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CIDR Calculator & VLSM Planner

An interactive Classless Inter-Domain Routing (CIDR) calculator. Translate between CIDR blocks, netmasks, and host counts, plan Variable Length Subnet Mask (VLSM) structures, and aggregate routes.

CIDR Quick Converter

Please enter a valid CIDR block (e.g., 192.168.1.0/24).
Property Value

VLSM Subnet Planner

Subnet a base CIDR block into optimal variable-sized subnets based on required hosts.

Invalid base network CIDR.

IP Route Summarization (Supernetting)

Input multiple subnets or IP addresses to calculate the tightest aggregate CIDR block summarizing them.

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