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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.

Network8.192.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
8.192.0.0
Broadcast address
8.199.255.255
First usable
8.192.0.1
Last usable
8.199.255.254
Usable hosts
524,286 (524,288 less the network and broadcast addresses)
Subnet mask
255.248.0.0
Wildcard mask
0.7.255.255 (Cisco ACLs, OSPF)
Prefix length
/13
Type
Public public
Old class
A (default /8)
As numbers
Hex 08C00000 · Integer 146800640 to 147324927
Reverse DNS zones
192.8.in-addr.arpa
193.8.in-addr.arpa
194.8.in-addr.arpa
195.8.in-addr.arpa
196.8.in-addr.arpa
197.8.in-addr.arpa
198.8.in-addr.arpa
199.8.in-addr.arpa
/13 is not on a 8-bit boundary, so it takes 8 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00001000.11000000.00000000.000000008.192.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network00001000.11000000.00000000.000000008.192.0.0
Broadcast00001000.11000111.11111111.111111118.199.255.255
Split into smaller subnets/20
/14 (2)/15 (4)/16 (8)/17 (16)/18 (32)/19 (64)/20 (128)/21 (256)/22 (512)/23 (1,024)/24 (2,048)/25 (4,096)

8.192.0.0/13 makes 128 subnets of /20.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
18.192.0.0/208.192.0.1 to 8.192.15.2548.192.15.2554,094
28.192.16.0/208.192.16.1 to 8.192.31.2548.192.31.2554,094
38.192.32.0/208.192.32.1 to 8.192.47.2548.192.47.2554,094
48.192.48.0/208.192.48.1 to 8.192.63.2548.192.63.2554,094
58.192.64.0/208.192.64.1 to 8.192.79.2548.192.79.2554,094
68.192.80.0/208.192.80.1 to 8.192.95.2548.192.95.2554,094
78.192.96.0/208.192.96.1 to 8.192.111.2548.192.111.2554,094
88.192.112.0/208.192.112.1 to 8.192.127.2548.192.127.2554,094
98.192.128.0/208.192.128.1 to 8.192.143.2548.192.143.2554,094
108.192.144.0/208.192.144.1 to 8.192.159.2548.192.159.2554,094
118.192.160.0/208.192.160.1 to 8.192.175.2548.192.175.2554,094
128.192.176.0/208.192.176.1 to 8.192.191.2548.192.191.2554,094
138.192.192.0/208.192.192.1 to 8.192.207.2548.192.207.2554,094
148.192.208.0/208.192.208.1 to 8.192.223.2548.192.223.2554,094
158.192.224.0/208.192.224.1 to 8.192.239.2548.192.239.2554,094
168.192.240.0/208.192.240.1 to 8.192.255.2548.192.255.2554,094
178.193.0.0/208.193.0.1 to 8.193.15.2548.193.15.2554,094
188.193.16.0/208.193.16.1 to 8.193.31.2548.193.31.2554,094
198.193.32.0/208.193.32.1 to 8.193.47.2548.193.47.2554,094
208.193.48.0/208.193.48.1 to 8.193.63.2548.193.63.2554,094
218.193.64.0/208.193.64.1 to 8.193.79.2548.193.79.2554,094
228.193.80.0/208.193.80.1 to 8.193.95.2548.193.95.2554,094
238.193.96.0/208.193.96.1 to 8.193.111.2548.193.111.2554,094
248.193.112.0/208.193.112.1 to 8.193.127.2548.193.127.2554,094
258.193.128.0/208.193.128.1 to 8.193.143.2548.193.143.2554,094
268.193.144.0/208.193.144.1 to 8.193.159.2548.193.159.2554,094
278.193.160.0/208.193.160.1 to 8.193.175.2548.193.175.2554,094
288.193.176.0/208.193.176.1 to 8.193.191.2548.193.191.2554,094
298.193.192.0/208.193.192.1 to 8.193.207.2548.193.207.2554,094
308.193.208.0/208.193.208.1 to 8.193.223.2548.193.223.2554,094
