Worked example
192.168.1.0–192.168.1.255 converts exactly to 192.168.1.0/24.
IP Range to CIDR Converter
Enter a start and end IPv4 address to find the minimal set of CIDR blocks that cover the entire range. This tool automatically calculates the largest possible supernets to minimize your firewall or configuration.
Define Range
Enter a starting and ending IP address above to calculate the covering prefixes.
Why use CIDR instead of ranges?
While many systems support ranges, most networking equipment (routers, firewalls, BGP) and cloud providers (AWS, Azure, GCP) use CIDR (Classless Inter-Domain Routing) notation. CIDR is more efficient for routing table lookups and is the industry standard for defining network boundaries.
How to use IP Range Converter
Enter inclusive start and end IPv4 addresses to obtain the smallest exact set of CIDR blocks that covers the range.
Common mistake
A non-aligned range often requires several CIDRs; broadening it to one summary can unintentionally include extra addresses.