IPv4 Subnet Calculator
Enter an IP and CIDR or subnet mask to get the network, usable range, broadcast address and host counts.
Subnet results
Network address
CIDR block
First usable
Last usable
Broadcast address
Subnet mask
Wildcard mask
Total addresses
Usable hosts
Host bits
Network in binary
Your IP and mask are calculated in your browser. Nothing is uploaded to BroBroGo.
FAQ
Can I enter CIDR or a dotted subnet mask?
Yes. Use /24, 24, or a dotted mask such as 255.255.255.0. The calculator also accepts an IP written as 192.168.1.10/24.
Why do /31 and /32 show unusual usable counts?
/31 networks are commonly used for point-to-point links, where both addresses can be usable. /32 represents a single host route, so the one address is shown as usable.
Does this tell me if an address is public or private?
No. This tool focuses on subnet boundaries: network, broadcast, range and counts. Whether an address is routed publicly depends on the network it belongs to.