IP & CIDR Toolkit

Calculate subnets, convert IP ranges, and aggregate CIDRs. IPv4 and IPv6 supported, with exact address coverage.

Local calculations · Your entered addresses are not sent to a server

Input

Operation

IP address

Enter an IPv4 or IPv6 address, then select its prefix below.

Prefix length / subnet mask

IPv4: /0 to /32 · Each option shows its dotted-decimal subnet mask.

Review your address space.

Choose an operation and enter your addresses. Results appear here.

Aggregation preserves exactly the addresses you entered. It never widens coverage to fill gaps.

Three operations. Exact results.

Subnet calculator

Find network boundaries, address counts, and IPv4 subnet and wildcard masks. Host bits are normalized visibly.

Range conversion

Convert an inclusive address range into the smallest CIDR set, without adding addresses.

CIDR aggregation

Remove duplicates and overlaps, then combine adjacent networks wherever exact coverage allows.

Data processing & privacy

The tools process entered addresses and generate results locally in your browser. They do not send inputs or results to a server.

Cloudflare hosts this website and receives the connection information required to deliver its pages. Cloudflare Web Analytics collects aggregate usage and performance metrics without analytics cookies or visitor fingerprinting.

Results are copied or downloaded only when you choose to do so. Always review generated configuration before applying it.