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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.

Network62.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
62.0.0.0
Broadcast address
63.255.255.255
First usable
62.0.0.1
Last usable
63.255.255.254
Usable hosts
33,554,430 (33,554,432 less the network and broadcast addresses)
Subnet mask
254.0.0.0
Wildcard mask
1.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/7
Type
Public public
Old class
A (default /8)
As numbers
Hex 3E000000 · Integer 1040187392 to 1073741823
Reverse DNS zones
62.in-addr.arpa
63.in-addr.arpa
/7 is not on a 8-bit boundary, so it takes 2 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00111110.00000000.00000000.0000000062.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network00111110.00000000.00000000.0000000062.0.0.0
Broadcast00111111.11111111.11111111.1111111163.255.255.255
Split into smaller subnets/14
/8 (2)/9 (4)/10 (8)/11 (16)/12 (32)/13 (64)/14 (128)/15 (256)/16 (512)/17 (1,024)/18 (2,048)/19 (4,096)

62.0.0.0/7 makes 128 subnets of /14.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
162.0.0.0/1462.0.0.1 to 62.3.255.25462.3.255.255262,142
262.4.0.0/1462.4.0.1 to 62.7.255.25462.7.255.255262,142
362.8.0.0/1462.8.0.1 to 62.11.255.25462.11.255.255262,142
462.12.0.0/1462.12.0.1 to 62.15.255.25462.15.255.255262,142
562.16.0.0/1462.16.0.1 to 62.19.255.25462.19.255.255262,142
662.20.0.0/1462.20.0.1 to 62.23.255.25462.23.255.255262,142
762.24.0.0/1462.24.0.1 to 62.27.255.25462.27.255.255262,142
862.28.0.0/1462.28.0.1 to 62.31.255.25462.31.255.255262,142
962.32.0.0/1462.32.0.1 to 62.35.255.25462.35.255.255262,142
1062.36.0.0/1462.36.0.1 to 62.39.255.25462.39.255.255262,142
1162.40.0.0/1462.40.0.1 to 62.43.255.25462.43.255.255262,142
1262.44.0.0/1462.44.0.1 to 62.47.255.25462.47.255.255262,142
1362.48.0.0/1462.48.0.1 to 62.51.255.25462.51.255.255262,142
1462.52.0.0/1462.52.0.1 to 62.55.255.25462.55.255.255262,142
1562.56.0.0/1462.56.0.1 to 62.59.255.25462.59.255.255262,142
1662.60.0.0/1462.60.0.1 to 62.63.255.25462.63.255.255262,142
1762.64.0.0/1462.64.0.1 to 62.67.255.25462.67.255.255262,142
1862.68.0.0/1462.68.0.1 to 62.71.255.25462.71.255.255262,142
1962.72.0.0/1462.72.0.1 to 62.75.255.25462.75.255.255262,142
2062.76.0.0/1462.76.0.1 to 62.79.255.25462.79.255.255262,142
2162.80.0.0/1462.80.0.1 to 62.83.255.25462.83.255.255262,142
2262.84.0.0/1462.84.0.1 to 62.87.255.25462.87.255.255262,142
2362.88.0.0/1462.88.0.1 to 62.91.255.25462.91.255.255262,142
2462.92.0.0/1462.92.0.1 to 62.95.255.25462.95.255.255262,142
2562.96.0.0/1462.96.0.1 to 62.99.255.25462.99.255.255262,142
2662.100.0.0/1462.100.0.1 to 62.103.255.25462.103.255.255262,142
2762.104.0.0/1462.104.0.1 to 62.107.255.25462.107.255.255262,142
2862.108.0.0/1462.108.0.1 to 62.111.255.25462.111.255.255262,142
2962.112.0.0/1462.112.0.1 to 62.115.255.25462.115.255.255262,142
3062.116.0.0/1462.116.0.1 to 62.119.255.25462.119.255.255262,142
3162.120.0.0/1462.120.0.1 to 62.123.255.25462.123.255.255262,142
3262.124.0.0/1462.124.0.1 to 62.127.255.25462.127.255.255262,142
