// Network Tool

SUBNET CALCULATOR

Compute IPv4 and IPv6 subnet details from any CIDR block — netmask, wildcard, host ranges, IP class, and VLSM allocation. Instant, free, no sign-up.

IPv4 Subnet

CIDR / Netmask

Type CIDR like 192.168.1.10/24, or enter IP and pick prefix from the dropdown.

IPv6 Subnet

128-bit

Enter an IPv6 address with prefix length, e.g. 2001:db8::/32 or fe80::1%eth0/64.

VLSM Allocator

Variable Length Subnet Masking

Subnets are allocated largest-first from the base network.

Allocated Subnets

# Name / Label Subnet (CIDR) Netmask Network Addr Broadcast First Host Last Host Usable Hosts Requested