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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.

Network229.224.0.0/11
Usable hosts2,097,150
Subnet mask255.224.0.0
Addresses2,097,152
Network address
229.224.0.0
Broadcast address
229.255.255.255
First usable
229.224.0.1
Last usable
229.255.255.254
Usable hosts
2,097,150 (2,097,152 less the network and broadcast addresses)
Subnet mask
255.224.0.0
Wildcard mask
0.31.255.255 (Cisco ACLs, OSPF)
Prefix length
/11
Type
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E5E00000 · Integer 3856662528 to 3858759679
Reverse DNS zones
224.229.in-addr.arpa
225.229.in-addr.arpa
226.229.in-addr.arpa
227.229.in-addr.arpa
228.229.in-addr.arpa
229.229.in-addr.arpa
230.229.in-addr.arpa
231.229.in-addr.arpa
232.229.in-addr.arpa
233.229.in-addr.arpa
234.229.in-addr.arpa
235.229.in-addr.arpa
236.229.in-addr.arpa
237.229.in-addr.arpa
238.229.in-addr.arpa
239.229.in-addr.arpa
and 16 more
/11 is not on a 8-bit boundary, so it takes 32 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11100101.11100000.00000000.00000000229.224.0.0
Subnet mask11111111.11100000.00000000.00000000255.224.0.0
Network11100101.11100000.00000000.00000000229.224.0.0
Broadcast11100101.11111111.11111111.11111111229.255.255.255
Split into smaller subnets/17
/12 (2)/13 (4)/14 (8)/15 (16)/16 (32)/17 (64)/18 (128)/19 (256)/20 (512)/21 (1,024)/22 (2,048)/23 (4,096)

