How do I measure the width of the Linen High Breeches?

How do I measure the width of the Linen High Breeches?

The width-measurement is measured from side to side of the product as opposed to the full way around, which would be the full circumference.
The width is half of what the full circumference would be. 

When measuring Linen High Breeches the width is measured from side to side of the product across the waist-line.