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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.

Network88.0.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
88.0.0.0
Broadcast address
88.63.255.255
First usable
88.0.0.1
Last usable
88.63.255.254
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
A (default /8)
As numbers
Hex 58000000 · Integer 1476395008 to 1480589311
Reverse DNS zones
0.88.in-addr.arpa
1.88.in-addr.arpa
2.88.in-addr.arpa
3.88.in-addr.arpa
4.88.in-addr.arpa
5.88.in-addr.arpa
6.88.in-addr.arpa
7.88.in-addr.arpa
8.88.in-addr.arpa
9.88.in-addr.arpa
10.88.in-addr.arpa
11.88.in-addr.arpa
12.88.in-addr.arpa
13.88.in-addr.arpa
14.88.in-addr.arpa
15.88.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
Address01011000.00000000.00000000.0000000088.0.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network01011000.00000000.00000000.0000000088.0.0.0
Broadcast01011000.00111111.11111111.1111111188.63.255.255
Split into smaller subnets/17
/11 (2)/12 (4)/13 (8)/14 (16)/15 (32)/16 (64)/17 (128)/18 (256)/19 (512)/20 (1,024)/21 (2,048)/22 (4,096)

88.0.0.0/10 makes 128 subnets of /17.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
188.0.0.0/1788.0.0.1 to 88.0.127.25488.0.127.25532,766
288.0.128.0/1788.0.128.1 to 88.0.255.25488.0.255.25532,766
388.1.0.0/1788.1.0.1 to 88.1.127.25488.1.127.25532,766
488.1.128.0/1788.1.128.1 to 88.1.255.25488.1.255.25532,766
588.2.0.0/1788.2.0.1 to 88.2.127.25488.2.127.25532,766
688.2.128.0/1788.2.128.1 to 88.2.255.25488.2.255.25532,766
788.3.0.0/1788.3.0.1 to 88.3.127.25488.3.127.25532,766
888.3.128.0/1788.3.128.1 to 88.3.255.25488.3.255.25532,766
988.4.0.0/1788.4.0.1 to 88.4.127.25488.4.127.25532,766
1088.4.128.0/1788.4.128.1 to 88.4.255.25488.4.255.25532,766
1188.5.0.0/1788.5.0.1 to 88.5.127.25488.5.127.25532,766
1288.5.128.0/1788.5.128.1 to 88.5.255.25488.5.255.25532,766
1388.6.0.0/1788.6.0.1 to 88.6.127.25488.6.127.25532,766
1488.6.128.0/1788.6.128.1 to 88.6.255.25488.6.255.25532,766
1588.7.0.0/1788.7.0.1 to 88.7.127.25488.7.127.25532,766
1688.7.128.0/1788.7.128.1 to 88.7.255.25488.7.255.25532,766
1788.8.0.0/1788.8.0.1 to 88.8.127.25488.8.127.25532,766
1888.8.128.0/1788.8.128.1 to 88.8.255.25488.8.255.25532,766
1988.9.0.0/1788.9.0.1 to 88.9.127.25488.9.127.25532,766
2088.9.128.0/1788.9.128.1 to 88.9.255.25488.9.255.25532,766
2188.10.0.0/1788.10.0.1 to 88.10.127.25488.10.127.25532,766
2288.10.128.0/1788.10.128.1 to 88.10.255.25488.10.255.25532,766
2388.11.0.0/1788.11.0.1 to 88.11.127.25488.11.127.25532,766
2488.11.128.0/1788.11.128.1 to 88.11.255.25488.11.255.25532,766
2588.12.0.0/1788.12.0.1 to 88.12.127.25488.12.127.25532,766
2688.12.128.0/1788.12.128.1 to 88.12.255.25488.12.255.25532,766
2788.13.0.0/1788.13.0.1 to 88.13.127.25488.13.127.25532,766
2888.13.128.0/1788.13.128.1 to 88.13.255.25488.13.255.25532,766
2988.14.0.0/1788.14.0.1 to 88.14.127.25488.14.127.25532,766
3088.14.128.0/1788.14.128.1 to 88.14.255.25488.14.255.25532,766
3188.15.0.0/1788.15.0.1 to 88.15.127.25488.15.127.25532,766
3288.15.128.0/1788.15.128.1 to 88.15.255.25488.15.255.25532,766
