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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.

Network58.76.0.0/14
Usable hosts262,142
Subnet mask255.252.0.0
Addresses262,144
Network address
58.76.0.0
Broadcast address
58.79.255.255
First usable
58.76.0.1
Last usable
58.79.255.254
Usable hosts
262,142 (262,144 less the network and broadcast addresses)
Subnet mask
255.252.0.0
Wildcard mask
0.3.255.255 (Cisco ACLs, OSPF)
Prefix length
/14
Type
Public public
Old class
A (default /8)
As numbers
Hex 3A4C0000 · Integer 978059264 to 978321407
Reverse DNS zones
76.58.in-addr.arpa
77.58.in-addr.arpa
78.58.in-addr.arpa
79.58.in-addr.arpa
/14 is not on a 8-bit boundary, so it takes 4 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00111010.01001100.00000000.0000000058.76.0.0
Subnet mask11111111.11111100.00000000.00000000255.252.0.0
Network00111010.01001100.00000000.0000000058.76.0.0
Broadcast00111010.01001111.11111111.1111111158.79.255.255
Split into smaller subnets/21
/15 (2)/16 (4)/17 (8)/18 (16)/19 (32)/20 (64)/21 (128)/22 (256)/23 (512)/24 (1,024)/25 (2,048)/26 (4,096)

58.76.0.0/14 makes 128 subnets of /21.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
158.76.0.0/2158.76.0.1 to 58.76.7.25458.76.7.2552,046
258.76.8.0/2158.76.8.1 to 58.76.15.25458.76.15.2552,046
358.76.16.0/2158.76.16.1 to 58.76.23.25458.76.23.2552,046
458.76.24.0/2158.76.24.1 to 58.76.31.25458.76.31.2552,046
558.76.32.0/2158.76.32.1 to 58.76.39.25458.76.39.2552,046
658.76.40.0/2158.76.40.1 to 58.76.47.25458.76.47.2552,046
758.76.48.0/2158.76.48.1 to 58.76.55.25458.76.55.2552,046
858.76.56.0/2158.76.56.1 to 58.76.63.25458.76.63.2552,046
958.76.64.0/2158.76.64.1 to 58.76.71.25458.76.71.2552,046
1058.76.72.0/2158.76.72.1 to 58.76.79.25458.76.79.2552,046
1158.76.80.0/2158.76.80.1 to 58.76.87.25458.76.87.2552,046
1258.76.88.0/2158.76.88.1 to 58.76.95.25458.76.95.2552,046
1358.76.96.0/2158.76.96.1 to 58.76.103.25458.76.103.2552,046
1458.76.104.0/2158.76.104.1 to 58.76.111.25458.76.111.2552,046
1558.76.112.0/2158.76.112.1 to 58.76.119.25458.76.119.2552,046
1658.76.120.0/2158.76.120.1 to 58.76.127.25458.76.127.2552,046
1758.76.128.0/2158.76.128.1 to 58.76.135.25458.76.135.2552,046
1858.76.136.0/2158.76.136.1 to 58.76.143.25458.76.143.2552,046
1958.76.144.0/2158.76.144.1 to 58.76.151.25458.76.151.2552,046
2058.76.152.0/2158.76.152.1 to 58.76.159.25458.76.159.2552,046
2158.76.160.0/2158.76.160.1 to 58.76.167.25458.76.167.2552,046
2258.76.168.0/2158.76.168.1 to 58.76.175.25458.76.175.2552,046
2358.76.176.0/2158.76.176.1 to 58.76.183.25458.76.183.2552,046
2458.76.184.0/2158.76.184.1 to 58.76.191.25458.76.191.2552,046
2558.76.192.0/2158.76.192.1 to 58.76.199.25458.76.199.2552,046
2658.76.200.0/2158.76.200.1 to 58.76.207.25458.76.207.2552,046
2758.76.208.0/2158.76.208.1 to 58.76.215.25458.76.215.2552,046
2858.76.216.0/2158.76.216.1 to 58.76.223.25458.76.223.2552,046
2958.76.224.0/2158.76.224.1 to 58.76.231.25458.76.231.2552,046
3058.76.232.0/2158.76.232.1 to 58.76.239.25458.76.239.2552,046
