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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.

Network96.0.0.0/3
Usable hosts536,870,910
Subnet mask224.0.0.0
Addresses536,870,912
Network address
96.0.0.0
Broadcast address
127.255.255.255
First usable
96.0.0.1
Last usable
127.255.255.254
Usable hosts
536,870,910 (536,870,912 less the network and broadcast addresses)
Subnet mask
224.0.0.0
Wildcard mask
31.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/3
Type
Public public
Old class
A (default /8)
As numbers
Hex 60000000 · Integer 1610612736 to 2147483647
Reverse DNS zones
96.in-addr.arpa
97.in-addr.arpa
98.in-addr.arpa
99.in-addr.arpa
100.in-addr.arpa
101.in-addr.arpa
102.in-addr.arpa
103.in-addr.arpa
104.in-addr.arpa
105.in-addr.arpa
106.in-addr.arpa
107.in-addr.arpa
108.in-addr.arpa
109.in-addr.arpa
110.in-addr.arpa
111.in-addr.arpa
and 16 more
/3 is not on a 8-bit boundary, so it takes 32 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01100000.00000000.00000000.0000000096.0.0.0
Subnet mask11100000.00000000.00000000.00000000224.0.0.0
Network01100000.00000000.00000000.0000000096.0.0.0
Broadcast01111111.11111111.11111111.11111111127.255.255.255
Split into smaller subnets/10
/4 (2)/5 (4)/6 (8)/7 (16)/8 (32)/9 (64)/10 (128)/11 (256)/12 (512)/13 (1,024)/14 (2,048)/15 (4,096)

96.0.0.0/3 makes 128 subnets of /10.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
196.0.0.0/1096.0.0.1 to 96.63.255.25496.63.255.2554,194,302
296.64.0.0/1096.64.0.1 to 96.127.255.25496.127.255.2554,194,302
396.128.0.0/1096.128.0.1 to 96.191.255.25496.191.255.2554,194,302
496.192.0.0/1096.192.0.1 to 96.255.255.25496.255.255.2554,194,302
597.0.0.0/1097.0.0.1 to 97.63.255.25497.63.255.2554,194,302
697.64.0.0/1097.64.0.1 to 97.127.255.25497.127.255.2554,194,302
797.128.0.0/1097.128.0.1 to 97.191.255.25497.191.255.2554,194,302
897.192.0.0/1097.192.0.1 to 97.255.255.25497.255.255.2554,194,302
998.0.0.0/1098.0.0.1 to 98.63.255.25498.63.255.2554,194,302
1098.64.0.0/1098.64.0.1 to 98.127.255.25498.127.255.2554,194,302
1198.128.0.0/1098.128.0.1 to 98.191.255.25498.191.255.2554,194,302
1298.192.0.0/1098.192.0.1 to 98.255.255.25498.255.255.2554,194,302
1399.0.0.0/1099.0.0.1 to 99.63.255.25499.63.255.2554,194,302
1499.64.0.0/1099.64.0.1 to 99.127.255.25499.127.255.2554,194,302
1599.128.0.0/1099.128.0.1 to 99.191.255.25499.191.255.2554,194,302
1699.192.0.0/1099.192.0.1 to 99.255.255.25499.255.255.2554,194,302
17100.0.0.0/10100.0.0.1 to 100.63.255.254100.63.255.2554,194,302
18100.64.0.0/10100.64.0.1 to 100.127.255.254100.127.255.2554,194,302
19100.128.0.0/10100.128.0.1 to 100.191.255.254100.191.255.2554,194,302
20100.192.0.0/10100.192.0.1 to 100.255.255.254100.255.255.2554,194,302
21101.0.0.0/10101.0.0.1 to 101.63.255.254101.63.255.2554,194,302
22101.64.0.0/10101.64.0.1 to 101.127.255.254101.127.255.2554,194,302
23101.128.0.0/10101.128.0.1 to 101.191.255.254101.191.255.2554,194,302
24101.192.0.0/10101.192.0.1 to 101.255.255.254101.255.255.2554,194,302
25102.0.0.0/10102.0.0.1 to 102.63.255.254102.63.255.2554,194,302
26102.64.0.0/10102.64.0.1 to 102.127.255.254102.127.255.2554,194,302
27102.128.0.0/10102.128.0.1 to 102.191.255.254102.191.255.2554,194,302
28102.192.0.0/10102.192.0.1 to 102.255.255.254102.255.255.2554,194,302
29103.0.0.0/10103.0.0.1 to 103.63.255.254103.63.255.2554,194,302
30103.64.0.0/10103.64.0.1 to 103.127.255.254103.127.255.2554,194,302
