CALCULATE / IP60BPS / MODULE
IPV6 RANGE → CIDR
Convert an IPv6 start/end range into the smallest exact set of aligned CIDR prefixes with 128-bit browser-local arithmetic.
EXAMPLES
The result is an exact inclusive cover and never adds addresses outside the entered range. Calculation and export stay in this browser; no live route or ownership test is performed.
RESULT / EXPLAINED
Exact address math, with operational claims kept separate.
The network-planning tools perform deterministic IPv4/IPv6 arithmetic locally. They describe address-space relationships, not whether a network is deployed correctly.
What is exact
Network boundaries, containment, ranges, prefix lengths, masks and exact aggregation/splitting results come from deterministic address arithmetic.
Canonical output
Normalized network values remove host bits where appropriate. Containment means one calculated address range fully includes another; overlap means ranges intersect.
No live network validation
The browser does not confirm routing tables, VLANs, DHCP, firewall rules, ownership, reachability or whether the calculated prefix is appropriate for your deployment.
Before deployment
Use the arithmetic result as a planning input, then verify it against the real network design, routing/firewall policy and authoritative address allocation.
0BPS SHOWS MEASURED OR CALCULATED FACTS SEPARATELY FROM INTERPRETATION. WHERE A RESULT IS ADVISORY, ESTIMATED OR DESTINATION-SPECIFIC, THE LIMIT IS STATED IN THE TOOL.
REFERENCE / FAQ
COMMON QUESTIONS
How does IPv6 range-to-CIDR conversion work?
The calculator repeatedly chooses the largest correctly aligned IPv6 CIDR prefix that fits inside the remaining inclusive start/end range.
Can the generated prefixes include addresses outside my range?
No. The result is an exact CIDR cover of the entered IPv6 range and does not intentionally broaden the address set.
Is my IPv6 range sent to 0bps?
No. Start/end parsing and 128-bit range summarization are performed locally in your browser.
The calculator summarizes only the inclusive start/end IPv6 range and does not add addresses merely to reduce the number of prefixes.
BigInt preserves exact range and alignment boundaries across the full IPv6 address space without floating-point rounding.
PRACTICAL / EXAMPLES
PUT THE NUMBER IN CONTEXT.
Short examples using the same units and assumptions as this module.
This aligned 65,536-address range collapses exactly to 2001:db8::/112.
A range that starts or ends inside a prefix requires multiple CIDRs so no address outside the requested interval is included.