What is Subnet Mask Calculator?
Free online subnet calculator. Enter a CIDR notation to instantly get subnet mask, usable hosts, network address, broadcast address, and IP range. Essential for network engineers and IT admins.
Use Cases
- ◆Network planning
- ◆IP allocation
- ◆Subnetting
- ◆IT operations
How to Use
- 1Enter IP and CIDR (e.g., 192.168.1.0/24)
- 2Click calculate
- 3View subnet mask, hosts, and addresses
- 4Copy results
Features
- ✓CIDR calculation
- ✓Host count
- ✓Network/broadcast address
- ✓IP range
FAQ
How many usable hosts in /24?
254 usable host addresses (256 total minus network and broadcast).
Does it support IPv6?
Currently IPv4 only.
Is this tool free?
Yes — completely free. No accounts, no paywalls. Just open the page and go.
Does my data get sent to a server?
No. Everything runs in your browser. Your data never leaves your device.
Does it work on my phone?
Absolutely. Works great on phones, tablets, and desktops alike.
How fast is it?
Instant for most inputs. Large datasets might take a second or two.