$ netcalc --ipv4
IPv4 Network Calculator
Exact IPv4/CIDR calculations performed locally in your browser. No API, database, or server-side processing.
Network
Address details
- CIDR
- Input address
- Address binary
- Network binary
- Mask binary
- Wildcard binary
- Network integer
Subnet math
Enter either a subnet count or host requirement.
Compare two addresses
Subnet list
Generate child subnets by increasing the current prefix. Display is limited to 4,096 subnets.
Calculation notes
- IPv4 addresses are treated as 32-bit unsigned values.
- CIDR prefixes from
/0through/32are accepted. - For
/31, both addresses are counted as usable for point-to-point use, consistent with RFC 3021. - For
/32, the single address is represented as one address; there are no additional host addresses. - For prefixes
/0through/30, conventional usable-host count is total addresses minus network and broadcast addresses. - No IP address is sent to a server by this calculator.
Standards references: RFC 4632 (CIDR) and RFC 3021 (/31 point-to-point IPv4 subnets).