Enter an IPv4 address to see its classful network class, network/host split, and what it's used for
| Class | First octet range | Typical use |
|---|---|---|
| A | 0 – 127 | Very large networks (huge orgs, ISPs) |
| B | 128 – 191 | Medium-to-large networks |
| C | 192 – 223 | Small networks (homes, small offices) |
| D | 224 – 239 | Multicast groups |
| E | 240 – 255 | Reserved for experimental use |
Classful addressing was the original way IPv4 address space was divided, before CIDR (Classless Inter-Domain Routing) took over as the modern standard. Even though real-world routing today ignores these classes, the terminology still shows up constantly in networking courses, certification exams, and legacy documentation — so knowing at a glance whether an address falls in Class A, B, C, D or E is still a genuinely useful skill. This tool reads the first octet of any IPv4 address you enter and classifies it instantly, and for Class C addresses specifically, it also breaks the address into its network portion (the first three octets, which identify the network) and host portion (the last octet, which identifies a specific device on that network).
How to use it:
192.168.1.10).Tip: most home and small-office routers hand out addresses like 192.168.x.x — that's a Class C-range private address, which is why this class comes up so often in everyday networking.
A Class C network supports up to 254 usable host addresses (256 minus the network and broadcast addresses), which makes it the right size for small offices, home networks, and small LANs — much smaller than a Class A or B network, which can support millions or tens of thousands of hosts respectively.
Not for actual routing — the internet moved to CIDR (Classless Inter-Domain Routing) in the 1990s, which uses subnet masks like /24 instead of rigid classes. But the class terminology is still widely taught and referenced, especially for Class A/B/C private address ranges.
The private IP range 192.168.0.0–192.168.255.255 sits entirely inside the classful Class C range (192–223 in the first octet), which is why nearly every home router assigns Class C-style addresses to your devices by default.
Class D (224–239) is reserved for multicast — sending one stream to many recipients at once, used by things like video conferencing and routing protocols. Class E (240–255) is reserved for experimental/future use and isn't used on the public internet.
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