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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.

Network94.89.0.0/17
Usable hosts32,766
Subnet mask255.255.128.0
Addresses32,768
Network address
94.89.0.0
Broadcast address
94.89.127.255
First usable
94.89.0.1
Last usable
94.89.127.254
Usable hosts
32,766 (32,768 less the network and broadcast addresses)
Subnet mask
255.255.128.0
Wildcard mask
0.0.127.255 (Cisco ACLs, OSPF)
Prefix length
/17
Type
Public public
Old class
A (default /8)
As numbers
Hex 5E590000 · Integer 1582891008 to 1582923775
Reverse DNS zones
0.89.94.in-addr.arpa
1.89.94.in-addr.arpa
2.89.94.in-addr.arpa
3.89.94.in-addr.arpa
4.89.94.in-addr.arpa
5.89.94.in-addr.arpa
6.89.94.in-addr.arpa
7.89.94.in-addr.arpa
8.89.94.in-addr.arpa
9.89.94.in-addr.arpa
10.89.94.in-addr.arpa
11.89.94.in-addr.arpa
12.89.94.in-addr.arpa
13.89.94.in-addr.arpa
14.89.94.in-addr.arpa
15.89.94.in-addr.arpa
and 112 more
/17 is not on a 8-bit boundary, so it takes 128 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01011110.01011001.00000000.0000000094.89.0.0
Subnet mask11111111.11111111.10000000.00000000255.255.128.0
Network01011110.01011001.00000000.0000000094.89.0.0
Broadcast01011110.01011001.01111111.1111111194.89.127.255
Split into smaller subnets/24
/18 (2)/19 (4)/20 (8)/21 (16)/22 (32)/23 (64)/24 (128)/25 (256)/26 (512)/27 (1,024)/28 (2,048)/29 (4,096)

94.89.0.0/17 makes 128 subnets of /24.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
194.89.0.0/2494.89.0.1 to 94.89.0.25494.89.0.255254
294.89.1.0/2494.89.1.1 to 94.89.1.25494.89.1.255254
394.89.2.0/2494.89.2.1 to 94.89.2.25494.89.2.255254
494.89.3.0/2494.89.3.1 to 94.89.3.25494.89.3.255254
594.89.4.0/2494.89.4.1 to 94.89.4.25494.89.4.255254
694.89.5.0/2494.89.5.1 to 94.89.5.25494.89.5.255254
794.89.6.0/2494.89.6.1 to 94.89.6.25494.89.6.255254
894.89.7.0/2494.89.7.1 to 94.89.7.25494.89.7.255254
994.89.8.0/2494.89.8.1 to 94.89.8.25494.89.8.255254
1094.89.9.0/2494.89.9.1 to 94.89.9.25494.89.9.255254
1194.89.10.0/2494.89.10.1 to 94.89.10.25494.89.10.255254
1294.89.11.0/2494.89.11.1 to 94.89.11.25494.89.11.255254
1394.89.12.0/2494.89.12.1 to 94.89.12.25494.89.12.255254
1494.89.13.0/2494.89.13.1 to 94.89.13.25494.89.13.255254
1594.89.14.0/2494.89.14.1 to 94.89.14.25494.89.14.255254
1694.89.15.0/2494.89.15.1 to 94.89.15.25494.89.15.255254
1794.89.16.0/2494.89.16.1 to 94.89.16.25494.89.16.255254
1894.89.17.0/2494.89.17.1 to 94.89.17.25494.89.17.255254
1994.89.18.0/2494.89.18.1 to 94.89.18.25494.89.18.255254
2094.89.19.0/2494.89.19.1 to 94.89.19.25494.89.19.255254
2194.89.20.0/2494.89.20.1 to 94.89.20.25494.89.20.255254
2294.89.21.0/2494.89.21.1 to 94.89.21.25494.89.21.255254
2394.89.22.0/2494.89.22.1 to 94.89.22.25494.89.22.255254
2494.89.23.0/2494.89.23.1 to 94.89.23.25494.89.23.255254
2594.89.24.0/2494.89.24.1 to 94.89.24.25494.89.24.255254
2694.89.25.0/2494.89.25.1 to 94.89.25.25494.89.25.255254
2794.89.26.0/2494.89.26.1 to 94.89.26.25494.89.26.255254
