IP Subnet Calculator

Calculate subnet details from CIDR notation

Enter a valid IPv4 CIDR address — e.g. 10.0.0.0/8, 172.16.0.0/12, 192.168.1.0/24

Network Address
Broadcast Address
Subnet Mask
Usable Hosts
Subnet Details
IP Class
Address Type
First Usable IP
Last Usable IP
Total Addresses
Binary Visualization
IP Address
Subnet Mask
IP Addresses
#AddressType
Quick Reference
PrefixMaskUsable HostsCommon Use
/8255.0.0.016,777,214Single Class A network
/16255.255.0.065,534Single Class B network
/20255.255.240.04,094Small subnet (16x /24)
/24255.255.255.0254Standard LAN subnet
/25255.255.255.128126Two equal subnets
/28255.255.255.24014Small office / VLAN
/30255.255.255.2522Point-to-point link
/32255.255.255.2551Single host (loopback)
Enter a valid IPv6 CIDR address — e.g. 2001:db8::/32, fe80::/10, ::1/128

Network Address
Prefix
First Usable
Last Usable
Subnet Details
Address Type
Total Addresses
Expanded Notation
Binary Visualization
Network Address (128-bit)

IPv6 subnets contain too many addresses to list. The network and first/last usable addresses are shown above.

Quick Reference
PrefixAddressesCommon Use
/327.9 × 1028Typical ISP allocation
/481.2 × 1024Standard site allocation
/564.7 × 1021Small site / SOHO
/641.8 × 1019Standard LAN subnet
/11265,536SLAAC / device subnet
/1272Point-to-point link
/1281Single host (loopback)