– CIDR CALCULATOR · TSG LABS TOOLS
CIDR Range Calculator
IPv4 CIDR inspection and FLSM subnetting. Paste a CIDR like
10.42.67.0/24 to see the network, broadcast, mask,
wildcard, host range, and binary representation. Switch to subnet
mode to split a parent network into equal-size children by target
prefix or by required host count. Useful for VLAN sizing, address
plan scoping, and the "do these two ranges overlap" question
during commissioning.
IPv4 CIDR inspection and FLSM subnetting. Inspect mode breaks a CIDR down into network, broadcast, mask, wildcard, host range, and binary. Subnet mode splits a parent network into equal-size children, either by target prefix or by required host count. All math runs in the browser. Nothing leaves the page.
Network 00001010.00101010.01000011.00000000 Broadcast 00001010.00101010.01000011.11111111 Mask 11111111.11111111.11111111.00000000 Wildcard 00000000.00000000.00000000.11111111
BETA tool. IPv4 only. Pure browser, no telemetry, no signups. For VLSM-style mixed-size subnetting, run the subnet operation multiple times against successively smaller children.
When to use this
- Sizing a VLAN range and confirming the chosen prefix actually fits the device count.
- Sanity-checking an integrator's address plan submittal against the building's projected device load.
- Splitting a /16 into /24s for a multi-site rollout and exporting the table for documentation.
- Confirming the network and broadcast addresses for an ACL definition.
What it does not do (yet)
IPv6 inspection. VLSM-style mixed-size subnetting in one pass. CSV export. These are on the BETA roadmap. For mixed-size subnetting today, run the subnet operation iteratively against successively smaller children.
BETA notes
All math runs in the browser. Nothing leaves the page. Feedback to [email protected].