3362.128.0.0/1462.128.0.1 to 62.131.255.25462.131.255.255262,142
3462.132.0.0/1462.132.0.1 to 62.135.255.25462.135.255.255262,142
3562.136.0.0/1462.136.0.1 to 62.139.255.25462.139.255.255262,142
3662.140.0.0/1462.140.0.1 to 62.143.255.25462.143.255.255262,142
3762.144.0.0/1462.144.0.1 to 62.147.255.25462.147.255.255262,142
3862.148.0.0/1462.148.0.1 to 62.151.255.25462.151.255.255262,142
3962.152.0.0/1462.152.0.1 to 62.155.255.25462.155.255.255262,142
4062.156.0.0/1462.156.0.1 to 62.159.255.25462.159.255.255262,142
4162.160.0.0/1462.160.0.1 to 62.163.255.25462.163.255.255262,142
4262.164.0.0/1462.164.0.1 to 62.167.255.25462.167.255.255262,142
4362.168.0.0/1462.168.0.1 to 62.171.255.25462.171.255.255262,142
4462.172.0.0/1462.172.0.1 to 62.175.255.25462.175.255.255262,142
4562.176.0.0/1462.176.0.1 to 62.179.255.25462.179.255.255262,142
4662.180.0.0/1462.180.0.1 to 62.183.255.25462.183.255.255262,142
4762.184.0.0/1462.184.0.1 to 62.187.255.25462.187.255.255262,142
4862.188.0.0/1462.188.0.1 to 62.191.255.25462.191.255.255262,142
4962.192.0.0/1462.192.0.1 to 62.195.255.25462.195.255.255262,142
5062.196.0.0/1462.196.0.1 to 62.199.255.25462.199.255.255262,142
5162.200.0.0/1462.200.0.1 to 62.203.255.25462.203.255.255262,142
5262.204.0.0/1462.204.0.1 to 62.207.255.25462.207.255.255262,142
5362.208.0.0/1462.208.0.1 to 62.211.255.25462.211.255.255262,142
5462.212.0.0/1462.212.0.1 to 62.215.255.25462.215.255.255262,142
5562.216.0.0/1462.216.0.1 to 62.219.255.25462.219.255.255262,142
5662.220.0.0/1462.220.0.1 to 62.223.255.25462.223.255.255262,142
5762.224.0.0/1462.224.0.1 to 62.227.255.25462.227.255.255262,142
5862.228.0.0/1462.228.0.1 to 62.231.255.25462.231.255.255262,142
5962.232.0.0/1462.232.0.1 to 62.235.255.25462.235.255.255262,142
6062.236.0.0/1462.236.0.1 to 62.239.255.25462.239.255.255262,142
6162.240.0.0/1462.240.0.1 to 62.243.255.25462.243.255.255262,142
6262.244.0.0/1462.244.0.1 to 62.247.255.25462.247.255.255262,142
6362.248.0.0/1462.248.0.1 to 62.251.255.25462.251.255.255262,142
6462.252.0.0/1462.252.0.1 to 62.255.255.25462.255.255.255262,142
6563.0.0.0/1463.0.0.1 to 63.3.255.25463.3.255.255262,142
6663.4.0.0/1463.4.0.1 to 63.7.255.25463.7.255.255262,142
6763.8.0.0/1463.8.0.1 to 63.11.255.25463.11.255.255262,142
6863.12.0.0/1463.12.0.1 to 63.15.255.25463.15.255.255262,142
6963.16.0.0/1463.16.0.1 to 63.19.255.25463.19.255.255262,142
7063.20.0.0/1463.20.0.1 to 63.23.255.25463.23.255.255262,142
7163.24.0.0/1463.24.0.1 to 63.27.255.25463.27.255.255262,142
7263.28.0.0/1463.28.0.1 to 63.31.255.25463.31.255.255262,142
7363.32.0.0/1463.32.0.1 to 63.35.255.25463.35.255.255262,142
7463.36.0.0/1463.36.0.1 to 63.39.255.25463.39.255.255262,142
7563.40.0.0/1463.40.0.1 to 63.43.255.25463.43.255.255262,142
7663.44.0.0/1463.44.0.1 to 63.47.255.25463.47.255.255262,142
7763.48.0.0/1463.48.0.1 to 63.51.255.25463.51.255.255262,142
7863.52.0.0/1463.52.0.1 to 63.55.255.25463.55.255.255262,142
7963.56.0.0/1463.56.0.1 to 63.59.255.25463.59.255.255262,142
8063.60.0.0/1463.60.0.1 to 63.63.255.25463.63.255.255262,142
8163.64.0.0/1463.64.0.1 to 63.67.255.25463.67.255.255262,142
