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
- fc00::/7
- Canonical network
- fc00::/7
- IP version
- IPv6
- Prefix length
- 7
- Network address
- fc00::
- First address
- fc00::
- Last address
- fdff:ffff:ffff:ffff:ffff:ffff:ffff:ffff
- Total addresses
- 2658455991569831745807614120560689152
- Netmask
- Not used for IPv6
- Broadcast
- Not used for IPv6
- Usable hosts
- N/A
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.