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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.

Network60.76.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
60.76.0.0
Broadcast address
60.77.255.255
First usable
60.76.0.1
Last usable
60.77.255.254
Usable hosts
131,070 (131,072 less the network and broadcast addresses)
Subnet mask
255.254.0.0
Wildcard mask
0.1.255.255 (Cisco ACLs, OSPF)
Prefix length
/15
Type
Public public
Old class
A (default /8)
As numbers
Hex 3C4C0000 · Integer 1011613696 to 1011744767
Reverse DNS zones
76.60.in-addr.arpa
77.60.in-addr.arpa
/15 is not on a 8-bit boundary, so it takes 2 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00111100.01001100.00000000.0000000060.76.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network00111100.01001100.00000000.0000000060.76.0.0
Broadcast00111100.01001101.11111111.1111111160.77.255.255
Split into smaller subnets/22
/16 (2)/17 (4)/18 (8)/19 (16)/20 (32)/21 (64)/22 (128)/23 (256)/24 (512)/25 (1,024)/26 (2,048)/27 (4,096)

60.76.0.0/15 makes 128 subnets of /22.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
160.76.0.0/2260.76.0.1 to 60.76.3.25460.76.3.2551,022
260.76.4.0/2260.76.4.1 to 60.76.7.25460.76.7.2551,022
360.76.8.0/2260.76.8.1 to 60.76.11.25460.76.11.2551,022
460.76.12.0/2260.76.12.1 to 60.76.15.25460.76.15.2551,022
560.76.16.0/2260.76.16.1 to 60.76.19.25460.76.19.2551,022
660.76.20.0/2260.76.20.1 to 60.76.23.25460.76.23.2551,022
760.76.24.0/2260.76.24.1 to 60.76.27.25460.76.27.2551,022
860.76.28.0/2260.76.28.1 to 60.76.31.25460.76.31.2551,022
960.76.32.0/2260.76.32.1 to 60.76.35.25460.76.35.2551,022
1060.76.36.0/2260.76.36.1 to 60.76.39.25460.76.39.2551,022
1160.76.40.0/2260.76.40.1 to 60.76.43.25460.76.43.2551,022
1260.76.44.0/2260.76.44.1 to 60.76.47.25460.76.47.2551,022
1360.76.48.0/2260.76.48.1 to 60.76.51.25460.76.51.2551,022
1460.76.52.0/2260.76.52.1 to 60.76.55.25460.76.55.2551,022
1560.76.56.0/2260.76.56.1 to 60.76.59.25460.76.59.2551,022
1660.76.60.0/2260.76.60.1 to 60.76.63.25460.76.63.2551,022
1760.76.64.0/2260.76.64.1 to 60.76.67.25460.76.67.2551,022
1860.76.68.0/2260.76.68.1 to 60.76.71.25460.76.71.2551,022
1960.76.72.0/2260.76.72.1 to 60.76.75.25460.76.75.2551,022
2060.76.76.0/2260.76.76.1 to 60.76.79.25460.76.79.2551,022
2160.76.80.0/2260.76.80.1 to 60.76.83.25460.76.83.2551,022
2260.76.84.0/2260.76.84.1 to 60.76.87.25460.76.87.2551,022
2360.76.88.0/2260.76.88.1 to 60.76.91.25460.76.91.2551,022
2460.76.92.0/2260.76.92.1 to 60.76.95.25460.76.95.2551,022
2560.76.96.0/2260.76.96.1 to 60.76.99.25460.76.99.2551,022
2660.76.100.0/2260.76.100.1 to 60.76.103.25460.76.103.2551,022
2760.76.104.0/2260.76.104.1 to 60.76.107.25460.76.107.2551,022
2860.76.108.0/2260.76.108.1 to 60.76.111.25460.76.111.2551,022
2960.76.112.0/2260.76.112.1 to 60.76.115.25460.76.115.2551,022
3060.76.116.0/2260.76.116.1 to 60.76.119.25460.76.119.2551,022
3160.76.120.0/2260.76.120.1 to 60.76.123.25460.76.123.2551,022
3260.76.124.0/2260.76.124.1 to 60.76.127.25460.76.127.2551,022
