Subnet Calculator
Calculate network information from CIDR notation. Enter an IP address and prefix length to see subnet details, usable hosts, and more.
Common Subnet Masks
/24
→ 255.255.255.0 (254 hosts)
/16
→ 255.255.0.0 (65K hosts)
/8
→ 255.0.0.0 (16M hosts)
/30
→ 255.255.255.252 (2 hosts)
/31
→ Point-to-point (2 hosts)
/32
→ Host route (1 host)