About CIDR Calculator

CIDR Calculator

Convert between subnet mask and CIDR notation. CIDR (Classless Inter-Domain Routing) provides a more flexible way to allocate IP addresses. Read comprehensive guide →

How to Use:

• Enter network address (e.g., 192.168.1.0)
• Enter subnet mask (e.g., 255.255.255.0)
• Get CIDR notation and prefix

Subnet Mask Reference:

255.255.255.0 = /24

255.255.254.0 = /23

255.255.252.0 = /22

255.255.248.0 = /21

255.255.240.0 = /20

Benefits:

• Efficient IP address utilization
• Reduced routing table size
• Flexible network design

CIDR Calculator

Network Address:

Subnet Mask:

Quick Examples

Results

Enter IP/CIDR and click Calculate to see results

Disclaimer: All content, tools, and calculators are provided for informational purposes only. Please verify information from authorized sources before making any decisions.