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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.

Network60.89.0.0/17
Usable hosts32,766
Subnet mask255.255.128.0
Addresses32,768
Network address
60.89.0.0
Broadcast address
60.89.127.255
First usable
60.89.0.1
Last usable
60.89.127.254
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 3C590000 · Integer 1012465664 to 1012498431
Reverse DNS zones
0.89.60.in-addr.arpa
1.89.60.in-addr.arpa
2.89.60.in-addr.arpa
3.89.60.in-addr.arpa
4.89.60.in-addr.arpa
5.89.60.in-addr.arpa
6.89.60.in-addr.arpa
7.89.60.in-addr.arpa
8.89.60.in-addr.arpa
9.89.60.in-addr.arpa
10.89.60.in-addr.arpa
11.89.60.in-addr.arpa
12.89.60.in-addr.arpa
13.89.60.in-addr.arpa
14.89.60.in-addr.arpa
15.89.60.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
Address00111100.01011001.00000000.0000000060.89.0.0
Subnet mask11111111.11111111.10000000.00000000255.255.128.0
Network00111100.01011001.00000000.0000000060.89.0.0
Broadcast00111100.01011001.01111111.1111111160.89.127.255
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)

60.89.0.0/17 makes 128 subnets of /24.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
160.89.0.0/2460.89.0.1 to 60.89.0.25460.89.0.255254
260.89.1.0/2460.89.1.1 to 60.89.1.25460.89.1.255254
360.89.2.0/2460.89.2.1 to 60.89.2.25460.89.2.255254
460.89.3.0/2460.89.3.1 to 60.89.3.25460.89.3.255254
560.89.4.0/2460.89.4.1 to 60.89.4.25460.89.4.255254
660.89.5.0/2460.89.5.1 to 60.89.5.25460.89.5.255254
760.89.6.0/2460.89.6.1 to 60.89.6.25460.89.6.255254
860.89.7.0/2460.89.7.1 to 60.89.7.25460.89.7.255254
960.89.8.0/2460.89.8.1 to 60.89.8.25460.89.8.255254
1060.89.9.0/2460.89.9.1 to 60.89.9.25460.89.9.255254
1160.89.10.0/2460.89.10.1 to 60.89.10.25460.89.10.255254
1260.89.11.0/2460.89.11.1 to 60.89.11.25460.89.11.255254
1360.89.12.0/2460.89.12.1 to 60.89.12.25460.89.12.255254
1460.89.13.0/2460.89.13.1 to 60.89.13.25460.89.13.255254
1560.89.14.0/2460.89.14.1 to 60.89.14.25460.89.14.255254
1660.89.15.0/2460.89.15.1 to 60.89.15.25460.89.15.255254
1760.89.16.0/2460.89.16.1 to 60.89.16.25460.89.16.255254
1860.89.17.0/2460.89.17.1 to 60.89.17.25460.89.17.255254
1960.89.18.0/2460.89.18.1 to 60.89.18.25460.89.18.255254
2060.89.19.0/2460.89.19.1 to 60.89.19.25460.89.19.255254
2160.89.20.0/2460.89.20.1 to 60.89.20.25460.89.20.255254
2260.89.21.0/2460.89.21.1 to 60.89.21.25460.89.21.255254
2360.89.22.0/2460.89.22.1 to 60.89.22.25460.89.22.255254
2460.89.23.0/2460.89.23.1 to 60.89.23.25460.89.23.255254
2560.89.24.0/2460.89.24.1 to 60.89.24.25460.89.24.255254
2660.89.25.0/2460.89.25.1 to 60.89.25.25460.89.25.255254
2760.89.26.0/2460.89.26.1 to 60.89.26.25460.89.26.255254
2860.89.27.0/2460.89.27.1 to 60.89.27.25460.89.27.255254
2960.89.28.0/2460.89.28.1 to 60.89.28.25460.89.28.255254
3060.89.29.0/2460.89.29.1 to 60.89.29.25460.89.29.255254
3160.89.30.0/2460.89.30.1 to 60.89.30.25460.89.30.255254
