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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.

Network227.76.0.0/14
Usable hosts262,142
Subnet mask255.252.0.0
Addresses262,144
Network address
227.76.0.0
Broadcast address
227.79.255.255
First usable
227.76.0.1
Last usable
227.79.255.254
Usable hosts
262,142 (262,144 less the network and broadcast addresses)
Subnet mask
255.252.0.0
Wildcard mask
0.3.255.255 (Cisco ACLs, OSPF)
Prefix length
/14
Type
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E34C0000 · Integer 3813408768 to 3813670911
Reverse DNS zones
76.227.in-addr.arpa
77.227.in-addr.arpa
78.227.in-addr.arpa
79.227.in-addr.arpa
/14 is not on a 8-bit boundary, so it takes 4 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11100011.01001100.00000000.00000000227.76.0.0
Subnet mask11111111.11111100.00000000.00000000255.252.0.0
Network11100011.01001100.00000000.00000000227.76.0.0
Broadcast11100011.01001111.11111111.11111111227.79.255.255
Split into smaller subnets/21
/15 (2)/16 (4)/17 (8)/18 (16)/19 (32)/20 (64)/21 (128)/22 (256)/23 (512)/24 (1,024)/25 (2,048)/26 (4,096)

227.76.0.0/14 makes 128 subnets of /21.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1227.76.0.0/21227.76.0.1 to 227.76.7.254227.76.7.2552,046
2227.76.8.0/21227.76.8.1 to 227.76.15.254227.76.15.2552,046
3227.76.16.0/21227.76.16.1 to 227.76.23.254227.76.23.2552,046
4227.76.24.0/21227.76.24.1 to 227.76.31.254227.76.31.2552,046
5227.76.32.0/21227.76.32.1 to 227.76.39.254227.76.39.2552,046
6227.76.40.0/21227.76.40.1 to 227.76.47.254227.76.47.2552,046
7227.76.48.0/21227.76.48.1 to 227.76.55.254227.76.55.2552,046
8227.76.56.0/21227.76.56.1 to 227.76.63.254227.76.63.2552,046
9227.76.64.0/21227.76.64.1 to 227.76.71.254227.76.71.2552,046
10227.76.72.0/21227.76.72.1 to 227.76.79.254227.76.79.2552,046
11227.76.80.0/21227.76.80.1 to 227.76.87.254227.76.87.2552,046
12227.76.88.0/21227.76.88.1 to 227.76.95.254227.76.95.2552,046
13227.76.96.0/21227.76.96.1 to 227.76.103.254227.76.103.2552,046
14227.76.104.0/21227.76.104.1 to 227.76.111.254227.76.111.2552,046
15227.76.112.0/21227.76.112.1 to 227.76.119.254227.76.119.2552,046
16227.76.120.0/21227.76.120.1 to 227.76.127.254227.76.127.2552,046
17227.76.128.0/21227.76.128.1 to 227.76.135.254227.76.135.2552,046
18227.76.136.0/21227.76.136.1 to 227.76.143.254227.76.143.2552,046
19227.76.144.0/21227.76.144.1 to 227.76.151.254227.76.151.2552,046
20227.76.152.0/21227.76.152.1 to 227.76.159.254227.76.159.2552,046
21227.76.160.0/21227.76.160.1 to 227.76.167.254227.76.167.2552,046
22227.76.168.0/21227.76.168.1 to 227.76.175.254227.76.175.2552,046
23227.76.176.0/21227.76.176.1 to 227.76.183.254227.76.183.2552,046
24227.76.184.0/21227.76.184.1 to 227.76.191.254227.76.191.2552,046
25227.76.192.0/21227.76.192.1 to 227.76.199.254227.76.199.2552,046
26227.76.200.0/21227.76.200.1 to 227.76.207.254227.76.207.2552,046
27227.76.208.0/21227.76.208.1 to 227.76.215.254227.76.215.2552,046
28227.76.216.0/21227.76.216.1 to 227.76.223.254227.76.223.2552,046
29227.76.224.0/21227.76.224.1 to 227.76.231.254227.76.231.2552,046
30227.76.232.0/21227.76.232.1 to 227.76.239.254227.76.239.2552,046
31227.76.240.0/21227.76.240.1 to 227.76.247.254227.76.247.2552,046
