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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.

Network35.192.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
35.192.0.0
Broadcast address
35.255.255.255
First usable
35.192.0.1
Last usable
35.255.255.254
Usable hosts
4,194,302 (4,194,304 less the network and broadcast addresses)
Subnet mask
255.192.0.0
Wildcard mask
0.63.255.255 (Cisco ACLs, OSPF)
Prefix length
/10
Type
Public public
Old class
A (default /8)
As numbers
Hex 23C00000 · Integer 599785472 to 603979775
Reverse DNS zones
192.35.in-addr.arpa
193.35.in-addr.arpa
194.35.in-addr.arpa
195.35.in-addr.arpa
196.35.in-addr.arpa
197.35.in-addr.arpa
198.35.in-addr.arpa
199.35.in-addr.arpa
200.35.in-addr.arpa
201.35.in-addr.arpa
202.35.in-addr.arpa
203.35.in-addr.arpa
204.35.in-addr.arpa
205.35.in-addr.arpa
206.35.in-addr.arpa
207.35.in-addr.arpa
and 48 more
/10 is not on a 8-bit boundary, so it takes 64 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00100011.11000000.00000000.0000000035.192.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network00100011.11000000.00000000.0000000035.192.0.0
Broadcast00100011.11111111.11111111.1111111135.255.255.255
Split into smaller subnets/17
/11 (2)/12 (4)/13 (8)/14 (16)/15 (32)/16 (64)/17 (128)/18 (256)/19 (512)/20 (1,024)/21 (2,048)/22 (4,096)

35.192.0.0/10 makes 128 subnets of /17.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
135.192.0.0/1735.192.0.1 to 35.192.127.25435.192.127.25532,766
235.192.128.0/1735.192.128.1 to 35.192.255.25435.192.255.25532,766
335.193.0.0/1735.193.0.1 to 35.193.127.25435.193.127.25532,766
435.193.128.0/1735.193.128.1 to 35.193.255.25435.193.255.25532,766
535.194.0.0/1735.194.0.1 to 35.194.127.25435.194.127.25532,766
635.194.128.0/1735.194.128.1 to 35.194.255.25435.194.255.25532,766
735.195.0.0/1735.195.0.1 to 35.195.127.25435.195.127.25532,766
835.195.128.0/1735.195.128.1 to 35.195.255.25435.195.255.25532,766
935.196.0.0/1735.196.0.1 to 35.196.127.25435.196.127.25532,766
1035.196.128.0/1735.196.128.1 to 35.196.255.25435.196.255.25532,766
1135.197.0.0/1735.197.0.1 to 35.197.127.25435.197.127.25532,766
1235.197.128.0/1735.197.128.1 to 35.197.255.25435.197.255.25532,766
1335.198.0.0/1735.198.0.1 to 35.198.127.25435.198.127.25532,766
1435.198.128.0/1735.198.128.1 to 35.198.255.25435.198.255.25532,766
1535.199.0.0/1735.199.0.1 to 35.199.127.25435.199.127.25532,766
1635.199.128.0/1735.199.128.1 to 35.199.255.25435.199.255.25532,766
1735.200.0.0/1735.200.0.1 to 35.200.127.25435.200.127.25532,766
1835.200.128.0/1735.200.128.1 to 35.200.255.25435.200.255.25532,766
1935.201.0.0/1735.201.0.1 to 35.201.127.25435.201.127.25532,766
2035.201.128.0/1735.201.128.1 to 35.201.255.25435.201.255.25532,766
2135.202.0.0/1735.202.0.1 to 35.202.127.25435.202.127.25532,766
2235.202.128.0/1735.202.128.1 to 35.202.255.25435.202.255.25532,766
2335.203.0.0/1735.203.0.1 to 35.203.127.25435.203.127.25532,766
2435.203.128.0/1735.203.128.1 to 35.203.255.25435.203.255.25532,766
2535.204.0.0/1735.204.0.1 to 35.204.127.25435.204.127.25532,766
2635.204.128.0/1735.204.128.1 to 35.204.255.25435.204.255.25532,766
2735.205.0.0/1735.205.0.1 to 35.205.127.25435.205.127.25532,766
2835.205.128.0/1735.205.128.1 to 35.205.255.25435.205.255.25532,766
2935.206.0.0/1735.206.0.1 to 35.206.127.25435.206.127.25532,766