3260.89.31.0/2460.89.31.1 to 60.89.31.25460.89.31.255254
3360.89.32.0/2460.89.32.1 to 60.89.32.25460.89.32.255254
3460.89.33.0/2460.89.33.1 to 60.89.33.25460.89.33.255254
3560.89.34.0/2460.89.34.1 to 60.89.34.25460.89.34.255254
3660.89.35.0/2460.89.35.1 to 60.89.35.25460.89.35.255254
3760.89.36.0/2460.89.36.1 to 60.89.36.25460.89.36.255254
3860.89.37.0/2460.89.37.1 to 60.89.37.25460.89.37.255254
3960.89.38.0/2460.89.38.1 to 60.89.38.25460.89.38.255254
4060.89.39.0/2460.89.39.1 to 60.89.39.25460.89.39.255254
4160.89.40.0/2460.89.40.1 to 60.89.40.25460.89.40.255254
4260.89.41.0/2460.89.41.1 to 60.89.41.25460.89.41.255254
4360.89.42.0/2460.89.42.1 to 60.89.42.25460.89.42.255254
4460.89.43.0/2460.89.43.1 to 60.89.43.25460.89.43.255254
4560.89.44.0/2460.89.44.1 to 60.89.44.25460.89.44.255254
4660.89.45.0/2460.89.45.1 to 60.89.45.25460.89.45.255254
4760.89.46.0/2460.89.46.1 to 60.89.46.25460.89.46.255254
4860.89.47.0/2460.89.47.1 to 60.89.47.25460.89.47.255254
4960.89.48.0/2460.89.48.1 to 60.89.48.25460.89.48.255254
5060.89.49.0/2460.89.49.1 to 60.89.49.25460.89.49.255254
5160.89.50.0/2460.89.50.1 to 60.89.50.25460.89.50.255254
5260.89.51.0/2460.89.51.1 to 60.89.51.25460.89.51.255254
5360.89.52.0/2460.89.52.1 to 60.89.52.25460.89.52.255254
5460.89.53.0/2460.89.53.1 to 60.89.53.25460.89.53.255254
5560.89.54.0/2460.89.54.1 to 60.89.54.25460.89.54.255254
5660.89.55.0/2460.89.55.1 to 60.89.55.25460.89.55.255254
5760.89.56.0/2460.89.56.1 to 60.89.56.25460.89.56.255254
5860.89.57.0/2460.89.57.1 to 60.89.57.25460.89.57.255254
5960.89.58.0/2460.89.58.1 to 60.89.58.25460.89.58.255254
6060.89.59.0/2460.89.59.1 to 60.89.59.25460.89.59.255254
6160.89.60.0/2460.89.60.1 to 60.89.60.25460.89.60.255254
6260.89.61.0/2460.89.61.1 to 60.89.61.25460.89.61.255254
6360.89.62.0/2460.89.62.1 to 60.89.62.25460.89.62.255254
6460.89.63.0/2460.89.63.1 to 60.89.63.25460.89.63.255254
6560.89.64.0/2460.89.64.1 to 60.89.64.25460.89.64.255254
6660.89.65.0/2460.89.65.1 to 60.89.65.25460.89.65.255254
6760.89.66.0/2460.89.66.1 to 60.89.66.25460.89.66.255254
6860.89.67.0/2460.89.67.1 to 60.89.67.25460.89.67.255254
6960.89.68.0/2460.89.68.1 to 60.89.68.25460.89.68.255254
7060.89.69.0/2460.89.69.1 to 60.89.69.25460.89.69.255254
7160.89.70.0/2460.89.70.1 to 60.89.70.25460.89.70.255254
7260.89.71.0/2460.89.71.1 to 60.89.71.25460.89.71.255254
7360.89.72.0/2460.89.72.1 to 60.89.72.25460.89.72.255254
7460.89.73.0/2460.89.73.1 to 60.89.73.25460.89.73.255254
7560.89.74.0/2460.89.74.1 to 60.89.74.25460.89.74.255254
7660.89.75.0/2460.89.75.1 to 60.89.75.25460.89.75.255254
7760.89.76.0/2460.89.76.1 to 60.89.76.25460.89.76.255254
7860.89.77.0/2460.89.77.1 to 60.89.77.25460.89.77.255254
7960.89.78.0/2460.89.78.1 to 60.89.78.25460.89.78.255254
8060.89.79.0/2460.89.79.1 to 60.89.79.25460.89.79.255254
8160.89.80.0/2460.89.80.1 to 60.89.80.25460.89.80.255254
