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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.

Network41.64.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
41.64.0.0
Broadcast address
41.127.255.255
First usable
41.64.0.1
Last usable
41.127.255.254
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 29400000 · Integer 692060160 to 696254463
Reverse DNS zones
64.41.in-addr.arpa
65.41.in-addr.arpa
66.41.in-addr.arpa
67.41.in-addr.arpa
68.41.in-addr.arpa
69.41.in-addr.arpa
70.41.in-addr.arpa
71.41.in-addr.arpa
72.41.in-addr.arpa
73.41.in-addr.arpa
74.41.in-addr.arpa
75.41.in-addr.arpa
76.41.in-addr.arpa
77.41.in-addr.arpa
78.41.in-addr.arpa
79.41.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
Address00101001.01000000.00000000.0000000041.64.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network00101001.01000000.00000000.0000000041.64.0.0
Broadcast00101001.01111111.11111111.1111111141.127.255.255
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)

41.64.0.0/10 makes 1,024 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
141.64.0.0/2041.64.0.1 to 41.64.15.25441.64.15.2554,094
241.64.16.0/2041.64.16.1 to 41.64.31.25441.64.31.2554,094
341.64.32.0/2041.64.32.1 to 41.64.47.25441.64.47.2554,094
441.64.48.0/2041.64.48.1 to 41.64.63.25441.64.63.2554,094
541.64.64.0/2041.64.64.1 to 41.64.79.25441.64.79.2554,094
641.64.80.0/2041.64.80.1 to 41.64.95.25441.64.95.2554,094
741.64.96.0/2041.64.96.1 to 41.64.111.25441.64.111.2554,094
841.64.112.0/2041.64.112.1 to 41.64.127.25441.64.127.2554,094
941.64.128.0/2041.64.128.1 to 41.64.143.25441.64.143.2554,094
1041.64.144.0/2041.64.144.1 to 41.64.159.25441.64.159.2554,094
1141.64.160.0/2041.64.160.1 to 41.64.175.25441.64.175.2554,094
1241.64.176.0/2041.64.176.1 to 41.64.191.25441.64.191.2554,094
1341.64.192.0/2041.64.192.1 to 41.64.207.25441.64.207.2554,094
1441.64.208.0/2041.64.208.1 to 41.64.223.25441.64.223.2554,094
1541.64.224.0/2041.64.224.1 to 41.64.239.25441.64.239.2554,094
1641.64.240.0/2041.64.240.1 to 41.64.255.25441.64.255.2554,094
1741.65.0.0/2041.65.0.1 to 41.65.15.25441.65.15.2554,094
1841.65.16.0/2041.65.16.1 to 41.65.31.25441.65.31.2554,094
1941.65.32.0/2041.65.32.1 to 41.65.47.25441.65.47.2554,094
2041.65.48.0/2041.65.48.1 to 41.65.63.25441.65.63.2554,094
2141.65.64.0/2041.65.64.1 to 41.65.79.25441.65.79.2554,094
2241.65.80.0/2041.65.80.1 to 41.65.95.25441.65.95.2554,094
2341.65.96.0/2041.65.96.1 to 41.65.111.25441.65.111.2554,094
2441.65.112.0/2041.65.112.1 to 41.65.127.25441.65.127.2554,094
2541.65.128.0/2041.65.128.1 to 41.65.143.25441.65.143.2554,094
2641.65.144.0/2041.65.144.1 to 41.65.159.25441.65.159.2554,094
2741.65.160.0/2041.65.160.1 to 41.65.175.25441.65.175.2554,094
2841.65.176.0/2041.65.176.1 to 41.65.191.25441.65.191.2554,094
2941.65.192.0/2041.65.192.1 to 41.65.207.25441.65.207.2554,094
