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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.

Network65.24.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
65.24.0.0
Broadcast address
65.24.255.255
First usable
65.24.0.1
Last usable
65.24.255.254
Usable hosts
65,534 (65,536 less the network and broadcast addresses)
Subnet mask
255.255.0.0
Wildcard mask
0.0.255.255 (Cisco ACLs, OSPF)
Prefix length
/16
Type
Public public
Old class
A (default /8)
As numbers
Hex 41180000 · Integer 1092091904 to 1092157439
Reverse DNS zone
24.65.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01000001.00011000..00000000.0000000065.24.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network01000001.00011000..00000000.0000000065.24.0.0
Broadcast01000001.00011000..11111111.1111111165.24.255.255
Split into smaller subnets/23

65.24.0.0/16 makes 128 subnets of /23.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
165.24.0.0/2365.24.0.1 to 65.24.1.25465.24.1.255510
265.24.2.0/2365.24.2.1 to 65.24.3.25465.24.3.255510
365.24.4.0/2365.24.4.1 to 65.24.5.25465.24.5.255510
465.24.6.0/2365.24.6.1 to 65.24.7.25465.24.7.255510
565.24.8.0/2365.24.8.1 to 65.24.9.25465.24.9.255510
665.24.10.0/2365.24.10.1 to 65.24.11.25465.24.11.255510
765.24.12.0/2365.24.12.1 to 65.24.13.25465.24.13.255510
865.24.14.0/2365.24.14.1 to 65.24.15.25465.24.15.255510
965.24.16.0/2365.24.16.1 to 65.24.17.25465.24.17.255510
1065.24.18.0/2365.24.18.1 to 65.24.19.25465.24.19.255510
1165.24.20.0/2365.24.20.1 to 65.24.21.25465.24.21.255510
1265.24.22.0/2365.24.22.1 to 65.24.23.25465.24.23.255510
1365.24.24.0/2365.24.24.1 to 65.24.25.25465.24.25.255510
1465.24.26.0/2365.24.26.1 to 65.24.27.25465.24.27.255510
1565.24.28.0/2365.24.28.1 to 65.24.29.25465.24.29.255510
1665.24.30.0/2365.24.30.1 to 65.24.31.25465.24.31.255510
1765.24.32.0/2365.24.32.1 to 65.24.33.25465.24.33.255510
1865.24.34.0/2365.24.34.1 to 65.24.35.25465.24.35.255510
1965.24.36.0/2365.24.36.1 to 65.24.37.25465.24.37.255510
2065.24.38.0/2365.24.38.1 to 65.24.39.25465.24.39.255510
2165.24.40.0/2365.24.40.1 to 65.24.41.25465.24.41.255510
2265.24.42.0/2365.24.42.1 to 65.24.43.25465.24.43.255510
2365.24.44.0/2365.24.44.1 to 65.24.45.25465.24.45.255510
2465.24.46.0/2365.24.46.1 to 65.24.47.25465.24.47.255510
2565.24.48.0/2365.24.48.1 to 65.24.49.25465.24.49.255510
2665.24.50.0/2365.24.50.1 to 65.24.51.25465.24.51.255510
2765.24.52.0/2365.24.52.1 to 65.24.53.25465.24.53.255510
2865.24.54.0/2365.24.54.1 to 65.24.55.25465.24.55.255510
2965.24.56.0/2365.24.56.1 to 65.24.57.25465.24.57.255510
3065.24.58.0/2365.24.58.1 to 65.24.59.25465.24.59.255510
3165.24.60.0/2365.24.60.1 to 65.24.61.25465.24.61.255510
3265.24.62.0/2365.24.62.1 to 65.24.63.25465.24.63.255510
3365.24.64.0/2365.24.64.1 to 65.24.65.25465.24.65.255510
3465.24.66.0/2365.24.66.1 to 65.24.67.25465.24.67.255510