318.193.224.0/208.193.224.1 to 8.193.239.2548.193.239.2554,094
328.193.240.0/208.193.240.1 to 8.193.255.2548.193.255.2554,094
338.194.0.0/208.194.0.1 to 8.194.15.2548.194.15.2554,094
348.194.16.0/208.194.16.1 to 8.194.31.2548.194.31.2554,094
358.194.32.0/208.194.32.1 to 8.194.47.2548.194.47.2554,094
368.194.48.0/208.194.48.1 to 8.194.63.2548.194.63.2554,094
378.194.64.0/208.194.64.1 to 8.194.79.2548.194.79.2554,094
388.194.80.0/208.194.80.1 to 8.194.95.2548.194.95.2554,094
398.194.96.0/208.194.96.1 to 8.194.111.2548.194.111.2554,094
408.194.112.0/208.194.112.1 to 8.194.127.2548.194.127.2554,094
418.194.128.0/208.194.128.1 to 8.194.143.2548.194.143.2554,094
428.194.144.0/208.194.144.1 to 8.194.159.2548.194.159.2554,094
438.194.160.0/208.194.160.1 to 8.194.175.2548.194.175.2554,094
448.194.176.0/208.194.176.1 to 8.194.191.2548.194.191.2554,094
458.194.192.0/208.194.192.1 to 8.194.207.2548.194.207.2554,094
468.194.208.0/208.194.208.1 to 8.194.223.2548.194.223.2554,094
478.194.224.0/208.194.224.1 to 8.194.239.2548.194.239.2554,094
488.194.240.0/208.194.240.1 to 8.194.255.2548.194.255.2554,094
498.195.0.0/208.195.0.1 to 8.195.15.2548.195.15.2554,094
508.195.16.0/208.195.16.1 to 8.195.31.2548.195.31.2554,094
518.195.32.0/208.195.32.1 to 8.195.47.2548.195.47.2554,094
528.195.48.0/208.195.48.1 to 8.195.63.2548.195.63.2554,094
538.195.64.0/208.195.64.1 to 8.195.79.2548.195.79.2554,094
548.195.80.0/208.195.80.1 to 8.195.95.2548.195.95.2554,094
558.195.96.0/208.195.96.1 to 8.195.111.2548.195.111.2554,094
568.195.112.0/208.195.112.1 to 8.195.127.2548.195.127.2554,094
578.195.128.0/208.195.128.1 to 8.195.143.2548.195.143.2554,094
588.195.144.0/208.195.144.1 to 8.195.159.2548.195.159.2554,094
598.195.160.0/208.195.160.1 to 8.195.175.2548.195.175.2554,094
608.195.176.0/208.195.176.1 to 8.195.191.2548.195.191.2554,094
618.195.192.0/208.195.192.1 to 8.195.207.2548.195.207.2554,094
628.195.208.0/208.195.208.1 to 8.195.223.2548.195.223.2554,094
638.195.224.0/208.195.224.1 to 8.195.239.2548.195.239.2554,094
648.195.240.0/208.195.240.1 to 8.195.255.2548.195.255.2554,094
658.196.0.0/208.196.0.1 to 8.196.15.2548.196.15.2554,094
668.196.16.0/208.196.16.1 to 8.196.31.2548.196.31.2554,094
678.196.32.0/208.196.32.1 to 8.196.47.2548.196.47.2554,094
688.196.48.0/208.196.48.1 to 8.196.63.2548.196.63.2554,094
698.196.64.0/208.196.64.1 to 8.196.79.2548.196.79.2554,094
708.196.80.0/208.196.80.1 to 8.196.95.2548.196.95.2554,094
718.196.96.0/208.196.96.1 to 8.196.111.2548.196.111.2554,094
728.196.112.0/208.196.112.1 to 8.196.127.2548.196.127.2554,094
738.196.128.0/208.196.128.1 to 8.196.143.2548.196.143.2554,094
748.196.144.0/208.196.144.1 to 8.196.159.2548.196.159.2554,094
758.196.160.0/208.196.160.1 to 8.196.175.2548.196.175.2554,094
768.196.176.0/208.196.176.1 to 8.196.191.2548.196.191.2554,094
778.196.192.0/208.196.192.1 to 8.196.207.2548.196.207.2554,094
788.196.208.0/208.196.208.1 to 8.196.223.2548.196.223.2554,094
798.196.224.0/208.196.224.1 to 8.196.239.2548.196.239.2554,094
808.196.240.0/208.196.240.1 to 8.196.255.2548.196.255.2554,094