3041.65.208.0/2041.65.208.1 to 41.65.223.25441.65.223.2554,094
3141.65.224.0/2041.65.224.1 to 41.65.239.25441.65.239.2554,094
3241.65.240.0/2041.65.240.1 to 41.65.255.25441.65.255.2554,094
3341.66.0.0/2041.66.0.1 to 41.66.15.25441.66.15.2554,094
3441.66.16.0/2041.66.16.1 to 41.66.31.25441.66.31.2554,094
3541.66.32.0/2041.66.32.1 to 41.66.47.25441.66.47.2554,094
3641.66.48.0/2041.66.48.1 to 41.66.63.25441.66.63.2554,094
3741.66.64.0/2041.66.64.1 to 41.66.79.25441.66.79.2554,094
3841.66.80.0/2041.66.80.1 to 41.66.95.25441.66.95.2554,094
3941.66.96.0/2041.66.96.1 to 41.66.111.25441.66.111.2554,094
4041.66.112.0/2041.66.112.1 to 41.66.127.25441.66.127.2554,094
4141.66.128.0/2041.66.128.1 to 41.66.143.25441.66.143.2554,094
4241.66.144.0/2041.66.144.1 to 41.66.159.25441.66.159.2554,094
4341.66.160.0/2041.66.160.1 to 41.66.175.25441.66.175.2554,094
4441.66.176.0/2041.66.176.1 to 41.66.191.25441.66.191.2554,094
4541.66.192.0/2041.66.192.1 to 41.66.207.25441.66.207.2554,094
4641.66.208.0/2041.66.208.1 to 41.66.223.25441.66.223.2554,094
4741.66.224.0/2041.66.224.1 to 41.66.239.25441.66.239.2554,094
4841.66.240.0/2041.66.240.1 to 41.66.255.25441.66.255.2554,094
4941.67.0.0/2041.67.0.1 to 41.67.15.25441.67.15.2554,094
5041.67.16.0/2041.67.16.1 to 41.67.31.25441.67.31.2554,094
5141.67.32.0/2041.67.32.1 to 41.67.47.25441.67.47.2554,094
5241.67.48.0/2041.67.48.1 to 41.67.63.25441.67.63.2554,094
5341.67.64.0/2041.67.64.1 to 41.67.79.25441.67.79.2554,094
5441.67.80.0/2041.67.80.1 to 41.67.95.25441.67.95.2554,094
5541.67.96.0/2041.67.96.1 to 41.67.111.25441.67.111.2554,094
5641.67.112.0/2041.67.112.1 to 41.67.127.25441.67.127.2554,094
5741.67.128.0/2041.67.128.1 to 41.67.143.25441.67.143.2554,094
5841.67.144.0/2041.67.144.1 to 41.67.159.25441.67.159.2554,094
5941.67.160.0/2041.67.160.1 to 41.67.175.25441.67.175.2554,094
6041.67.176.0/2041.67.176.1 to 41.67.191.25441.67.191.2554,094
6141.67.192.0/2041.67.192.1 to 41.67.207.25441.67.207.2554,094
6241.67.208.0/2041.67.208.1 to 41.67.223.25441.67.223.2554,094
6341.67.224.0/2041.67.224.1 to 41.67.239.25441.67.239.2554,094
6441.67.240.0/2041.67.240.1 to 41.67.255.25441.67.255.2554,094
6541.68.0.0/2041.68.0.1 to 41.68.15.25441.68.15.2554,094
6641.68.16.0/2041.68.16.1 to 41.68.31.25441.68.31.2554,094
6741.68.32.0/2041.68.32.1 to 41.68.47.25441.68.47.2554,094
6841.68.48.0/2041.68.48.1 to 41.68.63.25441.68.63.2554,094
6941.68.64.0/2041.68.64.1 to 41.68.79.25441.68.79.2554,094
7041.68.80.0/2041.68.80.1 to 41.68.95.25441.68.95.2554,094
7141.68.96.0/2041.68.96.1 to 41.68.111.25441.68.111.2554,094
7241.68.112.0/2041.68.112.1 to 41.68.127.25441.68.127.2554,094
7341.68.128.0/2041.68.128.1 to 41.68.143.25441.68.143.2554,094
7441.68.144.0/2041.68.144.1 to 41.68.159.25441.68.159.2554,094
7541.68.160.0/2041.68.160.1 to 41.68.175.25441.68.175.2554,094
