IP Subnet Calculator
Work out an IPv4 subnet from a CIDR or netmask: network and broadcast address, mask, host range and how many addresses are usable.
IPv4 subnet calculator
Enter an address with a CIDR prefix or a dotted netmask.
Nothing calculated yet
Enter an address above, then press “Calculate”.
IPv4 only. /31 is treated as a point-to-point link with two usable addresses and /32 as a single host (RFC 3021).
Runs entirely in your browser. Nothing is uploaded.
How it works
This utility runs locally in your browser for privacy and speed.
1 ⚡
Unlimited local toolsThis run costs 1 credit(s) and is saved to your history automatically.
Log in to save and view your usage history.
My usage history
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Frequently asked questions
- Do I get free credits to try IP Subnet Calculator?
- Yes — new accounts get 3 free credits to spend on any tool, IP Subnet Calculator included. After that you only pay for what you run.
- How many credits does IP Subnet Calculator cost?
- Everything runs in your browser and nothing is uploaded: free accounts pay 1 credit per run, and Pro or Pro+ members run it as often as they like.
- Is the content I paste private?
- IP Subnet Calculator uses your input only to generate the result. Stored results are deleted automatically by our retention policy, and you can remove any run from your history.
- Do I need to install anything?
- No. IP Subnet Calculator works in any modern browser — nothing to download or install.
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