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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.

Network0.212.0.0/14
Usable hosts262,142
Subnet mask255.252.0.0
Addresses262,144
Network address
0.212.0.0
Broadcast address
0.215.255.255
First usable
0.212.0.1
Last usable
0.215.255.254
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
This network 0.0.0.0/8
Not routed; 0.0.0.0 means "any address" in settings
Old class
A (default /8)
As numbers
Hex 00D40000 · Integer 13893632 to 14155775
Reverse DNS zones
212.0.in-addr.arpa
213.0.in-addr.arpa
214.0.in-addr.arpa
215.0.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
Address00000000.11010100.00000000.000000000.212.0.0
Subnet mask11111111.11111100.00000000.00000000255.252.0.0
Network00000000.11010100.00000000.000000000.212.0.0
Broadcast00000000.11010111.11111111.111111110.215.255.255
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)

0.212.0.0/14 makes 128 subnets of /21.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
10.212.0.0/210.212.0.1 to 0.212.7.2540.212.7.2552,046
20.212.8.0/210.212.8.1 to 0.212.15.2540.212.15.2552,046
30.212.16.0/210.212.16.1 to 0.212.23.2540.212.23.2552,046
40.212.24.0/210.212.24.1 to 0.212.31.2540.212.31.2552,046
50.212.32.0/210.212.32.1 to 0.212.39.2540.212.39.2552,046
60.212.40.0/210.212.40.1 to 0.212.47.2540.212.47.2552,046
70.212.48.0/210.212.48.1 to 0.212.55.2540.212.55.2552,046
80.212.56.0/210.212.56.1 to 0.212.63.2540.212.63.2552,046
90.212.64.0/210.212.64.1 to 0.212.71.2540.212.71.2552,046
100.212.72.0/210.212.72.1 to 0.212.79.2540.212.79.2552,046
110.212.80.0/210.212.80.1 to 0.212.87.2540.212.87.2552,046
120.212.88.0/210.212.88.1 to 0.212.95.2540.212.95.2552,046
130.212.96.0/210.212.96.1 to 0.212.103.2540.212.103.2552,046
140.212.104.0/210.212.104.1 to 0.212.111.2540.212.111.2552,046
150.212.112.0/210.212.112.1 to 0.212.119.2540.212.119.2552,046
160.212.120.0/210.212.120.1 to 0.212.127.2540.212.127.2552,046
170.212.128.0/210.212.128.1 to 0.212.135.2540.212.135.2552,046
180.212.136.0/210.212.136.1 to 0.212.143.2540.212.143.2552,046
190.212.144.0/210.212.144.1 to 0.212.151.2540.212.151.2552,046
200.212.152.0/210.212.152.1 to 0.212.159.2540.212.159.2552,046
210.212.160.0/210.212.160.1 to 0.212.167.2540.212.167.2552,046
220.212.168.0/210.212.168.1 to 0.212.175.2540.212.175.2552,046
230.212.176.0/210.212.176.1 to 0.212.183.2540.212.183.2552,046
240.212.184.0/210.212.184.1 to 0.212.191.2540.212.191.2552,046
250.212.192.0/210.212.192.1 to 0.212.199.2540.212.199.2552,046
260.212.200.0/210.212.200.1 to 0.212.207.2540.212.207.2552,046
270.212.208.0/210.212.208.1 to 0.212.215.2540.212.215.2552,046
280.212.216.0/210.212.216.1 to 0.212.223.2540.212.223.2552,046
290.212.224.0/210.212.224.1 to 0.212.231.2540.212.231.2552,046
300.212.232.0/210.212.232.1 to 0.212.239.2540.212.239.2552,046
310.212.240.0/210.212.240.1 to 0.212.247.2540.212.247.2552,046
320.212.248.0/210.212.248.1 to 0.212.255.2540.212.255.2552,046
