Hi
No one has responded to you!! Not very nice. I have been doing a lot of research and have found that size appearance is mostly based on the spread....ie the dimensions across the top in millimetres. A 1.5c usually has around 7.4mm diameter lets say. Table doesn't have too much impact as you could have various table percentages but the diameter around the girdle is not going to change. However, a deeper depth percentage indicates you have a bit more weight in the pavillion (ie beneath the ring which isn't seen when the ring is set), so comparing identicle weighted stones, the spread on a stone with a deeper depth percentage tends to be less than that for a shallower depth percentage. This is not always the case. You need to look at dimensions for lots of stones and kind of build up in your mind what a large or small spread is for a given sized diamond. Don't go too shallow or you lose light return. You need that depth to help the internal light come back out the top rather than the sides.