Calculate IPv4 range size, exact subnet alignment, smallest covering CIDR, and minimal CIDR block decomposition.
Calculate the size and CIDR coverage of an IPv4 address range using a start and end address.
Range size, exact block match status, smallest covering CIDR, and minimal CIDR block decomposition.
The IPv4 range from 10.20.30.0 to 10.20.30.255 contains 256 address(es).
The range aligns exactly to a single CIDR block: 10.20.30.0/24. The smallest covering CIDR is identical.
Use this tool to translate arbitrary address spans into precise CIDR objects for ACLs, route policies, firewall rules, IPAM records, and infrastructure planning.
Practical reminders for working with arbitrary IPv4 ranges.
A start and end IP might define a valid range without matching a single clean CIDR network boundary.
The smallest covering CIDR may include addresses outside the requested range if the range is not perfectly aligned.
Breaking a range into minimal CIDR blocks helps with route summaries, firewall objects, ACLs, and IPAM work.
Typical situations where range calculations matter.
Translate arbitrary IP spans into minimal CIDR blocks for firewalls, route tables, and network policies.
Validate whether a range is an exact subnet or just a partial address slice.
Estimate address counts before applying changes in IPAM, segmentation, and infrastructure rollout workflows.