330.213.0.0/210.213.0.1 to 0.213.7.2540.213.7.2552,046
340.213.8.0/210.213.8.1 to 0.213.15.2540.213.15.2552,046
350.213.16.0/210.213.16.1 to 0.213.23.2540.213.23.2552,046
360.213.24.0/210.213.24.1 to 0.213.31.2540.213.31.2552,046
370.213.32.0/210.213.32.1 to 0.213.39.2540.213.39.2552,046
380.213.40.0/210.213.40.1 to 0.213.47.2540.213.47.2552,046
390.213.48.0/210.213.48.1 to 0.213.55.2540.213.55.2552,046
400.213.56.0/210.213.56.1 to 0.213.63.2540.213.63.2552,046
410.213.64.0/210.213.64.1 to 0.213.71.2540.213.71.2552,046
420.213.72.0/210.213.72.1 to 0.213.79.2540.213.79.2552,046
430.213.80.0/210.213.80.1 to 0.213.87.2540.213.87.2552,046
440.213.88.0/210.213.88.1 to 0.213.95.2540.213.95.2552,046
450.213.96.0/210.213.96.1 to 0.213.103.2540.213.103.2552,046
460.213.104.0/210.213.104.1 to 0.213.111.2540.213.111.2552,046
470.213.112.0/210.213.112.1 to 0.213.119.2540.213.119.2552,046
480.213.120.0/210.213.120.1 to 0.213.127.2540.213.127.2552,046
490.213.128.0/210.213.128.1 to 0.213.135.2540.213.135.2552,046
500.213.136.0/210.213.136.1 to 0.213.143.2540.213.143.2552,046
510.213.144.0/210.213.144.1 to 0.213.151.2540.213.151.2552,046
520.213.152.0/210.213.152.1 to 0.213.159.2540.213.159.2552,046
530.213.160.0/210.213.160.1 to 0.213.167.2540.213.167.2552,046
540.213.168.0/210.213.168.1 to 0.213.175.2540.213.175.2552,046
550.213.176.0/210.213.176.1 to 0.213.183.2540.213.183.2552,046
560.213.184.0/210.213.184.1 to 0.213.191.2540.213.191.2552,046
570.213.192.0/210.213.192.1 to 0.213.199.2540.213.199.2552,046
580.213.200.0/210.213.200.1 to 0.213.207.2540.213.207.2552,046
590.213.208.0/210.213.208.1 to 0.213.215.2540.213.215.2552,046
600.213.216.0/210.213.216.1 to 0.213.223.2540.213.223.2552,046
610.213.224.0/210.213.224.1 to 0.213.231.2540.213.231.2552,046
620.213.232.0/210.213.232.1 to 0.213.239.2540.213.239.2552,046
630.213.240.0/210.213.240.1 to 0.213.247.2540.213.247.2552,046
640.213.248.0/210.213.248.1 to 0.213.255.2540.213.255.2552,046
650.214.0.0/210.214.0.1 to 0.214.7.2540.214.7.2552,046
660.214.8.0/210.214.8.1 to 0.214.15.2540.214.15.2552,046
670.214.16.0/210.214.16.1 to 0.214.23.2540.214.23.2552,046
680.214.24.0/210.214.24.1 to 0.214.31.2540.214.31.2552,046
690.214.32.0/210.214.32.1 to 0.214.39.2540.214.39.2552,046
700.214.40.0/210.214.40.1 to 0.214.47.2540.214.47.2552,046
710.214.48.0/210.214.48.1 to 0.214.55.2540.214.55.2552,046
720.214.56.0/210.214.56.1 to 0.214.63.2540.214.63.2552,046
730.214.64.0/210.214.64.1 to 0.214.71.2540.214.71.2552,046
740.214.72.0/210.214.72.1 to 0.214.79.2540.214.79.2552,046
750.214.80.0/210.214.80.1 to 0.214.87.2540.214.87.2552,046
760.214.88.0/210.214.88.1 to 0.214.95.2540.214.95.2552,046
770.214.96.0/210.214.96.1 to 0.214.103.2540.214.103.2552,046
780.214.104.0/210.214.104.1 to 0.214.111.2540.214.111.2552,046
790.214.112.0/210.214.112.1 to 0.214.119.2540.214.119.2552,046
800.214.120.0/210.214.120.1 to 0.214.127.2540.214.127.2552,046
810.214.128.0/210.214.128.1 to 0.214.135.2540.214.135.2552,046
