Pan Size Detection Myths: What Really Happens Under the Glass

Induction hobs feel like magic — put a pan down, press a button, and heat appears instantly. But many myths still surround how they judge whether a pan is “big enough”, “in the right place”, or even suitable at all. Here’s a simple breakdown of what’s really happening under the glass.

How Pan Size Detection Actually Works

Your hob isn’t measuring diameter, weight, or volume. Instead, it uses an internal induction coil to check how much magnetic energy the pan absorbs. If the magnetic load is strong enough, the hob activates. If not, it won’t heat.

This means the hob reacts to **magnetic coverage**, not physical size. A small, high-quality ferrous pan will activate more easily than a larger one with a weak or mixed-metal base.

Common Myths – Busted

💡 “The hob weighs the pan”

It detects magnetic load, not weight.

💡 “It measures diameter”

No diameter sensor — only magnetic coverage.

💡 “A tiny movement stops heating”

Minor shifts are fine — only big misalignment matters.

Why Pans Sometimes Don’t Work

The base is too small for the zone’s minimum detection area
The pan is made from mixed metals with low magnetic response
A warped base prevents good surface contact
The pan isn’t covering enough of the magnetic field

What This Means for Everyday Cooking

Your pan doesn’t need to match the circle perfectly — induction is flexible. But for fast, consistent heat, choose pans with a strong, flat, fully ferrous base. A quick magnetic check with a fridge magnet is usually all you need.

Want to learn more about induction cooking? Explore the CATA induction hob collection or visit the CATA blog for more guides.