3565.24.68.0/2365.24.68.1 to 65.24.69.25465.24.69.255510
3665.24.70.0/2365.24.70.1 to 65.24.71.25465.24.71.255510
3765.24.72.0/2365.24.72.1 to 65.24.73.25465.24.73.255510
3865.24.74.0/2365.24.74.1 to 65.24.75.25465.24.75.255510
3965.24.76.0/2365.24.76.1 to 65.24.77.25465.24.77.255510
4065.24.78.0/2365.24.78.1 to 65.24.79.25465.24.79.255510
4165.24.80.0/2365.24.80.1 to 65.24.81.25465.24.81.255510
4265.24.82.0/2365.24.82.1 to 65.24.83.25465.24.83.255510
4365.24.84.0/2365.24.84.1 to 65.24.85.25465.24.85.255510
4465.24.86.0/2365.24.86.1 to 65.24.87.25465.24.87.255510
4565.24.88.0/2365.24.88.1 to 65.24.89.25465.24.89.255510
4665.24.90.0/2365.24.90.1 to 65.24.91.25465.24.91.255510
4765.24.92.0/2365.24.92.1 to 65.24.93.25465.24.93.255510
4865.24.94.0/2365.24.94.1 to 65.24.95.25465.24.95.255510
4965.24.96.0/2365.24.96.1 to 65.24.97.25465.24.97.255510
5065.24.98.0/2365.24.98.1 to 65.24.99.25465.24.99.255510
5165.24.100.0/2365.24.100.1 to 65.24.101.25465.24.101.255510
5265.24.102.0/2365.24.102.1 to 65.24.103.25465.24.103.255510
5365.24.104.0/2365.24.104.1 to 65.24.105.25465.24.105.255510
5465.24.106.0/2365.24.106.1 to 65.24.107.25465.24.107.255510
5565.24.108.0/2365.24.108.1 to 65.24.109.25465.24.109.255510
5665.24.110.0/2365.24.110.1 to 65.24.111.25465.24.111.255510
5765.24.112.0/2365.24.112.1 to 65.24.113.25465.24.113.255510
5865.24.114.0/2365.24.114.1 to 65.24.115.25465.24.115.255510
5965.24.116.0/2365.24.116.1 to 65.24.117.25465.24.117.255510
6065.24.118.0/2365.24.118.1 to 65.24.119.25465.24.119.255510
6165.24.120.0/2365.24.120.1 to 65.24.121.25465.24.121.255510
6265.24.122.0/2365.24.122.1 to 65.24.123.25465.24.123.255510
6365.24.124.0/2365.24.124.1 to 65.24.125.25465.24.125.255510
6465.24.126.0/2365.24.126.1 to 65.24.127.25465.24.127.255510
6565.24.128.0/2365.24.128.1 to 65.24.129.25465.24.129.255510
6665.24.130.0/2365.24.130.1 to 65.24.131.25465.24.131.255510
6765.24.132.0/2365.24.132.1 to 65.24.133.25465.24.133.255510
6865.24.134.0/2365.24.134.1 to 65.24.135.25465.24.135.255510
6965.24.136.0/2365.24.136.1 to 65.24.137.25465.24.137.255510
7065.24.138.0/2365.24.138.1 to 65.24.139.25465.24.139.255510
7165.24.140.0/2365.24.140.1 to 65.24.141.25465.24.141.255510
7265.24.142.0/2365.24.142.1 to 65.24.143.25465.24.143.255510
7365.24.144.0/2365.24.144.1 to 65.24.145.25465.24.145.255510
7465.24.146.0/2365.24.146.1 to 65.24.147.25465.24.147.255510
7565.24.148.0/2365.24.148.1 to 65.24.149.25465.24.149.255510
7665.24.150.0/2365.24.150.1 to 65.24.151.25465.24.151.255510
7765.24.152.0/2365.24.152.1 to 65.24.153.25465.24.153.255510
7865.24.154.0/2365.24.154.1 to 65.24.155.25465.24.155.255510
7965.24.156.0/2365.24.156.1 to 65.24.157.25465.24.157.255510
8065.24.158.0/2365.24.158.1 to 65.24.159.25465.24.159.255510
8165.24.160.0/2365.24.160.1 to 65.24.161.25465.24.161.255510
8265.24.162.0/2365.24.162.1 to 65.24.163.25465.24.163.255510
