IP Subnet Calculator
The essential tool for network administrators, students, and IT professionals. Quickly determine network configuration details from any IPv4 address and subnet mask. Eliminate errors and save time with our accurate, easy-to-use network calculator.
Host Information
Network Details
Binary Representation
Fast, Free, Private IP Subnet Calculator
Calculate network address, broadcast address, usable host range, subnet mask, wildcard mask, and binary representation for any IPv4/CIDR. Top, Fast, Best and Lifetime Free Unlimited your information is 100% confidential and secure (processing happens locally in your browser).
Why professionals love this subnet calculator
Instant results
Get network/broadcast addresses and usable hosts in real time from any IPv4/CIDR input.
CIDR ↔ Mask
Convert between CIDR and dotted-decimal subnet masks automatically.
Wildcard masks
Generate wildcard masks for ACLs and firewall rules (Cisco/Juniper).
Binary view
See the bitwise binary of IP, mask, and network for easy subnetting practice.
Private by design
No uploads, no tracking. Everything runs locally on your device.
Mobile friendly
Optimized for Chrome, Edge, Firefox, and Safari on desktop and mobile.
Popular uses worldwide
Network design
Plan IPv4 subnets for offices, data centers, and on-prem networks with precise host counts.
Cloud VPC/VNet
Create clean subnets for AWS VPC, Azure VNet, and Google Cloud VPC deployments.
Security & ACLs
Get wildcard masks for firewall and router ACLs with confidence.
Education & Exams
Perfect for CCNA/CompTIA subnetting practice: classes, masks, and binary breakdowns.
Troubleshooting
Verify if an IP is private/public and confirm address ranges quickly.
Automation
Use predictable CIDR blocks while scripting or building infra-as-code.
Note: Always follow your organization’s IP addressing policies and RFC guidelines.
How to use this tool
- Enter an IPv4 address (e.g., 192.168.1.100).
- Enter a subnet in CIDR (e.g., /24) or mask (e.g., 255.255.255.0) the tool converts both ways.
- Click “Calculate” to get network address, broadcast, usable host range, masks, and binary.
Global availability (GEO)
Built for network engineers and students in the USA, UK, Canada, Australia, India, and across the EU (Germany, France, Spain, Italy, Netherlands), Middle East (UAE, Saudi Arabia), Asia (Singapore, Malaysia, Philippines, Indonesia, Japan, South Korea), Africa (Nigeria, South Africa, Egypt), and Latin America (Brazil, Mexico, Argentina). If your browser works, our IP subnet calculator works.
CIDR quick reference
| CIDR | Subnet Mask | Usable Hosts | Wildcard |
|---|---|---|---|
| /24 | 255.255.255.0 | 254 | 0.0.0.255 |
| /25 | 255.255.255.128 | 126 | 0.0.0.127 |
| /26 | 255.255.255.192 | 62 | 0.0.0.63 |
| /27 | 255.255.255.224 | 30 | 0.0.0.31 |
| /28 | 255.255.255.240 | 14 | 0.0.0.15 |
| /29 | 255.255.255.248 | 6 | 0.0.0.7 |
| /30 | 255.255.255.252 | 2 | 0.0.0.3 |
| /31 | 255.255.255.254 | 2 (point-to-point) | 0.0.0.1 |
| /32 | 255.255.255.255 | 1 (host route) | 0.0.0.0 |
Frequently Asked Questions
Is it private and secure?
Yes. All calculations happen in your browser. Your data never leaves your device.
Which inputs are supported?
Enter IPv4 and CIDR (e.g., 10.0.0.1/24) or IPv4 with a mask (e.g., 10.0.0.1 and 255.255.255.0).
What is a wildcard mask?
It’s the inverse of the subnet mask. Commonly used for firewall/ACL match rules (e.g., 0.0.0.255 for /24).
Is it really free forever?
Yes lifetime free and unlimited. No signup, no paywalls, no watermarks.
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