32227.76.248.0/21227.76.248.1 to 227.76.255.254227.76.255.2552,046
33227.77.0.0/21227.77.0.1 to 227.77.7.254227.77.7.2552,046
34227.77.8.0/21227.77.8.1 to 227.77.15.254227.77.15.2552,046
35227.77.16.0/21227.77.16.1 to 227.77.23.254227.77.23.2552,046
36227.77.24.0/21227.77.24.1 to 227.77.31.254227.77.31.2552,046
37227.77.32.0/21227.77.32.1 to 227.77.39.254227.77.39.2552,046
38227.77.40.0/21227.77.40.1 to 227.77.47.254227.77.47.2552,046
39227.77.48.0/21227.77.48.1 to 227.77.55.254227.77.55.2552,046
40227.77.56.0/21227.77.56.1 to 227.77.63.254227.77.63.2552,046
41227.77.64.0/21227.77.64.1 to 227.77.71.254227.77.71.2552,046
42227.77.72.0/21227.77.72.1 to 227.77.79.254227.77.79.2552,046
43227.77.80.0/21227.77.80.1 to 227.77.87.254227.77.87.2552,046
44227.77.88.0/21227.77.88.1 to 227.77.95.254227.77.95.2552,046
45227.77.96.0/21227.77.96.1 to 227.77.103.254227.77.103.2552,046
46227.77.104.0/21227.77.104.1 to 227.77.111.254227.77.111.2552,046
47227.77.112.0/21227.77.112.1 to 227.77.119.254227.77.119.2552,046
48227.77.120.0/21227.77.120.1 to 227.77.127.254227.77.127.2552,046
49227.77.128.0/21227.77.128.1 to 227.77.135.254227.77.135.2552,046
50227.77.136.0/21227.77.136.1 to 227.77.143.254227.77.143.2552,046
51227.77.144.0/21227.77.144.1 to 227.77.151.254227.77.151.2552,046
52227.77.152.0/21227.77.152.1 to 227.77.159.254227.77.159.2552,046
53227.77.160.0/21227.77.160.1 to 227.77.167.254227.77.167.2552,046
54227.77.168.0/21227.77.168.1 to 227.77.175.254227.77.175.2552,046
55227.77.176.0/21227.77.176.1 to 227.77.183.254227.77.183.2552,046
56227.77.184.0/21227.77.184.1 to 227.77.191.254227.77.191.2552,046
57227.77.192.0/21227.77.192.1 to 227.77.199.254227.77.199.2552,046
58227.77.200.0/21227.77.200.1 to 227.77.207.254227.77.207.2552,046
59227.77.208.0/21227.77.208.1 to 227.77.215.254227.77.215.2552,046
60227.77.216.0/21227.77.216.1 to 227.77.223.254227.77.223.2552,046
61227.77.224.0/21227.77.224.1 to 227.77.231.254227.77.231.2552,046
62227.77.232.0/21227.77.232.1 to 227.77.239.254227.77.239.2552,046
63227.77.240.0/21227.77.240.1 to 227.77.247.254227.77.247.2552,046
64227.77.248.0/21227.77.248.1 to 227.77.255.254227.77.255.2552,046
65227.78.0.0/21227.78.0.1 to 227.78.7.254227.78.7.2552,046
66227.78.8.0/21227.78.8.1 to 227.78.15.254227.78.15.2552,046
67227.78.16.0/21227.78.16.1 to 227.78.23.254227.78.23.2552,046
68227.78.24.0/21227.78.24.1 to 227.78.31.254227.78.31.2552,046
69227.78.32.0/21227.78.32.1 to 227.78.39.254227.78.39.2552,046
70227.78.40.0/21227.78.40.1 to 227.78.47.254227.78.47.2552,046
71227.78.48.0/21227.78.48.1 to 227.78.55.254227.78.55.2552,046
72227.78.56.0/21227.78.56.1 to 227.78.63.254227.78.63.2552,046
73227.78.64.0/21227.78.64.1 to 227.78.71.254227.78.71.2552,046
74227.78.72.0/21227.78.72.1 to 227.78.79.254227.78.79.2552,046
75227.78.80.0/21227.78.80.1 to 227.78.87.254227.78.87.2552,046
76227.78.88.0/21227.78.88.1 to 227.78.95.254227.78.95.2552,046
77227.78.96.0/21227.78.96.1 to 227.78.103.254227.78.103.2552,046
78227.78.104.0/21227.78.104.1 to 227.78.111.254227.78.111.2552,046
79227.78.112.0/21227.78.112.1 to 227.78.119.254227.78.119.2552,046
80227.78.120.0/21227.78.120.1 to 227.78.127.254227.78.127.2552,046
81227.78.128.0/21227.78.128.1 to 227.78.135.254227.78.135.2552,046
