IPv4 Subnet & CIDR Mask Calculator
Calculate essential TCP/IP networking parameters from any IP address and CIDR prefix (e.g. 192.168.1.0/24). View the Network Address, Usable Host Range, Broadcast Address, Subnet Mask, and total usable hosts.
How to Use Subnet Mask & CIDR Calculator (IPv4)
Input IP Address
Enter any IPv4 address (e.g., 10.0.0.1 or 192.168.1.100).
Select CIDR Prefix
Choose CIDR prefix length from /1 to /32 (or select standard subnet mask like 255.255.255.0).
View Network Details
Inspect the network address, broadcast address, binary masks, and host capacity.
About Subnet Mask & CIDR Calculator (IPv4)
IPv4 subnetting partitions a 32-bit address into a network portion and a host portion. The subnet mask uses consecutive binary 1s to identify the network portion. Two addresses are always reserved per subnet: all host bits as 0 (Network ID) and all host bits as 1 (Broadcast Address).
Key Features
- Calculates Network Address, Broadcast Address, and First/Last Usable Host
- Total host capacity vs usable host capacity (2^(32-prefix) - 2)
- Displays dotted decimal, hexadecimal, and full 32-bit binary representations
- Wildcard mask calculation (crucial for Cisco router ACL configuration)
- Standard Class A, Class B, Class C, and Private IP range detection
Frequently Asked Questions
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