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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.

Network131.0.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
131.0.0.0
Broadcast address
131.63.255.255
First usable
131.0.0.1
Last usable
131.63.255.254
Usable hosts
4,194,302 (4,194,304 less the network and broadcast addresses)
Subnet mask
255.192.0.0
Wildcard mask
0.63.255.255 (Cisco ACLs, OSPF)
Prefix length
/10
Type
Public public
Old class
B (default /16)
As numbers
Hex 83000000 · Integer 2197815296 to 2202009599
Reverse DNS zones
0.131.in-addr.arpa
1.131.in-addr.arpa
2.131.in-addr.arpa
3.131.in-addr.arpa
4.131.in-addr.arpa
5.131.in-addr.arpa
6.131.in-addr.arpa
7.131.in-addr.arpa
8.131.in-addr.arpa
9.131.in-addr.arpa
10.131.in-addr.arpa
11.131.in-addr.arpa
12.131.in-addr.arpa
13.131.in-addr.arpa
14.131.in-addr.arpa
15.131.in-addr.arpa
and 48 more
/10 is not on a 8-bit boundary, so it takes 64 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10000011.00000000.00000000.00000000131.0.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network10000011.00000000.00000000.00000000131.0.0.0
Broadcast10000011.00111111.11111111.11111111131.63.255.255
Split into smaller subnets/17

131.0.0.0/10 makes 128 subnets of /17.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1131.0.0.0/17131.0.0.1 to 131.0.127.254131.0.127.25532,766
2131.0.128.0/17131.0.128.1 to 131.0.255.254131.0.255.25532,766
3131.1.0.0/17131.1.0.1 to 131.1.127.254131.1.127.25532,766
4131.1.128.0/17131.1.128.1 to 131.1.255.254131.1.255.25532,766
5131.2.0.0/17131.2.0.1 to 131.2.127.254131.2.127.25532,766
6131.2.128.0/17131.2.128.1 to 131.2.255.254131.2.255.25532,766
7131.3.0.0/17131.3.0.1 to 131.3.127.254131.3.127.25532,766
8131.3.128.0/17131.3.128.1 to 131.3.255.254131.3.255.25532,766
9131.4.0.0/17131.4.0.1 to 131.4.127.254131.4.127.25532,766
10131.4.128.0/17131.4.128.1 to 131.4.255.254131.4.255.25532,766
11131.5.0.0/17131.5.0.1 to 131.5.127.254131.5.127.25532,766
12131.5.128.0/17131.5.128.1 to 131.5.255.254131.5.255.25532,766
13131.6.0.0/17131.6.0.1 to 131.6.127.254131.6.127.25532,766
14131.6.128.0/17131.6.128.1 to 131.6.255.254131.6.255.25532,766
15131.7.0.0/17131.7.0.1 to 131.7.127.254131.7.127.25532,766
16131.7.128.0/17131.7.128.1 to 131.7.255.254131.7.255.25532,766
17131.8.0.0/17131.8.0.1 to 131.8.127.254131.8.127.25532,766
18131.8.128.0/17131.8.128.1 to 131.8.255.254131.8.255.25532,766
19131.9.0.0/17131.9.0.1 to 131.9.127.254131.9.127.25532,766
20131.9.128.0/17131.9.128.1 to 131.9.255.254131.9.255.25532,766
21131.10.0.0/17131.10.0.1 to 131.10.127.254131.10.127.25532,766
22131.10.128.0/17131.10.128.1 to 131.10.255.254131.10.255.25532,766
23131.11.0.0/17131.11.0.1 to 131.11.127.254131.11.127.25532,766
24131.11.128.0/17131.11.128.1 to 131.11.255.254131.11.255.25532,766
25131.12.0.0/17131.12.0.1 to 131.12.127.254131.12.127.25532,766
26131.12.128.0/17131.12.128.1 to 131.12.255.254131.12.255.25532,766
27131.13.0.0/17131.13.0.1 to 131.13.127.254131.13.127.25532,766
28131.13.128.0/17131.13.128.1 to 131.13.255.254131.13.255.25532,766
29131.14.0.0/17131.14.0.1 to 131.14.127.254131.14.127.25532,766
30131.14.128.0/17131.14.128.1 to 131.14.255.254131.14.255.25532,766
31131.15.0.0/17131.15.0.1 to 131.15.127.254131.15.127.25532,766
