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 Cases4 scenarios
- ◆Network planning
- ◆IP allocation
- ◆Subnetting
- ◆IT operations
▶How to Use4 steps
- 1Enter IP and CIDR (e.g., 192.168.1.0/24)
- 2Click calculate
- 3View subnet mask, hosts, and addresses
- 4Copy results
▶Features4 features
- ✓CIDR calculation
- ✓Host count
- ✓Network/broadcast address
- ✓IP range
▶FAQ7 questions
What is Subnet Mask Calculator?
An online subnet calculator. Calculate subnet masks, usable hosts, and network addresses from CIDR. Supports multiple input formats with one-click copy or download. All operations run locally in your browser — no uploads.
How many usable hosts in /24?
254 usable host addresses (256 total minus network and broadcast).
Does it support IPv6?
Currently IPv4 only.
How accurate is Subnet Mask Calculator?
Accurate. Uses standard algorithms. Precisely calculates subnet mask, host count, network address, and broadcast address.
Will my input data be saved?
No. All calculations happen locally in your browser. Input is never uploaded or stored.
Can I use this on my phone?
Yes. Responsive design works smoothly on phones, tablets, and desktops.
Do I need to sign up or pay?
No. Completely free, no signup, no usage limits.