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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.

Network127.128.0.0/11
Usable hosts2,097,150
Subnet mask255.224.0.0
Addresses2,097,152
Network address
127.128.0.0
Broadcast address
127.159.255.255
First usable
127.128.0.1
Last usable
127.159.255.254
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
Loopback 127.0.0.0/8
This computer
Old class
A (default /8)
As numbers
Hex 7F800000 · Integer 2139095040 to 2141192191
Reverse DNS zones
128.127.in-addr.arpa
129.127.in-addr.arpa
130.127.in-addr.arpa
131.127.in-addr.arpa
132.127.in-addr.arpa
133.127.in-addr.arpa
134.127.in-addr.arpa
135.127.in-addr.arpa
136.127.in-addr.arpa
137.127.in-addr.arpa
138.127.in-addr.arpa
139.127.in-addr.arpa
140.127.in-addr.arpa
141.127.in-addr.arpa
142.127.in-addr.arpa
143.127.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
Address01111111.10000000.00000000.00000000127.128.0.0
Subnet mask11111111.11100000.00000000.00000000255.224.0.0
Network01111111.10000000.00000000.00000000127.128.0.0
Broadcast01111111.10011111.11111111.11111111127.159.255.255
Split into smaller subnets/18

127.128.0.0/11 makes 128 subnets of /18.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1127.128.0.0/18127.128.0.1 to 127.128.63.254127.128.63.25516,382
2127.128.64.0/18127.128.64.1 to 127.128.127.254127.128.127.25516,382
3127.128.128.0/18127.128.128.1 to 127.128.191.254127.128.191.25516,382
4127.128.192.0/18127.128.192.1 to 127.128.255.254127.128.255.25516,382
5127.129.0.0/18127.129.0.1 to 127.129.63.254127.129.63.25516,382
6127.129.64.0/18127.129.64.1 to 127.129.127.254127.129.127.25516,382
7127.129.128.0/18127.129.128.1 to 127.129.191.254127.129.191.25516,382
8127.129.192.0/18127.129.192.1 to 127.129.255.254127.129.255.25516,382
9127.130.0.0/18127.130.0.1 to 127.130.63.254127.130.63.25516,382
10127.130.64.0/18127.130.64.1 to 127.130.127.254127.130.127.25516,382
11127.130.128.0/18127.130.128.1 to 127.130.191.254127.130.191.25516,382
12127.130.192.0/18127.130.192.1 to 127.130.255.254127.130.255.25516,382
13127.131.0.0/18127.131.0.1 to 127.131.63.254127.131.63.25516,382
14127.131.64.0/18127.131.64.1 to 127.131.127.254127.131.127.25516,382
15127.131.128.0/18127.131.128.1 to 127.131.191.254127.131.191.25516,382
16127.131.192.0/18127.131.192.1 to 127.131.255.254127.131.255.25516,382
17127.132.0.0/18127.132.0.1 to 127.132.63.254127.132.63.25516,382
18127.132.64.0/18127.132.64.1 to 127.132.127.254127.132.127.25516,382
19127.132.128.0/18127.132.128.1 to 127.132.191.254127.132.191.25516,382
20127.132.192.0/18127.132.192.1 to 127.132.255.254127.132.255.25516,382
21127.133.0.0/18127.133.0.1 to 127.133.63.254127.133.63.25516,382
22127.133.64.0/18127.133.64.1 to 127.133.127.254127.133.127.25516,382
23127.133.128.0/18127.133.128.1 to 127.133.191.254127.133.191.25516,382
24127.133.192.0/18127.133.192.1 to 127.133.255.254127.133.255.25516,382
25127.134.0.0/18127.134.0.1 to 127.134.63.254127.134.63.25516,382
26127.134.64.0/18127.134.64.1 to 127.134.127.254127.134.127.25516,382
27127.134.128.0/18127.134.128.1 to 127.134.191.254127.134.191.25516,382
28127.134.192.0/18127.134.192.1 to 127.134.255.254127.134.255.25516,382
29127.135.0.0/18127.135.0.1 to 127.135.63.254127.135.63.25516,382
30127.135.64.0/18127.135.64.1 to 127.135.127.254127.135.127.25516,382
31127.135.128.0/18127.135.128.1 to 127.135.191.254127.135.191.25516,382
