Know the boundaries
See the canonical network, inclusive first and last address, mask, inverse wildcard and host-count conventions.
NETWORK ENGINEERING PRO WORKSPACE
Subnet & IP Calculator Pro
Calculate IPv4 and IPv6 networks, plan address space, split CIDR blocks and spot overlaps—with exact arithmetic and no data leaving your browser.
✓ IPv4 + IPv6✓ Exact 128-bit math✓ VLSM planning✓ Copy & export
YOUR NETWORK WORKSPACE
Subnet & IP Calculator Pro
✧ No account. No uploads.
01
Analyze any IP network
Enter an IP address with its CIDR prefix (or IPv4 netmask).
NETWORK ANALYSIS
Calculated results
CANONICAL NETWORK——
IP version—
Prefix / host bits—
Total addresses—
Usable IPv4 addresses—
Address space visualizationNetwork vs host bits
Prefix Host02
Split a parent network
Divide a CIDR block into equally sized child subnets.
SUBNET EXPLORER
Subnet map
Parent—
Total child subnets—
| # | Subnet | Last address | Open |
|---|
Page 1
03
Allocate address space
Build a practical VLSM plan with exclusions and no overlapping allocations.
CAPACITY PLAN
Address allocations
Allocated—
Reserved—
Remaining—
Positional address map (left = first address; right = last). Tiny ranges may be too narrow to see; use the exported plan for exact boundaries.
| Network name | Requested | Allocated CIDR | Addresses |
|---|
04
Compare network ranges
Detect overlap, containment, adjacency and possible aggregation. Summarize multiple networks or arbitrary ranges below.
RANGE RELATIONSHIP
Comparison result
RELATIONSHIP—
05
CIDR summary & range converter
Combine overlapping routes or convert an inclusive address range into the smallest exact CIDR list.
Unique addresses—
Output CIDRs—
A LITTLE NETWORK KNOW-HOW
Everything you need for confident subnetting.
Plan at any scale
Explore child prefixes by page, from a few IPv4 /26 blocks to huge IPv6 address spaces.
Allocate without overlap
Reserve existing ranges and place new network requirements in a repeatable VLSM allocation plan.
Double-check routes
Compare CIDRs for containment, intersection, adjacency and exact aggregation before documenting your plan.
Frequently asked questions
Can I calculate IPv4 and IPv6 subnets?
Yes. CIDR analysis, splitting, comparison and allocation support both. IPv4 uses netmask and wildcard notation; IPv6 uses 128-bit prefixes and does not have broadcast addresses.
What happens for IPv4 /31 and /32?
A /31 offers two point-to-point addresses under RFC 3021, while a /32 identifies one address. Neither uses the traditional network/broadcast subtraction.
Does VLSM allocation modify any live network?
No. Plans are calculated locally and can be exported for review. No routers, address management systems, cloud services or DNS records are changed.
Are inputs sent to PixelOkay?
No. The calculations run in JavaScript in your browser; this tool does not upload CIDR inputs. Like any website, hosting may still receive ordinary page requests.