7641.68.176.0/2041.68.176.1 to 41.68.191.25441.68.191.2554,094
7741.68.192.0/2041.68.192.1 to 41.68.207.25441.68.207.2554,094
7841.68.208.0/2041.68.208.1 to 41.68.223.25441.68.223.2554,094
7941.68.224.0/2041.68.224.1 to 41.68.239.25441.68.239.2554,094
8041.68.240.0/2041.68.240.1 to 41.68.255.25441.68.255.2554,094
8141.69.0.0/2041.69.0.1 to 41.69.15.25441.69.15.2554,094
8241.69.16.0/2041.69.16.1 to 41.69.31.25441.69.31.2554,094
8341.69.32.0/2041.69.32.1 to 41.69.47.25441.69.47.2554,094
8441.69.48.0/2041.69.48.1 to 41.69.63.25441.69.63.2554,094
8541.69.64.0/2041.69.64.1 to 41.69.79.25441.69.79.2554,094
8641.69.80.0/2041.69.80.1 to 41.69.95.25441.69.95.2554,094
8741.69.96.0/2041.69.96.1 to 41.69.111.25441.69.111.2554,094
8841.69.112.0/2041.69.112.1 to 41.69.127.25441.69.127.2554,094
8941.69.128.0/2041.69.128.1 to 41.69.143.25441.69.143.2554,094
9041.69.144.0/2041.69.144.1 to 41.69.159.25441.69.159.2554,094
9141.69.160.0/2041.69.160.1 to 41.69.175.25441.69.175.2554,094
9241.69.176.0/2041.69.176.1 to 41.69.191.25441.69.191.2554,094
9341.69.192.0/2041.69.192.1 to 41.69.207.25441.69.207.2554,094
9441.69.208.0/2041.69.208.1 to 41.69.223.25441.69.223.2554,094
9541.69.224.0/2041.69.224.1 to 41.69.239.25441.69.239.2554,094
9641.69.240.0/2041.69.240.1 to 41.69.255.25441.69.255.2554,094
9741.70.0.0/2041.70.0.1 to 41.70.15.25441.70.15.2554,094
9841.70.16.0/2041.70.16.1 to 41.70.31.25441.70.31.2554,094
9941.70.32.0/2041.70.32.1 to 41.70.47.25441.70.47.2554,094
10041.70.48.0/2041.70.48.1 to 41.70.63.25441.70.63.2554,094
10141.70.64.0/2041.70.64.1 to 41.70.79.25441.70.79.2554,094
10241.70.80.0/2041.70.80.1 to 41.70.95.25441.70.95.2554,094
10341.70.96.0/2041.70.96.1 to 41.70.111.25441.70.111.2554,094
10441.70.112.0/2041.70.112.1 to 41.70.127.25441.70.127.2554,094
10541.70.128.0/2041.70.128.1 to 41.70.143.25441.70.143.2554,094
10641.70.144.0/2041.70.144.1 to 41.70.159.25441.70.159.2554,094
10741.70.160.0/2041.70.160.1 to 41.70.175.25441.70.175.2554,094
10841.70.176.0/2041.70.176.1 to 41.70.191.25441.70.191.2554,094
10941.70.192.0/2041.70.192.1 to 41.70.207.25441.70.207.2554,094
11041.70.208.0/2041.70.208.1 to 41.70.223.25441.70.223.2554,094
11141.70.224.0/2041.70.224.1 to 41.70.239.25441.70.239.2554,094
11241.70.240.0/2041.70.240.1 to 41.70.255.25441.70.255.2554,094
11341.71.0.0/2041.71.0.1 to 41.71.15.25441.71.15.2554,094
11441.71.16.0/2041.71.16.1 to 41.71.31.25441.71.31.2554,094
11541.71.32.0/2041.71.32.1 to 41.71.47.25441.71.47.2554,094
11641.71.48.0/2041.71.48.1 to 41.71.63.25441.71.63.2554,094
11741.71.64.0/2041.71.64.1 to 41.71.79.25441.71.79.2554,094
11841.71.80.0/2041.71.80.1 to 41.71.95.25441.71.95.2554,094
11941.71.96.0/2041.71.96.1 to 41.71.111.25441.71.111.2554,094
12041.71.112.0/2041.71.112.1 to 41.71.127.25441.71.127.2554,094
12141.71.128.0/2041.71.128.1 to 41.71.143.25441.71.143.2554,094
