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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.

Network92.74.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
92.74.0.0
Broadcast address
92.75.255.255
First usable
92.74.0.1
Last usable
92.75.255.254
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 5C4A0000 · Integer 1548353536 to 1548484607
Reverse DNS zones
74.92.in-addr.arpa
75.92.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
Address01011100.01001010.00000000.0000000092.74.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network01011100.01001010.00000000.0000000092.74.0.0
Broadcast01011100.01001011.11111111.1111111192.75.255.255
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)

92.74.0.0/15 makes 128 subnets of /22.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
192.74.0.0/2292.74.0.1 to 92.74.3.25492.74.3.2551,022
292.74.4.0/2292.74.4.1 to 92.74.7.25492.74.7.2551,022
392.74.8.0/2292.74.8.1 to 92.74.11.25492.74.11.2551,022
492.74.12.0/2292.74.12.1 to 92.74.15.25492.74.15.2551,022
592.74.16.0/2292.74.16.1 to 92.74.19.25492.74.19.2551,022
692.74.20.0/2292.74.20.1 to 92.74.23.25492.74.23.2551,022
792.74.24.0/2292.74.24.1 to 92.74.27.25492.74.27.2551,022
892.74.28.0/2292.74.28.1 to 92.74.31.25492.74.31.2551,022
992.74.32.0/2292.74.32.1 to 92.74.35.25492.74.35.2551,022
1092.74.36.0/2292.74.36.1 to 92.74.39.25492.74.39.2551,022
1192.74.40.0/2292.74.40.1 to 92.74.43.25492.74.43.2551,022
1292.74.44.0/2292.74.44.1 to 92.74.47.25492.74.47.2551,022
1392.74.48.0/2292.74.48.1 to 92.74.51.25492.74.51.2551,022
1492.74.52.0/2292.74.52.1 to 92.74.55.25492.74.55.2551,022
1592.74.56.0/2292.74.56.1 to 92.74.59.25492.74.59.2551,022
1692.74.60.0/2292.74.60.1 to 92.74.63.25492.74.63.2551,022
1792.74.64.0/2292.74.64.1 to 92.74.67.25492.74.67.2551,022
1892.74.68.0/2292.74.68.1 to 92.74.71.25492.74.71.2551,022
1992.74.72.0/2292.74.72.1 to 92.74.75.25492.74.75.2551,022
2092.74.76.0/2292.74.76.1 to 92.74.79.25492.74.79.2551,022
2192.74.80.0/2292.74.80.1 to 92.74.83.25492.74.83.2551,022
2292.74.84.0/2292.74.84.1 to 92.74.87.25492.74.87.2551,022
2392.74.88.0/2292.74.88.1 to 92.74.91.25492.74.91.2551,022
2492.74.92.0/2292.74.92.1 to 92.74.95.25492.74.95.2551,022
2592.74.96.0/2292.74.96.1 to 92.74.99.25492.74.99.2551,022
2692.74.100.0/2292.74.100.1 to 92.74.103.25492.74.103.2551,022
2792.74.104.0/2292.74.104.1 to 92.74.107.25492.74.107.2551,022
2892.74.108.0/2292.74.108.1 to 92.74.111.25492.74.111.2551,022
2992.74.112.0/2292.74.112.1 to 92.74.115.25492.74.115.2551,022
3092.74.116.0/2292.74.116.1 to 92.74.119.25492.74.119.2551,022
3192.74.120.0/2292.74.120.1 to 92.74.123.25492.74.123.2551,022
3292.74.124.0/2292.74.124.1 to 92.74.127.25492.74.127.2551,022
3392.74.128.0/2292.74.128.1 to 92.74.131.25492.74.131.2551,022
3492.74.132.0/2292.74.132.1 to 92.74.135.25492.74.135.2551,022
3592.74.136.0/2292.74.136.1 to 92.74.139.25492.74.139.2551,022
