IP Subnet Calculator

IPv4 Subnet Calculator

Network Class      
Subnet
IP Address
 

IPv6 Subnet Calculator

Prefix Length:
IP Address
 

RelatedBandwidth Calculator | Binary Calculator


A subnet is a way of dividing a network into multiple networks. Routers are used as boundaries between the subnets for traffic exchange. IP addresses are allocated to connected devices in a subnet. An IP address is the combination of two sets of information — a network or routing prefix and the rest field or host identifier.

Normally, the routing prefix is represented with CIDR notation, which is the first address of the subnet, followed with /, and the bit-length of the prefix. For example, 232.108.25.0/24 means the subnet started with the address of 232.108.25.0 and 24 bits are allocated for the network prefix. Since an IPv4 address has a total of 32 bit. The remaining 8 bits are reserved for hosting addressing. For IPv6, there are a total of 128 bits.

The following are typical subnets for IPv4:

Prefix size Network mask Usable hosts per subnet
/1128.0.0.02,147,483,646
/2192.0.0.01,073,741,822
/3224.0.0.0536,870,910
/4240.0.0.0268,435,454
/5248.0.0.0134,217,726
/6252.0.0.067,108,862
/7254.0.0.033,554,430
Class A
/8255.0.0.016,777,214
/9255.128.0.08,388,606
/10255.192.0.04,194,302
/11255.224.0.02,097,150
/12255.240.0.01,048,574
/13255.248.0.0524,286
/14255.252.0.0262,142
/15255.254.0.0131,070
Class B
/16255.255.0.065,534
/17255.255.128.032,766
/18255.255.192.016,382
/19255.255.224.08,190
/20255.255.240.04,094
/21255.255.248.02,046
/22255.255.252.01,022
/23255.255.254.0510
Class C
/24255.255.255.0254
/25255.255.255.128126
/26255.255.255.19262
/27255.255.255.22430
/28255.255.255.24014
/29255.255.255.2486
/30255.255.255.2522
/31255.255.255.2540
/32255.255.255.2550