IP & Subnet Toolkit
Subnet Calculator and Quick Reference
IP & Subnet Toolkit
CIDR quick reference • Subnet calculator with tips • IP intake & class explanations
CIDR Notation Table (IPv4)
Quick reference for common prefixes.
| Prefix | Subnet Mask | Wildcard | Hosts / Subnet | Usable Hosts | Block Size (4th Octet*) |
|---|
*Block size shown for the octet where subnetting occurs (typical /24+). For shorter prefixes, the block size applies to earlier octets.