The subnet calculator converts an IPv4 address and prefix into the boundaries used for routing and address planning. It is a quick offline-style reference during network configuration and troubleshooting.
How it works
The CIDR prefix defines which bits belong to the network. From that mask, the calculator derives the network address, broadcast behavior, and usable range, including the special handling needed for /31 and /32 prefixes.
How to use it in Network Toolkit
- Enter an IPv4 address and CIDR prefix.
- Review the calculated network and mask.
- Check the first and last addresses for the intended topology.
- Use the result to verify DHCP, static addressing, or scan scope.
What information you can see
- Network address and subnet mask
- Broadcast address where applicable
- Address range and subnet size
- Correct /31 and /32 handling
Common use cases
- Verify whether two hosts share a subnet
- Plan a small static address range
- Confirm the scope for an authorized scan
- Check a router or VPN prefix
Limitations and Android considerations
Related network tools
IP Scanner for Android, Network Scanner for Android, Ping Tool for Android can help confirm the result from another angle.
Frequently asked questions
What does /24 mean?
It means the first 24 bits identify the network, equivalent to the mask 255.255.255.0.
Are /31 subnets usable?
Yes. They are commonly used on point-to-point links and are handled differently from traditional host subnets.
What is a /32?
A /32 identifies one IPv4 address rather than a multi-address subnet.