.0/2044.71.80.1 to 44.71.95.25444.71.95.2554,094
11944.71.96.0/2044.71.96.1 to 44.71.111.25444.71.111.2554,094
12044.71.112.0/2044.71.112.1 to 44.71.127.25444.71.127.2554,094
12144.71.128.0/2044.71.128.1 to 44.71.143.25444.71.143.2554,094
12244.71.144.0/2044.71.144.1 to 44.71.159.25444.71.159.2554,094
12344.71.160.0/2044.71.160.1 to 44.71.175.25444.71.175.2554,094
12444.71.176.0/2044.71.176.1 to 44.71.191.25444.71.191.2554,094
12544.71.192.0/2044.71.192.1 to 44.71.207.25444.71.207.2554,094
12644.71.208.0/2044.71.208.1 to 44.71.223.25444.71.223.2554,094
12744.71.224.0/2044.71.224.1 to 44.71.239.25444.71.239.2554,094
12844.71.240.0/2044.71.240.1 to 44.71.255.25444.71.255.2554,094
12944.72.0.0/2044.72.0.1 to 44.72.15.25444.72.15.2554,094
13044.72.16.0/2044.72.16.1 to 44.72.31.25444.72.31.2554,094
13144.72.32.0/2044.72.32.1 to 44.72.47.25444.72.47.2554,094
13244.72.48.0/2044.72.48.1 to 44.72.63.25444.72.63.2554,094
13344.72.64.0/2044.72.64.1 to 44.72.79.25444.72.79.2554,094
13444.72.80.0/2044.72.80.1 to 44.72.95.25444.72.95.2554,094
13544.72.96.0/2044.72.96.1 to 44.72.111.25444.72.111.2554,094
13644.72.112.0/2044.72.112.1 to 44.72.127.25444.72.127.2554,094
13744.72.128.0/2044.72.128.1 to 44.72.143.25444.72.143.2554,094
13844.72.144.0/2044.72.144.1 to 44.72.159.25444.72.159.2554,094
13944.72.160.0/2044.72.160.1 to 44.72.175.25444.72.175.2554,094
14044.72.176.0/2044.72.176.1 to 44.72.191.25444.72.191.2554,094
14144.72.192.0/2044.72.192.1 to 44.72.207.25444.72.207.2554,094
14244.72.208.0/2044.72.208.1 to 44.72.223.25444.72.223.2554,094
14344.72.224.0/2044.72.224.1 to 44.72.239.25444.72.239.2554,094
14444.72.240.0/2044.72.240.1 to 44.72.255.25444.72.255.2554,094
14544.73.0.0/2044.73.0.1 to 44.73.15.25444.73.15.2554,094
14644.73.16.0/2044.73.16.1 to 44.73.31.25444.73.31.2554,094
14744.73.32.0/2044.73.32.1 to 44.73.47.25444.73.47.2554,094
14844.73.48.0/2044.73.48.1 to 44.73.63.25444.73.63.2554,094
14944.73.64.0/2044.73.64.1 to 44.73.79.25444.73.79.2554,094
15044.73.80.0/2044.73.80.1 to 44.73.95.25444.73.95.2554,094
15144.73.96.0/2044.73.96.1 to 44.73.111.25444.73.111.2554,094
15244.73.112.0/2044.73.112.1 to 44.73.127.25444.73.127.2554,094
15344.73.128.0/2044.73.128.1 to 44.73.143.25444.73.143.2554,094
15444.73.144.0/2044.73.144.1 to 44.73.159.25444.73.159.2554,094
15544.73.160.0/2044.73.160.1 to 44.73.175.25444.73.175.2554,094
15644.73.176.0/2044.73.176.1 to 44.73.191.25444.73.191.2554,094
15744.73.192.0/2044.73.192.1 to 44.73.207.25444.73.207.2554,094
15844.73.208.0/2044.73.208.1 to 44.73.223.25444.73.223.2554,094
15944.73.224.0/2044.73.224.1 to 44.73.239.25444.73.239.2554,094
16044.73.240.0/2044.73.240.1 to 44.73.255.25444.73.255.2554,094
16144.74.0.0/2044.74.0.1 to 44.74.15.25444.74.15.2554,094
16244.74.16.0/2044.74.16.1 to 44.74.31.25444.74.31.2554,094
16344.74.32.0/2044.74.32.1 to 44.74.47.25444.74.47.2554,094
16444.74.48.0/2044.74.48.1 to 44.74.63.25444.74.63.2554,094
16544.74.64.0/2044.74.64.1 to 44.74.79.25444.74.79.2554,094
16644.74.80.0/2044.74.80.1 to 44.74.95.25444.74.95.2554,094
16744.74.96.0/2044.74.96.1 to 44.74.111.25444.74.111.2554,094
16844.74.112.0/2044.74.112.1 to 44.74.127.25444.74.127.2554,094
