Network tool
CIDR calculator
Enter an IPv4 or IPv6 CIDR network. Host-prefix input such as 8.8.8.8/24 is accepted and normalized to the canonical network.
- Input
- 8.8.8.0/24
- Canonical network
- 8.8.8.0/24
- IP version
- IPv4
- Prefix length
- 24
- Network address
- 8.8.8.0
- First address
- 8.8.8.0
- Last address
- 8.8.8.255
- Total addresses
- 256
- Netmask
- 255.255.255.0
- Broadcast
- 8.8.8.255
- Usable hosts
- 254
What this tool does
The CIDR calculator normalizes a network, calculates its first and last address, counts total addresses, and shows IPv4-specific netmask, broadcast, and usable host values.
Use it when a firewall, DNS provider, hosting panel, or network document gives you CIDR notation and you need the actual address range. Start with the CIDR notation guide if the slash number is unfamiliar.