Tech
Subnet Calculator
This subnet calculator computes key IPv4 subnet details from an IP address and CIDR prefix.
Quick answer
Network address identifies the subnet.
What this tells you
- •Network address identifies the subnet.
- •Broadcast address is the last address in the subnet.
- •Usable hosts exclude network and broadcast in standard subnets.
How to Use
- 1Enter an IPv4 address.
- 2Enter CIDR prefix (0-32).
- 3Calculate to view subnet mask and host range.
How It Works
Formula
Mask from CIDR, Network = IP AND Mask, Broadcast = Network OR inverse maskBitwise operations derive all subnet boundaries and host ranges.
Calculation note: values are processed in the order shown above, using the current input units.
Worked Examples
Typical /24 subnet
I P192.168.1.34
C I D R24
ResultNetwork 192.168.1.0, Broadcast 192.168.1.255, Hosts 254
Common mistakes
- Using invalid IPv4 formats
- Confusing CIDR and subnet mask notation
- Assuming /31 and /32 have normal host ranges
Frequently Asked Questions
CIDR is prefix-length notation indicating how many leading bits are network bits.
A /24 typically has 254 usable host addresses.
Yes, but standard usable-host logic differs for those edge cases.