3035.206.128.0/1735.206.128.1 to 35.206.255.25435.206.255.25532,766
3135.207.0.0/1735.207.0.1 to 35.207.127.25435.207.127.25532,766
3235.207.128.0/1735.207.128.1 to 35.207.255.25435.207.255.25532,766
3335.208.0.0/1735.208.0.1 to 35.208.127.25435.208.127.25532,766
3435.208.128.0/1735.208.128.1 to 35.208.255.25435.208.255.25532,766
3535.209.0.0/1735.209.0.1 to 35.209.127.25435.209.127.25532,766
3635.209.128.0/1735.209.128.1 to 35.209.255.25435.209.255.25532,766
3735.210.0.0/1735.210.0.1 to 35.210.127.25435.210.127.25532,766
3835.210.128.0/1735.210.128.1 to 35.210.255.25435.210.255.25532,766
3935.211.0.0/1735.211.0.1 to 35.211.127.25435.211.127.25532,766
4035.211.128.0/1735.211.128.1 to 35.211.255.25435.211.255.25532,766
4135.212.0.0/1735.212.0.1 to 35.212.127.25435.212.127.25532,766
4235.212.128.0/1735.212.128.1 to 35.212.255.25435.212.255.25532,766
4335.213.0.0/1735.213.0.1 to 35.213.127.25435.213.127.25532,766
4435.213.128.0/1735.213.128.1 to 35.213.255.25435.213.255.25532,766
4535.214.0.0/1735.214.0.1 to 35.214.127.25435.214.127.25532,766
4635.214.128.0/1735.214.128.1 to 35.214.255.25435.214.255.25532,766
4735.215.0.0/1735.215.0.1 to 35.215.127.25435.215.127.25532,766
4835.215.128.0/1735.215.128.1 to 35.215.255.25435.215.255.25532,766
4935.216.0.0/1735.216.0.1 to 35.216.127.25435.216.127.25532,766
5035.216.128.0/1735.216.128.1 to 35.216.255.25435.216.255.25532,766
5135.217.0.0/1735.217.0.1 to 35.217.127.25435.217.127.25532,766
5235.217.128.0/1735.217.128.1 to 35.217.255.25435.217.255.25532,766
5335.218.0.0/1735.218.0.1 to 35.218.127.25435.218.127.25532,766
5435.218.128.0/1735.218.128.1 to 35.218.255.25435.218.255.25532,766
5535.219.0.0/1735.219.0.1 to 35.219.127.25435.219.127.25532,766
5635.219.128.0/1735.219.128.1 to 35.219.255.25435.219.255.25532,766
5735.220.0.0/1735.220.0.1 to 35.220.127.25435.220.127.25532,766
5835.220.128.0/1735.220.128.1 to 35.220.255.25435.220.255.25532,766
5935.221.0.0/1735.221.0.1 to 35.221.127.25435.221.127.25532,766
6035.221.128.0/1735.221.128.1 to 35.221.255.25435.221.255.25532,766
6135.222.0.0/1735.222.0.1 to 35.222.127.25435.222.127.25532,766
6235.222.128.0/1735.222.128.1 to 35.222.255.25435.222.255.25532,766
6335.223.0.0/1735.223.0.1 to 35.223.127.25435.223.127.25532,766
6435.223.128.0/1735.223.128.1 to 35.223.255.25435.223.255.25532,766
6535.224.0.0/1735.224.0.1 to 35.224.127.25435.224.127.25532,766
6635.224.128.0/1735.224.128.1 to 35.224.255.25435.224.255.25532,766
6735.225.0.0/1735.225.0.1 to 35.225.127.25435.225.127.25532,766
6835.225.128.0/1735.225.128.1 to 35.225.255.25435.225.255.25532,766
6935.226.0.0/1735.226.0.1 to 35.226.127.25435.226.127.25532,766
7035.226.128.0/1735.226.128.1 to 35.226.255.25435.226.255.25532,766
7135.227.0.0/1735.227.0.1 to 35.227.127.25435.227.127.25532,766
7235.227.128.0/1735.227.128.1 to 35.227.255.25435.227.255.25532,766
7335.228.0.0/1735.228.0.1 to 35.228.127.25435.228.127.25532,766
7435.228.128.0/1735.228.128.1 to 35.228.255.25435.228.255.25532,766
7535.229.0.0/1735.229.0.1 to 35.229.127.25435.229.127.25532,766
7635.229.128.0/1735.229.128.1 to 35.229.255.25435.229.255.25532,766
7735.230.0.0/1735.230.0.1 to 35.230.127.25435.230.127.25532,766
7835.230.128.0/1735.230.128.1 to 35.230.255.25435.230.255.25532,766
7935.231.0.0/1735.231.0.1 to 35.231.127.25435.231.127.25532,766
