CSS Zoom property not working with BoundingClientRectangle

This comment on the bug report goes into some detail reg. the issue, but its status appears to be 'WontFix', so you're probably out of luck there.

Some alternatives:

• If you were to use transform: scale(1.5) instead of zoom, you'd get the correct value in getBoundingClientRect(), but it would mess with the page layout.
• You could use window.getComputedStyle(div[0]).zoom to get the zoom value of the element (in decimals) and multiply it with the width from getBoundingClientRect()