3388.16.0.0/1788.16.0.1 to 88.16.127.25488.16.127.25532,766
3488.16.128.0/1788.16.128.1 to 88.16.255.25488.16.255.25532,766
3588.17.0.0/1788.17.0.1 to 88.17.127.25488.17.127.25532,766
3688.17.128.0/1788.17.128.1 to 88.17.255.25488.17.255.25532,766
3788.18.0.0/1788.18.0.1 to 88.18.127.25488.18.127.25532,766
3888.18.128.0/1788.18.128.1 to 88.18.255.25488.18.255.25532,766
3988.19.0.0/1788.19.0.1 to 88.19.127.25488.19.127.25532,766
4088.19.128.0/1788.19.128.1 to 88.19.255.25488.19.255.25532,766
4188.20.0.0/1788.20.0.1 to 88.20.127.25488.20.127.25532,766
4288.20.128.0/1788.20.128.1 to 88.20.255.25488.20.255.25532,766
4388.21.0.0/1788.21.0.1 to 88.21.127.25488.21.127.25532,766
4488.21.128.0/1788.21.128.1 to 88.21.255.25488.21.255.25532,766
4588.22.0.0/1788.22.0.1 to 88.22.127.25488.22.127.25532,766
4688.22.128.0/1788.22.128.1 to 88.22.255.25488.22.255.25532,766
4788.23.0.0/1788.23.0.1 to 88.23.127.25488.23.127.25532,766
4888.23.128.0/1788.23.128.1 to 88.23.255.25488.23.255.25532,766
4988.24.0.0/1788.24.0.1 to 88.24.127.25488.24.127.25532,766
5088.24.128.0/1788.24.128.1 to 88.24.255.25488.24.255.25532,766
5188.25.0.0/1788.25.0.1 to 88.25.127.25488.25.127.25532,766
5288.25.128.0/1788.25.128.1 to 88.25.255.25488.25.255.25532,766
5388.26.0.0/1788.26.0.1 to 88.26.127.25488.26.127.25532,766
5488.26.128.0/1788.26.128.1 to 88.26.255.25488.26.255.25532,766
5588.27.0.0/1788.27.0.1 to 88.27.127.25488.27.127.25532,766
5688.27.128.0/1788.27.128.1 to 88.27.255.25488.27.255.25532,766
5788.28.0.0/1788.28.0.1 to 88.28.127.25488.28.127.25532,766
5888.28.128.0/1788.28.128.1 to 88.28.255.25488.28.255.25532,766
5988.29.0.0/1788.29.0.1 to 88.29.127.25488.29.127.25532,766
6088.29.128.0/1788.29.128.1 to 88.29.255.25488.29.255.25532,766
6188.30.0.0/1788.30.0.1 to 88.30.127.25488.30.127.25532,766
6288.30.128.0/1788.30.128.1 to 88.30.255.25488.30.255.25532,766
6388.31.0.0/1788.31.0.1 to 88.31.127.25488.31.127.25532,766
6488.31.128.0/1788.31.128.1 to 88.31.255.25488.31.255.25532,766
6588.32.0.0/1788.32.0.1 to 88.32.127.25488.32.127.25532,766
6688.32.128.0/1788.32.128.1 to 88.32.255.25488.32.255.25532,766
6788.33.0.0/1788.33.0.1 to 88.33.127.25488.33.127.25532,766
6888.33.128.0/1788.33.128.1 to 88.33.255.25488.33.255.25532,766
6988.34.0.0/1788.34.0.1 to 88.34.127.25488.34.127.25532,766
7088.34.128.0/1788.34.128.1 to 88.34.255.25488.34.255.25532,766
7188.35.0.0/1788.35.0.1 to 88.35.127.25488.35.127.25532,766
7288.35.128.0/1788.35.128.1 to 88.35.255.25488.35.255.25532,766
7388.36.0.0/1788.36.0.1 to 88.36.127.25488.36.127.25532,766
7488.36.128.0/1788.36.128.1 to 88.36.255.25488.36.255.25532,766
7588.37.0.0/1788.37.0.1 to 88.37.127.25488.37.127.25532,766
7688.37.128.0/1788.37.128.1 to 88.37.255.25488.37.255.25532,766
7788.38.0.0/1788.38.0.1 to 88.38.127.25488.38.127.25532,766
7888.38.128.0/1788.38.128.1 to 88.38.255.25488.38.255.25532,766
7988.39.0.0/1788.39.0.1 to 88.39.127.25488.39.127.25532,766
8088.39.128.0/1788.39.128.1 to 88.39.255.25488.39.255.25532,766
8188.40.0.0/1788.40.0.1 to 88.40.127.25488.40.127.25532,766