8035.231.128.0/1735.231.128.1 to 35.231.255.25435.231.255.25532,766
8135.232.0.0/1735.232.0.1 to 35.232.127.25435.232.127.25532,766
8235.232.128.0/1735.232.128.1 to 35.232.255.25435.232.255.25532,766
8335.233.0.0/1735.233.0.1 to 35.233.127.25435.233.127.25532,766
8435.233.128.0/1735.233.128.1 to 35.233.255.25435.233.255.25532,766
8535.234.0.0/1735.234.0.1 to 35.234.127.25435.234.127.25532,766
8635.234.128.0/1735.234.128.1 to 35.234.255.25435.234.255.25532,766
8735.235.0.0/1735.235.0.1 to 35.235.127.25435.235.127.25532,766
8835.235.128.0/1735.235.128.1 to 35.235.255.25435.235.255.25532,766
8935.236.0.0/1735.236.0.1 to 35.236.127.25435.236.127.25532,766
9035.236.128.0/1735.236.128.1 to 35.236.255.25435.236.255.25532,766
9135.237.0.0/1735.237.0.1 to 35.237.127.25435.237.127.25532,766
9235.237.128.0/1735.237.128.1 to 35.237.255.25435.237.255.25532,766
9335.238.0.0/1735.238.0.1 to 35.238.127.25435.238.127.25532,766
9435.238.128.0/1735.238.128.1 to 35.238.255.25435.238.255.25532,766
9535.239.0.0/1735.239.0.1 to 35.239.127.25435.239.127.25532,766
9635.239.128.0/1735.239.128.1 to 35.239.255.25435.239.255.25532,766
9735.240.0.0/1735.240.0.1 to 35.240.127.25435.240.127.25532,766
9835.240.128.0/1735.240.128.1 to 35.240.255.25435.240.255.25532,766
9935.241.0.0/1735.241.0.1 to 35.241.127.25435.241.127.25532,766
10035.241.128.0/1735.241.128.1 to 35.241.255.25435.241.255.25532,766
10135.242.0.0/1735.242.0.1 to 35.242.127.25435.242.127.25532,766
10235.242.128.0/1735.242.128.1 to 35.242.255.25435.242.255.25532,766
10335.243.0.0/1735.243.0.1 to 35.243.127.25435.243.127.25532,766
10435.243.128.0/1735.243.128.1 to 35.243.255.25435.243.255.25532,766
10535.244.0.0/1735.244.0.1 to 35.244.127.25435.244.127.25532,766
10635.244.128.0/1735.244.128.1 to 35.244.255.25435.244.255.25532,766
10735.245.0.0/1735.245.0.1 to 35.245.127.25435.245.127.25532,766
10835.245.128.0/1735.245.128.1 to 35.245.255.25435.245.255.25532,766
10935.246.0.0/1735.246.0.1 to 35.246.127.25435.246.127.25532,766
11035.246.128.0/1735.246.128.1 to 35.246.255.25435.246.255.25532,766
11135.247.0.0/1735.247.0.1 to 35.247.127.25435.247.127.25532,766
11235.247.128.0/1735.247.128.1 to 35.247.255.25435.247.255.25532,766
11335.248.0.0/1735.248.0.1 to 35.248.127.25435.248.127.25532,766
11435.248.128.0/1735.248.128.1 to 35.248.255.25435.248.255.25532,766
11535.249.0.0/1735.249.0.1 to 35.249.127.25435.249.127.25532,766
11635.249.128.0/1735.249.128.1 to 35.249.255.25435.249.255.25532,766
11735.250.0.0/1735.250.0.1 to 35.250.127.25435.250.127.25532,766
11835.250.128.0/1735.250.128.1 to 35.250.255.25435.250.255.25532,766
11935.251.0.0/1735.251.0.1 to 35.251.127.25435.251.127.25532,766
12035.251.128.0/1735.251.128.1 to 35.251.255.25435.251.255.25532,766
12135.252.0.0/1735.252.0.1 to 35.252.127.25435.252.127.25532,766
12235.252.128.0/1735.252.128.1 to 35.252.255.25435.252.255.25532,766
12335.253.0.0/1735.253.0.1 to 35.253.127.25435.253.127.25532,766
12435.253.128.0/1735.253.128.1 to 35.253.255.25435.253.255.25532,766
12535.254.0.0/1735.254.0.1 to 35.254.127.25435.254.127.25532,766
12635.254.128.0/1735.254.128.1 to 35.254.255.25435.254.255.25532,766
12735.255.0.0/1735.255.0.1 to 35.255.127.25435.255.127.25532,766
12835.255.128.0/1735.255.128.1 to 35.255.255.25435.255.255.25532,766

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.