31103.128.0.0/10103.128.0.1 to 103.191.255.254103.191.255.2554,194,302
32103.192.0.0/10103.192.0.1 to 103.255.255.254103.255.255.2554,194,302
33104.0.0.0/10104.0.0.1 to 104.63.255.254104.63.255.2554,194,302
34104.64.0.0/10104.64.0.1 to 104.127.255.254104.127.255.2554,194,302
35104.128.0.0/10104.128.0.1 to 104.191.255.254104.191.255.2554,194,302
36104.192.0.0/10104.192.0.1 to 104.255.255.254104.255.255.2554,194,302
37105.0.0.0/10105.0.0.1 to 105.63.255.254105.63.255.2554,194,302
38105.64.0.0/10105.64.0.1 to 105.127.255.254105.127.255.2554,194,302
39105.128.0.0/10105.128.0.1 to 105.191.255.254105.191.255.2554,194,302
40105.192.0.0/10105.192.0.1 to 105.255.255.254105.255.255.2554,194,302
41106.0.0.0/10106.0.0.1 to 106.63.255.254106.63.255.2554,194,302
42106.64.0.0/10106.64.0.1 to 106.127.255.254106.127.255.2554,194,302
43106.128.0.0/10106.128.0.1 to 106.191.255.254106.191.255.2554,194,302
44106.192.0.0/10106.192.0.1 to 106.255.255.254106.255.255.2554,194,302
45107.0.0.0/10107.0.0.1 to 107.63.255.254107.63.255.2554,194,302
46107.64.0.0/10107.64.0.1 to 107.127.255.254107.127.255.2554,194,302
47107.128.0.0/10107.128.0.1 to 107.191.255.254107.191.255.2554,194,302
48107.192.0.0/10107.192.0.1 to 107.255.255.254107.255.255.2554,194,302
49108.0.0.0/10108.0.0.1 to 108.63.255.254108.63.255.2554,194,302
50108.64.0.0/10108.64.0.1 to 108.127.255.254108.127.255.2554,194,302
51108.128.0.0/10108.128.0.1 to 108.191.255.254108.191.255.2554,194,302
52108.192.0.0/10108.192.0.1 to 108.255.255.254108.255.255.2554,194,302
53109.0.0.0/10109.0.0.1 to 109.63.255.254109.63.255.2554,194,302
54109.64.0.0/10109.64.0.1 to 109.127.255.254109.127.255.2554,194,302
55109.128.0.0/10109.128.0.1 to 109.191.255.254109.191.255.2554,194,302
56109.192.0.0/10109.192.0.1 to 109.255.255.254109.255.255.2554,194,302
57110.0.0.0/10110.0.0.1 to 110.63.255.254110.63.255.2554,194,302
58110.64.0.0/10110.64.0.1 to 110.127.255.254110.127.255.2554,194,302
59110.128.0.0/10110.128.0.1 to 110.191.255.254110.191.255.2554,194,302
60110.192.0.0/10110.192.0.1 to 110.255.255.254110.255.255.2554,194,302
61111.0.0.0/10111.0.0.1 to 111.63.255.254111.63.255.2554,194,302
62111.64.0.0/10111.64.0.1 to 111.127.255.254111.127.255.2554,194,302
63111.128.0.0/10111.128.0.1 to 111.191.255.254111.191.255.2554,194,302
64111.192.0.0/10111.192.0.1 to 111.255.255.254111.255.255.2554,194,302
65112.0.0.0/10112.0.0.1 to 112.63.255.254112.63.255.2554,194,302
66112.64.0.0/10112.64.0.1 to 112.127.255.254112.127.255.2554,194,302
67112.128.0.0/10112.128.0.1 to 112.191.255.254112.191.255.2554,194,302
68112.192.0.0/10112.192.0.1 to 112.255.255.254112.255.255.2554,194,302
69113.0.0.0/10113.0.0.1 to 113.63.255.254113.63.255.2554,194,302
70113.64.0.0/10113.64.0.1 to 113.127.255.254113.127.255.2554,194,302
71113.128.0.0/10113.128.0.1 to 113.191.255.254113.191.255.2554,194,302
72113.192.0.0/10113.192.0.1 to 113.255.255.254113.255.255.2554,194,302
73114.0.0.0/10114.0.0.1 to 114.63.255.254114.63.255.2554,194,302
74114.64.0.0/10114.64.0.1 to 114.127.255.254114.127.255.2554,194,302
75114.128.0.0/10114.128.0.1 to 114.191.255.254114.191.255.2554,194,302
76114.192.0.0/10114.192.0.1 to 114.255.255.254114.255.255.2554,194,302
77115.0.0.0/10115.0.0.1 to 115.63.255.254115.63.255.2554,194,302
78115.64.0.0/10115.64.0.1 to 115.127.255.254115.127.255.2554,194,302
79115.128.0.0/10115.128.0.1 to 115.191.255.254115.191.255.2554,194,302
80115.192.0.0/10115.192.0.1 to 115.255.255.254115.255.255.2554,194,302
