×
carat vs. color  length*  width*
  ×

(or examine a )
* size in mm (optional)

15ct Diamond (Round, 16.03×16.03mm, White) vs 18ct Diamond (Round, 17.03×17.03mm, White)


Quick summary: When looked from above (face-up position), 18ct Diamond (17.03×17.03mm, round cut) appears 13% larger than 15ct Diamond (16.03×16.03mm, round cut). See below how they compare side-by-side on a ring and finger.

15ct Diamond (round cut)
vs
 18ct Diamond (round cut)
white
 
white
16.03×16.03 mm 17.03×17.03 mm
actual size
Actual size of 15ct Diamond (round cut, 16.03×16.03mm, White color)   Actual size of 18ct Diamond (round cut, 17.03×17.03mm, White color)
Actual size is set for screen
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
White 15ct Diamond (round cut, 16.03×16.03mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
White 18ct Diamond (round cut, 17.03×17.03mm) on a right ring and finger
Your settings
Ring
 Gold
Skin tone
 Light
Ring diameter
 16.9 mm
Ring width
 3.0 mm
Finger length
 64 mm
Finger coverage
 95% vs 101%
Saved...
Ring diameter: 16.9 mm
USA UK Asia EU1 EU2
Actual sizes of 15ct Diamond Round (16.03×16.03mm, White) and 18ct Diamond Round (17.03×17.03mm, White) as they would appear on a ring and finger. Adjust the ring and finger size to get an idea of how these gemstones would look on your finger.

Where to buy?

For certified gemstones, high-end gemstone jewelry, and birthstone jewelry, see Blue Nile

Face-up Size

The face-up size depends on the shape of the gem, its weight and the proportions of the cut. Face-up area is a measure of the size of the gem when viewed from above (as set in a ring). It tells you how big the gem is at the girdle plane.


15 Ct Diamond (Round) 18 Ct Diamond (Round)
16.03×16.03 mm vs 17.03×17.03 mm
201.82 mm²   227.78 mm²
Face-up size outline for 18ct Diamond (17.03×17.03mm, round cut)
Face-up size outline for 15ct Diamond (16.03×16.03mm, round cut)
15ct Diamond Round (16.03×16.03mm)
18ct Diamond Round (17.03×17.03mm)
Difference: 13% (25.96 mm²)
18ct Diamond (Round, 17.03×17.03mm) has approx. 13% more face-up area than 15ct Diamond (Round, 16.03×16.03mm).


Popular comparisons: