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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.

Network76.40.0.0/14
Usable hosts262,142
Subnet mask255.252.0.0
Addresses262,144
Network address
76.40.0.0
Broadcast address
76.43.255.255
First usable
76.40.0.1
Last usable
76.43.255.254
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 4C280000 · Integer 1277689856 to 1277951999
Reverse DNS zones
40.76.in-addr.arpa
41.76.in-addr.arpa
42.76.in-addr.arpa
43.76.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
Address01001100.00101000.00000000.0000000076.40.0.0
Subnet mask11111111.11111100.00000000.00000000255.252.0.0
Network01001100.00101000.00000000.0000000076.40.0.0
Broadcast01001100.00101011.11111111.1111111176.43.255.255
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)

76.40.0.0/14 makes 128 subnets of /21.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
176.40.0.0/2176.40.0.1 to 76.40.7.25476.40.7.2552,046
276.40.8.0/2176.40.8.1 to 76.40.15.25476.40.15.2552,046
376.40.16.0/2176.40.16.1 to 76.40.23.25476.40.23.2552,046
476.40.24.0/2176.40.24.1 to 76.40.31.25476.40.31.2552,046
576.40.32.0/2176.40.32.1 to 76.40.39.25476.40.39.2552,046
676.40.40.0/2176.40.40.1 to 76.40.47.25476.40.47.2552,046
776.40.48.0/2176.40.48.1 to 76.40.55.25476.40.55.2552,046
876.40.56.0/2176.40.56.1 to 76.40.63.25476.40.63.2552,046
976.40.64.0/2176.40.64.1 to 76.40.71.25476.40.71.2552,046
1076.40.72.0/2176.40.72.1 to 76.40.79.25476.40.79.2552,046
1176.40.80.0/2176.40.80.1 to 76.40.87.25476.40.87.2552,046
1276.40.88.0/2176.40.88.1 to 76.40.95.25476.40.95.2552,046
1376.40.96.0/2176.40.96.1 to 76.40.103.25476.40.103.2552,046
1476.40.104.0/2176.40.104.1 to 76.40.111.25476.40.111.2552,046
1576.40.112.0/2176.40.112.1 to 76.40.119.25476.40.119.2552,046
1676.40.120.0/2176.40.120.1 to 76.40.127.25476.40.127.2552,046
1776.40.128.0/2176.40.128.1 to 76.40.135.25476.40.135.2552,046
1876.40.136.0/2176.40.136.1 to 76.40.143.25476.40.143.2552,046
1976.40.144.0/2176.40.144.1 to 76.40.151.25476.40.151.2552,046
2076.40.152.0/2176.40.152.1 to 76.40.159.25476.40.159.2552,046
2176.40.160.0/2176.40.160.1 to 76.40.167.25476.40.167.2552,046
2276.40.168.0/2176.40.168.1 to 76.40.175.25476.40.175.2552,046
2376.40.176.0/2176.40.176.1 to 76.40.183.25476.40.183.2552,046
2476.40.184.0/2176.40.184.1 to 76.40.191.25476.40.191.2552,046
2576.40.192.0/2176.40.192.1 to 76.40.199.25476.40.199.2552,046
2676.40.200.0/2176.40.200.1 to 76.40.207.25476.40.207.2552,046
2776.40.208.0/2176.40.208.1 to 76.40.215.25476.40.215.2552,046
2876.40.216.0/2176.40.216.1 to 76.40.223.25476.40.223.2552,046
2976.40.224.0/2176.40.224.1 to 76.40.231.25476.40.231.2552,046
3076.40.232.0/2176.40.232.1 to 76.40.239.25476.40.239.2552,046
3176.40.240.0/2176.40.240.1 to 76.40.247.25476.40.247.2552,046
3276.40.248.0/2176.40.248.1 to 76.40.255.25476.40.255.2552,046
3376.41.0.0/2176.41.0.1 to 76.41.7.25476.41.7.2552,046
3476.41.8.0/2176.41.8.1 to 76.41.15.25476.41.15.2552,046
