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CIDR Calculator

Calculate network address, broadcast, and host range from CIDR notation

Network Tool · v1.0

CIDR Calculator

Real-time IPv4 subnet calculation

Format: IP/prefix (e.g., 10.0.0.0/8, 192.168.1.0/24, 172.16.0.0/12)

What is CIDR?

CIDR (Classless Inter-Domain Routing) is a method for allocating IP addresses and routing. Format: IP/prefix where prefix (0-32) indicates the number of network bits.

Common CIDR

•/8 — 16,777,214 hosts (Class A)
•/16 — 65,534 hosts (Class B)
•/24 — 254 hosts (Class C)
•/32 — 1 host (single IP)

Private Ranges

•10.0.0.0/8 — 16M hosts
•172.16.0.0/12 — 1M hosts
•192.168.0.0/16 — 65K hosts