32127.135.192.0/18127.135.192.1 to 127.135.255.254127.135.255.25516,382
33127.136.0.0/18127.136.0.1 to 127.136.63.254127.136.63.25516,382
34127.136.64.0/18127.136.64.1 to 127.136.127.254127.136.127.25516,382
35127.136.128.0/18127.136.128.1 to 127.136.191.254127.136.191.25516,382
36127.136.192.0/18127.136.192.1 to 127.136.255.254127.136.255.25516,382
37127.137.0.0/18127.137.0.1 to 127.137.63.254127.137.63.25516,382
38127.137.64.0/18127.137.64.1 to 127.137.127.254127.137.127.25516,382
39127.137.128.0/18127.137.128.1 to 127.137.191.254127.137.191.25516,382
40127.137.192.0/18127.137.192.1 to 127.137.255.254127.137.255.25516,382
41127.138.0.0/18127.138.0.1 to 127.138.63.254127.138.63.25516,382
42127.138.64.0/18127.138.64.1 to 127.138.127.254127.138.127.25516,382
43127.138.128.0/18127.138.128.1 to 127.138.191.254127.138.191.25516,382
44127.138.192.0/18127.138.192.1 to 127.138.255.254127.138.255.25516,382
45127.139.0.0/18127.139.0.1 to 127.139.63.254127.139.63.25516,382
46127.139.64.0/18127.139.64.1 to 127.139.127.254127.139.127.25516,382
47127.139.128.0/18127.139.128.1 to 127.139.191.254127.139.191.25516,382
48127.139.192.0/18127.139.192.1 to 127.139.255.254127.139.255.25516,382
49127.140.0.0/18127.140.0.1 to 127.140.63.254127.140.63.25516,382
50127.140.64.0/18127.140.64.1 to 127.140.127.254127.140.127.25516,382
51127.140.128.0/18127.140.128.1 to 127.140.191.254127.140.191.25516,382
52127.140.192.0/18127.140.192.1 to 127.140.255.254127.140.255.25516,382
53127.141.0.0/18127.141.0.1 to 127.141.63.254127.141.63.25516,382
54127.141.64.0/18127.141.64.1 to 127.141.127.254127.141.127.25516,382
55127.141.128.0/18127.141.128.1 to 127.141.191.254127.141.191.25516,382
56127.141.192.0/18127.141.192.1 to 127.141.255.254127.141.255.25516,382
57127.142.0.0/18127.142.0.1 to 127.142.63.254127.142.63.25516,382
58127.142.64.0/18127.142.64.1 to 127.142.127.254127.142.127.25516,382
59127.142.128.0/18127.142.128.1 to 127.142.191.254127.142.191.25516,382
60127.142.192.0/18127.142.192.1 to 127.142.255.254127.142.255.25516,382
61127.143.0.0/18127.143.0.1 to 127.143.63.254127.143.63.25516,382
62127.143.64.0/18127.143.64.1 to 127.143.127.254127.143.127.25516,382
63127.143.128.0/18127.143.128.1 to 127.143.191.254127.143.191.25516,382
64127.143.192.0/18127.143.192.1 to 127.143.255.254127.143.255.25516,382
65127.144.0.0/18127.144.0.1 to 127.144.63.254127.144.63.25516,382
66127.144.64.0/18127.144.64.1 to 127.144.127.254127.144.127.25516,382
67127.144.128.0/18127.144.128.1 to 127.144.191.254127.144.191.25516,382
68127.144.192.0/18127.144.192.1 to 127.144.255.254127.144.255.25516,382
69127.145.0.0/18127.145.0.1 to 127.145.63.254127.145.63.25516,382
70127.145.64.0/18127.145.64.1 to 127.145.127.254127.145.127.25516,382
71127.145.128.0/18127.145.128.1 to 127.145.191.254127.145.191.25516,382
72127.145.192.0/18127.145.192.1 to 127.145.255.254127.145.255.25516,382
73127.146.0.0/18127.146.0.1 to 127.146.63.254127.146.63.25516,382
74127.146.64.0/18127.146.64.1 to 127.146.127.254127.146.127.25516,382
75127.146.128.0/18127.146.128.1 to 127.146.191.254127.146.191.25516,382
76127.146.192.0/18127.146.192.1 to 127.146.255.254127.146.255.25516,382
77127.147.0.0/18127.147.0.1 to 127.147.63.254127.147.63.25516,382
78127.147.64.0/18127.147.64.1 to 127.147.127.254127.147.127.25516,382
79127.147.128.0/18127.147.128.1 to 127.147.191.254127.147.191.25516,382
80127.147.192.0/18127.147.192.1 to 127.147.255.254127.147.255.25516,382
