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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.

Network98.0.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
98.0.0.0
Broadcast address
98.127.255.255
First usable
98.0.0.1
Last usable
98.127.255.254
Usable hosts
8,388,606 (8,388,608 less the network and broadcast addresses)
Subnet mask
255.128.0.0
Wildcard mask
0.127.255.255 (Cisco ACLs, OSPF)
Prefix length
/9
Type
Public public
Old class
A (default /8)
As numbers
Hex 62000000 · Integer 1644167168 to 1652555775
Reverse DNS zones
0.98.in-addr.arpa
1.98.in-addr.arpa
2.98.in-addr.arpa
3.98.in-addr.arpa
4.98.in-addr.arpa
5.98.in-addr.arpa
6.98.in-addr.arpa
7.98.in-addr.arpa
8.98.in-addr.arpa
9.98.in-addr.arpa
10.98.in-addr.arpa
11.98.in-addr.arpa
12.98.in-addr.arpa
13.98.in-addr.arpa
14.98.in-addr.arpa
15.98.in-addr.arpa
and 112 more
/9 is not on a 8-bit boundary, so it takes 128 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01100010.00000000.00000000.0000000098.0.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network01100010.00000000.00000000.0000000098.0.0.0
Broadcast01100010.01111111.11111111.1111111198.127.255.255
Split into smaller subnets/16
/10 (2)/11 (4)/12 (8)/13 (16)/14 (32)/15 (64)/16 (128)/17 (256)/18 (512)/19 (1,024)/20 (2,048)/21 (4,096)

98.0.0.0/9 makes 128 subnets of /16.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
198.0.0.0/1698.0.0.1 to 98.0.255.25498.0.255.25565,534
298.1.0.0/1698.1.0.1 to 98.1.255.25498.1.255.25565,534
398.2.0.0/1698.2.0.1 to 98.2.255.25498.2.255.25565,534
498.3.0.0/1698.3.0.1 to 98.3.255.25498.3.255.25565,534
598.4.0.0/1698.4.0.1 to 98.4.255.25498.4.255.25565,534
698.5.0.0/1698.5.0.1 to 98.5.255.25498.5.255.25565,534
798.6.0.0/1698.6.0.1 to 98.6.255.25498.6.255.25565,534
898.7.0.0/1698.7.0.1 to 98.7.255.25498.7.255.25565,534
998.8.0.0/1698.8.0.1 to 98.8.255.25498.8.255.25565,534
1098.9.0.0/1698.9.0.1 to 98.9.255.25498.9.255.25565,534
1198.10.0.0/1698.10.0.1 to 98.10.255.25498.10.255.25565,534
1298.11.0.0/1698.11.0.1 to 98.11.255.25498.11.255.25565,534
1398.12.0.0/1698.12.0.1 to 98.12.255.25498.12.255.25565,534
1498.13.0.0/1698.13.0.1 to 98.13.255.25498.13.255.25565,534
1598.14.0.0/1698.14.0.1 to 98.14.255.25498.14.255.25565,534
1698.15.0.0/1698.15.0.1 to 98.15.255.25498.15.255.25565,534
1798.16.0.0/1698.16.0.1 to 98.16.255.25498.16.255.25565,534
1898.17.0.0/1698.17.0.1 to 98.17.255.25498.17.255.25565,534
1998.18.0.0/1698.18.0.1 to 98.18.255.25498.18.255.25565,534
2098.19.0.0/1698.19.0.1 to 98.19.255.25498.19.255.25565,534
2198.20.0.0/1698.20.0.1 to 98.20.255.25498.20.255.25565,534
2298.21.0.0/1698.21.0.1 to 98.21.255.25498.21.255.25565,534
2398.22.0.0/1698.22.0.1 to 98.22.255.25498.22.255.25565,534
2498.23.0.0/1698.23.0.1 to 98.23.255.25498.23.255.25565,534
2598.24.0.0/1698.24.0.1 to 98.24.255.25498.24.255.25565,534
2698.25.0.0/1698.25.0.1 to 98.25.255.25498.25.255.25565,534
2798.26.0.0/1698.26.0.1 to 98.26.255.25498.26.255.25565,534
2898.27.0.0/1698.27.0.1 to 98.27.255.25498.27.255.25565,534
2998.28.0.0/1698.28.0.1 to 98.28.255.25498.28.255.25565,534