82227.78.136.0/21227.78.136.1 to 227.78.143.254227.78.143.2552,046
83227.78.144.0/21227.78.144.1 to 227.78.151.254227.78.151.2552,046
84227.78.152.0/21227.78.152.1 to 227.78.159.254227.78.159.2552,046
85227.78.160.0/21227.78.160.1 to 227.78.167.254227.78.167.2552,046
86227.78.168.0/21227.78.168.1 to 227.78.175.254227.78.175.2552,046
87227.78.176.0/21227.78.176.1 to 227.78.183.254227.78.183.2552,046
88227.78.184.0/21227.78.184.1 to 227.78.191.254227.78.191.2552,046
89227.78.192.0/21227.78.192.1 to 227.78.199.254227.78.199.2552,046
90227.78.200.0/21227.78.200.1 to 227.78.207.254227.78.207.2552,046
91227.78.208.0/21227.78.208.1 to 227.78.215.254227.78.215.2552,046
92227.78.216.0/21227.78.216.1 to 227.78.223.254227.78.223.2552,046
93227.78.224.0/21227.78.224.1 to 227.78.231.254227.78.231.2552,046
94227.78.232.0/21227.78.232.1 to 227.78.239.254227.78.239.2552,046
95227.78.240.0/21227.78.240.1 to 227.78.247.254227.78.247.2552,046
96227.78.248.0/21227.78.248.1 to 227.78.255.254227.78.255.2552,046
97227.79.0.0/21227.79.0.1 to 227.79.7.254227.79.7.2552,046
98227.79.8.0/21227.79.8.1 to 227.79.15.254227.79.15.2552,046
99227.79.16.0/21227.79.16.1 to 227.79.23.254227.79.23.2552,046
100227.79.24.0/21227.79.24.1 to 227.79.31.254227.79.31.2552,046
101227.79.32.0/21227.79.32.1 to 227.79.39.254227.79.39.2552,046
102227.79.40.0/21227.79.40.1 to 227.79.47.254227.79.47.2552,046
103227.79.48.0/21227.79.48.1 to 227.79.55.254227.79.55.2552,046
104227.79.56.0/21227.79.56.1 to 227.79.63.254227.79.63.2552,046
105227.79.64.0/21227.79.64.1 to 227.79.71.254227.79.71.2552,046
106227.79.72.0/21227.79.72.1 to 227.79.79.254227.79.79.2552,046
107227.79.80.0/21227.79.80.1 to 227.79.87.254227.79.87.2552,046
108227.79.88.0/21227.79.88.1 to 227.79.95.254227.79.95.2552,046
109227.79.96.0/21227.79.96.1 to 227.79.103.254227.79.103.2552,046
110227.79.104.0/21227.79.104.1 to 227.79.111.254227.79.111.2552,046
111227.79.112.0/21227.79.112.1 to 227.79.119.254227.79.119.2552,046
112227.79.120.0/21227.79.120.1 to 227.79.127.254227.79.127.2552,046
113227.79.128.0/21227.79.128.1 to 227.79.135.254227.79.135.2552,046
114227.79.136.0/21227.79.136.1 to 227.79.143.254227.79.143.2552,046
115227.79.144.0/21227.79.144.1 to 227.79.151.254227.79.151.2552,046
116227.79.152.0/21227.79.152.1 to 227.79.159.254227.79.159.2552,046
117227.79.160.0/21227.79.160.1 to 227.79.167.254227.79.167.2552,046
118227.79.168.0/21227.79.168.1 to 227.79.175.254227.79.175.2552,046
119227.79.176.0/21227.79.176.1 to 227.79.183.254227.79.183.2552,046
120227.79.184.0/21227.79.184.1 to 227.79.191.254227.79.191.2552,046
121227.79.192.0/21227.79.192.1 to 227.79.199.254227.79.199.2552,046
122227.79.200.0/21227.79.200.1 to 227.79.207.254227.79.207.2552,046
123227.79.208.0/21227.79.208.1 to 227.79.215.254227.79.215.2552,046
124227.79.216.0/21227.79.216.1 to 227.79.223.254227.79.223.2552,046
125227.79.224.0/21227.79.224.1 to 227.79.231.254227.79.231.2552,046
126227.79.232.0/21227.79.232.1 to 227.79.239.254227.79.239.2552,046
127227.79.240.0/21227.79.240.1 to 227.79.247.254227.79.247.2552,046
128227.79.248.0/21227.79.248.1 to 227.79.255.254227.79.255.2552,046

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.