81127.148.0.0/18127.148.0.1 to 127.148.63.254127.148.63.25516,382
82127.148.64.0/18127.148.64.1 to 127.148.127.254127.148.127.25516,382
83127.148.128.0/18127.148.128.1 to 127.148.191.254127.148.191.25516,382
84127.148.192.0/18127.148.192.1 to 127.148.255.254127.148.255.25516,382
85127.149.0.0/18127.149.0.1 to 127.149.63.254127.149.63.25516,382
86127.149.64.0/18127.149.64.1 to 127.149.127.254127.149.127.25516,382
87127.149.128.0/18127.149.128.1 to 127.149.191.254127.149.191.25516,382
88127.149.192.0/18127.149.192.1 to 127.149.255.254127.149.255.25516,382
89127.150.0.0/18127.150.0.1 to 127.150.63.254127.150.63.25516,382
90127.150.64.0/18127.150.64.1 to 127.150.127.254127.150.127.25516,382
91127.150.128.0/18127.150.128.1 to 127.150.191.254127.150.191.25516,382
92127.150.192.0/18127.150.192.1 to 127.150.255.254127.150.255.25516,382
93127.151.0.0/18127.151.0.1 to 127.151.63.254127.151.63.25516,382
94127.151.64.0/18127.151.64.1 to 127.151.127.254127.151.127.25516,382
95127.151.128.0/18127.151.128.1 to 127.151.191.254127.151.191.25516,382
96127.151.192.0/18127.151.192.1 to 127.151.255.254127.151.255.25516,382
97127.152.0.0/18127.152.0.1 to 127.152.63.254127.152.63.25516,382
98127.152.64.0/18127.152.64.1 to 127.152.127.254127.152.127.25516,382
99127.152.128.0/18127.152.128.1 to 127.152.191.254127.152.191.25516,382
100127.152.192.0/18127.152.192.1 to 127.152.255.254127.152.255.25516,382
101127.153.0.0/18127.153.0.1 to 127.153.63.254127.153.63.25516,382
102127.153.64.0/18127.153.64.1 to 127.153.127.254127.153.127.25516,382
103127.153.128.0/18127.153.128.1 to 127.153.191.254127.153.191.25516,382
104127.153.192.0/18127.153.192.1 to 127.153.255.254127.153.255.25516,382
105127.154.0.0/18127.154.0.1 to 127.154.63.254127.154.63.25516,382
106127.154.64.0/18127.154.64.1 to 127.154.127.254127.154.127.25516,382
107127.154.128.0/18127.154.128.1 to 127.154.191.254127.154.191.25516,382
108127.154.192.0/18127.154.192.1 to 127.154.255.254127.154.255.25516,382
109127.155.0.0/18127.155.0.1 to 127.155.63.254127.155.63.25516,382
110127.155.64.0/18127.155.64.1 to 127.155.127.254127.155.127.25516,382
111127.155.128.0/18127.155.128.1 to 127.155.191.254127.155.191.25516,382
112127.155.192.0/18127.155.192.1 to 127.155.255.254127.155.255.25516,382
113127.156.0.0/18127.156.0.1 to 127.156.63.254127.156.63.25516,382
114127.156.64.0/18127.156.64.1 to 127.156.127.254127.156.127.25516,382
115127.156.128.0/18127.156.128.1 to 127.156.191.254127.156.191.25516,382
116127.156.192.0/18127.156.192.1 to 127.156.255.254127.156.255.25516,382
117127.157.0.0/18127.157.0.1 to 127.157.63.254127.157.63.25516,382
118127.157.64.0/18127.157.64.1 to 127.157.127.254127.157.127.25516,382
119127.157.128.0/18127.157.128.1 to 127.157.191.254127.157.191.25516,382
120127.157.192.0/18127.157.192.1 to 127.157.255.254127.157.255.25516,382
121127.158.0.0/18127.158.0.1 to 127.158.63.254127.158.63.25516,382
122127.158.64.0/18127.158.64.1 to 127.158.127.254127.158.127.25516,382
123127.158.128.0/18127.158.128.1 to 127.158.191.254127.158.191.25516,382
124127.158.192.0/18127.158.192.1 to 127.158.255.254127.158.255.25516,382
125127.159.0.0/18127.159.0.1 to 127.159.63.254127.159.63.25516,382
126127.159.64.0/18127.159.64.1 to 127.159.127.254127.159.127.25516,382
127127.159.128.0/18127.159.128.1 to 127.159.191.254127.159.191.25516,382
128127.159.192.0/18127.159.192.1 to 127.159.255.254127.159.255.25516,382

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