2894.89.27.0/2494.89.27.1 to 94.89.27.25494.89.27.255254
2994.89.28.0/2494.89.28.1 to 94.89.28.25494.89.28.255254
3094.89.29.0/2494.89.29.1 to 94.89.29.25494.89.29.255254
3194.89.30.0/2494.89.30.1 to 94.89.30.25494.89.30.255254
3294.89.31.0/2494.89.31.1 to 94.89.31.25494.89.31.255254
3394.89.32.0/2494.89.32.1 to 94.89.32.25494.89.32.255254
3494.89.33.0/2494.89.33.1 to 94.89.33.25494.89.33.255254
3594.89.34.0/2494.89.34.1 to 94.89.34.25494.89.34.255254
3694.89.35.0/2494.89.35.1 to 94.89.35.25494.89.35.255254
3794.89.36.0/2494.89.36.1 to 94.89.36.25494.89.36.255254
3894.89.37.0/2494.89.37.1 to 94.89.37.25494.89.37.255254
3994.89.38.0/2494.89.38.1 to 94.89.38.25494.89.38.255254
4094.89.39.0/2494.89.39.1 to 94.89.39.25494.89.39.255254
4194.89.40.0/2494.89.40.1 to 94.89.40.25494.89.40.255254
4294.89.41.0/2494.89.41.1 to 94.89.41.25494.89.41.255254
4394.89.42.0/2494.89.42.1 to 94.89.42.25494.89.42.255254
4494.89.43.0/2494.89.43.1 to 94.89.43.25494.89.43.255254
4594.89.44.0/2494.89.44.1 to 94.89.44.25494.89.44.255254
4694.89.45.0/2494.89.45.1 to 94.89.45.25494.89.45.255254
4794.89.46.0/2494.89.46.1 to 94.89.46.25494.89.46.255254
4894.89.47.0/2494.89.47.1 to 94.89.47.25494.89.47.255254
4994.89.48.0/2494.89.48.1 to 94.89.48.25494.89.48.255254
5094.89.49.0/2494.89.49.1 to 94.89.49.25494.89.49.255254
5194.89.50.0/2494.89.50.1 to 94.89.50.25494.89.50.255254
5294.89.51.0/2494.89.51.1 to 94.89.51.25494.89.51.255254
5394.89.52.0/2494.89.52.1 to 94.89.52.25494.89.52.255254
5494.89.53.0/2494.89.53.1 to 94.89.53.25494.89.53.255254
5594.89.54.0/2494.89.54.1 to 94.89.54.25494.89.54.255254
5694.89.55.0/2494.89.55.1 to 94.89.55.25494.89.55.255254
5794.89.56.0/2494.89.56.1 to 94.89.56.25494.89.56.255254
5894.89.57.0/2494.89.57.1 to 94.89.57.25494.89.57.255254
5994.89.58.0/2494.89.58.1 to 94.89.58.25494.89.58.255254
6094.89.59.0/2494.89.59.1 to 94.89.59.25494.89.59.255254
6194.89.60.0/2494.89.60.1 to 94.89.60.25494.89.60.255254
6294.89.61.0/2494.89.61.1 to 94.89.61.25494.89.61.255254
6394.89.62.0/2494.89.62.1 to 94.89.62.25494.89.62.255254
6494.89.63.0/2494.89.63.1 to 94.89.63.25494.89.63.255254
6594.89.64.0/2494.89.64.1 to 94.89.64.25494.89.64.255254
6694.89.65.0/2494.89.65.1 to 94.89.65.25494.89.65.255254
6794.89.66.0/2494.89.66.1 to 94.89.66.25494.89.66.255254
6894.89.67.0/2494.89.67.1 to 94.89.67.25494.89.67.255254
6994.89.68.0/2494.89.68.1 to 94.89.68.25494.89.68.255254
7094.89.69.0/2494.89.69.1 to 94.89.69.25494.89.69.255254
7194.89.70.0/2494.89.70.1 to 94.89.70.25494.89.70.255254
7294.89.71.0/2494.89.71.1 to 94.89.71.25494.89.71.255254
7394.89.72.0/2494.89.72.1 to 94.89.72.25494.89.72.255254
7494.89.73.0/2494.89.73.1 to 94.89.73.25494.89.73.255254
7594.89.74.0/2494.89.74.1 to 94.89.74.25494.89.74.255254
7694.89.75.0/2494.89.75.1 to 94.89.75.25494.89.75.255254
7794.89.76.0/2494.89.76.1 to 94.89.76.25494.89.76.255254
7894.89.77.0/2494.89.77.1 to 94.89.77.25494.89.77.255254
7994.89.78.0/2494.89.78.1 to 94.89.78.25494.89.78.255254