12241.71.144.0/2041.71.144.1 to 41.71.159.25441.71.159.2554,094
12341.71.160.0/2041.71.160.1 to 41.71.175.25441.71.175.2554,094
12441.71.176.0/2041.71.176.1 to 41.71.191.25441.71.191.2554,094
12541.71.192.0/2041.71.192.1 to 41.71.207.25441.71.207.2554,094
12641.71.208.0/2041.71.208.1 to 41.71.223.25441.71.223.2554,094
12741.71.224.0/2041.71.224.1 to 41.71.239.25441.71.239.2554,094
12841.71.240.0/2041.71.240.1 to 41.71.255.25441.71.255.2554,094
12941.72.0.0/2041.72.0.1 to 41.72.15.25441.72.15.2554,094
13041.72.16.0/2041.72.16.1 to 41.72.31.25441.72.31.2554,094
13141.72.32.0/2041.72.32.1 to 41.72.47.25441.72.47.2554,094
13241.72.48.0/2041.72.48.1 to 41.72.63.25441.72.63.2554,094
13341.72.64.0/2041.72.64.1 to 41.72.79.25441.72.79.2554,094
13441.72.80.0/2041.72.80.1 to 41.72.95.25441.72.95.2554,094
13541.72.96.0/2041.72.96.1 to 41.72.111.25441.72.111.2554,094
13641.72.112.0/2041.72.112.1 to 41.72.127.25441.72.127.2554,094
13741.72.128.0/2041.72.128.1 to 41.72.143.25441.72.143.2554,094
13841.72.144.0/2041.72.144.1 to 41.72.159.25441.72.159.2554,094
13941.72.160.0/2041.72.160.1 to 41.72.175.25441.72.175.2554,094
14041.72.176.0/2041.72.176.1 to 41.72.191.25441.72.191.2554,094
14141.72.192.0/2041.72.192.1 to 41.72.207.25441.72.207.2554,094
14241.72.208.0/2041.72.208.1 to 41.72.223.25441.72.223.2554,094
14341.72.224.0/2041.72.224.1 to 41.72.239.25441.72.239.2554,094
14441.72.240.0/2041.72.240.1 to 41.72.255.25441.72.255.2554,094
14541.73.0.0/2041.73.0.1 to 41.73.15.25441.73.15.2554,094
14641.73.16.0/2041.73.16.1 to 41.73.31.25441.73.31.2554,094
14741.73.32.0/2041.73.32.1 to 41.73.47.25441.73.47.2554,094
14841.73.48.0/2041.73.48.1 to 41.73.63.25441.73.63.2554,094
14941.73.64.0/2041.73.64.1 to 41.73.79.25441.73.79.2554,094
15041.73.80.0/2041.73.80.1 to 41.73.95.25441.73.95.2554,094
15141.73.96.0/2041.73.96.1 to 41.73.111.25441.73.111.2554,094
15241.73.112.0/2041.73.112.1 to 41.73.127.25441.73.127.2554,094
15341.73.128.0/2041.73.128.1 to 41.73.143.25441.73.143.2554,094
15441.73.144.0/2041.73.144.1 to 41.73.159.25441.73.159.2554,094
15541.73.160.0/2041.73.160.1 to 41.73.175.25441.73.175.2554,094
15641.73.176.0/2041.73.176.1 to 41.73.191.25441.73.191.2554,094
15741.73.192.0/2041.73.192.1 to 41.73.207.25441.73.207.2554,094
15841.73.208.0/2041.73.208.1 to 41.73.223.25441.73.223.2554,094
15941.73.224.0/2041.73.224.1 to 41.73.239.25441.73.239.2554,094
16041.73.240.0/2041.73.240.1 to 41.73.255.25441.73.255.2554,094
16141.74.0.0/2041.74.0.1 to 41.74.15.25441.74.15.2554,094
16241.74.16.0/2041.74.16.1 to 41.74.31.25441.74.31.2554,094
16341.74.32.0/2041.74.32.1 to 41.74.47.25441.74.47.2554,094
16441.74.48.0/2041.74.48.1 to 41.74.63.25441.74.63.2554,094
16541.74.64.0/2041.74.64.1 to 41.74.79.25441.74.79.2554,094
16641.74.80.0/2041.74.80.1 to 41.74.95.25441.74.95.2554,094
