Subnet calculator
CIDR → network, range & hosts
Calculate everything about an IPv4 CIDR block: network and broadcast addresses, usable host range, host count, subnet mask and wildcard. A quick reference for network planning and firewall rules.
How it works
- Open the tool and add your file (or paste your text).
- Adjust the options — everything previews instantly.
- Download the result. Done.
Private by design
This tool runs 100% in your browser. Your files are never uploaded to a server, never stored, and never seen by anyone — close the tab and nothing remains.
Free, no limits
No account, no watermarks, no daily caps. If you also need full design tools, the Ijodly editor is one click away.
Frequently asked questions
Is Subnet calculator free to use?
Yes — Subnet calculator is completely free. There is no account to create, no watermark on your results and no daily limits.
Are my files uploaded when I use Subnet calculator?
No. Subnet calculator runs entirely in your browser. Your files never leave your device and nothing is stored on a server — close the tab and nothing remains.
Do I need to install anything or sign up?
Neither. Open the page, use Subnet calculator straight away and download your result. No install, no signup.