820.214.136.0/210.214.136.1 to 0.214.143.2540.214.143.2552,046
830.214.144.0/210.214.144.1 to 0.214.151.2540.214.151.2552,046
840.214.152.0/210.214.152.1 to 0.214.159.2540.214.159.2552,046
850.214.160.0/210.214.160.1 to 0.214.167.2540.214.167.2552,046
860.214.168.0/210.214.168.1 to 0.214.175.2540.214.175.2552,046
870.214.176.0/210.214.176.1 to 0.214.183.2540.214.183.2552,046
880.214.184.0/210.214.184.1 to 0.214.191.2540.214.191.2552,046
890.214.192.0/210.214.192.1 to 0.214.199.2540.214.199.2552,046
900.214.200.0/210.214.200.1 to 0.214.207.2540.214.207.2552,046
910.214.208.0/210.214.208.1 to 0.214.215.2540.214.215.2552,046
920.214.216.0/210.214.216.1 to 0.214.223.2540.214.223.2552,046
930.214.224.0/210.214.224.1 to 0.214.231.2540.214.231.2552,046
940.214.232.0/210.214.232.1 to 0.214.239.2540.214.239.2552,046
950.214.240.0/210.214.240.1 to 0.214.247.2540.214.247.2552,046
960.214.248.0/210.214.248.1 to 0.214.255.2540.214.255.2552,046
970.215.0.0/210.215.0.1 to 0.215.7.2540.215.7.2552,046
980.215.8.0/210.215.8.1 to 0.215.15.2540.215.15.2552,046
990.215.16.0/210.215.16.1 to 0.215.23.2540.215.23.2552,046
1000.215.24.0/210.215.24.1 to 0.215.31.2540.215.31.2552,046
1010.215.32.0/210.215.32.1 to 0.215.39.2540.215.39.2552,046
1020.215.40.0/210.215.40.1 to 0.215.47.2540.215.47.2552,046
1030.215.48.0/210.215.48.1 to 0.215.55.2540.215.55.2552,046
1040.215.56.0/210.215.56.1 to 0.215.63.2540.215.63.2552,046
1050.215.64.0/210.215.64.1 to 0.215.71.2540.215.71.2552,046
1060.215.72.0/210.215.72.1 to 0.215.79.2540.215.79.2552,046
1070.215.80.0/210.215.80.1 to 0.215.87.2540.215.87.2552,046
1080.215.88.0/210.215.88.1 to 0.215.95.2540.215.95.2552,046
1090.215.96.0/210.215.96.1 to 0.215.103.2540.215.103.2552,046
1100.215.104.0/210.215.104.1 to 0.215.111.2540.215.111.2552,046
1110.215.112.0/210.215.112.1 to 0.215.119.2540.215.119.2552,046
1120.215.120.0/210.215.120.1 to 0.215.127.2540.215.127.2552,046
1130.215.128.0/210.215.128.1 to 0.215.135.2540.215.135.2552,046
1140.215.136.0/210.215.136.1 to 0.215.143.2540.215.143.2552,046
1150.215.144.0/210.215.144.1 to 0.215.151.2540.215.151.2552,046
1160.215.152.0/210.215.152.1 to 0.215.159.2540.215.159.2552,046
1170.215.160.0/210.215.160.1 to 0.215.167.2540.215.167.2552,046
1180.215.168.0/210.215.168.1 to 0.215.175.2540.215.175.2552,046
1190.215.176.0/210.215.176.1 to 0.215.183.2540.215.183.2552,046
1200.215.184.0/210.215.184.1 to 0.215.191.2540.215.191.2552,046
1210.215.192.0/210.215.192.1 to 0.215.199.2540.215.199.2552,046
1220.215.200.0/210.215.200.1 to 0.215.207.2540.215.207.2552,046
1230.215.208.0/210.215.208.1 to 0.215.215.2540.215.215.2552,046
1240.215.216.0/210.215.216.1 to 0.215.223.2540.215.223.2552,046
1250.215.224.0/210.215.224.1 to 0.215.231.2540.215.231.2552,046
1260.215.232.0/210.215.232.1 to 0.215.239.2540.215.239.2552,046
1270.215.240.0/210.215.240.1 to 0.215.247.2540.215.247.2552,046
1280.215.248.0/210.215.248.1 to 0.215.255.2540.215.255.2552,046

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.