CIDR Quick Converter
| Property | Value |
|---|
VLSM Subnet Planner
Subnet a base CIDR block into optimal variable-sized subnets based on required hosts.
IP Route Summarization (Supernetting)
Input multiple subnets or IP addresses to calculate the tightest aggregate CIDR block summarizing them.
How to Use CIDR Calculator & VLSM Planner
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1. Enter a CIDR Block
Type an IP address with its prefix length (e.g. 192.168.1.0/24) into the CIDR Block field.
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2. Design Subnets or Summarize Routes
Add subnets with required host counts to generate a VLSM plan, or paste routes one per line to summarize them into a supernet.
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3. Review the Plan
See the calculated network address, usable host range, netmask, broadcast address, and subnet details.
The Technical Details
This interactive web utility provides fast, reliable, and completely private data transformations. In modern workflows, quick formatting, conversions, or estimations are essential. By running all logic entirely in your browser with client-side JavaScript, this tool guarantees that your data never leaves your machine. This approach delivers maximum performance and absolute data privacy, as no information is ever sent to a server.
Frequently Asked Questions
What is CIDR notation?
CIDR (Classless Inter-Domain Routing) notation represents an IP address and its network prefix together, e.g. 10.0.0.0/8 means the first 8 bits define the network and the remaining 24 bits identify hosts.
What is VLSM?
Variable Length Subnet Masking (VLSM) lets you divide a network block into subnets of different sizes based on each subnet's host requirements, allocating IP space efficiently.
Can I summarize multiple routes into one?
Yes. Paste one route per line into the Summarize Routes section and the tool computes the smallest supernet that covers all the provided blocks.
Is this tool suitable for real-world network planning?
Yes. It calculates all subnet details including broadcast address, wildcard mask, usable IP ranges, and host counts, making it useful for network design, documentation, and study.