IP Subnet Calculator with Binary Verification
Enter an IPv4 address and CIDR prefix to calculate network address, broadcast address, subnet mask, wildcard mask, usable host range, address count and binary representations. Special /31 and /32 rules are identified.
IPv4 address and prefix
IPv4 subnet details
IP subnet calculator: formulas, interpretation and worked use
This IP subnet calculator performs unsigned 32-bit arithmetic without relying on signed JavaScript bitwise results. It reports both dotted-decimal and binary values for verification.
Transparent calculation steps
The IP subnet calculator displays the intermediate values used in the result so users can audit the calculation rather than receiving an unexplained answer.
Input validation and edge cases
Impossible, incomplete and non-finite inputs are rejected with a specific message. Boundary cases are handled explicitly instead of being silently rounded into a misleading result.
Units and precision
Where units apply, inputs are converted to a consistent internal basis before the formula is evaluated. Results retain enough precision for checking and are then formatted for practical reading.
Worked interpretation
The result panel separates the primary answer, supporting quantities and a formula trace. This makes the calculator suitable for checking homework, planning scenarios and comparing alternatives.
CIDR prefix meaning
The prefix counts leading network bits. The remaining 32 minus prefix bits identify addresses within the subnet.
Boundary verification
The entered address is confirmed to lie between the calculated network and broadcast values, and every dotted value is also shown in 32-bit binary.
IPv4 network boundaries
The IP subnet calculator combines an IPv4 address with a CIDR prefix, applies the subnet mask bit by bit, and reports network address, broadcast address, wildcard mask, total addresses and host range. Prefix length controls the number of network bits; for example, /24 leaves eight host bits and contains 256 total addresses.
Usable-host conventions
The IP subnet calculator treats /31 point-to-point networks and /32 single-host routes using modern special-case conventions rather than subtracting two addresses blindly. For ordinary subnets, the network and broadcast addresses are excluded from the traditional usable-host count. Actual device availability can be lower because routers, gateways, redundancy and provider reservations consume addresses. The tool covers IPv4 only; IPv6 uses different address length and subnet-planning practices.
How are /31 networks handled?
The calculator identifies both addresses as usable for point-to-point semantics rather than subtracting network and broadcast addresses.
What does /32 mean?
A /32 identifies one host address with no host-bit range.
What is the wildcard mask?
It is the inverse of the subnet mask and is often used in access-control and routing configurations.