🌐 IP Address Range Calculator
Calculate subnet ranges, usable hosts, network & broadcast addresses from any IP and CIDR prefix or subnet mask
| CIDR Prefix | Subnet Mask | Total IPs | Usable Hosts | Typical Use |
|---|---|---|---|---|
| /8 | 255.0.0.0 | 16,777,216 | 16,777,214 | Class A Private (10.x.x.x) |
| /12 | 255.240.0.0 | 1,048,576 | 1,048,574 | 172.16.0.0/12 Private |
| /16 | 255.255.0.0 | 65,536 | 65,534 | Class B LAN |
| /20 | 255.255.240.0 | 4,096 | 4,094 | Mid-size Campus |
| /22 | 255.255.252.0 | 1,024 | 1,022 | Enterprise VLAN |
| /23 | 255.255.254.0 | 512 | 510 | Dual-class C |
| /24 | 255.255.255.0 | 256 | 254 | Home / SMB LAN |
| /25 | 255.255.255.128 | 128 | 126 | Half-class C |
| /26 | 255.255.255.192 | 64 | 62 | VLAN Segment |
| /27 | 255.255.255.224 | 32 | 30 | Small VLAN |
| /28 | 255.255.255.240 | 16 | 14 | Small Segment |
| /29 | 255.255.255.248 | 8 | 6 | Tiny Segment |
| /30 | 255.255.255.252 | 4 | 2 | Point-to-Point |
| /31 | 255.255.255.254 | 2 | 2* | P2P (RFC 3021) |
| /32 | 255.255.255.255 | 1 | 1* | Host Route / Loopback |
| Class | Range | CIDR | Total IPs | Common Use |
|---|---|---|---|---|
| Class A | 10.0.0.0 – 10.255.255.255 | 10.0.0.0/8 | 16,777,216 | Large enterprise |
| Class B | 172.16.0.0 – 172.31.255.255 | 172.16.0.0/12 | 1,048,576 | Corporate / ISP |
| Class C | 192.168.0.0 – 192.168.255.255 | 192.168.0.0/16 | 65,536 | Home / SOHO |
| APIPA | 169.254.0.0 – 169.254.255.255 | 169.254.0.0/16 | 65,536 | Auto-config (no DHCP) |
| Loopback | 127.0.0.0 – 127.255.255.255 | 127.0.0.0/8 | 16,777,216 | Local host testing |
| Multicast | 224.0.0.0 – 239.255.255.255 | 224.0.0.0/4 | 268,435,456 | Multicast groups |
| Scenario | Recommended CIDR | Usable Hosts | Subnets from /24 |
|---|---|---|---|
| Home Lab (Proxmox / VMs) | /24 | 254 | 1 |
| IoT VLAN Isolation | /26 | 62 | 4 |
| Guest WiFi Network | /25 | 126 | 2 |
| Management VLAN | /27 or /28 | 14–30 | 8–16 |
| Point-to-Point WAN | /30 | 2 | 64 |
| Server Farm VLAN | /25 | 126 | 2 |
| DMZ Segment | /28 | 14 | 16 |
| Campus Building | /22 | 1,022 | — |
IP Address is made up of groups of numbers and dots, that marks a unique device. Every device in networks requires one for communication. Samples of IPv4 addresses, like 192.168.1.1, have four groups of numbers split by dots.
Every group Range between 0 and 255. Those numbers stand for eight bits of data, also called octets. Together they create a 32-bit address.
IPv4 Addresses and How They Work
Like this IPv4 allow from 0.0.0.0 until 255.255.255.255, what matches around 4.3 billions of possible addresses.
Three main Range of private IP Address are saved for local networks. The first Range goes from 10.0.0.0 until 10.255.255.255, what belongs to Class A. It provides almost 16 millions of addresses, a really huge amount. The second ranges from 172.16.0.0 until 172.31.255.255.
The thrid covers 192.168.0.0 until 192.168.255.255. Private addresses do not travel through the whole internet. Every address, that starts with 10, belongs to that private category.
Administrators of networks commonly split big blocks into smaller subnets. Home routers usually choose automatically the Range of 192.168.0.0 until 192.168.0.255, marked as 192.168.0.0/24. In one subnet, the addresses follow won after the other, set by the address of the net and the subnet mask.
To find the Range of used hosts in a subnet, the process is easy. First, one counts the address of the net by bit-AND between the IP Address and the mask. Later, for the broadcast address, one does OR between the net address and the reverse mask.
Used hosts go from net address plus one until broadcast address minus one. Like this the first and the final addresses stay separated. The first serves for the net itself, and the last for broadcast.
Many err, when they believe, that 169.254.0.0/16 is a private Range for IP Address. Really it serves for automatic setup of link-local. Also 127.0.0.0/8 is saved for local address.
Pinging 127.0.0.1 tests, if the TCP/IP stack works well. Addresses like 127.0.0.2 in that Range will not get an answer, unless a program listens here.
IPv4 addresses ended, and now one gets them only on a second market, often for extra cost. The smallest block, shared by BGP, is /24. One of the main reasons for IPv6 was to grow the address space from 32 bits to 128 bits, giving much more than needed unique addresses for the coming years.
Suppliers of internet service should use the Range 100.64.0.0/10 for NAT at carrier level. CGNAT helps ISPs share small groups of public addresses between many end users. The default gateway in a home router usually is the first or the last used address in the Range, for instance.1 or.254.
Important is to choose a different address in the allowed limits, because one cannot repeat ittwice in the same net.
