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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.

Network6.167.136.0/22
Usable hosts1,022
Subnet mask255.255.252.0
Addresses1,024
Network address
6.167.136.0
Broadcast address
6.167.139.255
First usable
6.167.136.1
Last usable
6.167.139.254
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 06A78800 · Integer 111642624 to 111643647
Reverse DNS zones
136.167.6.in-addr.arpa
137.167.6.in-addr.arpa
138.167.6.in-addr.arpa
139.167.6.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
Address00000110.10100111.10001000.000000006.167.136.0
Subnet mask11111111.11111111.11111100.00000000255.255.252.0
Network00000110.10100111.10001000.000000006.167.136.0
Broadcast00000110.10100111.10001011.111111116.167.139.255
Split into smaller subnets/29
/23 (2)/24 (4)/25 (8)/26 (16)/27 (32)/28 (64)/29 (128)/30 (256)/31 (512)/32 (1,024)

6.167.136.0/22 makes 128 subnets of /29.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
16.167.136.0/296.167.136.1 to 6.167.136.66.167.136.76
26.167.136.8/296.167.136.9 to 6.167.136.146.167.136.156
36.167.136.16/296.167.136.17 to 6.167.136.226.167.136.236
46.167.136.24/296.167.136.25 to 6.167.136.306.167.136.316
56.167.136.32/296.167.136.33 to 6.167.136.386.167.136.396
66.167.136.40/296.167.136.41 to 6.167.136.466.167.136.476
76.167.136.48/296.167.136.49 to 6.167.136.546.167.136.556
86.167.136.56/296.167.136.57 to 6.167.136.626.167.136.636
96.167.136.64/296.167.136.65 to 6.167.136.706.167.136.716
106.167.136.72/296.167.136.73 to 6.167.136.786.167.136.796
116.167.136.80/296.167.136.81 to 6.167.136.866.167.136.876
126.167.136.88/296.167.136.89 to 6.167.136.946.167.136.956
136.167.136.96/296.167.136.97 to 6.167.136.1026.167.136.1036
146.167.136.104/296.167.136.105 to 6.167.136.1106.167.136.1116
156.167.136.112/296.167.136.113 to 6.167.136.1186.167.136.1196
166.167.136.120/296.167.136.121 to 6.167.136.1266.167.136.1276
176.167.136.128/296.167.136.129 to 6.167.136.1346.167.136.1356
186.167.136.136/296.167.136.137 to 6.167.136.1426.167.136.1436
196.167.136.144/296.167.136.145 to 6.167.136.1506.167.136.1516
206.167.136.152/296.167.136.153 to 6.167.136.1586.167.136.1596
216.167.136.160/296.167.136.161 to 6.167.136.1666.167.136.1676
226.167.136.168/296.167.136.169 to 6.167.136.1746.167.136.1756
236.167.136.176/296.167.136.177 to 6.167.136.1826.167.136.1836
246.167.136.184/296.167.136.185 to 6.167.136.1906.167.136.1916
256.167.136.192/296.167.136.193 to 6.167.136.1986.167.136.1996
266.167.136.200/296.167.136.201 to 6.167.136.2066.167.136.2076
276.167.136.208/296.167.136.209 to 6.167.136.2146.167.136.2156
286.167.136.216/296.167.136.217 to 6.167.136.2226.167.136.2236
296.167.136.224/296.167.136.225 to 6.167.136.2306.167.136.2316
306.167.136.232/296.167.136.233 to 6.167.136.2386.167.136.2396
316.167.136.240/296.167.136.241 to 6.167.136.2466.167.136.2476
326.167.136.248/296.167.136.249 to 6.167.136.2546.167.136.2556
336.167.137.0/296.167.137.1 to 6.167.137.66.167.137.76
