Conversions
Data storage converter
Convert decimal gigabytes into common decimal and binary storage units.
Calculators / Technology / IPv4 subnet
IPv4 subnet calculator
Calculate address counts and mask information from an IPv4 prefix length.
On this page
Subnet mask255.255.255.0
Total addresses256
Traditional usable hosts254
Calculator controls
How to calculate
Calculate address counts and mask information from an IPv4 prefix length.
Total addresses = 2^(32−prefix); mask contains prefix one-bits followed by zero-bits.
Worked example
CIDR prefix length: 24.
Subnet mask: 255.255.255.0 ; Total addresses: 256 ; Traditional usable hosts: 254 .
Assumptions and limits
Usable-host conventions differ for /31 and /32 networks. This tool describes IPv4 only and does not allocate a network address.
Results are rounded for display; calculations use unrounded values. Read our calculation methodology.
Understanding the result
Calculate address counts and mask information from an IPv4 prefix length. The displayed figures use the inputs and formula shown on this page.
When this tool is useful
Use the ipv4 subnet to compare a scenario, check an estimate, or verify a manual calculation.
Understanding your inputs
| Input | What to enter |
|---|---|
| CIDR prefix length | Enter a number of at least 0 and no more than 32. |
Frequently asked questions
What should I check before using the ipv4 subnet result?
Usable-host conventions differ for /31 and /32 networks. This tool describes IPv4 only and does not allocate a network address.
Is this ipv4 subnet result exact?
It is exact for the stated mathematical model and entered values. Real-world results can differ when rates, timing, fees, definitions or measurement conditions differ.