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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.

Network29.167.4.0/22
Usable hosts1,022
Subnet mask255.255.252.0
Addresses1,024
Network address
29.167.4.0
Broadcast address
29.167.7.255
First usable
29.167.4.1
Last usable
29.167.7.254
Usable hosts
1,022 (1,024 less the network and broadcast addresses)
Subnet mask
255.255.252.0
Wildcard mask
0.0.3.255 (Cisco ACLs, OSPF)
Prefix length
/22
Type
Public public
Old class
A (default /8)
As numbers
Hex 1DA70400 · Integer 497484800 to 497485823
Reverse DNS zones
4.167.29.in-addr.arpa
5.167.29.in-addr.arpa
6.167.29.in-addr.arpa
7.167.29.in-addr.arpa
/22 is not on a 8-bit boundary, so it takes 4 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00011101.10100111.00000100.0000000029.167.4.0
Subnet mask11111111.11111111.11111100.00000000255.255.252.0
Network00011101.10100111.00000100.0000000029.167.4.0
Broadcast00011101.10100111.00000111.1111111129.167.7.255
Split into smaller subnets/28
/23 (2)/24 (4)/25 (8)/26 (16)/27 (32)/28 (64)/29 (128)/30 (256)/31 (512)/32 (1,024)

29.167.4.0/22 makes 64 subnets of /28.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
129.167.4.0/2829.167.4.1 to 29.167.4.1429.167.4.1514
229.167.4.16/2829.167.4.17 to 29.167.4.3029.167.4.3114
329.167.4.32/2829.167.4.33 to 29.167.4.4629.167.4.4714
429.167.4.48/2829.167.4.49 to 29.167.4.6229.167.4.6314
529.167.4.64/2829.167.4.65 to 29.167.4.7829.167.4.7914
629.167.4.80/2829.167.4.81 to 29.167.4.9429.167.4.9514
729.167.4.96/2829.167.4.97 to 29.167.4.11029.167.4.11114
829.167.4.112/2829.167.4.113 to 29.167.4.12629.167.4.12714
929.167.4.128/2829.167.4.129 to 29.167.4.14229.167.4.14314
1029.167.4.144/2829.167.4.145 to 29.167.4.15829.167.4.15914
1129.167.4.160/2829.167.4.161 to 29.167.4.17429.167.4.17514
1229.167.4.176/2829.167.4.177 to 29.167.4.19029.167.4.19114
1329.167.4.192/2829.167.4.193 to 29.167.4.20629.167.4.20714
1429.167.4.208/2829.167.4.209 to 29.167.4.22229.167.4.22314
1529.167.4.224/2829.167.4.225 to 29.167.4.23829.167.4.23914
1629.167.4.240/2829.167.4.241 to 29.167.4.25429.167.4.25514
1729.167.5.0/2829.167.5.1 to 29.167.5.1429.167.5.1514
1829.167.5.16/2829.167.5.17 to 29.167.5.3029.167.5.3114
1929.167.5.32/2829.167.5.33 to 29.167.5.4629.167.5.4714
2029.167.5.48/2829.167.5.49 to 29.167.5.6229.167.5.6314
2129.167.5.64/2829.167.5.65 to 29.167.5.7829.167.5.7914
2229.167.5.80/2829.167.5.81 to 29.167.5.9429.167.5.9514
2329.167.5.96/2829.167.5.97 to 29.167.5.11029.167.5.11114
2429.167.5.112/2829.167.5.113 to 29.167.5.12629.167.5.12714
2529.167.5.128/2829.167.5.129 to 29.167.5.14229.167.5.14314
2629.167.5.144/2829.167.5.145 to 29.167.5.15829.167.5.15914
2729.167.5.160/2829.167.5.161 to 29.167.5.17429.167.5.17514
2829.167.5.176/2829.167.5.177 to 29.167.5.19029.167.5.19114
2929.167.5.192/2829.167.5.193 to 29.167.5.20629.167.5.20714
3029.167.5.208/2829.167.5.209 to 29.167.5.22229.167.5.22314
3129.167.5.224/2829.167.5.225 to 29.167.5.23829.167.5.23914
3229.167.5.240/2829.167.5.241 to 29.167.5.25429.167.5.25514
3329.167.6.0/2829.167.6.1 to 29.167.6.1429.167.6.1514
3429.167.6.16/2829.167.6.17 to 29.167.6.3029.167.6.3114
3529.167.6.32/2829.167.6.33 to 29.167.6.4629.167.6.4714
3629.167.6.48/2829.167.6.49 to 29.167.6.6229.167.6.6314
3729.167.6.64/2829.167.6.65 to 29.167.6.7829.167.6.7914
3829.167.6.80/2829.167.6.81 to 29.167.6.9429.167.6.9514
3929.167.6.96/2829.167.6.97 to 29.167.6.11029.167.6.11114
4029.167.6.112/2829.167.6.113 to 29.167.6.12629.167.6.12714
4129.167.6.128/2829.167.6.129 to 29.167.6.14229.167.6.14314
4229.167.6.144/2829.167.6.145 to 29.167.6.15829.167.6.15914
4329.167.6.160/2829.167.6.161 to 29.167.6.17429.167.6.17514
4429.167.6.176/2829.167.6.177 to 29.167.6.19029.167.6.19114
4529.167.6.192/2829.167.6.193 to 29.167.6.20629.167.6.20714
4629.167.6.208/2829.167.6.209 to 29.167.6.22229.167.6.22314
4729.167.6.224/2829.167.6.225 to 29.167.6.23829.167.6.23914
4829.167.6.240/2829.167.6.241 to 29.167.6.25429.167.6.25514
4929.167.7.0/2829.167.7.1 to 29.167.7.1429.167.7.1514
5029.167.7.16/2829.167.7.17 to 29.167.7.3029.167.7.3114
5129.167.7.32/2829.167.7.33 to 29.167.7.4629.167.7.4714
5229.167.7.48/2829.167.7.49 to 29.167.7.6229.167.7.6314
5329.167.7.64/2829.167.7.65 to 29.167.7.7829.167.7.7914
5429.167.7.80/2829.167.7.81 to 29.167.7.9429.167.7.9514
5529.167.7.96/2829.167.7.97 to 29.167.7.11029.167.7.11114
5629.167.7.112/2829.167.7.113 to 29.167.7.12629.167.7.12714
5729.167.7.128/2829.167.7.129 to 29.167.7.14229.167.7.14314
5829.167.7.144/2829.167.7.145 to 29.167.7.15829.167.7.15914
5929.167.7.160/2829.167.7.161 to 29.167.7.17429.167.7.17514
6029.167.7.176/2829.167.7.177 to 29.167.7.19029.167.7.19114
6129.167.7.192/2829.167.7.193 to 29.167.7.20629.167.7.20714
6229.167.7.208/2829.167.7.209 to 29.167.7.22229.167.7.22314
6329.167.7.224/2829.167.7.225 to 29.167.7.23829.167.7.23914
6429.167.7.240/2829.167.7.241 to 29.167.7.25429.167.7.25514

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.