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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.

Network46.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
46.0.0.0
Broadcast address
47.255.255.255
First usable
46.0.0.1
Last usable
47.255.255.254
Usable hosts
33,554,430 (33,554,432 less the network and broadcast addresses)
Subnet mask
254.0.0.0
Wildcard mask
1.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/7
Type
Public public
Old class
A (default /8)
As numbers
Hex 2E000000 · Integer 771751936 to 805306367
Reverse DNS zones
46.in-addr.arpa
47.in-addr.arpa
/7 is not on a 8-bit boundary, so it takes 2 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00101110.00000000.00000000.0000000046.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network00101110.00000000.00000000.0000000046.0.0.0
Broadcast00101111.11111111.11111111.1111111147.255.255.255
Split into smaller subnets/14
/8 (2)/9 (4)/10 (8)/11 (16)/12 (32)/13 (64)/14 (128)/15 (256)/16 (512)/17 (1,024)/18 (2,048)/19 (4,096)

46.0.0.0/7 makes 128 subnets of /14.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
146.0.0.0/1446.0.0.1 to 46.3.255.25446.3.255.255262,142
246.4.0.0/1446.4.0.1 to 46.7.255.25446.7.255.255262,142
346.8.0.0/1446.8.0.1 to 46.11.255.25446.11.255.255262,142
446.12.0.0/1446.12.0.1 to 46.15.255.25446.15.255.255262,142
546.16.0.0/1446.16.0.1 to 46.19.255.25446.19.255.255262,142
646.20.0.0/1446.20.0.1 to 46.23.255.25446.23.255.255262,142
746.24.0.0/1446.24.0.1 to 46.27.255.25446.27.255.255262,142
846.28.0.0/1446.28.0.1 to 46.31.255.25446.31.255.255262,142
946.32.0.0/1446.32.0.1 to 46.35.255.25446.35.255.255262,142
1046.36.0.0/1446.36.0.1 to 46.39.255.25446.39.255.255262,142
1146.40.0.0/1446.40.0.1 to 46.43.255.25446.43.255.255262,142
1246.44.0.0/1446.44.0.1 to 46.47.255.25446.47.255.255262,142
1346.48.0.0/1446.48.0.1 to 46.51.255.25446.51.255.255262,142
1446.52.0.0/1446.52.0.1 to 46.55.255.25446.55.255.255262,142
1546.56.0.0/1446.56.0.1 to 46.59.255.25446.59.255.255262,142
1646.60.0.0/1446.60.0.1 to 46.63.255.25446.63.255.255262,142
1746.64.0.0/1446.64.0.1 to 46.67.255.25446.67.255.255262,142
1846.68.0.0/1446.68.0.1 to 46.71.255.25446.71.255.255262,142
1946.72.0.0/1446.72.0.1 to 46.75.255.25446.75.255.255262,142
2046.76.0.0/1446.76.0.1 to 46.79.255.25446.79.255.255262,142
2146.80.0.0/1446.80.0.1 to 46.83.255.25446.83.255.255262,142
2246.84.0.0/1446.84.0.1 to 46.87.255.25446.87.255.255262,142
2346.88.0.0/1446.88.0.1 to 46.91.255.25446.91.255.255262,142
2446.92.0.0/1446.92.0.1 to 46.95.255.25446.95.255.255262,142
2546.96.0.0/1446.96.0.1 to 46.99.255.25446.99.255.255262,142
2646.100.0.0/1446.100.0.1 to 46.103.255.25446.103.255.255262,142
2746.104.0.0/1446.104.0.1 to 46.107.255.25446.107.255.255262,142
2846.108.0.0/1446.108.0.1 to 46.111.255.25446.111.255.255262,142
2946.112.0.0/1446.112.0.1 to 46.115.255.25446.115.255.255262,142
3046.116.0.0/1446.116.0.1 to 46.119.255.25446.119.255.255262,142
3146.120.0.0/1446.120.0.1 to 46.123.255.25446.123.255.255262,142
3246.124.0.0/1446.124.0.1 to 46.127.255.25446.127.255.255262,142