16741.74.96.0/2041.74.96.1 to 41.74.111.25441.74.111.2554,094
16841.74.112.0/2041.74.112.1 to 41.74.127.25441.74.127.2554,094
16941.74.128.0/2041.74.128.1 to 41.74.143.25441.74.143.2554,094
17041.74.144.0/2041.74.144.1 to 41.74.159.25441.74.159.2554,094
17141.74.160.0/2041.74.160.1 to 41.74.175.25441.74.175.2554,094
17241.74.176.0/2041.74.176.1 to 41.74.191.25441.74.191.2554,094
17341.74.192.0/2041.74.192.1 to 41.74.207.25441.74.207.2554,094
17441.74.208.0/2041.74.208.1 to 41.74.223.25441.74.223.2554,094
17541.74.224.0/2041.74.224.1 to 41.74.239.25441.74.239.2554,094
17641.74.240.0/2041.74.240.1 to 41.74.255.25441.74.255.2554,094
17741.75.0.0/2041.75.0.1 to 41.75.15.25441.75.15.2554,094
17841.75.16.0/2041.75.16.1 to 41.75.31.25441.75.31.2554,094
17941.75.32.0/2041.75.32.1 to 41.75.47.25441.75.47.2554,094
18041.75.48.0/2041.75.48.1 to 41.75.63.25441.75.63.2554,094
18141.75.64.0/2041.75.64.1 to 41.75.79.25441.75.79.2554,094
18241.75.80.0/2041.75.80.1 to 41.75.95.25441.75.95.2554,094
18341.75.96.0/2041.75.96.1 to 41.75.111.25441.75.111.2554,094
18441.75.112.0/2041.75.112.1 to 41.75.127.25441.75.127.2554,094
18541.75.128.0/2041.75.128.1 to 41.75.143.25441.75.143.2554,094
18641.75.144.0/2041.75.144.1 to 41.75.159.25441.75.159.2554,094
18741.75.160.0/2041.75.160.1 to 41.75.175.25441.75.175.2554,094
18841.75.176.0/2041.75.176.1 to 41.75.191.25441.75.191.2554,094
18941.75.192.0/2041.75.192.1 to 41.75.207.25441.75.207.2554,094
19041.75.208.0/2041.75.208.1 to 41.75.223.25441.75.223.2554,094
19141.75.224.0/2041.75.224.1 to 41.75.239.25441.75.239.2554,094
19241.75.240.0/2041.75.240.1 to 41.75.255.25441.75.255.2554,094
19341.76.0.0/2041.76.0.1 to 41.76.15.25441.76.15.2554,094
19441.76.16.0/2041.76.16.1 to 41.76.31.25441.76.31.2554,094
19541.76.32.0/2041.76.32.1 to 41.76.47.25441.76.47.2554,094
19641.76.48.0/2041.76.48.1 to 41.76.63.25441.76.63.2554,094
19741.76.64.0/2041.76.64.1 to 41.76.79.25441.76.79.2554,094
19841.76.80.0/2041.76.80.1 to 41.76.95.25441.76.95.2554,094
19941.76.96.0/2041.76.96.1 to 41.76.111.25441.76.111.2554,094
20041.76.112.0/2041.76.112.1 to 41.76.127.25441.76.127.2554,094
20141.76.128.0/2041.76.128.1 to 41.76.143.25441.76.143.2554,094
20241.76.144.0/2041.76.144.1 to 41.76.159.25441.76.159.2554,094
20341.76.160.0/2041.76.160.1 to 41.76.175.25441.76.175.2554,094
20441.76.176.0/2041.76.176.1 to 41.76.191.25441.76.191.2554,094
20541.76.192.0/2041.76.192.1 to 41.76.207.25441.76.207.2554,094
20641.76.208.0/2041.76.208.1 to 41.76.223.25441.76.223.2554,094
20741.76.224.0/2041.76.224.1 to 41.76.239.25441.76.239.2554,094
20841.76.240.0/2041.76.240.1 to 41.76.255.25441.76.255.2554,094
20941.77.0.0/2041.77.0.1 to 41.77.15.25441.77.15.2554,094
21041.77.16.0/2041.77.16.1 to 41.77.31.25441.77.31.2554,094
21141.77.32.0/2041.77.32.1 to 41.77.47.25441.77.47.2554,094
21241.77.48.0/2041.77.48.1 to 41.77.63.25441.77.63.2554,094