8260.89.81.0/2460.89.81.1 to 60.89.81.25460.89.81.255254
8360.89.82.0/2460.89.82.1 to 60.89.82.25460.89.82.255254
8460.89.83.0/2460.89.83.1 to 60.89.83.25460.89.83.255254
8560.89.84.0/2460.89.84.1 to 60.89.84.25460.89.84.255254
8660.89.85.0/2460.89.85.1 to 60.89.85.25460.89.85.255254
8760.89.86.0/2460.89.86.1 to 60.89.86.25460.89.86.255254
8860.89.87.0/2460.89.87.1 to 60.89.87.25460.89.87.255254
8960.89.88.0/2460.89.88.1 to 60.89.88.25460.89.88.255254
9060.89.89.0/2460.89.89.1 to 60.89.89.25460.89.89.255254
9160.89.90.0/2460.89.90.1 to 60.89.90.25460.89.90.255254
9260.89.91.0/2460.89.91.1 to 60.89.91.25460.89.91.255254
9360.89.92.0/2460.89.92.1 to 60.89.92.25460.89.92.255254
9460.89.93.0/2460.89.93.1 to 60.89.93.25460.89.93.255254
9560.89.94.0/2460.89.94.1 to 60.89.94.25460.89.94.255254
9660.89.95.0/2460.89.95.1 to 60.89.95.25460.89.95.255254
9760.89.96.0/2460.89.96.1 to 60.89.96.25460.89.96.255254
9860.89.97.0/2460.89.97.1 to 60.89.97.25460.89.97.255254
9960.89.98.0/2460.89.98.1 to 60.89.98.25460.89.98.255254
10060.89.99.0/2460.89.99.1 to 60.89.99.25460.89.99.255254
10160.89.100.0/2460.89.100.1 to 60.89.100.25460.89.100.255254
10260.89.101.0/2460.89.101.1 to 60.89.101.25460.89.101.255254
10360.89.102.0/2460.89.102.1 to 60.89.102.25460.89.102.255254
10460.89.103.0/2460.89.103.1 to 60.89.103.25460.89.103.255254
10560.89.104.0/2460.89.104.1 to 60.89.104.25460.89.104.255254
10660.89.105.0/2460.89.105.1 to 60.89.105.25460.89.105.255254
10760.89.106.0/2460.89.106.1 to 60.89.106.25460.89.106.255254
10860.89.107.0/2460.89.107.1 to 60.89.107.25460.89.107.255254
10960.89.108.0/2460.89.108.1 to 60.89.108.25460.89.108.255254
11060.89.109.0/2460.89.109.1 to 60.89.109.25460.89.109.255254
11160.89.110.0/2460.89.110.1 to 60.89.110.25460.89.110.255254
11260.89.111.0/2460.89.111.1 to 60.89.111.25460.89.111.255254
11360.89.112.0/2460.89.112.1 to 60.89.112.25460.89.112.255254
11460.89.113.0/2460.89.113.1 to 60.89.113.25460.89.113.255254
11560.89.114.0/2460.89.114.1 to 60.89.114.25460.89.114.255254
11660.89.115.0/2460.89.115.1 to 60.89.115.25460.89.115.255254
11760.89.116.0/2460.89.116.1 to 60.89.116.25460.89.116.255254
11860.89.117.0/2460.89.117.1 to 60.89.117.25460.89.117.255254
11960.89.118.0/2460.89.118.1 to 60.89.118.25460.89.118.255254
12060.89.119.0/2460.89.119.1 to 60.89.119.25460.89.119.255254
12160.89.120.0/2460.89.120.1 to 60.89.120.25460.89.120.255254
12260.89.121.0/2460.89.121.1 to 60.89.121.25460.89.121.255254
12360.89.122.0/2460.89.122.1 to 60.89.122.25460.89.122.255254
12460.89.123.0/2460.89.123.1 to 60.89.123.25460.89.123.255254
12560.89.124.0/2460.89.124.1 to 60.89.124.25460.89.124.255254
12660.89.125.0/2460.89.125.1 to 60.89.125.25460.89.125.255254
12760.89.126.0/2460.89.126.1 to 60.89.126.25460.89.126.255254
12860.89.127.0/2460.89.127.1 to 60.89.127.25460.89.127.255254

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.