16944.74.128.0/2044.74.128.1 to 44.74.143.25444.74.143.2554,094
17044.74.144.0/2044.74.144.1 to 44.74.159.25444.74.159.2554,094
17144.74.160.0/2044.74.160.1 to 44.74.175.25444.74.175.2554,094
17244.74.176.0/2044.74.176.1 to 44.74.191.25444.74.191.2554,094
17344.74.192.0/2044.74.192.1 to 44.74.207.25444.74.207.2554,094
17444.74.208.0/2044.74.208.1 to 44.74.223.25444.74.223.2554,094
17544.74.224.0/2044.74.224.1 to 44.74.239.25444.74.239.2554,094
17644.74.240.0/2044.74.240.1 to 44.74.255.25444.74.255.2554,094
17744.75.0.0/2044.75.0.1 to 44.75.15.25444.75.15.2554,094
17844.75.16.0/2044.75.16.1 to 44.75.31.25444.75.31.2554,094
17944.75.32.0/2044.75.32.1 to 44.75.47.25444.75.47.2554,094
18044.75.48.0/2044.75.48.1 to 44.75.63.25444.75.63.2554,094
18144.75.64.0/2044.75.64.1 to 44.75.79.25444.75.79.2554,094
18244.75.80.0/2044.75.80.1 to 44.75.95.25444.75.95.2554,094
18344.75.96.0/2044.75.96.1 to 44.75.111.25444.75.111.2554,094
18444.75.112.0/2044.75.112.1 to 44.75.127.25444.75.127.2554,094
18544.75.128.0/2044.75.128.1 to 44.75.143.25444.75.143.2554,094
18644.75.144.0/2044.75.144.1 to 44.75.159.25444.75.159.2554,094
18744.75.160.0/2044.75.160.1 to 44.75.175.25444.75.175.2554,094
18844.75.176.0/2044.75.176.1 to 44.75.191.25444.75.191.2554,094
18944.75.192.0/2044.75.192.1 to 44.75.207.25444.75.207.2554,094
19044.75.208.0/2044.75.208.1 to 44.75.223.25444.75.223.2554,094
19144.75.224.0/2044.75.224.1 to 44.75.239.25444.75.239.2554,094
19244.75.240.0/2044.75.240.1 to 44.75.255.25444.75.255.2554,094
19344.76.0.0/2044.76.0.1 to 44.76.15.25444.76.15.2554,094
19444.76.16.0/2044.76.16.1 to 44.76.31.25444.76.31.2554,094
19544.76.32.0/2044.76.32.1 to 44.76.47.25444.76.47.2554,094
19644.76.48.0/2044.76.48.1 to 44.76.63.25444.76.63.2554,094
19744.76.64.0/2044.76.64.1 to 44.76.79.25444.76.79.2554,094
19844.76.80.0/2044.76.80.1 to 44.76.95.25444.76.95.2554,094
19944.76.96.0/2044.76.96.1 to 44.76.111.25444.76.111.2554,094
20044.76.112.0/2044.76.112.1 to 44.76.127.25444.76.127.2554,094
20144.76.128.0/2044.76.128.1 to 44.76.143.25444.76.143.2554,094
20244.76.144.0/2044.76.144.1 to 44.76.159.25444.76.159.2554,094
20344.76.160.0/2044.76.160.1 to 44.76.175.25444.76.175.2554,094
20444.76.176.0/2044.76.176.1 to 44.76.191.25444.76.191.2554,094
20544.76.192.0/2044.76.192.1 to 44.76.207.25444.76.207.2554,094
20644.76.208.0/2044.76.208.1 to 44.76.223.25444.76.223.2554,094
20744.76.224.0/2044.76.224.1 to 44.76.239.25444.76.239.2554,094
20844.76.240.0/2044.76.240.1 to 44.76.255.25444.76.255.2554,094
20944.77.0.0/2044.77.0.1 to 44.77.15.25444.77.15.2554,094
21044.77.16.0/2044.77.16.1 to 44.77.31.25444.77.31.2554,094
21144.77.32.0/2044.77.32.1 to 44.77.47.25444.77.47.2554,094
21244.77.48.0/2044.77.48.1 to 44.77.63.25444.77.63.2554,094
21344.77.64.0/2044.77.64.1 to 44.77.79.25444.77.79.2554,094
21444.77.80.0/2044.77.80.1 to 44.77.95.25444.77.95.2554,094
21544.77.96.0/2044.77.96.1 to 44.77.111.25444.77.111.2554,094
21644.77.112.0/2044.77.112.1 to 44.77.127.25444.77.127.2554,094
21744.77.128.0/2044.77.128.1 to 44.77.143.25444.77.143.2554,094
21844.77.144.0/2044.77.144.1 to 44.77.159.25444.77.159.2554,094
21944.77.160.0/2044.77.160.1 to 44.77.175.25444.77.175.2554,094
