What size diamond for a size 6.5 finger?

By HeyGema™ · Updated

In short

On a size 6.5 finger, a classic look is a round diamond of 0.49 to 1.64 carat (5.1 to 7.6 mm), which covers 30% to 44% of the finger's 16.9 mm width. Bolder looks start at 1.64 carat.

Diamond carat range for a size 6.5 finger

A size 6.5 finger is 16.9 mm wide at the ring (53.1 mm around). Here is the carat weight at which a diamond covers each share of that width. Pick the look you want and read across.

Round
Delicate: up to 0.49 ct
Classic: 0.49 to 1.64 ct
Bold: 1.64 to 3.89 ct
Statement: 3.89 and up ct
Oval
Delicate: up to 0.79 ct
Classic: 0.79 to 2.65 ct
Bold: 2.65 to 6.28 ct
Statement: 6.28 and up ct
Cushion
Delicate: up to 0.74 ct
Classic: 0.74 to 2.51 ct
Bold: 2.51 to 5.95 ct
Statement: 5.95 and up ct
Emerald cut
Delicate: up to 1.05 ct
Classic: 1.05 to 3.53 ct
Bold: 3.53 to 8.36 ct
Statement: 8.36 and up ct
Princess
Delicate: up to 0.79 ct
Classic: 0.79 to 2.65 ct
Bold: 2.65 to 6.28 ct
Statement: 6.28 and up ct
Pear
Delicate: up to 0.79 ct
Classic: 0.79 to 2.65 ct
Bold: 2.65 to 6.28 ct
Statement: 6.28 and up ct

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.

A 1 carat round on a size 6.5 finger

6.5 mm
6.5 mm stone on a 16.9 mm finger: it covers 38% of the widthA 1 carat round diamond, a classic look on a size 6.5 finger.

A 1.6 carat oval on a size 6.5 finger

6.4 mm
6.4 mm stone on a 16.9 mm finger: it covers 38% of the widthA 1.6 carat oval, 9.4 x 6.4 mm.

Every carat weight on a size 6.5 finger

0.5 ct
Round size: 5.1 mm
Round covers: 30%
Look: Classic
Oval covers: 26%
0.75 ct
Round size: 5.9 mm
Round covers: 35%
Look: Classic
Oval covers: 30%
1 ct
Round size: 6.5 mm
Round covers: 38%
Look: Classic
Oval covers: 33%
1.5 ct
Round size: 7.4 mm
Round covers: 44%
Look: Classic
Oval covers: 37%
2 ct
Round size: 8.1 mm
Round covers: 48%
Look: Bold
Oval covers: 41%
2.5 ct
Round size: 8.8 mm
Round covers: 52%
Look: Bold
Oval covers: 44%
3 ct
Round size: 9.3 mm
Round covers: 55%
Look: Bold
Oval covers: 47%
4 ct
Round size: 10.2 mm
Round covers: 61%
Look: Statement
Oval covers: 52%
5 ct
Round size: 11.0 mm
Round covers: 65%
Look: Statement
Oval covers: 56%

If your ring size is between sizes

Ring sizes move in steps of half a size. The widths here are for the inside of the ring at your size. A finger is wider at the knuckle than at the base, so a ring that has to pass the knuckle is sometimes sized up. Neighboring sizes: size 5.5, size 6, size 7.

Questions

There is no single best size. On a size 6.5 finger a round diamond of 0.49 to 1.64 carat reads as a classic look, 1.64 to 3.89 carat as bold and 3.89 and up carat as a statement. 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.
A round 1 carat covers 38% of the width of a size 6.5 finger, a classic look.
A round 2 carat covers 48% of a size 6.5 finger, a bold look. An oval of 2 carat covers 41% across its width.
A size 6.5 ring is 16.9 mm (0.67 in) across the inside and 53.1 mm around.

More size charts