Down and Dirty Subnet Calculator
ExtensionTools2 users
Overview
Offline IPv4 subnet calculator with CIDR and subnet mask conversion, live results, and one-click copying.
Down and Dirty Subnet Calculator makes IPv4 subnet calculations quick and straightforward. Enter an IP address and prefix to see the network address, usable host range, broadcast address, and adjacent subnets—or convert between CIDR notation and subnet masks without entering an IP. Results update as you type, with copy buttons for individual values or the complete calculation. It works offline, requires no browser permissions, and keeps entered addresses on your device. A practical tool for network planning, troubleshooting, and checking subnet details without opening another website.
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Details
- Version1.1.0
- UpdatedOctober 20, 2026
- Size9.79KiB
- LanguagesEnglish
- Developer
Email
messenger.erich1@gmail.com - Non-traderThis developer has not identified itself as a trader. For consumers in the European Union, please note that consumer rights do not apply to contracts between you and this developer.
Privacy
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The developer has disclosed that it will not collect or use your data.
This developer declares that your data is
- Not being sold to third parties, outside of the approved use cases
- Not being used or transferred for purposes that are unrelated to the item's core functionality
- Not being used or transferred to determine creditworthiness or for lending purposes