Specs Frame Size Chart: My Simple Breakdown

When I first looked at a specs frame size chart, I was confused by all the numbers and diagrams. Here’s how I finally made sense of it all.

The Basic Three Numbers

Every pair of specs has three key measurements printed inside, like “52-18-140”:

• 52 – Lens width in millimeters
• 18 – Bridge width in millimeters
• 140 – Temple length in millimeters

Why These Numbers Matter

Each measurement affects fit differently:

• Lens width – Determines if frames look proportionate on your face
• Bridge width – Affects comfort on your nose
• Temple length – Ensures arms reach properly behind ears

How I Use Size Charts

My process is simple:

1. Find specs I own that fit well
2. Write down their three numbers
3. Look for new specs with similar measurements
4. Stay within 1-2mm of my ideal size

Common Size Ranges

Most specs fall into these categories:

• Small: 48-50mm lens width
• Medium: 51-54mm lens width
• Large: 55mm+ lens width

My Key Takeaway

Once I understood what the numbers mean, size charts became incredibly useful. They’re not complicated – just three simple measurements that ensure proper fit.