CIDR / Subnet Calculator
Network/broadcast/hosts with binary steps.
How to use
Enter CIDR into CIDR / Subnet Calculator and press Run — or just type, live results update as you edit. DevUtility computes the answer instantly with a pure JavaScript engine (Web Worker for heavy inputs) on this page. Nothing is sent anywhere: no signup, no server round-trip, same inputs always give same outputs.
Steps
- Open the tool below (or scroll to the interactive CIDR / Subnet Calculator).
- Enter CIDR.
- Press Run (Ctrl+Enter) — or keep typing for live results.
- Copy the answer, download it, or share the link.
FAQ
Is CIDR / Subnet Calculator really free?
Yes — free with no signup, no credits and no limits on this tool. It is supported by clearly labeled ads placed away from the buttons, never by paywalls.
Is anything I type into CIDR / Subnet Calculator sent to a server?
No. Every keystroke is computed with a pure JavaScript engine (Web Worker for heavy inputs) inside this page. Close the tab and your data is gone — unless you explicitly download or share it.
What should I enter in "CIDR"?
Put your cidr here — for example: 192.168.1.0/24. Leave the defaults first to see how it works, then adjust. Every field is validated with a plain-language message if something is off.
I normally use Base64Decode — why switch?
If you are tired of one-box pages full of ads with no validation, error locations or download, DevUtility is the alternative: encode, decode, validate and download in one box — offline and keyboard-first.
How accurate is CIDR / Subnet Calculator?
Everything runs on your device, so results are instant and repeatable — same inputs, same outputs, no server involved.
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Free alternative
Free alternative to RapidTables and Base64Decode for encoders, formatters, hashes and network tools — encode, decode, validate and download in one box — offline and keyboard-first. RapidTables vs Base64Decode vs DevUtility.
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