32131.15.128.0/17131.15.128.1 to 131.15.255.254131.15.255.25532,766
33131.16.0.0/17131.16.0.1 to 131.16.127.254131.16.127.25532,766
34131.16.128.0/17131.16.128.1 to 131.16.255.254131.16.255.25532,766
35131.17.0.0/17131.17.0.1 to 131.17.127.254131.17.127.25532,766
36131.17.128.0/17131.17.128.1 to 131.17.255.254131.17.255.25532,766
37131.18.0.0/17131.18.0.1 to 131.18.127.254131.18.127.25532,766
38131.18.128.0/17131.18.128.1 to 131.18.255.254131.18.255.25532,766
39131.19.0.0/17131.19.0.1 to 131.19.127.254131.19.127.25532,766
40131.19.128.0/17131.19.128.1 to 131.19.255.254131.19.255.25532,766
41131.20.0.0/17131.20.0.1 to 131.20.127.254131.20.127.25532,766
42131.20.128.0/17131.20.128.1 to 131.20.255.254131.20.255.25532,766
43131.21.0.0/17131.21.0.1 to 131.21.127.254131.21.127.25532,766
44131.21.128.0/17131.21.128.1 to 131.21.255.254131.21.255.25532,766
45131.22.0.0/17131.22.0.1 to 131.22.127.254131.22.127.25532,766
46131.22.128.0/17131.22.128.1 to 131.22.255.254131.22.255.25532,766
47131.23.0.0/17131.23.0.1 to 131.23.127.254131.23.127.25532,766
48131.23.128.0/17131.23.128.1 to 131.23.255.254131.23.255.25532,766
49131.24.0.0/17131.24.0.1 to 131.24.127.254131.24.127.25532,766
50131.24.128.0/17131.24.128.1 to 131.24.255.254131.24.255.25532,766
51131.25.0.0/17131.25.0.1 to 131.25.127.254131.25.127.25532,766
52131.25.128.0/17131.25.128.1 to 131.25.255.254131.25.255.25532,766
53131.26.0.0/17131.26.0.1 to 131.26.127.254131.26.127.25532,766
54131.26.128.0/17131.26.128.1 to 131.26.255.254131.26.255.25532,766
55131.27.0.0/17131.27.0.1 to 131.27.127.254131.27.127.25532,766
56131.27.128.0/17131.27.128.1 to 131.27.255.254131.27.255.25532,766
57131.28.0.0/17131.28.0.1 to 131.28.127.254131.28.127.25532,766
58131.28.128.0/17131.28.128.1 to 131.28.255.254131.28.255.25532,766
59131.29.0.0/17131.29.0.1 to 131.29.127.254131.29.127.25532,766
60131.29.128.0/17131.29.128.1 to 131.29.255.254131.29.255.25532,766
61131.30.0.0/17131.30.0.1 to 131.30.127.254131.30.127.25532,766
62131.30.128.0/17131.30.128.1 to 131.30.255.254131.30.255.25532,766
63131.31.0.0/17131.31.0.1 to 131.31.127.254131.31.127.25532,766
64131.31.128.0/17131.31.128.1 to 131.31.255.254131.31.255.25532,766
65131.32.0.0/17131.32.0.1 to 131.32.127.254131.32.127.25532,766
66131.32.128.0/17131.32.128.1 to 131.32.255.254131.32.255.25532,766
67131.33.0.0/17131.33.0.1 to 131.33.127.254131.33.127.25532,766
68131.33.128.0/17131.33.128.1 to 131.33.255.254131.33.255.25532,766
69131.34.0.0/17131.34.0.1 to 131.34.127.254131.34.127.25532,766
70131.34.128.0/17131.34.128.1 to 131.34.255.254131.34.255.25532,766
71131.35.0.0/17131.35.0.1 to 131.35.127.254131.35.127.25532,766
72131.35.128.0/17131.35.128.1 to 131.35.255.254131.35.255.25532,766
73131.36.0.0/17131.36.0.1 to 131.36.127.254131.36.127.25532,766
74131.36.128.0/17131.36.128.1 to 131.36.255.254131.36.255.25532,766
75131.37.0.0/17131.37.0.1 to 131.37.127.254131.37.127.25532,766
76131.37.128.0/17131.37.128.1 to 131.37.255.254131.37.255.25532,766
77131.38.0.0/17131.38.0.1 to 131.38.127.254131.38.127.25532,766
78131.38.128.0/17131.38.128.1 to 131.38.255.254131.38.255.25532,766
79131.39.0.0/17131.39.0.1 to 131.39.127.254131.39.127.25532,766
80131.39.128.0/17131.39.128.1 to 131.39.255.254131.39.255.25532,766