3158.76.240.0/2158.76.240.1 to 58.76.247.25458.76.247.2552,046
3258.76.248.0/2158.76.248.1 to 58.76.255.25458.76.255.2552,046
3358.77.0.0/2158.77.0.1 to 58.77.7.25458.77.7.2552,046
3458.77.8.0/2158.77.8.1 to 58.77.15.25458.77.15.2552,046
3558.77.16.0/2158.77.16.1 to 58.77.23.25458.77.23.2552,046
3658.77.24.0/2158.77.24.1 to 58.77.31.25458.77.31.2552,046
3758.77.32.0/2158.77.32.1 to 58.77.39.25458.77.39.2552,046
3858.77.40.0/2158.77.40.1 to 58.77.47.25458.77.47.2552,046
3958.77.48.0/2158.77.48.1 to 58.77.55.25458.77.55.2552,046
4058.77.56.0/2158.77.56.1 to 58.77.63.25458.77.63.2552,046
4158.77.64.0/2158.77.64.1 to 58.77.71.25458.77.71.2552,046
4258.77.72.0/2158.77.72.1 to 58.77.79.25458.77.79.2552,046
4358.77.80.0/2158.77.80.1 to 58.77.87.25458.77.87.2552,046
4458.77.88.0/2158.77.88.1 to 58.77.95.25458.77.95.2552,046
4558.77.96.0/2158.77.96.1 to 58.77.103.25458.77.103.2552,046
4658.77.104.0/2158.77.104.1 to 58.77.111.25458.77.111.2552,046
4758.77.112.0/2158.77.112.1 to 58.77.119.25458.77.119.2552,046
4858.77.120.0/2158.77.120.1 to 58.77.127.25458.77.127.2552,046
4958.77.128.0/2158.77.128.1 to 58.77.135.25458.77.135.2552,046
5058.77.136.0/2158.77.136.1 to 58.77.143.25458.77.143.2552,046
5158.77.144.0/2158.77.144.1 to 58.77.151.25458.77.151.2552,046
5258.77.152.0/2158.77.152.1 to 58.77.159.25458.77.159.2552,046
5358.77.160.0/2158.77.160.1 to 58.77.167.25458.77.167.2552,046
5458.77.168.0/2158.77.168.1 to 58.77.175.25458.77.175.2552,046
5558.77.176.0/2158.77.176.1 to 58.77.183.25458.77.183.2552,046
5658.77.184.0/2158.77.184.1 to 58.77.191.25458.77.191.2552,046
5758.77.192.0/2158.77.192.1 to 58.77.199.25458.77.199.2552,046
5858.77.200.0/2158.77.200.1 to 58.77.207.25458.77.207.2552,046
5958.77.208.0/2158.77.208.1 to 58.77.215.25458.77.215.2552,046
6058.77.216.0/2158.77.216.1 to 58.77.223.25458.77.223.2552,046
6158.77.224.0/2158.77.224.1 to 58.77.231.25458.77.231.2552,046
6258.77.232.0/2158.77.232.1 to 58.77.239.25458.77.239.2552,046
6358.77.240.0/2158.77.240.1 to 58.77.247.25458.77.247.2552,046
6458.77.248.0/2158.77.248.1 to 58.77.255.25458.77.255.2552,046
6558.78.0.0/2158.78.0.1 to 58.78.7.25458.78.7.2552,046
6658.78.8.0/2158.78.8.1 to 58.78.15.25458.78.15.2552,046
6758.78.16.0/2158.78.16.1 to 58.78.23.25458.78.23.2552,046
6858.78.24.0/2158.78.24.1 to 58.78.31.25458.78.31.2552,046
6958.78.32.0/2158.78.32.1 to 58.78.39.25458.78.39.2552,046
7058.78.40.0/2158.78.40.1 to 58.78.47.25458.78.47.2552,046
7158.78.48.0/2158.78.48.1 to 58.78.55.25458.78.55.2552,046
7258.78.56.0/2158.78.56.1 to 58.78.63.25458.78.63.2552,046
7358.78.64.0/2158.78.64.1 to 58.78.71.25458.78.71.2552,046
7458.78.72.0/2158.78.72.1 to 58.78.79.25458.78.79.2552,046
7558.78.80.0/2158.78.80.1 to 58.78.87.25458.78.87.2552,046
7658.78.88.0/2158.78.88.1 to 58.78.95.25458.78.95.2552,046
7758.78.96.0/2158.78.96.1 to 58.78.103.25458.78.103.2552,046
7858.78.104.0/2158.78.104.1 to 58.78.111.25458.78.111.2552,046
7958.78.112.0/2158.78.112.1 to 58.78.119.25458.78.119.2552,046
8058.78.120.0/2158.78.120.1 to 58.78.127.25458.78.127.2552,046
