IPv4 subnet calculator
Enter any IPv4 address and a prefix length (the number after the slash, such as /24). The calculator shows the network range, subnet mask, wildcard mask and how many devices fit.
Common network sizes
| Prefix | Subnet mask | Usable hosts | Typical use |
|---|---|---|---|
| /24 | 255.255.255.0 | 254 | Most home routers |
| /16 | 255.255.0.0 | 65,534 | Large private networks |
| /25 | 255.255.255.128 | 126 | A /24 split in two |
| /30 | 255.255.255.252 | 2 | Point-to-point links |
| /32 | 255.255.255.255 | 1 | A single address |
What the results mean
- Network address — the first address; it names the subnet and is not given to a device.
- Broadcast address — the last address; messages sent to it reach every device in the subnet.
- First and last usable host — the range you can assign to routers, phones and computers.
- Wildcard mask — the mask inverted, used in router access lists and some routing settings.
Frequently asked questions
Why are two addresses not usable?
In a normal subnet the first address is the network address and the last is the broadcast address, so they are not given to devices. A /31 is an exception used for point-to-point links (both addresses usable), and a /32 is a single address.
Which subnet does my home router use?
Almost all home routers use a /24 network (mask 255.255.255.0), for example 192.168.1.0 to 192.168.1.255 with the router at 192.168.1.1.
Tools
Router FinderPick your country and provider to get the router IP, login hint and full guide.
IP Typo FixerTurns 192.168.l.l, 192.168.o.1 or 1921681254 into the correct router IP.
What Is My IPShows your public IP and explains how it differs from your router IP.
WiFi QR Code GeneratorCreate a QR code so guests can join your WiFi without typing.