Networking fundamentals — IPs, subnets, ports, HTTP status codes, MIME types — are things every developer needs to look up occasionally. Having them in one searchable place eliminates the documentation rabbit hole.
What Is the CIDR Calculator?
CIDR Calculator is one of the tools in WebdevToolbox’s Networking category. Calculate IP ranges, subnet masks, and broadcast addresses from CIDR notation. It runs entirely in your browser — no server uploads, no accounts, no waiting.
How to Use It
- Open CIDR Calculator.
- Enter a CIDR block (e.g.
192.168.1.0/24). - The tool shows network address, broadcast address, usable host range, and subnet mask.
- Use this when configuring VPCs, firewall rules, or network segmentation.
Key Features
- 100% client-side — all processing happens in your browser. Nothing is sent to a server.
- Real-time output — results update as you type, with no submit button required.
- One-click copy — copy the output to your clipboard with a single button press.
- PWA-ready — works offline when installed as a Progressive Web App.
When to Use the CIDR Calculator
- Infrastructure planning — calculate subnet ranges before provisioning cloud VPCs.
- API development — look up correct HTTP status codes and headers for your API responses.
- Incident response — quickly reference port numbers or MIME types during a production issue.
Try It Now
Open CIDR Calculator directly from anywhere on the site using ⌘K and typing the tool name. No login required — everything runs offline-capable in your browser.
Part of the Networking collection on WebdevToolbox — free, browser-based developer tools with no login required.