IP Range Calculator
A free, browser-based calculator. Runs entirely in your browser — no sign up, nothing stored.
Enter an address
Subnet details
Enter an address and prefix, then press Calculate.
How to use this calculator
- Enter an IPv4 address (for example 192.168.1.10).
- Enter the CIDR prefix (for example 24 for a /24).
- Press Calculate for the network, broadcast, host range, mask and wildcard.
How it works
An IPv4 address is 32 bits. The CIDR prefix says how many leading bits are the network, leaving the rest for hosts. The subnet mask is those network bits set to 1.
The network address is the IP with all host bits set to 0; the broadcast address sets them all to 1. The usable hosts sit between the two — so a /24 has 256 addresses and 254 usable hosts.
Worked example
192.168.1.10 /24. Network 192.168.1.0, broadcast 192.168.1.255, hosts 192.168.1.1–.254 (254 usable), mask 255.255.255.0.
Frequently asked questions
Why are there two fewer usable hosts?
The network and broadcast addresses are reserved, so a /24 gives 256 − 2 = 254 usable hosts.
What about /31 and /32?
A /31 is used for point-to-point links and a /32 is a single host, so neither has a usable host pair in the normal sense.
Related tools
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.