CIDR / Subnet Calculator

Calculate IPv4 subnet details from CIDR notation. Instant results — no server required.

Split into equal subnets

CIDR Cheat Sheet

CIDRSubnet MaskHostsCommon Use
/8255.0.0.016,777,214Class A
/16255.255.0.065,534Class B
/24255.255.255.0254Typical LAN
/25255.255.255.128126Half /24
/28255.255.255.24014Small subnet
/32255.255.255.2551Single host