CIDR Calculator
Convert between CIDR notation and IP ranges, calculate hosts, split subnets
CIDR to IP Range
IP Range to CIDR
Split CIDR into Smaller Subnets
Quick Reference
/8 = 16.7M hosts
/16 = 65,534 hosts
/24 = 254 hosts
/28 = 14 hosts
/29 = 6 hosts
/30 = 2 hosts
/31 = 2 hosts*
/32 = 1 host
* /31 is used for point-to-point links (RFC 3021)