3360.76.128.0/2260.76.128.1 to 60.76.131.25460.76.131.2551,022
3460.76.132.0/2260.76.132.1 to 60.76.135.25460.76.135.2551,022
3560.76.136.0/2260.76.136.1 to 60.76.139.25460.76.139.2551,022
3660.76.140.0/2260.76.140.1 to 60.76.143.25460.76.143.2551,022
3760.76.144.0/2260.76.144.1 to 60.76.147.25460.76.147.2551,022
3860.76.148.0/2260.76.148.1 to 60.76.151.25460.76.151.2551,022
3960.76.152.0/2260.76.152.1 to 60.76.155.25460.76.155.2551,022
4060.76.156.0/2260.76.156.1 to 60.76.159.25460.76.159.2551,022
4160.76.160.0/2260.76.160.1 to 60.76.163.25460.76.163.2551,022
4260.76.164.0/2260.76.164.1 to 60.76.167.25460.76.167.2551,022
4360.76.168.0/2260.76.168.1 to 60.76.171.25460.76.171.2551,022
4460.76.172.0/2260.76.172.1 to 60.76.175.25460.76.175.2551,022
4560.76.176.0/2260.76.176.1 to 60.76.179.25460.76.179.2551,022
4660.76.180.0/2260.76.180.1 to 60.76.183.25460.76.183.2551,022
4760.76.184.0/2260.76.184.1 to 60.76.187.25460.76.187.2551,022
4860.76.188.0/2260.76.188.1 to 60.76.191.25460.76.191.2551,022
4960.76.192.0/2260.76.192.1 to 60.76.195.25460.76.195.2551,022
5060.76.196.0/2260.76.196.1 to 60.76.199.25460.76.199.2551,022
5160.76.200.0/2260.76.200.1 to 60.76.203.25460.76.203.2551,022
5260.76.204.0/2260.76.204.1 to 60.76.207.25460.76.207.2551,022
5360.76.208.0/2260.76.208.1 to 60.76.211.25460.76.211.2551,022
5460.76.212.0/2260.76.212.1 to 60.76.215.25460.76.215.2551,022
5560.76.216.0/2260.76.216.1 to 60.76.219.25460.76.219.2551,022
5660.76.220.0/2260.76.220.1 to 60.76.223.25460.76.223.2551,022
5760.76.224.0/2260.76.224.1 to 60.76.227.25460.76.227.2551,022
5860.76.228.0/2260.76.228.1 to 60.76.231.25460.76.231.2551,022
5960.76.232.0/2260.76.232.1 to 60.76.235.25460.76.235.2551,022
6060.76.236.0/2260.76.236.1 to 60.76.239.25460.76.239.2551,022
6160.76.240.0/2260.76.240.1 to 60.76.243.25460.76.243.2551,022
6260.76.244.0/2260.76.244.1 to 60.76.247.25460.76.247.2551,022
6360.76.248.0/2260.76.248.1 to 60.76.251.25460.76.251.2551,022
6460.76.252.0/2260.76.252.1 to 60.76.255.25460.76.255.2551,022
6560.77.0.0/2260.77.0.1 to 60.77.3.25460.77.3.2551,022
6660.77.4.0/2260.77.4.1 to 60.77.7.25460.77.7.2551,022
6760.77.8.0/2260.77.8.1 to 60.77.11.25460.77.11.2551,022
6860.77.12.0/2260.77.12.1 to 60.77.15.25460.77.15.2551,022
6960.77.16.0/2260.77.16.1 to 60.77.19.25460.77.19.2551,022
7060.77.20.0/2260.77.20.1 to 60.77.23.25460.77.23.2551,022
7160.77.24.0/2260.77.24.1 to 60.77.27.25460.77.27.2551,022
7260.77.28.0/2260.77.28.1 to 60.77.31.25460.77.31.2551,022
7360.77.32.0/2260.77.32.1 to 60.77.35.25460.77.35.2551,022
7460.77.36.0/2260.77.36.1 to 60.77.39.25460.77.39.2551,022
7560.77.40.0/2260.77.40.1 to 60.77.43.25460.77.43.2551,022
7660.77.44.0/2260.77.44.1 to 60.77.47.25460.77.47.2551,022
7760.77.48.0/2260.77.48.1 to 60.77.51.25460.77.51.2551,022
7860.77.52.0/2260.77.52.1 to 60.77.55.25460.77.55.2551,022
7960.77.56.0/2260.77.56.1 to 60.77.59.25460.77.59.2551,022
8060.77.60.0/2260.77.60.1 to 60.77.63.25460.77.63.2551,022
8160.77.64.0/2260.77.64.1 to 60.77.67.25460.77.67.2551,022
