Networking tools to calculate, convert and verify.
Interactive utilities for subnetting, CIDR, IPv4, IPv6, DNS and diagnostics. Use them for quick calculations or alongside the guides.
From a quick mask conversion to a complete address plan.
Tools are grouped by the kind of problem they solve. Start with your goal, then use each landing page to understand how to interpret the result.
Subnetting & CIDR
13 toolsCalculate, compare and validate IPv4 networks: prefixes, masks, block sizes, FLSM and VLSM.
CIDR / Host Calculator
Convert host requirements into CIDR prefixes, or a prefix into usable address capacity. Optionally calculate the IPv4 network, broadcast, block size and host range.
Subnet Mask ↔ CIDR Converter
Convert IPv4 CIDR prefixes to dotted-decimal subnet masks and back, validate contiguous masks, and optionally inspect the resulting network range.
IPv4 Network / Broadcast Calculator
Calculate the IPv4 network address, broadcast address, mask, host range and usable capacity from an IP address plus CIDR prefix or subnet mask.
Subnet Block Size and Increment Calculator
Calculate IPv4 subnet block size and increment from a CIDR prefix or subnet mask, identify the changing octet, and practice finding subnet boundaries quickly.
FLSM Subnet Calculator
Split an IPv4 network into equal-size subnets with FLSM. Calculate the new prefix, mask, block size, ranges and capacity for each subnet.
VLSM Calculator
Design variable-size IPv4 subnets from host requirements. Calculate the smallest suitable prefix, allocate ranges in order, and reduce address waste.
Is This IP Inside a Subnet?
Check whether an IPv4 address belongs to a CIDR network, normalize the network address, and inspect the exact block boundaries.
CIDR Range Calculator
Calculate the normalized network, IPv4 range, broadcast boundary and total address count from an address and CIDR prefix.
CIDR Aggregator and Route Summarizer
Combine contiguous, correctly aligned IPv4 networks into the smallest exact set of CIDR prefixes without adding outside addresses.
Subnet Overlap Checker
Compare multiple IPv4 CIDR blocks and detect equality or containment before you deploy routes, VLANs, VPNs or address plans.
IPv4 Range to CIDR Converter
Convert a starting and ending IPv4 address into the smallest exact set of CIDR prefixes without including addresses outside the interval.
Interactive IPv4 CIDR Table
Explore IPv4 prefixes from /0 to /32 with dotted masks, host bits, block size, address capacity and subnet increment.
Wildcard Mask Converter
Convert subnet masks or CIDR prefixes to wildcard masks and back, with an optional ACL-style example for IPv4 policy work.
Conversion & IPv6
7 toolsConvert address representations and work with IPv6 prefixes.
Decimal ↔ Binary ↔ Hex Converter
Convert unsigned values between decimal, binary and hexadecimal in 8, 16 or 32 bits, with automatic padding and range validation.
IPv4 ↔ Binary Converter
Convert an IPv4 address to four 8-bit binary octets, edit octets interactively, and toggle individual bits to see the address change in real time.
IPv4 ↔ Hexadecimal Converter
Convert IPv4 addresses to hexadecimal by octet, as a continuous 32-bit value or with a 0x prefix, and convert 8-digit hex values back to IPv4.
IPv4 Classification: Private, Public and Special Ranges
Classify an IPv4 address by historical class and detect private, CGNAT, loopback, link-local, documentation, multicast and other special-use ranges.
IPv6 Compress / Expand Tool
Normalize an IPv6 address between its full eight-group representation and a valid compressed form, including IPv4-embedded notation.
IPv6 Prefix Calculator
Calculate the network prefix for an IPv6 address from /0 to /128 and inspect the normalized network in compressed and expanded form.
IPv6 Subnet Calculator
Split an IPv6 allocation into child prefixes, calculate the number of available subnets, and preview any section of the resulting prefix space by index.
Diagnostics & Public Network
3 toolsInspect public addressing, geolocation and DNS data.
What Is My Public IP? (IPv4 / IPv6)
Check the public IP used by your current Internet connection and inspect useful network context such as ISP, ASN, organization, hostname, country and timezone.
IP Geolocation: Locate a Public IPv4 or IPv6 Address
Geolocate a public IPv4 or IPv6 address and inspect approximate location, ISP, organization, ASN, timezone and coordinates for troubleshooting and security analysis.
DNS Lookup: Query Public DNS Records
Query public A, AAAA, CNAME, MX, TXT, NS, PTR, SOA, SRV and CAA records with TTL data through a server-side DNS resolver.
Every tool is paired with explanatory content.
The goal is not only to return a number. Each landing explains the logic, limits and edge cases so you can reproduce the reasoning without always depending on a calculator.
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