IPv4/CIDR calculator
IPv4/CIDR calculator lets you calculate IPv4 network, broadcast, mask, totals, and policy-aware host counts in your browser.
Subnet splitter
Subnet splitter lets you split equally or allocate VLSM requirements and report unassigned CIDRs in your browser.
Subnet splitter
⌂ Inputs and results stay in this browser and are not automatically stored or sent.
Waiting for input
Input and conditions
Calculations use your input only; no network queries or configuration changes.
Output
Waiting for input
Complete text result
How to use
Enter the parent CIDR and either a new prefix for equal splits or host requirements for VLSM.
Inspect each allocation's boundaries, alignment, and unused space. If requirements do not fit, reconsider the parent range or requirements rather than understating them. No device settings are changed.
Examples
192.0.2.0/24Principles and limits
Each input is limited to 1,048,576 bytes, output to 33,554,432 bytes, and processing to 5,000 ms. Input is never silently truncated.
Guides
Related tools
CIDR aggregation
CIDR aggregation lets you deduplicate and minimally aggregate CIDRs without widening their union in your browser.