3346.128.0.0/1446.128.0.1 to 46.131.255.25446.131.255.255262,142
3446.132.0.0/1446.132.0.1 to 46.135.255.25446.135.255.255262,142
3546.136.0.0/1446.136.0.1 to 46.139.255.25446.139.255.255262,142
3646.140.0.0/1446.140.0.1 to 46.143.255.25446.143.255.255262,142
3746.144.0.0/1446.144.0.1 to 46.147.255.25446.147.255.255262,142
3846.148.0.0/1446.148.0.1 to 46.151.255.25446.151.255.255262,142
3946.152.0.0/1446.152.0.1 to 46.155.255.25446.155.255.255262,142
4046.156.0.0/1446.156.0.1 to 46.159.255.25446.159.255.255262,142
4146.160.0.0/1446.160.0.1 to 46.163.255.25446.163.255.255262,142
4246.164.0.0/1446.164.0.1 to 46.167.255.25446.167.255.255262,142
4346.168.0.0/1446.168.0.1 to 46.171.255.25446.171.255.255262,142
4446.172.0.0/1446.172.0.1 to 46.175.255.25446.175.255.255262,142
4546.176.0.0/1446.176.0.1 to 46.179.255.25446.179.255.255262,142
4646.180.0.0/1446.180.0.1 to 46.183.255.25446.183.255.255262,142
4746.184.0.0/1446.184.0.1 to 46.187.255.25446.187.255.255262,142
4846.188.0.0/1446.188.0.1 to 46.191.255.25446.191.255.255262,142
4946.192.0.0/1446.192.0.1 to 46.195.255.25446.195.255.255262,142
5046.196.0.0/1446.196.0.1 to 46.199.255.25446.199.255.255262,142
5146.200.0.0/1446.200.0.1 to 46.203.255.25446.203.255.255262,142
5246.204.0.0/1446.204.0.1 to 46.207.255.25446.207.255.255262,142
5346.208.0.0/1446.208.0.1 to 46.211.255.25446.211.255.255262,142
5446.212.0.0/1446.212.0.1 to 46.215.255.25446.215.255.255262,142
5546.216.0.0/1446.216.0.1 to 46.219.255.25446.219.255.255262,142
5646.220.0.0/1446.220.0.1 to 46.223.255.25446.223.255.255262,142
5746.224.0.0/1446.224.0.1 to 46.227.255.25446.227.255.255262,142
5846.228.0.0/1446.228.0.1 to 46.231.255.25446.231.255.255262,142
5946.232.0.0/1446.232.0.1 to 46.235.255.25446.235.255.255262,142
6046.236.0.0/1446.236.0.1 to 46.239.255.25446.239.255.255262,142
6146.240.0.0/1446.240.0.1 to 46.243.255.25446.243.255.255262,142
6246.244.0.0/1446.244.0.1 to 46.247.255.25446.247.255.255262,142
6346.248.0.0/1446.248.0.1 to 46.251.255.25446.251.255.255262,142
6446.252.0.0/1446.252.0.1 to 46.255.255.25446.255.255.255262,142
6547.0.0.0/1447.0.0.1 to 47.3.255.25447.3.255.255262,142
6647.4.0.0/1447.4.0.1 to 47.7.255.25447.7.255.255262,142
6747.8.0.0/1447.8.0.1 to 47.11.255.25447.11.255.255262,142
6847.12.0.0/1447.12.0.1 to 47.15.255.25447.15.255.255262,142
6947.16.0.0/1447.16.0.1 to 47.19.255.25447.19.255.255262,142
7047.20.0.0/1447.20.0.1 to 47.23.255.25447.23.255.255262,142
7147.24.0.0/1447.24.0.1 to 47.27.255.25447.27.255.255262,142
7247.28.0.0/1447.28.0.1 to 47.31.255.25447.31.255.255262,142
7347.32.0.0/1447.32.0.1 to 47.35.255.25447.35.255.255262,142
7447.36.0.0/1447.36.0.1 to 47.39.255.25447.39.255.255262,142
7547.40.0.0/1447.40.0.1 to 47.43.255.25447.43.255.255262,142
7647.44.0.0/1447.44.0.1 to 47.47.255.25447.47.255.255262,142
7747.48.0.0/1447.48.0.1 to 47.51.255.25447.51.255.255262,142
7847.52.0.0/1447.52.0.1 to 47.55.255.25447.55.255.255262,142
7947.56.0.0/1447.56.0.1 to 47.59.255.25447.59.255.255262,142
8047.60.0.0/1447.60.0.1 to 47.63.255.25447.63.255.255262,142
8147.64.0.0/1447.64.0.1 to 47.67.255.25447.67.255.255262,142
