Subnet Calculator

IPv4/IPv6 CIDR — network, broadcast, host range, mask, total/usable host count

Calculate subnet boundaries from CIDR notation. IPv4 returns network/broadcast/usable host range and netmask; IPv6 returns network and total addresses (BigInt).

IPv4

IPv6

IPv4 CIDR

Subnet

Network	`192.168.1.0`⎘
Broadcast	`192.168.1.255`⎘
Netmask	`255.255.255.0`⎘
First host	`192.168.1.1`
Last host	`192.168.1.254`
Total hosts	256
Usable hosts	254

How to use

Select IPv4 or IPv6 using the segmented control.
Enter an IP address with a CIDR prefix in the input field (e.g. 192.168.1.10/24 or 2001:db8::/32).
Read the results: network address, broadcast address, netmask, usable host range, and total/usable host count.
Share the pre-filled calculation via the share link.
All computation runs in your browser.

Examples

Entering 192.168.1.10/24 shows network 192.168.1.0, broadcast 192.168.1.255, netmask 255.255.255.0, and 254 usable hosts.
Entering 10.0.0.0/8 shows a class A network with over 16 million usable host addresses.