8263.68.0.0/1463.68.0.1 to 63.71.255.25463.71.255.255262,142
8363.72.0.0/1463.72.0.1 to 63.75.255.25463.75.255.255262,142
8463.76.0.0/1463.76.0.1 to 63.79.255.25463.79.255.255262,142
8563.80.0.0/1463.80.0.1 to 63.83.255.25463.83.255.255262,142
8663.84.0.0/1463.84.0.1 to 63.87.255.25463.87.255.255262,142
8763.88.0.0/1463.88.0.1 to 63.91.255.25463.91.255.255262,142
8863.92.0.0/1463.92.0.1 to 63.95.255.25463.95.255.255262,142
8963.96.0.0/1463.96.0.1 to 63.99.255.25463.99.255.255262,142
9063.100.0.0/1463.100.0.1 to 63.103.255.25463.103.255.255262,142
9163.104.0.0/1463.104.0.1 to 63.107.255.25463.107.255.255262,142
9263.108.0.0/1463.108.0.1 to 63.111.255.25463.111.255.255262,142
9363.112.0.0/1463.112.0.1 to 63.115.255.25463.115.255.255262,142
9463.116.0.0/1463.116.0.1 to 63.119.255.25463.119.255.255262,142
9563.120.0.0/1463.120.0.1 to 63.123.255.25463.123.255.255262,142
9663.124.0.0/1463.124.0.1 to 63.127.255.25463.127.255.255262,142
9763.128.0.0/1463.128.0.1 to 63.131.255.25463.131.255.255262,142
9863.132.0.0/1463.132.0.1 to 63.135.255.25463.135.255.255262,142
9963.136.0.0/1463.136.0.1 to 63.139.255.25463.139.255.255262,142
10063.140.0.0/1463.140.0.1 to 63.143.255.25463.143.255.255262,142
10163.144.0.0/1463.144.0.1 to 63.147.255.25463.147.255.255262,142
10263.148.0.0/1463.148.0.1 to 63.151.255.25463.151.255.255262,142
10363.152.0.0/1463.152.0.1 to 63.155.255.25463.155.255.255262,142
10463.156.0.0/1463.156.0.1 to 63.159.255.25463.159.255.255262,142
10563.160.0.0/1463.160.0.1 to 63.163.255.25463.163.255.255262,142
10663.164.0.0/1463.164.0.1 to 63.167.255.25463.167.255.255262,142
10763.168.0.0/1463.168.0.1 to 63.171.255.25463.171.255.255262,142
10863.172.0.0/1463.172.0.1 to 63.175.255.25463.175.255.255262,142
10963.176.0.0/1463.176.0.1 to 63.179.255.25463.179.255.255262,142
11063.180.0.0/1463.180.0.1 to 63.183.255.25463.183.255.255262,142
11163.184.0.0/1463.184.0.1 to 63.187.255.25463.187.255.255262,142
11263.188.0.0/1463.188.0.1 to 63.191.255.25463.191.255.255262,142
11363.192.0.0/1463.192.0.1 to 63.195.255.25463.195.255.255262,142
11463.196.0.0/1463.196.0.1 to 63.199.255.25463.199.255.255262,142
11563.200.0.0/1463.200.0.1 to 63.203.255.25463.203.255.255262,142
11663.204.0.0/1463.204.0.1 to 63.207.255.25463.207.255.255262,142
11763.208.0.0/1463.208.0.1 to 63.211.255.25463.211.255.255262,142
11863.212.0.0/1463.212.0.1 to 63.215.255.25463.215.255.255262,142
11963.216.0.0/1463.216.0.1 to 63.219.255.25463.219.255.255262,142
12063.220.0.0/1463.220.0.1 to 63.223.255.25463.223.255.255262,142
12163.224.0.0/1463.224.0.1 to 63.227.255.25463.227.255.255262,142
12263.228.0.0/1463.228.0.1 to 63.231.255.25463.231.255.255262,142
12363.232.0.0/1463.232.0.1 to 63.235.255.25463.235.255.255262,142
12463.236.0.0/1463.236.0.1 to 63.239.255.25463.239.255.255262,142
12563.240.0.0/1463.240.0.1 to 63.243.255.25463.243.255.255262,142
12663.244.0.0/1463.244.0.1 to 63.247.255.25463.247.255.255262,142
12763.248.0.0/1463.248.0.1 to 63.251.255.25463.251.255.255262,142
12863.252.0.0/1463.252.0.1 to 63.255.255.25463.255.255.255262,142

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.