8247.68.0.0/1447.68.0.1 to 47.71.255.25447.71.255.255262,142
8347.72.0.0/1447.72.0.1 to 47.75.255.25447.75.255.255262,142
8447.76.0.0/1447.76.0.1 to 47.79.255.25447.79.255.255262,142
8547.80.0.0/1447.80.0.1 to 47.83.255.25447.83.255.255262,142
8647.84.0.0/1447.84.0.1 to 47.87.255.25447.87.255.255262,142
8747.88.0.0/1447.88.0.1 to 47.91.255.25447.91.255.255262,142
8847.92.0.0/1447.92.0.1 to 47.95.255.25447.95.255.255262,142
8947.96.0.0/1447.96.0.1 to 47.99.255.25447.99.255.255262,142
9047.100.0.0/1447.100.0.1 to 47.103.255.25447.103.255.255262,142
9147.104.0.0/1447.104.0.1 to 47.107.255.25447.107.255.255262,142
9247.108.0.0/1447.108.0.1 to 47.111.255.25447.111.255.255262,142
9347.112.0.0/1447.112.0.1 to 47.115.255.25447.115.255.255262,142
9447.116.0.0/1447.116.0.1 to 47.119.255.25447.119.255.255262,142
9547.120.0.0/1447.120.0.1 to 47.123.255.25447.123.255.255262,142
9647.124.0.0/1447.124.0.1 to 47.127.255.25447.127.255.255262,142
9747.128.0.0/1447.128.0.1 to 47.131.255.25447.131.255.255262,142
9847.132.0.0/1447.132.0.1 to 47.135.255.25447.135.255.255262,142
9947.136.0.0/1447.136.0.1 to 47.139.255.25447.139.255.255262,142
10047.140.0.0/1447.140.0.1 to 47.143.255.25447.143.255.255262,142
10147.144.0.0/1447.144.0.1 to 47.147.255.25447.147.255.255262,142
10247.148.0.0/1447.148.0.1 to 47.151.255.25447.151.255.255262,142
10347.152.0.0/1447.152.0.1 to 47.155.255.25447.155.255.255262,142
10447.156.0.0/1447.156.0.1 to 47.159.255.25447.159.255.255262,142
10547.160.0.0/1447.160.0.1 to 47.163.255.25447.163.255.255262,142
10647.164.0.0/1447.164.0.1 to 47.167.255.25447.167.255.255262,142
10747.168.0.0/1447.168.0.1 to 47.171.255.25447.171.255.255262,142
10847.172.0.0/1447.172.0.1 to 47.175.255.25447.175.255.255262,142
10947.176.0.0/1447.176.0.1 to 47.179.255.25447.179.255.255262,142
11047.180.0.0/1447.180.0.1 to 47.183.255.25447.183.255.255262,142
11147.184.0.0/1447.184.0.1 to 47.187.255.25447.187.255.255262,142
11247.188.0.0/1447.188.0.1 to 47.191.255.25447.191.255.255262,142
11347.192.0.0/1447.192.0.1 to 47.195.255.25447.195.255.255262,142
11447.196.0.0/1447.196.0.1 to 47.199.255.25447.199.255.255262,142
11547.200.0.0/1447.200.0.1 to 47.203.255.25447.203.255.255262,142
11647.204.0.0/1447.204.0.1 to 47.207.255.25447.207.255.255262,142
11747.208.0.0/1447.208.0.1 to 47.211.255.25447.211.255.255262,142
11847.212.0.0/1447.212.0.1 to 47.215.255.25447.215.255.255262,142
11947.216.0.0/1447.216.0.1 to 47.219.255.25447.219.255.255262,142
12047.220.0.0/1447.220.0.1 to 47.223.255.25447.223.255.255262,142
12147.224.0.0/1447.224.0.1 to 47.227.255.25447.227.255.255262,142
12247.228.0.0/1447.228.0.1 to 47.231.255.25447.231.255.255262,142
12347.232.0.0/1447.232.0.1 to 47.235.255.25447.235.255.255262,142
12447.236.0.0/1447.236.0.1 to 47.239.255.25447.239.255.255262,142
12547.240.0.0/1447.240.0.1 to 47.243.255.25447.243.255.255262,142
12647.244.0.0/1447.244.0.1 to 47.247.255.25447.247.255.255262,142
12747.248.0.0/1447.248.0.1 to 47.251.255.25447.251.255.255262,142
12847.252.0.0/1447.252.0.1 to 47.255.255.25447.255.255.255262,142

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.