8288.40.128.0/1788.40.128.1 to 88.40.255.25488.40.255.25532,766
8388.41.0.0/1788.41.0.1 to 88.41.127.25488.41.127.25532,766
8488.41.128.0/1788.41.128.1 to 88.41.255.25488.41.255.25532,766
8588.42.0.0/1788.42.0.1 to 88.42.127.25488.42.127.25532,766
8688.42.128.0/1788.42.128.1 to 88.42.255.25488.42.255.25532,766
8788.43.0.0/1788.43.0.1 to 88.43.127.25488.43.127.25532,766
8888.43.128.0/1788.43.128.1 to 88.43.255.25488.43.255.25532,766
8988.44.0.0/1788.44.0.1 to 88.44.127.25488.44.127.25532,766
9088.44.128.0/1788.44.128.1 to 88.44.255.25488.44.255.25532,766
9188.45.0.0/1788.45.0.1 to 88.45.127.25488.45.127.25532,766
9288.45.128.0/1788.45.128.1 to 88.45.255.25488.45.255.25532,766
9388.46.0.0/1788.46.0.1 to 88.46.127.25488.46.127.25532,766
9488.46.128.0/1788.46.128.1 to 88.46.255.25488.46.255.25532,766
9588.47.0.0/1788.47.0.1 to 88.47.127.25488.47.127.25532,766
9688.47.128.0/1788.47.128.1 to 88.47.255.25488.47.255.25532,766
9788.48.0.0/1788.48.0.1 to 88.48.127.25488.48.127.25532,766
9888.48.128.0/1788.48.128.1 to 88.48.255.25488.48.255.25532,766
9988.49.0.0/1788.49.0.1 to 88.49.127.25488.49.127.25532,766
10088.49.128.0/1788.49.128.1 to 88.49.255.25488.49.255.25532,766
10188.50.0.0/1788.50.0.1 to 88.50.127.25488.50.127.25532,766
10288.50.128.0/1788.50.128.1 to 88.50.255.25488.50.255.25532,766
10388.51.0.0/1788.51.0.1 to 88.51.127.25488.51.127.25532,766
10488.51.128.0/1788.51.128.1 to 88.51.255.25488.51.255.25532,766
10588.52.0.0/1788.52.0.1 to 88.52.127.25488.52.127.25532,766
10688.52.128.0/1788.52.128.1 to 88.52.255.25488.52.255.25532,766
10788.53.0.0/1788.53.0.1 to 88.53.127.25488.53.127.25532,766
10888.53.128.0/1788.53.128.1 to 88.53.255.25488.53.255.25532,766
10988.54.0.0/1788.54.0.1 to 88.54.127.25488.54.127.25532,766
11088.54.128.0/1788.54.128.1 to 88.54.255.25488.54.255.25532,766
11188.55.0.0/1788.55.0.1 to 88.55.127.25488.55.127.25532,766
11288.55.128.0/1788.55.128.1 to 88.55.255.25488.55.255.25532,766
11388.56.0.0/1788.56.0.1 to 88.56.127.25488.56.127.25532,766
11488.56.128.0/1788.56.128.1 to 88.56.255.25488.56.255.25532,766
11588.57.0.0/1788.57.0.1 to 88.57.127.25488.57.127.25532,766
11688.57.128.0/1788.57.128.1 to 88.57.255.25488.57.255.25532,766
11788.58.0.0/1788.58.0.1 to 88.58.127.25488.58.127.25532,766
11888.58.128.0/1788.58.128.1 to 88.58.255.25488.58.255.25532,766
11988.59.0.0/1788.59.0.1 to 88.59.127.25488.59.127.25532,766
12088.59.128.0/1788.59.128.1 to 88.59.255.25488.59.255.25532,766
12188.60.0.0/1788.60.0.1 to 88.60.127.25488.60.127.25532,766
12288.60.128.0/1788.60.128.1 to 88.60.255.25488.60.255.25532,766
12388.61.0.0/1788.61.0.1 to 88.61.127.25488.61.127.25532,766
12488.61.128.0/1788.61.128.1 to 88.61.255.25488.61.255.25532,766
12588.62.0.0/1788.62.0.1 to 88.62.127.25488.62.127.25532,766
12688.62.128.0/1788.62.128.1 to 88.62.255.25488.62.255.25532,766
12788.63.0.0/1788.63.0.1 to 88.63.127.25488.63.127.25532,766
12888.63.128.0/1788.63.128.1 to 88.63.255.25488.63.255.25532,766

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

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.