Center Stone Size Charts & Diagrams

What Size Stone for Your Engagement Ring?

One of the biggest challenges when shopping for an engagement ring is visualizing how the center stone will look once it’s on your hand. Carat weight alone can be misleading. A one-carat sapphire looks noticeably smaller than a one-carat diamond. What actually matters is stone size in millimeters (mm).

This stone size chart in mm illustrates how different cuts, shapes, and dimensions compare in the hand. Use it to determine what size stone for an engagement ring suits your style, finger size, and lifestyle. Each section pairs stone sizes for rings with millimeter measurements and approximate diamond carat weights for easy comparison.

Round Stone Sizes in MM

Round diamond stone size chart in mm on hand

Round diamonds are timeless, but their presence shifts dramatically as size increases. Use this image and the information below to compare different stone sizes on hand:

2mm → 0.03 ct round diamond
3mm → 0.10 ct round diamond
4mm → 0.25 ct round diamond
5mm → 0.50 ct round diamond
6mm → 0.90 ct round diamond
7mm → 1.25 ct round diamond
8mm → 2.00 ct round diamond

Princess Cut Stone Sizes in MM

Princess cut stone size chart in mm on hand

Princess cuts deliver bold brilliance with sharp edges. Compare their millimeter sizes to see how they look in proportion to the hand:

2.0mm → 0.05 ct princess cut diamond

3.0mm → 0.15 ct princess cut diamond
3.5mm → 0.25 ct princess cut diamond
4.0mm → 0.40 ct princess cut diamond
5.0mm → 0.75 ct princess cut diamond
6.0mm → 1.20 ct princess cut diamond
7.0mm → 2.00 ct princess cut diamond
8.0mm → 3.20 ct princess cut diamond

Oval Stone Sizes in MM

Oval diamond stone size chart in mm on hand

Ovals maximize surface area, creating the illusion of a larger stone for the same carat weight. 4x2mm → 0.10 ct oval cut diamond

5x3mm → 0.26 ct oval cut diamond
6x4mm → 0.50 ct oval cut diamond
7x5mm → 0.90 ct oval cut diamond
8x6mm → 1.50 ct oval cut diamond
9x7mm → 2.10 ct oval cut diamond
10x8mm → 3.00 ct oval cut diamond
11x9mm → 4.20 ct oval cut diamond

Pear Stone Sizes in MM

Pear cut diamond stone size chart in mm on hand

Pear-shaped stones balance elegance and sparkle, with their pointed tip creating length on your finger.

4x2.5mm → 0.12 ct pear cut diamond
5x3mm → 0.21 ct pear cut diamond
6x4mm → 0.43 ct pear cut diamond
7x5mm → 0.77 ct pear cut diamond
8x6mm → 1.00 ct pear cut diamond
9x6mm → 1.50 ct pear cut diamond
10x7mm → 2.00 ct pear cut diamond
12x7mm → 2.50 ct pear cut diamond
14x8mm → 4.00–5.00 ct pear cut diamond

Marquise Stone Sizes in MM

Marquise cut diamond stone size chart in mm on hand

The marquise cut makes a strong, dramatic visual impact with its unique, elongated form. 4x2mm → 0.07 ct marquise cut diamond

5x2.5mm → 0.13 ct marquise cut diamond
6x3mm → 0.23 ct marquise cut diamond
7x3.5mm → 0.35 ct marquise cut diamond
9x4.5mm → 0.70 ct marquise cut diamond
10x5mm → 1.00 ct marquise cut diamond
11x5.5mm → 1.50 ct marquise cut diamond
13x6.5mm → 2.50 ct marquise cut diamond
14x7.5mm → 3.50 ct marquise cut diamond

Heart Stone Sizes in MM

Heart cut diamond stone size chart in mm on hand

Heart-shaped stones are deeply symbolic and instantly recognizable, making them an ideal choice for sentimental buyers. 3.5mm → 0.15 ct heart cut diamond

4mm → 0.25 ct heart cut diamond
5mm → 0.50 ct heart cut diamond
6mm → 0.75 ct heart cut diamond
6.5mm → 1.00 ct heart cut diamond
8mm → 2.00 ct heart cut diamond
9mm → 3.00 ct heart cut diamond
10mm → 4.00 ct heart cut diamond
11mm → 5.00 ct heart cut diamond

Emerald Stone Sizes in MM

Emerald diamond stone size chart in mm on hand

Emerald cuts highlight clarity with broad, open facets. 3x1.5mm→0.04 ct emerald cut diamond

3.75x1.5mm: 0.07 ct emerald cut diamond
4x2mm→0.09 ct emerald cut diamond
5x3mm: 0.26 ct emerald cut diamond
6x4mm→0.56 ct emerald cut diamond
7x5mm: 1.02 ct emerald cut diamond
8x6mm→1.68 ct emerald cut diamond
9x7mm: 2.57 ct emerald cut diamond
11x9mm→5.19 ct emerald cut diamond

Trillion Stone Sizes in MM

Trillion diamond stone size chart in mm on hand

Triangular trillion cuts bring a contemporary edge and plenty of sparkle to capture the eye. 2x2mm→0.02 ct trillion cut diamond

3x3mm: 0.08 ct trillion cut diamond
4x4mm→0.18 ct trillion cut diamond
5x5mm: 0.30 ct trillion cut diamond
6x6mm→0.60 ct trillion cut diamond
7x7mm: 1.00 ct trillion cut diamond
8x8mm→1.50 ct trillion cut diamond
9x9mm: 2.00 ct trillion cut diamond
10x10mm→2.75 ct trillion cut diamond

Cushion Stone Sizes in MM

Cushion diamond stone size chart in mm on hand

The cushion cut combines vintage charm with modern brilliance.

2x2mm→0.04 ct cushion cut diamond
3x3mm→0.14 ct cushion cut diamond
4x4mm→0.33 ct cushion cut diamond
5x5mm→0.65 ct cushion cut diamond
6x6mm→1.12 ct cushion cut diamond
7x7mm→1.78 ct cushion cut diamond
8x8mm→2.66 ct cushion cut diamond
9x9mm→3.79 ct cushion cut diamond
10x10mm→5.20 ct cushion cut diamond

Stone Sizes for Rings Relative to Band Width

solitaire stone size comparison relative to band width

Band width influences how large or small a stone appears. Wider bands can make a center stone look smaller, while thinner bands amplify its size. .

8mm stone (2.00ct) on 6mm wide band
7mm stone (1.25ct) on 5mm wide band
6mm stone (0.90ct) on 3mm wide band
5mm stone (0.50ct) on 3mm wide band
4mm stone (0.40ct) on 2mm wide band

Key Things to Remember

When comparing ring stone sizes, keep these insights in mind as you do:

A 6mm stone looks much larger on a size 4 finger than a size 9 finger.
Carat weights vary by gem type; always compare stones in millimeters (mm) for accuracy.
Darker-colored stones, like sapphires or rubies, often appear smaller than white diamonds. If choosing one, consider going slightly larger.

See Your Stone the Way it Deserves to Be

Choosing a center stone can involve numbers on a chart, but it is most importantly about how you feel when you see it, on your hand, twinkling back at you. The right stone is one that should feel balanced on your hand, true to your style, and powerful enough to hold your love story for a lifetime.

At Krikawa, we bring your vision to life before crafting a single ring. Our team will mock up your chosen stone size in mm, pair it with your dream setting, and show you exactly how it will look, so you can move forward with joy, not guesswork and doubts.

Book your personal design consultation today. Let’s turn measurements into invaluable meaning, creating a ring that is unmistakably you, from dream concept to the moment it slips onto your finger.

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