IPv4 Subnet Chart

Complete IPv4 subnet reference with CIDR notation, subnet masks, and host calculations

CIDR Subnet Mask Wildcard Mask Network Bits Host Bits Total Hosts Usable Hosts Subnets
/32255.255.255.2550.0.0.032010 (Host)1
/31255.255.255.2540.0.0.131120 (P2P)2
/30255.255.255.2520.0.0.3302424
/29255.255.255.2480.0.0.7293868
/28255.255.255.2400.0.0.15284161416
/27255.255.255.2240.0.0.31275323032
/26255.255.255.1920.0.0.63266646264
/25255.255.255.1280.0.0.127257128126128
/24255.255.255.00.0.0.255248256254256
/23255.255.254.00.0.1.255239512510512
/22255.255.252.00.0.3.25522101,0241,0221,024
/21255.255.248.00.0.7.25521112,0482,0462,048
/20255.255.240.00.0.15.25520124,0964,0944,096
/19255.255.224.00.0.31.25519138,1928,1908,192
/18255.255.192.00.0.63.255181416,38416,38216,384
/17255.255.128.00.0.127.255171532,76832,76632,768
/16255.255.0.00.0.255.255161665,53665,53465,536
/15255.254.0.00.1.255.2551517131,072131,070131,072
/14255.252.0.00.3.255.2551418262,144262,142262,144
/13255.248.0.00.7.255.2551319524,288524,286524,288
/12255.240.0.00.15.255.25512201,048,5761,048,5741,048,576
/11255.224.0.00.31.255.25511212,097,1522,097,1502,097,152
/10255.192.0.00.63.255.25510224,194,3044,194,3024,194,304
/9255.128.0.00.127.255.2559238,388,6088,388,6068,388,608
/8255.0.0.00.255.255.25582416,777,21616,777,21416,777,216
/7254.0.0.01.255.255.25572533,554,43233,554,43033,554,432
/6252.0.0.03.255.255.25562667,108,86467,108,86267,108,864
/5248.0.0.07.255.255.255527134,217,728134,217,726134,217,728
/4240.0.0.015.255.255.255428268,435,456268,435,454268,435,456
/3224.0.0.031.255.255.255329536,870,912536,870,910536,870,912
/2192.0.0.063.255.255.2552301,073,741,8241,073,741,8221,073,741,824
/1128.0.0.0127.255.255.2551312,147,483,6482,147,483,6462,147,483,648
/00.0.0.0255.255.255.2550324,294,967,2964,294,967,2944,294,967,296

Private IP Address Ranges (RFC 1918)

Reserved private IP address ranges for internal networks

Class IP Range CIDR Notation Subnet Mask Total Addresses Usable Addresses Common Usage
Class A 10.0.0.0 - 10.255.255.255 10.0.0.0/8 255.0.0.0 16,777,216 16,777,214 Large enterprises, ISPs
Class B 172.16.0.0 - 172.31.255.255 172.16.0.0/12 255.240.0.0 1,048,576 1,048,574 Medium enterprises, campuses
Class C 192.168.0.0 - 192.168.255.255 192.168.0.0/16 255.255.0.0 65,536 65,534 Small offices, home networks
APIPA 169.254.0.0 - 169.254.255.255 169.254.0.0/16 255.255.0.0 65,536 65,534 Auto-configuration (APIPA)

IPv4 Address Classes & Public Ranges

IPv4 address classes and special use ranges organized by class

IPv4 Address Classes

Class Range CIDR Default Subnet Mask Networks Hosts per Network Usage
Class A 1.0.0.0 - 126.255.255.255 /8 255.0.0.0 126 16,777,214 Large organizations, ISPs
Class B 128.0.0.0 - 191.255.255.255 /16 255.255.0.0 16,384 65,534 Medium-sized organizations
Class C 192.0.0.0 - 223.255.255.255 /24 255.255.255.0 2,097,152 254 Small organizations
Class D 224.0.0.0 - 239.255.255.255 /4 N/A N/A N/A Multicast addresses
Class E 240.0.0.0 - 255.255.255.255 /4 N/A N/A N/A Reserved/Experimental

Special Use Ranges by Class

Class IP Range CIDR Notation Purpose RFC Description
Class A Special Ranges (1.0.0.0 - 126.255.255.255)
Class A 0.0.0.0 - 0.255.255.255 0.0.0.0/8 This Network RFC 1122 Current network (only valid as source address)
Class A 10.0.0.0 - 10.255.255.255 10.0.0.0/8 Private Network RFC 1918 Private-use networks (Class A private)
Class A 127.0.0.0 - 127.255.255.255 127.0.0.0/8 Loopback RFC 1122 Loopback addresses to localhost
Class B Special Ranges (128.0.0.0 - 191.255.255.255)
Class B 169.254.0.0 - 169.254.255.255 169.254.0.0/16 Link Local RFC 3927 Link-local addresses (APIPA)
Class B 172.16.0.0 - 172.31.255.255 172.16.0.0/12 Private Network RFC 1918 Private-use networks (Class B private)
Class C Special Ranges (192.0.0.0 - 223.255.255.255)
Class C 192.0.0.0 - 192.0.0.255 192.0.0.0/24 IETF Protocol RFC 6890 IETF Protocol Assignments
Class C 192.0.2.0 - 192.0.2.255 192.0.2.0/24 Documentation RFC 5737 Documentation and examples (TEST-NET-1)
Class C 192.88.99.0 - 192.88.99.255 192.88.99.0/24 IPv6 to IPv4 RFC 3068 6to4 relay anycast
Class C 192.168.0.0 - 192.168.255.255 192.168.0.0/16 Private Network RFC 1918 Private-use networks (Class C private)
Class C 198.18.0.0 - 198.19.255.255 198.18.0.0/15 Benchmark Testing RFC 2544 Network interconnect device benchmark testing
Class C 198.51.100.0 - 198.51.100.255 198.51.100.0/24 Documentation RFC 5737 Documentation and examples (TEST-NET-2)
Class C 203.0.113.0 - 203.0.113.255 203.0.113.0/24 Documentation RFC 5737 Documentation and examples (TEST-NET-3)
Class D - Multicast (224.0.0.0 - 239.255.255.255)
Class D 224.0.0.0 - 239.255.255.255 224.0.0.0/4 Multicast RFC 3171 Multicast addresses
Class E - Reserved (240.0.0.0 - 255.255.255.255)
Class E 240.0.0.0 - 255.255.255.254 240.0.0.0/4 Reserved RFC 1112 Reserved for future use
Class E 255.255.255.255 255.255.255.255/32 Broadcast RFC 919 Limited broadcast address
Other Special Use Ranges
Special 100.64.0.0 - 100.127.255.255 100.64.0.0/10 Carrier NAT RFC 6598 Shared address space for carrier-grade NAT