IPv4 Subnet Calculator
Network address, broadcast, host range, and masks from CIDR.
About this tool
Enter an IPv4 address with a prefix length (CIDR) and get network, broadcast, usable host range, subnet mask, and wildcard mask. Built for firewall rules, VPC planning, and quick CIDR math.
What you get
- Network and broadcast addresses
- First and last usable host
- Subnet mask and wildcard mask
- Total and usable host counts
- Common private-range presets (/24, /16, …)
How to use
Type a CIDR like 192.168.1.10/24 or pick a preset. Results update live — copy any value into your config.
FAQ
How to calculate subnet from CIDR notation?
Enter an IPv4 address with prefix length like 192.168.1.10/24 to get network address, broadcast, mask, and host range instantly.
What is the broadcast address for a subnet?
It is the last address in the network—shown in results alongside the network address and usable host bounds.
How many usable hosts in a /24 network?
A /24 has 256 addresses; typically 254 are usable for hosts after reserving network and broadcast addresses.
How to find subnet mask from prefix length?
Enter the CIDR prefix and read the dotted-decimal subnet mask and wildcard mask in the results table.
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