Miniature scale can be a little confusing at first. When a miniature is listed as 28mm, 32mm, 40mm, or 75mm, that number does not mean every figure is exactly that many millimetres tall from base to head.
Instead, the scale is a general size category. Depending on the sculpt, a “28mm” miniature might be shorter or taller than 28mm. A crouching rogue, a hunched goblin, a tall elf, a helmeted knight, and an ogre will all measure differently even if they belong to the same scale range. Some manufacturers measure to the eyes, some to the top of the head, and some use the number more as a style guide than a strict measurement.
The easiest way to think about scale is: the number tells you what size range the miniature is intended to match, not the exact height of every individual model.