Online Tool Store
IP Subnet Calculator
Calculate an IPv4 network address, subnet mask, broadcast, usable host range, wildcard mask, and capacity from CIDR notation in your browser.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
Example shown — enter any IPv4 address and prefix.
| CIDR notation | |
|---|---|
| Wildcard mask | |
| Address class | |
| Binary mask |
How it works
- Enter an IPv4 address and choose its CIDR prefix.
- The prefix creates a 32-bit subnet mask with network bits set to 1.
- A bitwise AND finds the network; setting host bits to 1 finds the broadcast.
- Review and copy the usable range, capacity, masks, and notation.
The formulas
Network = IP AND subnet mask Broadcast = Network OR wildcard mask Traditional usable hosts = 2^(32 − prefix) − 2
FAQ
Does this support IPv6?
This calculator focuses on IPv4 dotted-decimal addresses and prefixes from /0 through /32.
How many usable hosts are in a /24?
A traditional /24 has 256 total addresses and 254 usable host addresses after reserving network and broadcast addresses.
Why do /31 and /32 behave differently?
A /31 can be used for point-to-point links with both addresses usable, while a /32 identifies one specific host route.
Is any network request made?
No. The address is converted to a 32-bit number and calculated locally in your browser.
How we compare
| Feature | Online Tool Store | ipcalc command | Manual binary math |
|---|---|---|---|
| No install | ✓ | ✗ | ✓ |
| Private, offline calculation | ✓ | ✓ | ✓ |
| Readable result dashboard | ✓ | Terminal output | ✗ |
| IPv6 support | ✗ | ✓ | ✓ |
Use this for quick, visual IPv4 planning. The ipcalc command remains better for terminal automation and IPv6 workflows.