81116.0.0.0/10116.0.0.1 to 116.63.255.254116.63.255.2554,194,302
82116.64.0.0/10116.64.0.1 to 116.127.255.254116.127.255.2554,194,302
83116.128.0.0/10116.128.0.1 to 116.191.255.254116.191.255.2554,194,302
84116.192.0.0/10116.192.0.1 to 116.255.255.254116.255.255.2554,194,302
85117.0.0.0/10117.0.0.1 to 117.63.255.254117.63.255.2554,194,302
86117.64.0.0/10117.64.0.1 to 117.127.255.254117.127.255.2554,194,302
87117.128.0.0/10117.128.0.1 to 117.191.255.254117.191.255.2554,194,302
88117.192.0.0/10117.192.0.1 to 117.255.255.254117.255.255.2554,194,302
89118.0.0.0/10118.0.0.1 to 118.63.255.254118.63.255.2554,194,302
90118.64.0.0/10118.64.0.1 to 118.127.255.254118.127.255.2554,194,302
91118.128.0.0/10118.128.0.1 to 118.191.255.254118.191.255.2554,194,302
92118.192.0.0/10118.192.0.1 to 118.255.255.254118.255.255.2554,194,302
93119.0.0.0/10119.0.0.1 to 119.63.255.254119.63.255.2554,194,302
94119.64.0.0/10119.64.0.1 to 119.127.255.254119.127.255.2554,194,302
95119.128.0.0/10119.128.0.1 to 119.191.255.254119.191.255.2554,194,302
96119.192.0.0/10119.192.0.1 to 119.255.255.254119.255.255.2554,194,302
97120.0.0.0/10120.0.0.1 to 120.63.255.254120.63.255.2554,194,302
98120.64.0.0/10120.64.0.1 to 120.127.255.254120.127.255.2554,194,302
99120.128.0.0/10120.128.0.1 to 120.191.255.254120.191.255.2554,194,302
100120.192.0.0/10120.192.0.1 to 120.255.255.254120.255.255.2554,194,302
101121.0.0.0/10121.0.0.1 to 121.63.255.254121.63.255.2554,194,302
102121.64.0.0/10121.64.0.1 to 121.127.255.254121.127.255.2554,194,302
103121.128.0.0/10121.128.0.1 to 121.191.255.254121.191.255.2554,194,302
104121.192.0.0/10121.192.0.1 to 121.255.255.254121.255.255.2554,194,302
105122.0.0.0/10122.0.0.1 to 122.63.255.254122.63.255.2554,194,302
106122.64.0.0/10122.64.0.1 to 122.127.255.254122.127.255.2554,194,302
107122.128.0.0/10122.128.0.1 to 122.191.255.254122.191.255.2554,194,302
108122.192.0.0/10122.192.0.1 to 122.255.255.254122.255.255.2554,194,302
109123.0.0.0/10123.0.0.1 to 123.63.255.254123.63.255.2554,194,302
110123.64.0.0/10123.64.0.1 to 123.127.255.254123.127.255.2554,194,302
111123.128.0.0/10123.128.0.1 to 123.191.255.254123.191.255.2554,194,302
112123.192.0.0/10123.192.0.1 to 123.255.255.254123.255.255.2554,194,302
113124.0.0.0/10124.0.0.1 to 124.63.255.254124.63.255.2554,194,302
114124.64.0.0/10124.64.0.1 to 124.127.255.254124.127.255.2554,194,302
115124.128.0.0/10124.128.0.1 to 124.191.255.254124.191.255.2554,194,302
116124.192.0.0/10124.192.0.1 to 124.255.255.254124.255.255.2554,194,302
117125.0.0.0/10125.0.0.1 to 125.63.255.254125.63.255.2554,194,302
118125.64.0.0/10125.64.0.1 to 125.127.255.254125.127.255.2554,194,302
119125.128.0.0/10125.128.0.1 to 125.191.255.254125.191.255.2554,194,302
120125.192.0.0/10125.192.0.1 to 125.255.255.254125.255.255.2554,194,302
121126.0.0.0/10126.0.0.1 to 126.63.255.254126.63.255.2554,194,302
122126.64.0.0/10126.64.0.1 to 126.127.255.254126.127.255.2554,194,302
123126.128.0.0/10126.128.0.1 to 126.191.255.254126.191.255.2554,194,302
124126.192.0.0/10126.192.0.1 to 126.255.255.254126.255.255.2554,194,302
125127.0.0.0/10127.0.0.1 to 127.63.255.254127.63.255.2554,194,302
126127.64.0.0/10127.64.0.1 to 127.127.255.254127.127.255.2554,194,302
127127.128.0.0/10127.128.0.1 to 127.191.255.254127.191.255.2554,194,302
128127.192.0.0/10127.192.0.1 to 127.255.255.254127.255.255.2554,194,302

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.