81131.40.0.0/17131.40.0.1 to 131.40.127.254131.40.127.25532,766
82131.40.128.0/17131.40.128.1 to 131.40.255.254131.40.255.25532,766
83131.41.0.0/17131.41.0.1 to 131.41.127.254131.41.127.25532,766
84131.41.128.0/17131.41.128.1 to 131.41.255.254131.41.255.25532,766
85131.42.0.0/17131.42.0.1 to 131.42.127.254131.42.127.25532,766
86131.42.128.0/17131.42.128.1 to 131.42.255.254131.42.255.25532,766
87131.43.0.0/17131.43.0.1 to 131.43.127.254131.43.127.25532,766
88131.43.128.0/17131.43.128.1 to 131.43.255.254131.43.255.25532,766
89131.44.0.0/17131.44.0.1 to 131.44.127.254131.44.127.25532,766
90131.44.128.0/17131.44.128.1 to 131.44.255.254131.44.255.25532,766
91131.45.0.0/17131.45.0.1 to 131.45.127.254131.45.127.25532,766
92131.45.128.0/17131.45.128.1 to 131.45.255.254131.45.255.25532,766
93131.46.0.0/17131.46.0.1 to 131.46.127.254131.46.127.25532,766
94131.46.128.0/17131.46.128.1 to 131.46.255.254131.46.255.25532,766
95131.47.0.0/17131.47.0.1 to 131.47.127.254131.47.127.25532,766
96131.47.128.0/17131.47.128.1 to 131.47.255.254131.47.255.25532,766
97131.48.0.0/17131.48.0.1 to 131.48.127.254131.48.127.25532,766
98131.48.128.0/17131.48.128.1 to 131.48.255.254131.48.255.25532,766
99131.49.0.0/17131.49.0.1 to 131.49.127.254131.49.127.25532,766
100131.49.128.0/17131.49.128.1 to 131.49.255.254131.49.255.25532,766
101131.50.0.0/17131.50.0.1 to 131.50.127.254131.50.127.25532,766
102131.50.128.0/17131.50.128.1 to 131.50.255.254131.50.255.25532,766
103131.51.0.0/17131.51.0.1 to 131.51.127.254131.51.127.25532,766
104131.51.128.0/17131.51.128.1 to 131.51.255.254131.51.255.25532,766
105131.52.0.0/17131.52.0.1 to 131.52.127.254131.52.127.25532,766
106131.52.128.0/17131.52.128.1 to 131.52.255.254131.52.255.25532,766
107131.53.0.0/17131.53.0.1 to 131.53.127.254131.53.127.25532,766
108131.53.128.0/17131.53.128.1 to 131.53.255.254131.53.255.25532,766
109131.54.0.0/17131.54.0.1 to 131.54.127.254131.54.127.25532,766
110131.54.128.0/17131.54.128.1 to 131.54.255.254131.54.255.25532,766
111131.55.0.0/17131.55.0.1 to 131.55.127.254131.55.127.25532,766
112131.55.128.0/17131.55.128.1 to 131.55.255.254131.55.255.25532,766
113131.56.0.0/17131.56.0.1 to 131.56.127.254131.56.127.25532,766
114131.56.128.0/17131.56.128.1 to 131.56.255.254131.56.255.25532,766
115131.57.0.0/17131.57.0.1 to 131.57.127.254131.57.127.25532,766
116131.57.128.0/17131.57.128.1 to 131.57.255.254131.57.255.25532,766
117131.58.0.0/17131.58.0.1 to 131.58.127.254131.58.127.25532,766
118131.58.128.0/17131.58.128.1 to 131.58.255.254131.58.255.25532,766
119131.59.0.0/17131.59.0.1 to 131.59.127.254131.59.127.25532,766
120131.59.128.0/17131.59.128.1 to 131.59.255.254131.59.255.25532,766
121131.60.0.0/17131.60.0.1 to 131.60.127.254131.60.127.25532,766
122131.60.128.0/17131.60.128.1 to 131.60.255.254131.60.255.25532,766
123131.61.0.0/17131.61.0.1 to 131.61.127.254131.61.127.25532,766
124131.61.128.0/17131.61.128.1 to 131.61.255.254131.61.255.25532,766
125131.62.0.0/17131.62.0.1 to 131.62.127.254131.62.127.25532,766
126131.62.128.0/17131.62.128.1 to 131.62.255.254131.62.255.25532,766
127131.63.0.0/17131.63.0.1 to 131.63.127.254131.63.127.25532,766
128131.63.128.0/17131.63.128.1 to 131.63.255.254131.63.255.25532,766

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