Free IP Subnet Calculator Online – CIDR, Network & Host Range Calculator
Calculate network address, broadcast address, and host range for an IPv4 CIDR block
Features
- Network & broadcast address
- Subnet & wildcard mask
- Usable host range
- Total address count
- All CIDR prefixes /0–/32
- 100% free, browser-based
Frequently Asked Questions
CIDR (e.g. `/24`) specifies how many bits of the IP address are used for the network portion; the tool derives the subnet mask and host range from it.
No, this calculator currently supports IPv4 addresses only.
The network address is the first address in a subnet (identifies the network itself) and the broadcast address is the last (used to reach all hosts on that subnet) — neither is usable as a regular host address.
A /24 has 256 total addresses, with 254 usable for hosts after subtracting the network and broadcast addresses — the calculator shows this automatically for any prefix you enter.
Yes — it's handy for understanding your router's subnet, checking whether two devices are on the same network, or planning a home lab's IP ranges, not just enterprise networking.
How to Use IP Subnet Calculator
Using IP Subnet Calculator is simple and free. No sign-up required.
- Enter an IPv4 address.
- Select the CIDR prefix.
- Click 'Calculate'.
- View network address, broadcast address, mask, and usable host range.
About IP Subnet Calculator
IP Subnet Calculator computes the network address, broadcast address, subnet mask, wildcard mask, and usable host range for any IPv4 address and CIDR prefix. It's a standard tool for network administrators and students planning IP address allocation, verifying a subnet's host capacity, or checking which addresses fall within a given CIDR block before configuring a router or firewall rule.
All iLoveToolZone tools work directly in your browser — no software installation or account required.