IPv4 Subnet Mask Calculator

Enter an IPv4 address, mask, prefix, host count or subnet split and get the exact network, host range, wildcard mask and CIDR data instantly.

Network address + mask/prefix

Enter an IPv4 address, mask, prefix, host count or subnet split and get the exact network, host range, wildcard mask and CIDR data instantly.

IPv4 + subnet mask

Subnet details

Network address

Host range

Broadcast address

Wildcard mask

CIDR prefix

Subnet mask
First usable host
Last usable host
Total IP addresses
Usable hosts
Block size / increment
Class & scope

Generated subnets

# CIDR Network Host range Broadcast

No subnets to display yet.

IPv4 subnetting tips

  • CIDR prefixes are counted from the left: /24 equals 255.255.255.0 and provides 256 addresses.
  • /31 subnets are perfect for point-to-point links, while /32 reserves a single host (loopbacks, VIPs).
  • Plan ahead by checking if your subnet is within private ranges like 10/8, 172.16/12 or 192.168/16.