21341.77.64.0/2041.77.64.1 to 41.77.79.25441.77.79.2554,094
21441.77.80.0/2041.77.80.1 to 41.77.95.25441.77.95.2554,094
21541.77.96.0/2041.77.96.1 to 41.77.111.25441.77.111.2554,094
21641.77.112.0/2041.77.112.1 to 41.77.127.25441.77.127.2554,094
21741.77.128.0/2041.77.128.1 to 41.77.143.25441.77.143.2554,094
21841.77.144.0/2041.77.144.1 to 41.77.159.25441.77.159.2554,094
21941.77.160.0/2041.77.160.1 to 41.77.175.25441.77.175.2554,094
22041.77.176.0/2041.77.176.1 to 41.77.191.25441.77.191.2554,094
22141.77.192.0/2041.77.192.1 to 41.77.207.25441.77.207.2554,094
22241.77.208.0/2041.77.208.1 to 41.77.223.25441.77.223.2554,094
22341.77.224.0/2041.77.224.1 to 41.77.239.25441.77.239.2554,094
22441.77.240.0/2041.77.240.1 to 41.77.255.25441.77.255.2554,094
22541.78.0.0/2041.78.0.1 to 41.78.15.25441.78.15.2554,094
22641.78.16.0/2041.78.16.1 to 41.78.31.25441.78.31.2554,094
22741.78.32.0/2041.78.32.1 to 41.78.47.25441.78.47.2554,094
22841.78.48.0/2041.78.48.1 to 41.78.63.25441.78.63.2554,094
22941.78.64.0/2041.78.64.1 to 41.78.79.25441.78.79.2554,094
23041.78.80.0/2041.78.80.1 to 41.78.95.25441.78.95.2554,094
23141.78.96.0/2041.78.96.1 to 41.78.111.25441.78.111.2554,094
23241.78.112.0/2041.78.112.1 to 41.78.127.25441.78.127.2554,094
23341.78.128.0/2041.78.128.1 to 41.78.143.25441.78.143.2554,094
23441.78.144.0/2041.78.144.1 to 41.78.159.25441.78.159.2554,094
23541.78.160.0/2041.78.160.1 to 41.78.175.25441.78.175.2554,094
23641.78.176.0/2041.78.176.1 to 41.78.191.25441.78.191.2554,094
23741.78.192.0/2041.78.192.1 to 41.78.207.25441.78.207.2554,094
23841.78.208.0/2041.78.208.1 to 41.78.223.25441.78.223.2554,094
23941.78.224.0/2041.78.224.1 to 41.78.239.25441.78.239.2554,094
24041.78.240.0/2041.78.240.1 to 41.78.255.25441.78.255.2554,094
24141.79.0.0/2041.79.0.1 to 41.79.15.25441.79.15.2554,094
24241.79.16.0/2041.79.16.1 to 41.79.31.25441.79.31.2554,094
24341.79.32.0/2041.79.32.1 to 41.79.47.25441.79.47.2554,094
24441.79.48.0/2041.79.48.1 to 41.79.63.25441.79.63.2554,094
24541.79.64.0/2041.79.64.1 to 41.79.79.25441.79.79.2554,094
24641.79.80.0/2041.79.80.1 to 41.79.95.25441.79.95.2554,094
24741.79.96.0/2041.79.96.1 to 41.79.111.25441.79.111.2554,094
24841.79.112.0/2041.79.112.1 to 41.79.127.25441.79.127.2554,094
24941.79.128.0/2041.79.128.1 to 41.79.143.25441.79.143.2554,094
25041.79.144.0/2041.79.144.1 to 41.79.159.25441.79.159.2554,094
25141.79.160.0/2041.79.160.1 to 41.79.175.25441.79.175.2554,094
25241.79.176.0/2041.79.176.1 to 41.79.191.25441.79.191.2554,094
25341.79.192.0/2041.79.192.1 to 41.79.207.25441.79.207.2554,094
25441.79.208.0/2041.79.208.1 to 41.79.223.25441.79.223.2554,094
25541.79.224.0/2041.79.224.1 to 41.79.239.25441.79.239.2554,094
25641.79.240.0/2041.79.240.1 to 41.79.255.25441.79.255.2554,094

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.