IPv4 subnet calculator
Calculate an IPv4 network, mask and address range.
IPv4 subnet calculator
Type or paste to update the result automatically.
Your result appears here
Type, paste, or use an example. Copy your result when it is ready.
How to use IPv4 subnet calculator
The IPv4 subnet calculator takes an address with or without a /prefix and returns the network, first and last address, netmask, broadcast address, total addresses and usable hosts. Without a prefix it uses the CIDR setting, 24 by default. Calculations use exact integer arithmetic, and /31 and /32 networks follow point-to-point and single-host rules.
- Type or paste your source, or load an example.
- Change the basic settings or open Advanced mode to fine-tune the result.
- Review and copy or download your result. Pause Live results to run manually. Sources or individual settings above 20,000 characters require an explicit run.
What this tool supports
Calculate an IPv4 network, mask and address range.
- CIDR prefix (used if address has no /prefix)
- Range: 0 to 32
Limits and processing
Text operations generally accept up to 2,000,000 characters. Individual parsers, generators and formulas apply additional limits shown by their controls.
Example source
192.168.1.24/24
Frequently asked questions
How many usable hosts are in a /24 subnet?
A /24 has 256 total addresses and 254 usable hosts, because the network and broadcast addresses are subtracted. The calculator applies that subtraction for every prefix from /0 up to /30.
How does the subnet calculator handle /31 and /32?
For /31 it reports no broadcast address and counts both addresses as usable, following point-to-point link semantics. A /32 identifies a single host, so total and usable addresses are both 1.
Can I enter a host address instead of the network address?
Yes. Enter any address in the subnet, such as 192.168.1.24/24, and the calculator masks it to find the network 192.168.1.0/24 and its range. IPv6 input is rejected here; use the IPv6 subnet calculator for those.
Where is my input processed?
This operation processes its source in your browser. Copy and download are explicit actions; source input is not saved in an account or history.
What are the input limits?
Text operations generally accept up to 2,000,000 characters. Individual parsers, generators and formulas apply additional limits shown by their controls.