8158.78.128.0/2158.78.128.1 to 58.78.135.25458.78.135.2552,046
8258.78.136.0/2158.78.136.1 to 58.78.143.25458.78.143.2552,046
8358.78.144.0/2158.78.144.1 to 58.78.151.25458.78.151.2552,046
8458.78.152.0/2158.78.152.1 to 58.78.159.25458.78.159.2552,046
8558.78.160.0/2158.78.160.1 to 58.78.167.25458.78.167.2552,046
8658.78.168.0/2158.78.168.1 to 58.78.175.25458.78.175.2552,046
8758.78.176.0/2158.78.176.1 to 58.78.183.25458.78.183.2552,046
8858.78.184.0/2158.78.184.1 to 58.78.191.25458.78.191.2552,046
8958.78.192.0/2158.78.192.1 to 58.78.199.25458.78.199.2552,046
9058.78.200.0/2158.78.200.1 to 58.78.207.25458.78.207.2552,046
9158.78.208.0/2158.78.208.1 to 58.78.215.25458.78.215.2552,046
9258.78.216.0/2158.78.216.1 to 58.78.223.25458.78.223.2552,046
9358.78.224.0/2158.78.224.1 to 58.78.231.25458.78.231.2552,046
9458.78.232.0/2158.78.232.1 to 58.78.239.25458.78.239.2552,046
9558.78.240.0/2158.78.240.1 to 58.78.247.25458.78.247.2552,046
9658.78.248.0/2158.78.248.1 to 58.78.255.25458.78.255.2552,046
9758.79.0.0/2158.79.0.1 to 58.79.7.25458.79.7.2552,046
9858.79.8.0/2158.79.8.1 to 58.79.15.25458.79.15.2552,046
9958.79.16.0/2158.79.16.1 to 58.79.23.25458.79.23.2552,046
10058.79.24.0/2158.79.24.1 to 58.79.31.25458.79.31.2552,046
10158.79.32.0/2158.79.32.1 to 58.79.39.25458.79.39.2552,046
10258.79.40.0/2158.79.40.1 to 58.79.47.25458.79.47.2552,046
10358.79.48.0/2158.79.48.1 to 58.79.55.25458.79.55.2552,046
10458.79.56.0/2158.79.56.1 to 58.79.63.25458.79.63.2552,046
10558.79.64.0/2158.79.64.1 to 58.79.71.25458.79.71.2552,046
10658.79.72.0/2158.79.72.1 to 58.79.79.25458.79.79.2552,046
10758.79.80.0/2158.79.80.1 to 58.79.87.25458.79.87.2552,046
10858.79.88.0/2158.79.88.1 to 58.79.95.25458.79.95.2552,046
10958.79.96.0/2158.79.96.1 to 58.79.103.25458.79.103.2552,046
11058.79.104.0/2158.79.104.1 to 58.79.111.25458.79.111.2552,046
11158.79.112.0/2158.79.112.1 to 58.79.119.25458.79.119.2552,046
11258.79.120.0/2158.79.120.1 to 58.79.127.25458.79.127.2552,046
11358.79.128.0/2158.79.128.1 to 58.79.135.25458.79.135.2552,046
11458.79.136.0/2158.79.136.1 to 58.79.143.25458.79.143.2552,046
11558.79.144.0/2158.79.144.1 to 58.79.151.25458.79.151.2552,046
11658.79.152.0/2158.79.152.1 to 58.79.159.25458.79.159.2552,046
11758.79.160.0/2158.79.160.1 to 58.79.167.25458.79.167.2552,046
11858.79.168.0/2158.79.168.1 to 58.79.175.25458.79.175.2552,046
11958.79.176.0/2158.79.176.1 to 58.79.183.25458.79.183.2552,046
12058.79.184.0/2158.79.184.1 to 58.79.191.25458.79.191.2552,046
12158.79.192.0/2158.79.192.1 to 58.79.199.25458.79.199.2552,046
12258.79.200.0/2158.79.200.1 to 58.79.207.25458.79.207.2552,046
12358.79.208.0/2158.79.208.1 to 58.79.215.25458.79.215.2552,046
12458.79.216.0/2158.79.216.1 to 58.79.223.25458.79.223.2552,046
12558.79.224.0/2158.79.224.1 to 58.79.231.25458.79.231.2552,046
12658.79.232.0/2158.79.232.1 to 58.79.239.25458.79.239.2552,046
12758.79.240.0/2158.79.240.1 to 58.79.247.25458.79.247.2552,046
12858.79.248.0/2158.79.248.1 to 58.79.255.25458.79.255.2552,046

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.