8094.89.79.0/2494.89.79.1 to 94.89.79.25494.89.79.255254
8194.89.80.0/2494.89.80.1 to 94.89.80.25494.89.80.255254
8294.89.81.0/2494.89.81.1 to 94.89.81.25494.89.81.255254
8394.89.82.0/2494.89.82.1 to 94.89.82.25494.89.82.255254
8494.89.83.0/2494.89.83.1 to 94.89.83.25494.89.83.255254
8594.89.84.0/2494.89.84.1 to 94.89.84.25494.89.84.255254
8694.89.85.0/2494.89.85.1 to 94.89.85.25494.89.85.255254
8794.89.86.0/2494.89.86.1 to 94.89.86.25494.89.86.255254
8894.89.87.0/2494.89.87.1 to 94.89.87.25494.89.87.255254
8994.89.88.0/2494.89.88.1 to 94.89.88.25494.89.88.255254
9094.89.89.0/2494.89.89.1 to 94.89.89.25494.89.89.255254
9194.89.90.0/2494.89.90.1 to 94.89.90.25494.89.90.255254
9294.89.91.0/2494.89.91.1 to 94.89.91.25494.89.91.255254
9394.89.92.0/2494.89.92.1 to 94.89.92.25494.89.92.255254
9494.89.93.0/2494.89.93.1 to 94.89.93.25494.89.93.255254
9594.89.94.0/2494.89.94.1 to 94.89.94.25494.89.94.255254
9694.89.95.0/2494.89.95.1 to 94.89.95.25494.89.95.255254
9794.89.96.0/2494.89.96.1 to 94.89.96.25494.89.96.255254
9894.89.97.0/2494.89.97.1 to 94.89.97.25494.89.97.255254
9994.89.98.0/2494.89.98.1 to 94.89.98.25494.89.98.255254
10094.89.99.0/2494.89.99.1 to 94.89.99.25494.89.99.255254
10194.89.100.0/2494.89.100.1 to 94.89.100.25494.89.100.255254
10294.89.101.0/2494.89.101.1 to 94.89.101.25494.89.101.255254
10394.89.102.0/2494.89.102.1 to 94.89.102.25494.89.102.255254
10494.89.103.0/2494.89.103.1 to 94.89.103.25494.89.103.255254
10594.89.104.0/2494.89.104.1 to 94.89.104.25494.89.104.255254
10694.89.105.0/2494.89.105.1 to 94.89.105.25494.89.105.255254
10794.89.106.0/2494.89.106.1 to 94.89.106.25494.89.106.255254
10894.89.107.0/2494.89.107.1 to 94.89.107.25494.89.107.255254
10994.89.108.0/2494.89.108.1 to 94.89.108.25494.89.108.255254
11094.89.109.0/2494.89.109.1 to 94.89.109.25494.89.109.255254
11194.89.110.0/2494.89.110.1 to 94.89.110.25494.89.110.255254
11294.89.111.0/2494.89.111.1 to 94.89.111.25494.89.111.255254
11394.89.112.0/2494.89.112.1 to 94.89.112.25494.89.112.255254
11494.89.113.0/2494.89.113.1 to 94.89.113.25494.89.113.255254
11594.89.114.0/2494.89.114.1 to 94.89.114.25494.89.114.255254
11694.89.115.0/2494.89.115.1 to 94.89.115.25494.89.115.255254
11794.89.116.0/2494.89.116.1 to 94.89.116.25494.89.116.255254
11894.89.117.0/2494.89.117.1 to 94.89.117.25494.89.117.255254
11994.89.118.0/2494.89.118.1 to 94.89.118.25494.89.118.255254
12094.89.119.0/2494.89.119.1 to 94.89.119.25494.89.119.255254
12194.89.120.0/2494.89.120.1 to 94.89.120.25494.89.120.255254
12294.89.121.0/2494.89.121.1 to 94.89.121.25494.89.121.255254
12394.89.122.0/2494.89.122.1 to 94.89.122.25494.89.122.255254
12494.89.123.0/2494.89.123.1 to 94.89.123.25494.89.123.255254
12594.89.124.0/2494.89.124.1 to 94.89.124.25494.89.124.255254
12694.89.125.0/2494.89.125.1 to 94.89.125.25494.89.125.255254
12794.89.126.0/2494.89.126.1 to 94.89.126.25494.89.126.255254
12894.89.127.0/2494.89.127.1 to 94.89.127.25494.89.127.255254

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.