8260.77.68.0/2260.77.68.1 to 60.77.71.25460.77.71.2551,022
8360.77.72.0/2260.77.72.1 to 60.77.75.25460.77.75.2551,022
8460.77.76.0/2260.77.76.1 to 60.77.79.25460.77.79.2551,022
8560.77.80.0/2260.77.80.1 to 60.77.83.25460.77.83.2551,022
8660.77.84.0/2260.77.84.1 to 60.77.87.25460.77.87.2551,022
8760.77.88.0/2260.77.88.1 to 60.77.91.25460.77.91.2551,022
8860.77.92.0/2260.77.92.1 to 60.77.95.25460.77.95.2551,022
8960.77.96.0/2260.77.96.1 to 60.77.99.25460.77.99.2551,022
9060.77.100.0/2260.77.100.1 to 60.77.103.25460.77.103.2551,022
9160.77.104.0/2260.77.104.1 to 60.77.107.25460.77.107.2551,022
9260.77.108.0/2260.77.108.1 to 60.77.111.25460.77.111.2551,022
9360.77.112.0/2260.77.112.1 to 60.77.115.25460.77.115.2551,022
9460.77.116.0/2260.77.116.1 to 60.77.119.25460.77.119.2551,022
9560.77.120.0/2260.77.120.1 to 60.77.123.25460.77.123.2551,022
9660.77.124.0/2260.77.124.1 to 60.77.127.25460.77.127.2551,022
9760.77.128.0/2260.77.128.1 to 60.77.131.25460.77.131.2551,022
9860.77.132.0/2260.77.132.1 to 60.77.135.25460.77.135.2551,022
9960.77.136.0/2260.77.136.1 to 60.77.139.25460.77.139.2551,022
10060.77.140.0/2260.77.140.1 to 60.77.143.25460.77.143.2551,022
10160.77.144.0/2260.77.144.1 to 60.77.147.25460.77.147.2551,022
10260.77.148.0/2260.77.148.1 to 60.77.151.25460.77.151.2551,022
10360.77.152.0/2260.77.152.1 to 60.77.155.25460.77.155.2551,022
10460.77.156.0/2260.77.156.1 to 60.77.159.25460.77.159.2551,022
10560.77.160.0/2260.77.160.1 to 60.77.163.25460.77.163.2551,022
10660.77.164.0/2260.77.164.1 to 60.77.167.25460.77.167.2551,022
10760.77.168.0/2260.77.168.1 to 60.77.171.25460.77.171.2551,022
10860.77.172.0/2260.77.172.1 to 60.77.175.25460.77.175.2551,022
10960.77.176.0/2260.77.176.1 to 60.77.179.25460.77.179.2551,022
11060.77.180.0/2260.77.180.1 to 60.77.183.25460.77.183.2551,022
11160.77.184.0/2260.77.184.1 to 60.77.187.25460.77.187.2551,022
11260.77.188.0/2260.77.188.1 to 60.77.191.25460.77.191.2551,022
11360.77.192.0/2260.77.192.1 to 60.77.195.25460.77.195.2551,022
11460.77.196.0/2260.77.196.1 to 60.77.199.25460.77.199.2551,022
11560.77.200.0/2260.77.200.1 to 60.77.203.25460.77.203.2551,022
11660.77.204.0/2260.77.204.1 to 60.77.207.25460.77.207.2551,022
11760.77.208.0/2260.77.208.1 to 60.77.211.25460.77.211.2551,022
11860.77.212.0/2260.77.212.1 to 60.77.215.25460.77.215.2551,022
11960.77.216.0/2260.77.216.1 to 60.77.219.25460.77.219.2551,022
12060.77.220.0/2260.77.220.1 to 60.77.223.25460.77.223.2551,022
12160.77.224.0/2260.77.224.1 to 60.77.227.25460.77.227.2551,022
12260.77.228.0/2260.77.228.1 to 60.77.231.25460.77.231.2551,022
12360.77.232.0/2260.77.232.1 to 60.77.235.25460.77.235.2551,022
12460.77.236.0/2260.77.236.1 to 60.77.239.25460.77.239.2551,022
12560.77.240.0/2260.77.240.1 to 60.77.243.25460.77.243.2551,022
12660.77.244.0/2260.77.244.1 to 60.77.247.25460.77.247.2551,022
12760.77.248.0/2260.77.248.1 to 60.77.251.25460.77.251.2551,022
12860.77.252.0/2260.77.252.1 to 60.77.255.25460.77.255.2551,022

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.