Text & Web Utilities
IP Subnet Calculator
Calculate network, broadcast, and host range.
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About the IP Subnet Calculator
Plan and troubleshoot networks fast. Enter an IPv4 address and a CIDR prefix (like /24) and the calculator returns the network address, broadcast address, subnet mask, wildcard mask, usable host range, and the number of usable hosts. It's an essential tool for network admins, students, and anyone configuring routers or firewalls.
How to use the IP Subnet Calculator
- 01Enter your an IPv4 address and CIDR prefix.
- 02Read the result instantly — it recalculates as you type.
- 03Adjust the numbers to model different scenarios.
Frequently asked questions
What is CIDR notation?
A prefix like /24 that says how many leading bits are the network portion. /24 means a 255.255.255.0 mask and 254 usable hosts.
Why subtract 2 from the host count?
The first address is the network identifier and the last is the broadcast address, so both are reserved and not assignable to devices.