818.197.0.0/208.197.0.1 to 8.197.15.2548.197.15.2554,094
828.197.16.0/208.197.16.1 to 8.197.31.2548.197.31.2554,094
838.197.32.0/208.197.32.1 to 8.197.47.2548.197.47.2554,094
848.197.48.0/208.197.48.1 to 8.197.63.2548.197.63.2554,094
858.197.64.0/208.197.64.1 to 8.197.79.2548.197.79.2554,094
868.197.80.0/208.197.80.1 to 8.197.95.2548.197.95.2554,094
878.197.96.0/208.197.96.1 to 8.197.111.2548.197.111.2554,094
888.197.112.0/208.197.112.1 to 8.197.127.2548.197.127.2554,094
898.197.128.0/208.197.128.1 to 8.197.143.2548.197.143.2554,094
908.197.144.0/208.197.144.1 to 8.197.159.2548.197.159.2554,094
918.197.160.0/208.197.160.1 to 8.197.175.2548.197.175.2554,094
928.197.176.0/208.197.176.1 to 8.197.191.2548.197.191.2554,094
938.197.192.0/208.197.192.1 to 8.197.207.2548.197.207.2554,094
948.197.208.0/208.197.208.1 to 8.197.223.2548.197.223.2554,094
958.197.224.0/208.197.224.1 to 8.197.239.2548.197.239.2554,094
968.197.240.0/208.197.240.1 to 8.197.255.2548.197.255.2554,094
978.198.0.0/208.198.0.1 to 8.198.15.2548.198.15.2554,094
988.198.16.0/208.198.16.1 to 8.198.31.2548.198.31.2554,094
998.198.32.0/208.198.32.1 to 8.198.47.2548.198.47.2554,094
1008.198.48.0/208.198.48.1 to 8.198.63.2548.198.63.2554,094
1018.198.64.0/208.198.64.1 to 8.198.79.2548.198.79.2554,094
1028.198.80.0/208.198.80.1 to 8.198.95.2548.198.95.2554,094
1038.198.96.0/208.198.96.1 to 8.198.111.2548.198.111.2554,094
1048.198.112.0/208.198.112.1 to 8.198.127.2548.198.127.2554,094
1058.198.128.0/208.198.128.1 to 8.198.143.2548.198.143.2554,094
1068.198.144.0/208.198.144.1 to 8.198.159.2548.198.159.2554,094
1078.198.160.0/208.198.160.1 to 8.198.175.2548.198.175.2554,094
1088.198.176.0/208.198.176.1 to 8.198.191.2548.198.191.2554,094
1098.198.192.0/208.198.192.1 to 8.198.207.2548.198.207.2554,094
1108.198.208.0/208.198.208.1 to 8.198.223.2548.198.223.2554,094
1118.198.224.0/208.198.224.1 to 8.198.239.2548.198.239.2554,094
1128.198.240.0/208.198.240.1 to 8.198.255.2548.198.255.2554,094
1138.199.0.0/208.199.0.1 to 8.199.15.2548.199.15.2554,094
1148.199.16.0/208.199.16.1 to 8.199.31.2548.199.31.2554,094
1158.199.32.0/208.199.32.1 to 8.199.47.2548.199.47.2554,094
1168.199.48.0/208.199.48.1 to 8.199.63.2548.199.63.2554,094
1178.199.64.0/208.199.64.1 to 8.199.79.2548.199.79.2554,094
1188.199.80.0/208.199.80.1 to 8.199.95.2548.199.95.2554,094
1198.199.96.0/208.199.96.1 to 8.199.111.2548.199.111.2554,094
1208.199.112.0/208.199.112.1 to 8.199.127.2548.199.127.2554,094
1218.199.128.0/208.199.128.1 to 8.199.143.2548.199.143.2554,094
1228.199.144.0/208.199.144.1 to 8.199.159.2548.199.159.2554,094
1238.199.160.0/208.199.160.1 to 8.199.175.2548.199.175.2554,094
1248.199.176.0/208.199.176.1 to 8.199.191.2548.199.191.2554,094
1258.199.192.0/208.199.192.1 to 8.199.207.2548.199.207.2554,094
1268.199.208.0/208.199.208.1 to 8.199.223.2548.199.223.2554,094
1278.199.224.0/208.199.224.1 to 8.199.239.2548.199.239.2554,094
1288.199.240.0/208.199.240.1 to 8.199.255.2548.199.255.2554,094

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.