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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.

Network67.167.252.0/22
Usable hosts1,022
Subnet mask255.255.252.0
Addresses1,024
Network address
67.167.252.0
Broadcast address
67.167.255.255
First usable
67.167.252.1
Last usable
67.167.255.254
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 43A7FC00 · Integer 1135082496 to 1135083519
Reverse DNS zones
252.167.67.in-addr.arpa
253.167.67.in-addr.arpa
254.167.67.in-addr.arpa
255.167.67.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
Address01000011.10100111.11111100.0000000067.167.252.0
Subnet mask11111111.11111111.11111100.00000000255.255.252.0
Network01000011.10100111.11111100.0000000067.167.252.0
Broadcast01000011.10100111.11111111.1111111167.167.255.255
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)

67.167.252.0/22 makes 64 subnets of /28.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
167.167.252.0/2867.167.252.1 to 67.167.252.1467.167.252.1514
267.167.252.16/2867.167.252.17 to 67.167.252.3067.167.252.3114
367.167.252.32/2867.167.252.33 to 67.167.252.4667.167.252.4714
467.167.252.48/2867.167.252.49 to 67.167.252.6267.167.252.6314
567.167.252.64/2867.167.252.65 to 67.167.252.7867.167.252.7914
667.167.252.80/2867.167.252.81 to 67.167.252.9467.167.252.9514
767.167.252.96/2867.167.252.97 to 67.167.252.11067.167.252.11114
867.167.252.112/2867.167.252.113 to 67.167.252.12667.167.252.12714
967.167.252.128/2867.167.252.129 to 67.167.252.14267.167.252.14314
1067.167.252.144/2867.167.252.145 to 67.167.252.15867.167.252.15914
1167.167.252.160/2867.167.252.161 to 67.167.252.17467.167.252.17514
1267.167.252.176/2867.167.252.177 to 67.167.252.19067.167.252.19114
1367.167.252.192/2867.167.252.193 to 67.167.252.20667.167.252.20714
1467.167.252.208/2867.167.252.209 to 67.167.252.22267.167.252.22314
1567.167.252.224/2867.167.252.225 to 67.167.252.23867.167.252.23914
1667.167.252.240/2867.167.252.241 to 67.167.252.25467.167.252.25514
1767.167.253.0/2867.167.253.1 to 67.167.253.1467.167.253.1514
1867.167.253.16/2867.167.253.17 to 67.167.253.3067.167.253.3114
1967.167.253.32/2867.167.253.33 to 67.167.253.4667.167.253.4714
2067.167.253.48/2867.167.253.49 to 67.167.253.6267.167.253.6314
2167.167.253.64/2867.167.253.65 to 67.167.253.7867.167.253.7914
2267.167.253.80/2867.167.253.81 to 67.167.253.9467.167.253.9514
2367.167.253.96/2867.167.253.97 to 67.167.253.11067.167.253.11114
2467.167.253.112/2867.167.253.113 to 67.167.253.12667.167.253.12714
2567.167.253.128/2867.167.253.129 to 67.167.253.14267.167.253.14314
2667.167.253.144/2867.167.253.145 to 67.167.253.15867.167.253.15914
2767.167.253.160/2867.167.253.161 to 67.167.253.17467.167.253.17514
2867.167.253.176/2867.167.253.177 to 67.167.253.19067.167.253.19114
2967.167.253.192/2867.167.253.193 to 67.167.253.20667.167.253.20714
3067.167.253.208/2867.167.253.209 to 67.167.253.22267.167.253.22314
3167.167.253.224/2867.167.253.225 to 67.167.253.23867.167.253.23914
3267.167.253.240/2867.167.253.241 to 67.167.253.25467.167.253.25514
3367.167.254.0/2867.167.254.1 to 67.167.254.1467.167.254.1514
3467.167.254.16/2867.167.254.17 to 67.167.254.3067.167.254.3114
3567.167.254.32/2867.167.254.33 to 67.167.254.4667.167.254.4714
3667.167.254.48/2867.167.254.49 to 67.167.254.6267.167.254.6314
3767.167.254.64/2867.167.254.65 to 67.167.254.7867.167.254.7914
3867.167.254.80/2867.167.254.81 to 67.167.254.9467.167.254.9514
3967.167.254.96/2867.167.254.97 to 67.167.254.11067.167.254.11114
4067.167.254.112/2867.167.254.113 to 67.167.254.12667.167.254.12714
4167.167.254.128/2867.167.254.129 to 67.167.254.14267.167.254.14314
4267.167.254.144/2867.167.254.145 to 67.167.254.15867.167.254.15914
4367.167.254.160/2867.167.254.161 to 67.167.254.17467.167.254.17514
4467.167.254.176/2867.167.254.177 to 67.167.254.19067.167.254.19114
4567.167.254.192/2867.167.254.193 to 67.167.254.20667.167.254.20714
4667.167.254.208/2867.167.254.209 to 67.167.254.22267.167.254.22314
4767.167.254.224/2867.167.254.225 to 67.167.254.23867.167.254.23914
4867.167.254.240/2867.167.254.241 to 67.167.254.25467.167.254.25514
4967.167.255.0/2867.167.255.1 to 67.167.255.1467.167.255.1514
5067.167.255.16/2867.167.255.17 to 67.167.255.3067.167.255.3114
5167.167.255.32/2867.167.255.33 to 67.167.255.4667.167.255.4714
5267.167.255.48/2867.167.255.49 to 67.167.255.6267.167.255.6314
5367.167.255.64/2867.167.255.65 to 67.167.255.7867.167.255.7914
5467.167.255.80/2867.167.255.81 to 67.167.255.9467.167.255.9514
5567.167.255.96/2867.167.255.97 to 67.167.255.11067.167.255.11114
5667.167.255.112/2867.167.255.113 to 67.167.255.12667.167.255.12714
5767.167.255.128/2867.167.255.129 to 67.167.255.14267.167.255.14314
5867.167.255.144/2867.167.255.145 to 67.167.255.15867.167.255.15914
5967.167.255.160/2867.167.255.161 to 67.167.255.17467.167.255.17514
6067.167.255.176/2867.167.255.177 to 67.167.255.19067.167.255.19114
6167.167.255.192/2867.167.255.193 to 67.167.255.20667.167.255.20714
6267.167.255.208/2867.167.255.209 to 67.167.255.22267.167.255.22314
6367.167.255.224/2867.167.255.225 to 67.167.255.23867.167.255.23914
6467.167.255.240/2867.167.255.241 to 67.167.255.25467.167.255.25514

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.