3692.74.140.0/2292.74.140.1 to 92.74.143.25492.74.143.2551,022
3792.74.144.0/2292.74.144.1 to 92.74.147.25492.74.147.2551,022
3892.74.148.0/2292.74.148.1 to 92.74.151.25492.74.151.2551,022
3992.74.152.0/2292.74.152.1 to 92.74.155.25492.74.155.2551,022
4092.74.156.0/2292.74.156.1 to 92.74.159.25492.74.159.2551,022
4192.74.160.0/2292.74.160.1 to 92.74.163.25492.74.163.2551,022
4292.74.164.0/2292.74.164.1 to 92.74.167.25492.74.167.2551,022
4392.74.168.0/2292.74.168.1 to 92.74.171.25492.74.171.2551,022
4492.74.172.0/2292.74.172.1 to 92.74.175.25492.74.175.2551,022
4592.74.176.0/2292.74.176.1 to 92.74.179.25492.74.179.2551,022
4692.74.180.0/2292.74.180.1 to 92.74.183.25492.74.183.2551,022
4792.74.184.0/2292.74.184.1 to 92.74.187.25492.74.187.2551,022
4892.74.188.0/2292.74.188.1 to 92.74.191.25492.74.191.2551,022
4992.74.192.0/2292.74.192.1 to 92.74.195.25492.74.195.2551,022
5092.74.196.0/2292.74.196.1 to 92.74.199.25492.74.199.2551,022
5192.74.200.0/2292.74.200.1 to 92.74.203.25492.74.203.2551,022
5292.74.204.0/2292.74.204.1 to 92.74.207.25492.74.207.2551,022
5392.74.208.0/2292.74.208.1 to 92.74.211.25492.74.211.2551,022
5492.74.212.0/2292.74.212.1 to 92.74.215.25492.74.215.2551,022
5592.74.216.0/2292.74.216.1 to 92.74.219.25492.74.219.2551,022
5692.74.220.0/2292.74.220.1 to 92.74.223.25492.74.223.2551,022
5792.74.224.0/2292.74.224.1 to 92.74.227.25492.74.227.2551,022
5892.74.228.0/2292.74.228.1 to 92.74.231.25492.74.231.2551,022
5992.74.232.0/2292.74.232.1 to 92.74.235.25492.74.235.2551,022
6092.74.236.0/2292.74.236.1 to 92.74.239.25492.74.239.2551,022
6192.74.240.0/2292.74.240.1 to 92.74.243.25492.74.243.2551,022
6292.74.244.0/2292.74.244.1 to 92.74.247.25492.74.247.2551,022
6392.74.248.0/2292.74.248.1 to 92.74.251.25492.74.251.2551,022
6492.74.252.0/2292.74.252.1 to 92.74.255.25492.74.255.2551,022
6592.75.0.0/2292.75.0.1 to 92.75.3.25492.75.3.2551,022
6692.75.4.0/2292.75.4.1 to 92.75.7.25492.75.7.2551,022
6792.75.8.0/2292.75.8.1 to 92.75.11.25492.75.11.2551,022
6892.75.12.0/2292.75.12.1 to 92.75.15.25492.75.15.2551,022
6992.75.16.0/2292.75.16.1 to 92.75.19.25492.75.19.2551,022
7092.75.20.0/2292.75.20.1 to 92.75.23.25492.75.23.2551,022
7192.75.24.0/2292.75.24.1 to 92.75.27.25492.75.27.2551,022
7292.75.28.0/2292.75.28.1 to 92.75.31.25492.75.31.2551,022
7392.75.32.0/2292.75.32.1 to 92.75.35.25492.75.35.2551,022
7492.75.36.0/2292.75.36.1 to 92.75.39.25492.75.39.2551,022
7592.75.40.0/2292.75.40.1 to 92.75.43.25492.75.43.2551,022
7692.75.44.0/2292.75.44.1 to 92.75.47.25492.75.47.2551,022
7792.75.48.0/2292.75.48.1 to 92.75.51.25492.75.51.2551,022
7892.75.52.0/2292.75.52.1 to 92.75.55.25492.75.55.2551,022
7992.75.56.0/2292.75.56.1 to 92.75.59.25492.75.59.2551,022
8092.75.60.0/2292.75.60.1 to 92.75.63.25492.75.63.2551,022
8192.75.64.0/2292.75.64.1 to 92.75.67.25492.75.67.2551,022
8292.75.68.0/2292.75.68.1 to 92.75.71.25492.75.71.2551,022
8392.75.72.0/2292.75.72.1 to 92.75.75.25492.75.75.2551,022
