Subnet Calculator
Free IP subnet calculator for network administrators. Calculate subnet information, network ranges, host addresses, and CIDR notation instantly.
Powerful Subnetting Features
Everything you need for IP network planning and configuration
Network Information
Calculate network address, broadcast address, subnet mask, and CIDR notation for any IP subnet configuration.
Host Calculations
Determine total hosts, usable host addresses, and IP ranges for efficient network planning.
Common Subnets
Quick reference for common subnet sizes including /24, /30, /29, and other frequently used CIDR blocks.
How to Use the Subnet Calculator
Calculate subnet information in three simple steps
Enter IP Address
Input your network IP address. Use common private ranges like 192.168.1.0, 10.0.0.0, or 172.16.0.0.
Select Subnet Mask
Choose your subnet mask using CIDR notation (/24, /16, /8) or select from common subnet sizes.
Get Results
Instantly view network details, host ranges, and subnet information for your network configuration.
Common Subnet Calculator Use Cases
Network administrators and IT professionals use subnet calculators for
Network Planning
- •Design efficient network architectures
- •Plan IP address allocation
- •Optimize network segmentation
- •Configure VLANs and subnets
Troubleshooting
- •Verify network configurations
- •Debug connectivity issues
- •Calculate overlapping subnets
- •Plan network expansions
Understanding Subnetting
Essential concepts for IP network management
CIDR Notation
Classless Inter-Domain Routing (CIDR) notation represents subnet masks as a prefix length (/24, /16, /8) instead of dotted decimal notation.
Common CIDR Blocks:
- • /24 = 254 usable hosts (small networks)
- • /16 = 65,534 usable hosts (medium networks)
- • /8 = 16,777,214 usable hosts (large networks)
- • /30 = 2 usable hosts (point-to-point links)
Private IP Ranges
Private IP addresses are reserved for internal networks and not routed on the internet. Use these ranges for your local networks.
RFC 1918 Private Ranges:
- • 10.0.0.0 - 10.255.255.255 (8.0.0.0/8)
- • 172.16.0.0 - 172.31.255.255 (172.16.0.0/12)
- • 192.168.0.0 - 192.168.255.255 (192.168.0.0/16)
Start Calculating Your Subnets
Use our free subnet calculator to simplify network planning and IP address management.
Use Subnet Calculator