3576.41.16.0/2176.41.16.1 to 76.41.23.25476.41.23.2552,046
3676.41.24.0/2176.41.24.1 to 76.41.31.25476.41.31.2552,046
3776.41.32.0/2176.41.32.1 to 76.41.39.25476.41.39.2552,046
3876.41.40.0/2176.41.40.1 to 76.41.47.25476.41.47.2552,046
3976.41.48.0/2176.41.48.1 to 76.41.55.25476.41.55.2552,046
4076.41.56.0/2176.41.56.1 to 76.41.63.25476.41.63.2552,046
4176.41.64.0/2176.41.64.1 to 76.41.71.25476.41.71.2552,046
4276.41.72.0/2176.41.72.1 to 76.41.79.25476.41.79.2552,046
4376.41.80.0/2176.41.80.1 to 76.41.87.25476.41.87.2552,046
4476.41.88.0/2176.41.88.1 to 76.41.95.25476.41.95.2552,046
4576.41.96.0/2176.41.96.1 to 76.41.103.25476.41.103.2552,046
4676.41.104.0/2176.41.104.1 to 76.41.111.25476.41.111.2552,046
4776.41.112.0/2176.41.112.1 to 76.41.119.25476.41.119.2552,046
4876.41.120.0/2176.41.120.1 to 76.41.127.25476.41.127.2552,046
4976.41.128.0/2176.41.128.1 to 76.41.135.25476.41.135.2552,046
5076.41.136.0/2176.41.136.1 to 76.41.143.25476.41.143.2552,046
5176.41.144.0/2176.41.144.1 to 76.41.151.25476.41.151.2552,046
5276.41.152.0/2176.41.152.1 to 76.41.159.25476.41.159.2552,046
5376.41.160.0/2176.41.160.1 to 76.41.167.25476.41.167.2552,046
5476.41.168.0/2176.41.168.1 to 76.41.175.25476.41.175.2552,046
5576.41.176.0/2176.41.176.1 to 76.41.183.25476.41.183.2552,046
5676.41.184.0/2176.41.184.1 to 76.41.191.25476.41.191.2552,046
5776.41.192.0/2176.41.192.1 to 76.41.199.25476.41.199.2552,046
5876.41.200.0/2176.41.200.1 to 76.41.207.25476.41.207.2552,046
5976.41.208.0/2176.41.208.1 to 76.41.215.25476.41.215.2552,046
6076.41.216.0/2176.41.216.1 to 76.41.223.25476.41.223.2552,046
6176.41.224.0/2176.41.224.1 to 76.41.231.25476.41.231.2552,046
6276.41.232.0/2176.41.232.1 to 76.41.239.25476.41.239.2552,046
6376.41.240.0/2176.41.240.1 to 76.41.247.25476.41.247.2552,046
6476.41.248.0/2176.41.248.1 to 76.41.255.25476.41.255.2552,046
6576.42.0.0/2176.42.0.1 to 76.42.7.25476.42.7.2552,046
6676.42.8.0/2176.42.8.1 to 76.42.15.25476.42.15.2552,046
6776.42.16.0/2176.42.16.1 to 76.42.23.25476.42.23.2552,046
6876.42.24.0/2176.42.24.1 to 76.42.31.25476.42.31.2552,046
6976.42.32.0/2176.42.32.1 to 76.42.39.25476.42.39.2552,046
7076.42.40.0/2176.42.40.1 to 76.42.47.25476.42.47.2552,046
7176.42.48.0/2176.42.48.1 to 76.42.55.25476.42.55.2552,046
7276.42.56.0/2176.42.56.1 to 76.42.63.25476.42.63.2552,046
7376.42.64.0/2176.42.64.1 to 76.42.71.25476.42.71.2552,046
7476.42.72.0/2176.42.72.1 to 76.42.79.25476.42.79.2552,046
7576.42.80.0/2176.42.80.1 to 76.42.87.25476.42.87.2552,046
7676.42.88.0/2176.42.88.1 to 76.42.95.25476.42.95.2552,046
7776.42.96.0/2176.42.96.1 to 76.42.103.25476.42.103.2552,046
7876.42.104.0/2176.42.104.1 to 76.42.111.25476.42.111.2552,046
7976.42.112.0/2176.42.112.1 to 76.42.119.25476.42.119.2552,046
8076.42.120.0/2176.42.120.1 to 76.42.127.25476.42.127.2552,046
8176.42.128.0/2176.42.128.1 to 76.42.135.25476.42.135.2552,046
8276.42.136.0/2176.42.136.1 to 76.42.143.25476.42.143.2552,046