3098.29.0.0/1698.29.0.1 to 98.29.255.25498.29.255.25565,534
3198.30.0.0/1698.30.0.1 to 98.30.255.25498.30.255.25565,534
3298.31.0.0/1698.31.0.1 to 98.31.255.25498.31.255.25565,534
3398.32.0.0/1698.32.0.1 to 98.32.255.25498.32.255.25565,534
3498.33.0.0/1698.33.0.1 to 98.33.255.25498.33.255.25565,534
3598.34.0.0/1698.34.0.1 to 98.34.255.25498.34.255.25565,534
3698.35.0.0/1698.35.0.1 to 98.35.255.25498.35.255.25565,534
3798.36.0.0/1698.36.0.1 to 98.36.255.25498.36.255.25565,534
3898.37.0.0/1698.37.0.1 to 98.37.255.25498.37.255.25565,534
3998.38.0.0/1698.38.0.1 to 98.38.255.25498.38.255.25565,534
4098.39.0.0/1698.39.0.1 to 98.39.255.25498.39.255.25565,534
4198.40.0.0/1698.40.0.1 to 98.40.255.25498.40.255.25565,534
4298.41.0.0/1698.41.0.1 to 98.41.255.25498.41.255.25565,534
4398.42.0.0/1698.42.0.1 to 98.42.255.25498.42.255.25565,534
4498.43.0.0/1698.43.0.1 to 98.43.255.25498.43.255.25565,534
4598.44.0.0/1698.44.0.1 to 98.44.255.25498.44.255.25565,534
4698.45.0.0/1698.45.0.1 to 98.45.255.25498.45.255.25565,534
4798.46.0.0/1698.46.0.1 to 98.46.255.25498.46.255.25565,534
4898.47.0.0/1698.47.0.1 to 98.47.255.25498.47.255.25565,534
4998.48.0.0/1698.48.0.1 to 98.48.255.25498.48.255.25565,534
5098.49.0.0/1698.49.0.1 to 98.49.255.25498.49.255.25565,534
5198.50.0.0/1698.50.0.1 to 98.50.255.25498.50.255.25565,534
5298.51.0.0/1698.51.0.1 to 98.51.255.25498.51.255.25565,534
5398.52.0.0/1698.52.0.1 to 98.52.255.25498.52.255.25565,534
5498.53.0.0/1698.53.0.1 to 98.53.255.25498.53.255.25565,534
5598.54.0.0/1698.54.0.1 to 98.54.255.25498.54.255.25565,534
5698.55.0.0/1698.55.0.1 to 98.55.255.25498.55.255.25565,534
5798.56.0.0/1698.56.0.1 to 98.56.255.25498.56.255.25565,534
5898.57.0.0/1698.57.0.1 to 98.57.255.25498.57.255.25565,534
5998.58.0.0/1698.58.0.1 to 98.58.255.25498.58.255.25565,534
6098.59.0.0/1698.59.0.1 to 98.59.255.25498.59.255.25565,534
6198.60.0.0/1698.60.0.1 to 98.60.255.25498.60.255.25565,534
6298.61.0.0/1698.61.0.1 to 98.61.255.25498.61.255.25565,534
6398.62.0.0/1698.62.0.1 to 98.62.255.25498.62.255.25565,534
6498.63.0.0/1698.63.0.1 to 98.63.255.25498.63.255.25565,534
6598.64.0.0/1698.64.0.1 to 98.64.255.25498.64.255.25565,534
6698.65.0.0/1698.65.0.1 to 98.65.255.25498.65.255.25565,534
6798.66.0.0/1698.66.0.1 to 98.66.255.25498.66.255.25565,534
6898.67.0.0/1698.67.0.1 to 98.67.255.25498.67.255.25565,534
6998.68.0.0/1698.68.0.1 to 98.68.255.25498.68.255.25565,534
7098.69.0.0/1698.69.0.1 to 98.69.255.25498.69.255.25565,534
7198.70.0.0/1698.70.0.1 to 98.70.255.25498.70.255.25565,534
7298.71.0.0/1698.71.0.1 to 98.71.255.25498.71.255.25565,534
7398.72.0.0/1698.72.0.1 to 98.72.255.25498.72.255.25565,534
7498.73.0.0/1698.73.0.1 to 98.73.255.25498.73.255.25565,534
7598.74.0.0/1698.74.0.1 to 98.74.255.25498.74.255.25565,534
7698.75.0.0/1698.75.0.1 to 98.75.255.25498.75.255.25565,534
7798.76.0.0/1698.76.0.1 to 98.76.255.25498.76.255.25565,534
7898.77.0.0/1698.77.0.1 to 98.77.255.25498.77.255.25565,534
7998.78.0.0/1698.78.0.1 to 98.78.255.25498.78.255.25565,534
8098.79.0.0/1698.79.0.1 to 98.79.255.25498.79.255.25565,534
