Subnet splitter
Subnet splitter lets you split equally or allocate VLSM requirements and report unassigned CIDRs in your browser.
IPv4/CIDR calculator
IPv4/CIDR calculator lets you calculate IPv4 network, broadcast, mask, totals, and policy-aware host counts in your browser.
IPv4/CIDR calculator
⌂ 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 an address/prefix such as 192.0.2.10/24 and distinguish ordinary subnets from point-to-point usage.
Inspect network, end address, mask, and total count. Do not subtract two indiscriminately for /31 or /32. The calculation does not query reachability or allocation.
Examples
192.0.2.10/24Principles 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
IP range ⇔ CIDR
IP range ⇔ CIDR lets you convert IPv4 or IPv6 ranges to and from minimal CIDR sets in your browser.
IP and CIDR comparison
IP and CIDR comparison lets you calculate CIDR containment, overlap, intersection, and directional differences in your browser.