8376.42.144.0/2176.42.144.1 to 76.42.151.25476.42.151.2552,046
8476.42.152.0/2176.42.152.1 to 76.42.159.25476.42.159.2552,046
8576.42.160.0/2176.42.160.1 to 76.42.167.25476.42.167.2552,046
8676.42.168.0/2176.42.168.1 to 76.42.175.25476.42.175.2552,046
8776.42.176.0/2176.42.176.1 to 76.42.183.25476.42.183.2552,046
8876.42.184.0/2176.42.184.1 to 76.42.191.25476.42.191.2552,046
8976.42.192.0/2176.42.192.1 to 76.42.199.25476.42.199.2552,046
9076.42.200.0/2176.42.200.1 to 76.42.207.25476.42.207.2552,046
9176.42.208.0/2176.42.208.1 to 76.42.215.25476.42.215.2552,046
9276.42.216.0/2176.42.216.1 to 76.42.223.25476.42.223.2552,046
9376.42.224.0/2176.42.224.1 to 76.42.231.25476.42.231.2552,046
9476.42.232.0/2176.42.232.1 to 76.42.239.25476.42.239.2552,046
9576.42.240.0/2176.42.240.1 to 76.42.247.25476.42.247.2552,046
9676.42.248.0/2176.42.248.1 to 76.42.255.25476.42.255.2552,046
9776.43.0.0/2176.43.0.1 to 76.43.7.25476.43.7.2552,046
9876.43.8.0/2176.43.8.1 to 76.43.15.25476.43.15.2552,046
9976.43.16.0/2176.43.16.1 to 76.43.23.25476.43.23.2552,046
10076.43.24.0/2176.43.24.1 to 76.43.31.25476.43.31.2552,046
10176.43.32.0/2176.43.32.1 to 76.43.39.25476.43.39.2552,046
10276.43.40.0/2176.43.40.1 to 76.43.47.25476.43.47.2552,046
10376.43.48.0/2176.43.48.1 to 76.43.55.25476.43.55.2552,046
10476.43.56.0/2176.43.56.1 to 76.43.63.25476.43.63.2552,046
10576.43.64.0/2176.43.64.1 to 76.43.71.25476.43.71.2552,046
10676.43.72.0/2176.43.72.1 to 76.43.79.25476.43.79.2552,046
10776.43.80.0/2176.43.80.1 to 76.43.87.25476.43.87.2552,046
10876.43.88.0/2176.43.88.1 to 76.43.95.25476.43.95.2552,046
10976.43.96.0/2176.43.96.1 to 76.43.103.25476.43.103.2552,046
11076.43.104.0/2176.43.104.1 to 76.43.111.25476.43.111.2552,046
11176.43.112.0/2176.43.112.1 to 76.43.119.25476.43.119.2552,046
11276.43.120.0/2176.43.120.1 to 76.43.127.25476.43.127.2552,046
11376.43.128.0/2176.43.128.1 to 76.43.135.25476.43.135.2552,046
11476.43.136.0/2176.43.136.1 to 76.43.143.25476.43.143.2552,046
11576.43.144.0/2176.43.144.1 to 76.43.151.25476.43.151.2552,046
11676.43.152.0/2176.43.152.1 to 76.43.159.25476.43.159.2552,046
11776.43.160.0/2176.43.160.1 to 76.43.167.25476.43.167.2552,046
11876.43.168.0/2176.43.168.1 to 76.43.175.25476.43.175.2552,046
11976.43.176.0/2176.43.176.1 to 76.43.183.25476.43.183.2552,046
12076.43.184.0/2176.43.184.1 to 76.43.191.25476.43.191.2552,046
12176.43.192.0/2176.43.192.1 to 76.43.199.25476.43.199.2552,046
12276.43.200.0/2176.43.200.1 to 76.43.207.25476.43.207.2552,046
12376.43.208.0/2176.43.208.1 to 76.43.215.25476.43.215.2552,046
12476.43.216.0/2176.43.216.1 to 76.43.223.25476.43.223.2552,046
12576.43.224.0/2176.43.224.1 to 76.43.231.25476.43.231.2552,046
12676.43.232.0/2176.43.232.1 to 76.43.239.25476.43.239.2552,046
12776.43.240.0/2176.43.240.1 to 76.43.247.25476.43.247.2552,046
12876.43.248.0/2176.43.248.1 to 76.43.255.25476.43.255.2552,046

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.