229.224.0.0/11 makes 64 subnets of /17.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1229.224.0.0/17229.224.0.1 to 229.224.127.254229.224.127.25532,766
2229.224.128.0/17229.224.128.1 to 229.224.255.254229.224.255.25532,766
3229.225.0.0/17229.225.0.1 to 229.225.127.254229.225.127.25532,766
4229.225.128.0/17229.225.128.1 to 229.225.255.254229.225.255.25532,766
5229.226.0.0/17229.226.0.1 to 229.226.127.254229.226.127.25532,766
6229.226.128.0/17229.226.128.1 to 229.226.255.254229.226.255.25532,766
7229.227.0.0/17229.227.0.1 to 229.227.127.254229.227.127.25532,766
8229.227.128.0/17229.227.128.1 to 229.227.255.254229.227.255.25532,766
9229.228.0.0/17229.228.0.1 to 229.228.127.254229.228.127.25532,766
10229.228.128.0/17229.228.128.1 to 229.228.255.254229.228.255.25532,766
11229.229.0.0/17229.229.0.1 to 229.229.127.254229.229.127.25532,766
12229.229.128.0/17229.229.128.1 to 229.229.255.254229.229.255.25532,766
13229.230.0.0/17229.230.0.1 to 229.230.127.254229.230.127.25532,766
14229.230.128.0/17229.230.128.1 to 229.230.255.254229.230.255.25532,766
15229.231.0.0/17229.231.0.1 to 229.231.127.254229.231.127.25532,766
16229.231.128.0/17229.231.128.1 to 229.231.255.254229.231.255.25532,766
17229.232.0.0/17229.232.0.1 to 229.232.127.254229.232.127.25532,766
18229.232.128.0/17229.232.128.1 to 229.232.255.254229.232.255.25532,766
19229.233.0.0/17229.233.0.1 to 229.233.127.254229.233.127.25532,766
20229.233.128.0/17229.233.128.1 to 229.233.255.254229.233.255.25532,766
21229.234.0.0/17229.234.0.1 to 229.234.127.254229.234.127.25532,766
22229.234.128.0/17229.234.128.1 to 229.234.255.254229.234.255.25532,766
23229.235.0.0/17229.235.0.1 to 229.235.127.254229.235.127.25532,766
24229.235.128.0/17229.235.128.1 to 229.235.255.254229.235.255.25532,766
25229.236.0.0/17229.236.0.1 to 229.236.127.254229.236.127.25532,766
26229.236.128.0/17229.236.128.1 to 229.236.255.254229.236.255.25532,766
27229.237.0.0/17229.237.0.1 to 229.237.127.254229.237.127.25532,766
28229.237.128.0/17229.237.128.1 to 229.237.255.254229.237.255.25532,766
29229.238.0.0/17229.238.0.1 to 229.238.127.254229.238.127.25532,766
30229.238.128.0/17229.238.128.1 to 229.238.255.254229.238.255.25532,766
31229.239.0.0/17229.239.0.1 to 229.239.127.254229.239.127.25532,766
32229.239.128.0/17229.239.128.1 to 229.239.255.254229.239.255.25532,766
33229.240.0.0/17229.240.0.1 to 229.240.127.254229.240.127.25532,766
34229.240.128.0/17229.240.128.1 to 229.240.255.254229.240.255.25532,766
35229.241.0.0/17229.241.0.1 to 229.241.127.254229.241.127.25532,766
36229.241.128.0/17229.241.128.1 to 229.241.255.254229.241.255.25532,766
37229.242.0.0/17229.242.0.1 to 229.242.127.254229.242.127.25532,766
38229.242.128.0/17229.242.128.1 to 229.242.255.254229.242.255.25532,766
39229.243.0.0/17229.243.0.1 to 229.243.127.254229.243.127.25532,766
40229.243.128.0/17229.243.128.1 to 229.243.255.254229.243.255.25532,766
41229.244.0.0/17229.244.0.1 to 229.244.127.254229.244.127.25532,766
42229.244.128.0/17229.244.128.1 to 229.244.255.254229.244.255.25532,766
43229.245.0.0/17229.245.0.1 to 229.245.127.254229.245.127.25532,766
44229.245.128.0/17229.245.128.1 to 229.245.255.254229.245.255.25532,766
45229.246.0.0/17229.246.0.1 to 229.246.127.254229.246.127.25532,766
46229.246.128.0/17229.246.128.1 to 229.246.255.254229.246.255.25532,766
47229.247.0.0/17229.247.0.1 to 229.247.127.254229.247.127.25532,766
48229.247.128.0/17229.247.128.1 to 229.247.255.254229.247.255.25532,766
49229.248.0.0/17229.248.0.1 to 229.248.127.254229.248.127.25532,766
50229.248.128.0/17229.248.128.1 to 229.248.255.254229.248.255.25532,766
51229.249.0.0/17229.249.0.1 to 229.249.127.254229.249.127.25532,766
52229.249.128.0/17229.249.128.1 to 229.249.255.254229.249.255.25532,766
53229.250.0.0/17229.250.0.1 to 229.250.127.254229.250.127.25532,766
54229.250.128.0/17229.250.128.1 to 229.250.255.254229.250.255.25532,766
55229.251.0.0/17229.251.0.1 to 229.251.127.254229.251.127.25532,766
56229.251.128.0/17229.251.128.1 to 229.251.255.254229.251.255.25532,766
57229.252.0.0/17229.252.0.1 to 229.252.127.254229.252.127.25532,766
58229.252.128.0/17229.252.128.1 to 229.252.255.254229.252.255.25532,766
59229.253.0.0/17229.253.0.1 to 229.253.127.254229.253.127.25532,766
60229.253.128.0/17229.253.128.1 to 229.253.255.254229.253.255.25532,766
61229.254.0.0/17229.254.0.1 to 229.254.127.254229.254.127.25532,766
62229.254.128.0/17229.254.128.1 to 229.254.255.254229.254.255.25532,766
63229.255.0.0/17229.255.0.1 to 229.255.127.254229.255.127.25532,766
64229.255.128.0/17229.255.128.1 to 229.255.255.254229.255.255.25532,766

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.