CIDR Calc
Subnet math without the headache.
Switch between CIDR, masks, prefixes, or ranges and share the result instantly.
Range → Minimal CIDR
Switch to IP Range mode to get the smallest CIDR list.
Examples
Results
Calculated outputs
Network address
192.168.1.0
Broadcast address
192.168.1.255
First usable host
192.168.1.1
Last usable host
192.168.1.254
Total addresses
256
Usable hosts
254
Subnet mask
255.255.255.0 (/24)
Wildcard mask
0.0.0.255
Binary IP
11000000 10101000 00000001 00000000
Binary mask
11111111 11111111 11111111 00000000
Binary network
11000000 10101000 00000001 00000000
Binary broadcast
11000000 10101000 00000001 11111111
Class
Class C
Private
Public
FAQ
What is CIDR?
CIDR is a way to write an IP network using a prefix length (like /24) instead of a dotted mask.
How do I convert a range to CIDR?
Choose IP Range mode and enter start/end addresses to get the minimal CIDR list that covers the range.
What is a wildcard mask?
It is the inverse of the subnet mask, often used in ACLs to match host and network ranges.
Do /31 and /32 work?
Yes. The calculator handles /31 and /32 correctly for point-to-point and single-host networks.
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