346.167.137.8/296.167.137.9 to 6.167.137.146.167.137.156
356.167.137.16/296.167.137.17 to 6.167.137.226.167.137.236
366.167.137.24/296.167.137.25 to 6.167.137.306.167.137.316
376.167.137.32/296.167.137.33 to 6.167.137.386.167.137.396
386.167.137.40/296.167.137.41 to 6.167.137.466.167.137.476
396.167.137.48/296.167.137.49 to 6.167.137.546.167.137.556
406.167.137.56/296.167.137.57 to 6.167.137.626.167.137.636
416.167.137.64/296.167.137.65 to 6.167.137.706.167.137.716
426.167.137.72/296.167.137.73 to 6.167.137.786.167.137.796
436.167.137.80/296.167.137.81 to 6.167.137.866.167.137.876
446.167.137.88/296.167.137.89 to 6.167.137.946.167.137.956
456.167.137.96/296.167.137.97 to 6.167.137.1026.167.137.1036
466.167.137.104/296.167.137.105 to 6.167.137.1106.167.137.1116
476.167.137.112/296.167.137.113 to 6.167.137.1186.167.137.1196
486.167.137.120/296.167.137.121 to 6.167.137.1266.167.137.1276
496.167.137.128/296.167.137.129 to 6.167.137.1346.167.137.1356
506.167.137.136/296.167.137.137 to 6.167.137.1426.167.137.1436
516.167.137.144/296.167.137.145 to 6.167.137.1506.167.137.1516
526.167.137.152/296.167.137.153 to 6.167.137.1586.167.137.1596
536.167.137.160/296.167.137.161 to 6.167.137.1666.167.137.1676
546.167.137.168/296.167.137.169 to 6.167.137.1746.167.137.1756
556.167.137.176/296.167.137.177 to 6.167.137.1826.167.137.1836
566.167.137.184/296.167.137.185 to 6.167.137.1906.167.137.1916
576.167.137.192/296.167.137.193 to 6.167.137.1986.167.137.1996
586.167.137.200/296.167.137.201 to 6.167.137.2066.167.137.2076
596.167.137.208/296.167.137.209 to 6.167.137.2146.167.137.2156
606.167.137.216/296.167.137.217 to 6.167.137.2226.167.137.2236
616.167.137.224/296.167.137.225 to 6.167.137.2306.167.137.2316
626.167.137.232/296.167.137.233 to 6.167.137.2386.167.137.2396
636.167.137.240/296.167.137.241 to 6.167.137.2466.167.137.2476
646.167.137.248/296.167.137.249 to 6.167.137.2546.167.137.2556
656.167.138.0/296.167.138.1 to 6.167.138.66.167.138.76
666.167.138.8/296.167.138.9 to 6.167.138.146.167.138.156
676.167.138.16/296.167.138.17 to 6.167.138.226.167.138.236
686.167.138.24/296.167.138.25 to 6.167.138.306.167.138.316
696.167.138.32/296.167.138.33 to 6.167.138.386.167.138.396
706.167.138.40/296.167.138.41 to 6.167.138.466.167.138.476
716.167.138.48/296.167.138.49 to 6.167.138.546.167.138.556
726.167.138.56/296.167.138.57 to 6.167.138.626.167.138.636
736.167.138.64/296.167.138.65 to 6.167.138.706.167.138.716
746.167.138.72/296.167.138.73 to 6.167.138.786.167.138.796
756.167.138.80/296.167.138.81 to 6.167.138.866.167.138.876
766.167.138.88/296.167.138.89 to 6.167.138.946.167.138.956
776.167.138.96/296.167.138.97 to 6.167.138.1026.167.138.1036
786.167.138.104/296.167.138.105 to 6.167.138.1106.167.138.1116
796.167.138.112/296.167.138.113 to 6.167.138.1186.167.138.1196
806.167.138.120/296.167.138.121 to 6.167.138.1266.167.138.1276
816.167.138.128/296.167.138.129 to 6.167.138.1346.167.138.1356
