"picture element card" for "floorplan"

Hi.
i used a “picture element card” for “floorplan” in HA.
what’s the easy way to know the “left” and “top” percentage under the " style: "
is the only way is to estimate ?
left: xx%
top: xx%
hope i made myself clear.

Thanks
Refael

yes, figuring out left/top can be tricky.

Easiest way I found is using developer tools in the browser.

See Easily position elements in Picture Element cards with quick video.

Thanks.
Refael