8198.80.0.0/1698.80.0.1 to 98.80.255.25498.80.255.25565,534
8298.81.0.0/1698.81.0.1 to 98.81.255.25498.81.255.25565,534
8398.82.0.0/1698.82.0.1 to 98.82.255.25498.82.255.25565,534
8498.83.0.0/1698.83.0.1 to 98.83.255.25498.83.255.25565,534
8598.84.0.0/1698.84.0.1 to 98.84.255.25498.84.255.25565,534
8698.85.0.0/1698.85.0.1 to 98.85.255.25498.85.255.25565,534
8798.86.0.0/1698.86.0.1 to 98.86.255.25498.86.255.25565,534
8898.87.0.0/1698.87.0.1 to 98.87.255.25498.87.255.25565,534
8998.88.0.0/1698.88.0.1 to 98.88.255.25498.88.255.25565,534
9098.89.0.0/1698.89.0.1 to 98.89.255.25498.89.255.25565,534
9198.90.0.0/1698.90.0.1 to 98.90.255.25498.90.255.25565,534
9298.91.0.0/1698.91.0.1 to 98.91.255.25498.91.255.25565,534
9398.92.0.0/1698.92.0.1 to 98.92.255.25498.92.255.25565,534
9498.93.0.0/1698.93.0.1 to 98.93.255.25498.93.255.25565,534
9598.94.0.0/1698.94.0.1 to 98.94.255.25498.94.255.25565,534
9698.95.0.0/1698.95.0.1 to 98.95.255.25498.95.255.25565,534
9798.96.0.0/1698.96.0.1 to 98.96.255.25498.96.255.25565,534
9898.97.0.0/1698.97.0.1 to 98.97.255.25498.97.255.25565,534
9998.98.0.0/1698.98.0.1 to 98.98.255.25498.98.255.25565,534
10098.99.0.0/1698.99.0.1 to 98.99.255.25498.99.255.25565,534
10198.100.0.0/1698.100.0.1 to 98.100.255.25498.100.255.25565,534
10298.101.0.0/1698.101.0.1 to 98.101.255.25498.101.255.25565,534
10398.102.0.0/1698.102.0.1 to 98.102.255.25498.102.255.25565,534
10498.103.0.0/1698.103.0.1 to 98.103.255.25498.103.255.25565,534
10598.104.0.0/1698.104.0.1 to 98.104.255.25498.104.255.25565,534
10698.105.0.0/1698.105.0.1 to 98.105.255.25498.105.255.25565,534
10798.106.0.0/1698.106.0.1 to 98.106.255.25498.106.255.25565,534
10898.107.0.0/1698.107.0.1 to 98.107.255.25498.107.255.25565,534
10998.108.0.0/1698.108.0.1 to 98.108.255.25498.108.255.25565,534
11098.109.0.0/1698.109.0.1 to 98.109.255.25498.109.255.25565,534
11198.110.0.0/1698.110.0.1 to 98.110.255.25498.110.255.25565,534
11298.111.0.0/1698.111.0.1 to 98.111.255.25498.111.255.25565,534
11398.112.0.0/1698.112.0.1 to 98.112.255.25498.112.255.25565,534
11498.113.0.0/1698.113.0.1 to 98.113.255.25498.113.255.25565,534
11598.114.0.0/1698.114.0.1 to 98.114.255.25498.114.255.25565,534
11698.115.0.0/1698.115.0.1 to 98.115.255.25498.115.255.25565,534
11798.116.0.0/1698.116.0.1 to 98.116.255.25498.116.255.25565,534
11898.117.0.0/1698.117.0.1 to 98.117.255.25498.117.255.25565,534
11998.118.0.0/1698.118.0.1 to 98.118.255.25498.118.255.25565,534
12098.119.0.0/1698.119.0.1 to 98.119.255.25498.119.255.25565,534
12198.120.0.0/1698.120.0.1 to 98.120.255.25498.120.255.25565,534
12298.121.0.0/1698.121.0.1 to 98.121.255.25498.121.255.25565,534
12398.122.0.0/1698.122.0.1 to 98.122.255.25498.122.255.25565,534
12498.123.0.0/1698.123.0.1 to 98.123.255.25498.123.255.25565,534
12598.124.0.0/1698.124.0.1 to 98.124.255.25498.124.255.25565,534
12698.125.0.0/1698.125.0.1 to 98.125.255.25498.125.255.25565,534
12798.126.0.0/1698.126.0.1 to 98.126.255.25498.126.255.25565,534
12898.127.0.0/1698.127.0.1 to 98.127.255.25498.127.255.25565,534

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.