8365.24.164.0/2365.24.164.1 to 65.24.165.25465.24.165.255510
8465.24.166.0/2365.24.166.1 to 65.24.167.25465.24.167.255510
8565.24.168.0/2365.24.168.1 to 65.24.169.25465.24.169.255510
8665.24.170.0/2365.24.170.1 to 65.24.171.25465.24.171.255510
8765.24.172.0/2365.24.172.1 to 65.24.173.25465.24.173.255510
8865.24.174.0/2365.24.174.1 to 65.24.175.25465.24.175.255510
8965.24.176.0/2365.24.176.1 to 65.24.177.25465.24.177.255510
9065.24.178.0/2365.24.178.1 to 65.24.179.25465.24.179.255510
9165.24.180.0/2365.24.180.1 to 65.24.181.25465.24.181.255510
9265.24.182.0/2365.24.182.1 to 65.24.183.25465.24.183.255510
9365.24.184.0/2365.24.184.1 to 65.24.185.25465.24.185.255510
9465.24.186.0/2365.24.186.1 to 65.24.187.25465.24.187.255510
9565.24.188.0/2365.24.188.1 to 65.24.189.25465.24.189.255510
9665.24.190.0/2365.24.190.1 to 65.24.191.25465.24.191.255510
9765.24.192.0/2365.24.192.1 to 65.24.193.25465.24.193.255510
9865.24.194.0/2365.24.194.1 to 65.24.195.25465.24.195.255510
9965.24.196.0/2365.24.196.1 to 65.24.197.25465.24.197.255510
10065.24.198.0/2365.24.198.1 to 65.24.199.25465.24.199.255510
10165.24.200.0/2365.24.200.1 to 65.24.201.25465.24.201.255510
10265.24.202.0/2365.24.202.1 to 65.24.203.25465.24.203.255510
10365.24.204.0/2365.24.204.1 to 65.24.205.25465.24.205.255510
10465.24.206.0/2365.24.206.1 to 65.24.207.25465.24.207.255510
10565.24.208.0/2365.24.208.1 to 65.24.209.25465.24.209.255510
10665.24.210.0/2365.24.210.1 to 65.24.211.25465.24.211.255510
10765.24.212.0/2365.24.212.1 to 65.24.213.25465.24.213.255510
10865.24.214.0/2365.24.214.1 to 65.24.215.25465.24.215.255510
10965.24.216.0/2365.24.216.1 to 65.24.217.25465.24.217.255510
11065.24.218.0/2365.24.218.1 to 65.24.219.25465.24.219.255510
11165.24.220.0/2365.24.220.1 to 65.24.221.25465.24.221.255510
11265.24.222.0/2365.24.222.1 to 65.24.223.25465.24.223.255510
11365.24.224.0/2365.24.224.1 to 65.24.225.25465.24.225.255510
11465.24.226.0/2365.24.226.1 to 65.24.227.25465.24.227.255510
11565.24.228.0/2365.24.228.1 to 65.24.229.25465.24.229.255510
11665.24.230.0/2365.24.230.1 to 65.24.231.25465.24.231.255510
11765.24.232.0/2365.24.232.1 to 65.24.233.25465.24.233.255510
11865.24.234.0/2365.24.234.1 to 65.24.235.25465.24.235.255510
11965.24.236.0/2365.24.236.1 to 65.24.237.25465.24.237.255510
12065.24.238.0/2365.24.238.1 to 65.24.239.25465.24.239.255510
12165.24.240.0/2365.24.240.1 to 65.24.241.25465.24.241.255510
12265.24.242.0/2365.24.242.1 to 65.24.243.25465.24.243.255510
12365.24.244.0/2365.24.244.1 to 65.24.245.25465.24.245.255510
12465.24.246.0/2365.24.246.1 to 65.24.247.25465.24.247.255510
12565.24.248.0/2365.24.248.1 to 65.24.249.25465.24.249.255510
12665.24.250.0/2365.24.250.1 to 65.24.251.25465.24.251.255510
12765.24.252.0/2365.24.252.1 to 65.24.253.25465.24.253.255510
12865.24.254.0/2365.24.254.1 to 65.24.255.25465.24.255.255510

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