22044.77.176.0/2044.77.176.1 to 44.77.191.25444.77.191.2554,094
22144.77.192.0/2044.77.192.1 to 44.77.207.25444.77.207.2554,094
22244.77.208.0/2044.77.208.1 to 44.77.223.25444.77.223.2554,094
22344.77.224.0/2044.77.224.1 to 44.77.239.25444.77.239.2554,094
22444.77.240.0/2044.77.240.1 to 44.77.255.25444.77.255.2554,094
22544.78.0.0/2044.78.0.1 to 44.78.15.25444.78.15.2554,094
22644.78.16.0/2044.78.16.1 to 44.78.31.25444.78.31.2554,094
22744.78.32.0/2044.78.32.1 to 44.78.47.25444.78.47.2554,094
22844.78.48.0/2044.78.48.1 to 44.78.63.25444.78.63.2554,094
22944.78.64.0/2044.78.64.1 to 44.78.79.25444.78.79.2554,094
23044.78.80.0/2044.78.80.1 to 44.78.95.25444.78.95.2554,094
23144.78.96.0/2044.78.96.1 to 44.78.111.25444.78.111.2554,094
23244.78.112.0/2044.78.112.1 to 44.78.127.25444.78.127.2554,094
23344.78.128.0/2044.78.128.1 to 44.78.143.25444.78.143.2554,094
23444.78.144.0/2044.78.144.1 to 44.78.159.25444.78.159.2554,094
23544.78.160.0/2044.78.160.1 to 44.78.175.25444.78.175.2554,094
23644.78.176.0/2044.78.176.1 to 44.78.191.25444.78.191.2554,094
23744.78.192.0/2044.78.192.1 to 44.78.207.25444.78.207.2554,094
23844.78.208.0/2044.78.208.1 to 44.78.223.25444.78.223.2554,094
23944.78.224.0/2044.78.224.1 to 44.78.239.25444.78.239.2554,094
24044.78.240.0/2044.78.240.1 to 44.78.255.25444.78.255.2554,094
24144.79.0.0/2044.79.0.1 to 44.79.15.25444.79.15.2554,094
24244.79.16.0/2044.79.16.1 to 44.79.31.25444.79.31.2554,094
24344.79.32.0/2044.79.32.1 to 44.79.47.25444.79.47.2554,094
24444.79.48.0/2044.79.48.1 to 44.79.63.25444.79.63.2554,094
24544.79.64.0/2044.79.64.1 to 44.79.79.25444.79.79.2554,094
24644.79.80.0/2044.79.80.1 to 44.79.95.25444.79.95.2554,094
24744.79.96.0/2044.79.96.1 to 44.79.111.25444.79.111.2554,094
24844.79.112.0/2044.79.112.1 to 44.79.127.25444.79.127.2554,094
24944.79.128.0/2044.79.128.1 to 44.79.143.25444.79.143.2554,094
25044.79.144.0/2044.79.144.1 to 44.79.159.25444.79.159.2554,094
25144.79.160.0/2044.79.160.1 to 44.79.175.25444.79.175.2554,094
25244.79.176.0/2044.79.176.1 to 44.79.191.25444.79.191.2554,094
25344.79.192.0/2044.79.192.1 to 44.79.207.25444.79.207.2554,094
25444.79.208.0/2044.79.208.1 to 44.79.223.25444.79.223.2554,094
25544.79.224.0/2044.79.224.1 to 44.79.239.25444.79.239.2554,094
25644.79.240.0/2044.79.240.1 to 44.79.255.25444.79.255.2554,094

IPv4 CIDR reference (/0 to /32)

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

IPv6 prefix reference

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

Private and special ranges

IPv4

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

IPv6

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

About this tool

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

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

Common questions

Why are two addresses lost in every IPv4 subnet?

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

What size of IPv6 network should a LAN use?

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

What is a wildcard mask?

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

Which ranges can I use inside an office?

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