IP Subnet Calculator
Frequently Asked Questions
Everything you need to know about IP subnets
What is a subnet mask?
It says which part of an IP address identifies the network and which identifies the machine. A /24, that is 255.255.255.0, means the first 24 bits are the network and the last 8 the hosts: 256 addresses in all, 254 of them usable.
What are the network and broadcast addresses?
The network address is the first in the subnet and identifies the network itself, so it goes to no machine. The broadcast is the last and is used to send a packet to everyone at once. The usable hosts are all the addresses in between.
How do I pick the right subnet?
From the number of devices you expect, with some room to spare: /24 gives 254 hosts, /25 gives 126, /26 sixty-two, /27 thirty, /28 fourteen, /29 six, /30 two, which is the point to point case, and /32 a single address.
Does my data stay private?
Yes, and not because we promise it: this tool runs entirely inside your browser. What you type or upload never leaves your device, so it never reaches a server of ours and there is nothing we could keep, read or lose. You can check it yourself: open the page, disconnect from the internet, and the tool keeps working.
Do you store what I enter?
No. There is no database behind this tool: we do not store your files, your text or your results. When you close the tab nothing is left — not here with us, because it never arrived, and not anywhere else.
Do you profile me? Are you GDPR compliant?
We do not profile you: there is no account to create, we never ask for your email to use a tool, and we keep no profile of what you do. We are an Italian company and we work under the GDPR and the other European rules, with the privacy notice and the consent request in plain sight. One thing we say in full rather than hiding it behind a slogan: the ads on the page are Google's, and Google may use cookies to personalise them. You decide from the consent banner: if you say no the ads stay, but they are not personalised, and the tool works exactly the same.
If it is free, how do you make money?
From the ads on the page, and that is all. We do not sell your data, there is no hidden paid plan, there is no limit that eventually asks for your card, and you do not have to sign up. The ads pay for the servers and for the time we spend writing the tools: that is how we can keep them open to everyone.