CIDR How to Convert /24 to Subnet Mask in 5 Seconds! | Easy Networking Trick

CIDR How to Convert /24 to Subnet Mask in 5 Seconds! | Easy Networking Trick

Introduction
If you’re learning networking or preparing for your CCNA exam, you’ve probably seen CIDR notation like /24. But what exactly does /24 mean, and how can you quickly convert it into a subnet mask? In this guide, I’ll show you the fastest way to convert /24 into a subnet mask in just 5 seconds — perfect for students, IT professionals, and anyone working with IP networks.

---

Step 1: Understanding /24 in CIDR Notation
CIDR (Classless Inter-Domain Routing) notation is a shorthand way of representing an IP address and its subnet mask. The number after the slash — in this case, 24 — represents the number of bits set to 1 in the subnet mask.

---

Step 2: Write It in Binary
For /24, the first 24 bits are set to 1:

11111111.11111111.11111111.00000000

Each group of eight binary digits (an octet) corresponds to one section of the subnet mask.

---

Step 3: Convert Binary to Decimal

• 11111111 in binary equals 255 in decimal.

• /24 therefore equals:

255.255.255.0

---

Pro Tip for Quick Conversion
You can remember it easily:

• /8 → 255.0.0.0

• /16 → 255.255.0.0

• /24 → 255.255.255.0

---

Test Your Knowledge
Now it’s your turn: What does /16 mean? Write your answer in the comments section below!

---

Conclusion
Converting /24 to a subnet mask is quick once you understand the binary-to-decimal relationship. This skill is essential for networking exams, configuring routers, or working as a network engineer. Practice with different CIDR notations to master subnetting in no time!