What is Subnet Calculator
This tool performs IPv4 subnet planning, including CIDR calculation, subnet splitting, and VLSM allocation.
Key Features
- Calculate network details from CIDR or subnet mask.
- Show usable host range, broadcast, and capacity.
- Split networks by target subnet count.
- Allocate subnets by host requirements with VLSM.
Steps
- Enter network address and prefix/mask.
- Review base subnet results.
- Split subnets or run VLSM allocation as needed.
- Copy output for planning documents.
FAQ
Why is there no result after input?
Usually caused by invalid IP format, out-of-range prefix, or non-contiguous subnet mask.
Why can VLSM allocation fail?
Requested host totals may exceed parent network capacity, or requirement entries contain invalid values.