Subnet / CIDR calculator
Get network, broadcast, mask and host range for any IPv4 address.
Runs in your browserFree — no signup
How to use Subnet / CIDR calculator
Subnet calculator shows everything about an IPv4 network: network and broadcast address, subnet mask, usable host range and how many devices fit.
Step by step
- 1Type an IP with a prefix like 192.168.1.10/24, or with a mask.
- 2Use the quick buttons to try other sizes.
- 3Read the results table.
- 4Click any value to copy it.
What to expect
- Instant results as you type.
- Network, broadcast, mask, wildcard, first and last host.
- Whether the address is private or public.
Common use cases
- Checking structured text or settings copied from another program.
- Cleaning up data pasted out of a spreadsheet, email or log.
- Making a quick check without opening another program.
- Preparing content for a website, form or file import.
Privacy & data
Everything runs locally in your browser. Your file is never uploaded to a server, so nothing leaves your device.
Frequently asked questions
Related tools — send your output onward