826.167.138.136/296.167.138.137 to 6.167.138.1426.167.138.1436
836.167.138.144/296.167.138.145 to 6.167.138.1506.167.138.1516
846.167.138.152/296.167.138.153 to 6.167.138.1586.167.138.1596
856.167.138.160/296.167.138.161 to 6.167.138.1666.167.138.1676
866.167.138.168/296.167.138.169 to 6.167.138.1746.167.138.1756
876.167.138.176/296.167.138.177 to 6.167.138.1826.167.138.1836
886.167.138.184/296.167.138.185 to 6.167.138.1906.167.138.1916
896.167.138.192/296.167.138.193 to 6.167.138.1986.167.138.1996
906.167.138.200/296.167.138.201 to 6.167.138.2066.167.138.2076
916.167.138.208/296.167.138.209 to 6.167.138.2146.167.138.2156
926.167.138.216/296.167.138.217 to 6.167.138.2226.167.138.2236
936.167.138.224/296.167.138.225 to 6.167.138.2306.167.138.2316
946.167.138.232/296.167.138.233 to 6.167.138.2386.167.138.2396
956.167.138.240/296.167.138.241 to 6.167.138.2466.167.138.2476
966.167.138.248/296.167.138.249 to 6.167.138.2546.167.138.2556
976.167.139.0/296.167.139.1 to 6.167.139.66.167.139.76
986.167.139.8/296.167.139.9 to 6.167.139.146.167.139.156
996.167.139.16/296.167.139.17 to 6.167.139.226.167.139.236
1006.167.139.24/296.167.139.25 to 6.167.139.306.167.139.316
1016.167.139.32/296.167.139.33 to 6.167.139.386.167.139.396
1026.167.139.40/296.167.139.41 to 6.167.139.466.167.139.476
1036.167.139.48/296.167.139.49 to 6.167.139.546.167.139.556
1046.167.139.56/296.167.139.57 to 6.167.139.626.167.139.636
1056.167.139.64/296.167.139.65 to 6.167.139.706.167.139.716
1066.167.139.72/296.167.139.73 to 6.167.139.786.167.139.796
1076.167.139.80/296.167.139.81 to 6.167.139.866.167.139.876
1086.167.139.88/296.167.139.89 to 6.167.139.946.167.139.956
1096.167.139.96/296.167.139.97 to 6.167.139.1026.167.139.1036
1106.167.139.104/296.167.139.105 to 6.167.139.1106.167.139.1116
1116.167.139.112/296.167.139.113 to 6.167.139.1186.167.139.1196
1126.167.139.120/296.167.139.121 to 6.167.139.1266.167.139.1276
1136.167.139.128/296.167.139.129 to 6.167.139.1346.167.139.1356
1146.167.139.136/296.167.139.137 to 6.167.139.1426.167.139.1436
1156.167.139.144/296.167.139.145 to 6.167.139.1506.167.139.1516
1166.167.139.152/296.167.139.153 to 6.167.139.1586.167.139.1596
1176.167.139.160/296.167.139.161 to 6.167.139.1666.167.139.1676
1186.167.139.168/296.167.139.169 to 6.167.139.1746.167.139.1756
1196.167.139.176/296.167.139.177 to 6.167.139.1826.167.139.1836
1206.167.139.184/296.167.139.185 to 6.167.139.1906.167.139.1916
1216.167.139.192/296.167.139.193 to 6.167.139.1986.167.139.1996
1226.167.139.200/296.167.139.201 to 6.167.139.2066.167.139.2076
1236.167.139.208/296.167.139.209 to 6.167.139.2146.167.139.2156
1246.167.139.216/296.167.139.217 to 6.167.139.2226.167.139.2236
1256.167.139.224/296.167.139.225 to 6.167.139.2306.167.139.2316
1266.167.139.232/296.167.139.233 to 6.167.139.2386.167.139.2396
1276.167.139.240/296.167.139.241 to 6.167.139.2466.167.139.2476
1286.167.139.248/296.167.139.249 to 6.167.139.2546.167.139.2556

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.