IP Subnet Calculator - Find Subnet, CIDR, and IP Ranges

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About IP Subnet Calculator

Why I built this

I got tired of scribbling subnet math on paper, so this calculator shows the network address, broadcast, usable range, and host count as soon as you enter an IPv4 and pick a mask or CIDR.

How it works

Enter an IPv4 address.
Select the subnet mask or CIDR prefix.
See the network address, broadcast, usable IP range, and host totals right away.

Details it shows

Network & broadcast: The exact boundaries of the subnet.
Usable range: First and last IPs you can assign.
Host count: How many usable addresses you get.
CIDR and mask: Clear view of both notations.

Where it helps

Handy for lab builds, quick audits, cloud VPC planning, or study sessions when you just want to check your work without reaching for a calculator.

For related network tasks, also check IP Range Calculator, IP Address Lookup, and What Is My IP Address.

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