8492.75.76.0/2292.75.76.1 to 92.75.79.25492.75.79.2551,022
8592.75.80.0/2292.75.80.1 to 92.75.83.25492.75.83.2551,022
8692.75.84.0/2292.75.84.1 to 92.75.87.25492.75.87.2551,022
8792.75.88.0/2292.75.88.1 to 92.75.91.25492.75.91.2551,022
8892.75.92.0/2292.75.92.1 to 92.75.95.25492.75.95.2551,022
8992.75.96.0/2292.75.96.1 to 92.75.99.25492.75.99.2551,022
9092.75.100.0/2292.75.100.1 to 92.75.103.25492.75.103.2551,022
9192.75.104.0/2292.75.104.1 to 92.75.107.25492.75.107.2551,022
9292.75.108.0/2292.75.108.1 to 92.75.111.25492.75.111.2551,022
9392.75.112.0/2292.75.112.1 to 92.75.115.25492.75.115.2551,022
9492.75.116.0/2292.75.116.1 to 92.75.119.25492.75.119.2551,022
9592.75.120.0/2292.75.120.1 to 92.75.123.25492.75.123.2551,022
9692.75.124.0/2292.75.124.1 to 92.75.127.25492.75.127.2551,022
9792.75.128.0/2292.75.128.1 to 92.75.131.25492.75.131.2551,022
9892.75.132.0/2292.75.132.1 to 92.75.135.25492.75.135.2551,022
9992.75.136.0/2292.75.136.1 to 92.75.139.25492.75.139.2551,022
10092.75.140.0/2292.75.140.1 to 92.75.143.25492.75.143.2551,022
10192.75.144.0/2292.75.144.1 to 92.75.147.25492.75.147.2551,022
10292.75.148.0/2292.75.148.1 to 92.75.151.25492.75.151.2551,022
10392.75.152.0/2292.75.152.1 to 92.75.155.25492.75.155.2551,022
10492.75.156.0/2292.75.156.1 to 92.75.159.25492.75.159.2551,022
10592.75.160.0/2292.75.160.1 to 92.75.163.25492.75.163.2551,022
10692.75.164.0/2292.75.164.1 to 92.75.167.25492.75.167.2551,022
10792.75.168.0/2292.75.168.1 to 92.75.171.25492.75.171.2551,022
10892.75.172.0/2292.75.172.1 to 92.75.175.25492.75.175.2551,022
10992.75.176.0/2292.75.176.1 to 92.75.179.25492.75.179.2551,022
11092.75.180.0/2292.75.180.1 to 92.75.183.25492.75.183.2551,022
11192.75.184.0/2292.75.184.1 to 92.75.187.25492.75.187.2551,022
11292.75.188.0/2292.75.188.1 to 92.75.191.25492.75.191.2551,022
11392.75.192.0/2292.75.192.1 to 92.75.195.25492.75.195.2551,022
11492.75.196.0/2292.75.196.1 to 92.75.199.25492.75.199.2551,022
11592.75.200.0/2292.75.200.1 to 92.75.203.25492.75.203.2551,022
11692.75.204.0/2292.75.204.1 to 92.75.207.25492.75.207.2551,022
11792.75.208.0/2292.75.208.1 to 92.75.211.25492.75.211.2551,022
11892.75.212.0/2292.75.212.1 to 92.75.215.25492.75.215.2551,022
11992.75.216.0/2292.75.216.1 to 92.75.219.25492.75.219.2551,022
12092.75.220.0/2292.75.220.1 to 92.75.223.25492.75.223.2551,022
12192.75.224.0/2292.75.224.1 to 92.75.227.25492.75.227.2551,022
12292.75.228.0/2292.75.228.1 to 92.75.231.25492.75.231.2551,022
12392.75.232.0/2292.75.232.1 to 92.75.235.25492.75.235.2551,022
12492.75.236.0/2292.75.236.1 to 92.75.239.25492.75.239.2551,022
12592.75.240.0/2292.75.240.1 to 92.75.243.25492.75.243.2551,022
12692.75.244.0/2292.75.244.1 to 92.75.247.25492.75.247.2551,022
12792.75.248.0/2292.75.248.1 to 92.75.251.25492.75.251.2551,022
12892.75.252.0/2292.75.252.1 to 92.75.255.25492.75.255.2551,022

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.