Diamond size on finger: see any carat, shape and ring size

By HeyGema™ · Updated November 5, 2026

In short

A 1 carat round diamond covers 39% of the width of a size 6 finger, a 2 carat 49% and a 3 carat 56%. Use the tool to see your own combination, drawn to scale with the stone's size in millimeters.

ShapeGemCarat weightRing size (US)

Skin tone

7.4 mm stone on a 16.5 mm finger: it covers 45% of the width

1.5 ct diamond round: 7.4 mm, 45% of a size 6 finger.

The stone sits along the finger, so its width is what shows against the finger. Drawn to scale from the chart on this page.

Round diamond size on a finger by carat

The share of the finger's width that a round diamond covers on a small (4), average (6) and large (8) ring size, and the same for an oval on a size 6. Pick a weight for pictures of it in more shapes.

0.5 carat: Round, size 4: 34%; Round, size 6: 31%; Round, size 8: 28%; Oval, size 6: 26%

0.75 carat: Round, size 4: 39%; Round, size 6: 36%; Round, size 8: 32%; Oval, size 6: 30%

1 carat: Round, size 4: 43%; Round, size 6: 39%; Round, size 8: 36%; Oval, size 6: 33%

1.25 carat: Round, size 4: 47%; Round, size 6: 42%; Round, size 8: 38%; Oval, size 6: 36%

1.5 carat: Round, size 4: 50%; Round, size 6: 45%; Round, size 8: 41%; Oval, size 6: 38%

2 carat: Round, size 4: 55%; Round, size 6: 49%; Round, size 8: 45%; Oval, size 6: 42%

2.5 carat: Round, size 4: 59%; Round, size 6: 53%; Round, size 8: 48%; Oval, size 6: 45%

3 carat: Round, size 4: 63%; Round, size 6: 56%; Round, size 8: 51%; Oval, size 6: 48%

4 carat: Round, size 4: 69%; Round, size 6: 62%; Round, size 8: 56%; Oval, size 6: 53%

5 carat: Round, size 4: 74%; Round, size 6: 67%; Round, size 8: 61%; Oval, size 6: 57%

Carat	Round, size 4	Round, size 6	Round, size 8	Oval, size 6
0.5 carat	34%	31%	28%	26%
0.75 carat	39%	36%	32%	30%
1 carat	43%	39%	36%	33%
1.25 carat	47%	42%	38%	36%
1.5 carat	50%	45%	41%	38%
2 carat	55%	49%	45%	42%
2.5 carat	59%	53%	48%	45%
3 carat	63%	56%	51%	48%
4 carat	69%	62%	56%	53%
5 carat	74%	67%	61%	57%

How to read the numbers

The finger is as wide as the inside of a ring of its size: 14.9 mm for a size 4, 16.5 mm for a size 6 and 18.1 mm for a size 8. The stone sits along the finger, so a long shape such as an oval or an emerald cut shows its width across the finger and its length toward the fingertip.

The four looks are our own bands for the share of the finger's width a stone covers: delicate under 30% of the finger's width; classic 30% to 44%; bold 45% to 59%; statement 60% and more. They are a way to read the numbers, not a rule.

Find the size for your ring size

Size 4: Finger width: 14.9 mm; Classic round (30% to 44%): 0.33 to 1.12 carat; Bold round (45% to 59%): 1.12 to 2.65 carat

Size 5: Finger width: 15.7 mm; Classic round (30% to 44%): 0.39 to 1.31 carat; Bold round (45% to 59%): 1.31 to 3.11 carat

Size 6: Finger width: 16.5 mm; Classic round (30% to 44%): 0.45 to 1.53 carat; Bold round (45% to 59%): 1.53 to 3.62 carat

Size 7: Finger width: 17.3 mm; Classic round (30% to 44%): 0.52 to 1.76 carat; Bold round (45% to 59%): 1.76 to 4.18 carat

Size 8: Finger width: 18.1 mm; Classic round (30% to 44%): 0.6 to 2.02 carat; Bold round (45% to 59%): 2.02 to 4.8 carat

Size 9: Finger width: 18.9 mm; Classic round (30% to 44%): 0.68 to 2.31 carat; Bold round (45% to 59%): 2.31 to 5.47 carat

Ring size	Finger width	Classic round (30% to 44%)	Bold round (45% to 59%)
Size 4	14.9 mm	0.33 to 1.12 carat	1.12 to 2.65 carat
Size 5	15.7 mm	0.39 to 1.31 carat	1.31 to 3.11 carat
Size 6	16.5 mm	0.45 to 1.53 carat	1.53 to 3.62 carat
Size 7	17.3 mm	0.52 to 1.76 carat	1.76 to 4.18 carat
Size 8	18.1 mm	0.6 to 2.02 carat	2.02 to 4.8 carat
Size 9	18.9 mm	0.68 to 2.31 carat	2.31 to 5.47 carat

Not sure where to start? The what size diamond should I get page turns the look you want into a carat weight.

Questions

A round 1 carat diamond is 6.5 mm across. On a size 6 finger it covers 39% of the width, on a size 4 43% and on a size 8 36%.

A round 2 carat diamond is 8.1 mm across, 49% of the width of a size 6 finger. A 2 carat oval is 10.1 x 6.9 mm.

Choose the carat weight, shape and your ring size in the tool above. It draws the stone to scale on a finger of that width. For a real-size view, print the size chart at 100% and cut out the circles.

Yes. The same stone covers more of a narrow finger than of a wide one: a round 1 carat covers 43% of a size 4 finger and 36% of a size 8.

Long shapes such as oval, pear, marquise and emerald cut run along the finger and have more face-up area than a round of the same weight. See the shapes that look biggest.