Carat & Millimetre Guide

Diamond Size & Finger Coverage Chart

Carat weight alone does not indicate face-up size. Compare mm diameters and finger coverage on standard ring sizes to find your ideal proportion.

“See real-world millimetre dimensions and finger coverage percentages across all 10 classic diamond cuts.”

The Kleora Founders

Visual Proportion Tool

Atelier Sizing & Proportion Guide

Diamond Size Chart: Carat to MM Matrix

Carat is a measure of diamond weight, not physical size. Explore the exact millimeter (mm) dimensions, surface area, and finger coverage for all 10 certified diamond silhouettes.

Shape & Faceting Round Brilliant 58-Facet Brilliant Cut

Ideal L/W Ratio 1.00 : 1.00 Ideal Symmetry

Proportion Insight

The universal benchmark for optical light refraction and maximum fire. Symmetrical proportions distribute weight evenly between crown and pavilion.

Round Brilliant Proportion Matrix Standard Size 6 (16.5 mm) reference diameter

Carat Weight	Dimensions (L × W)	Surface Area	Finger Coverage	Recommended Setting
0.50 ct	5.1 × 5.1 mm	20.4 mm²	31%	Classic 4 or 6-Prong Solitaire
0.75 ct	5.8 × 5.8 mm	26.4 mm²	35%	Pavé Band Solitaire
1.00 ct	6.5 × 6.5 mm	33.2 mm²	39%	Cathedral Solitaire / Bezel
1.25 ct	6.9 × 6.9 mm	37.4 mm²	42%	Three-Stone Diamond Band
1.50 ct	7.4 × 7.4 mm	43.0 mm²	45%	Hidden Halo Atelier Mount
1.75 ct	7.7 × 7.7 mm	46.6 mm²	47%	Tapered Baguette Mount
2.00 ct	8.1 × 8.1 mm	51.5 mm²	49%	High-Profile Platinum 6-Prong
2.50 ct	8.8 × 8.8 mm	60.8 mm²	53%	Signature Maison Mount
3.00 ct	9.3 × 9.3 mm	67.9 mm²	56%	Split-Shank Atelier Solitaire
4.00 ct	10.2 × 10.2 mm	81.7 mm²	62%	Custom Master Atelier Setting
5.00 ct	11.0 × 11.0 mm	95.0 mm²	67%	High-Jewellery Platinum Masterpiece

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Shape & Faceting Oval Modified Brilliant Cut

Ideal L/W Ratio 1.35 – 1.50 Elongated Luxury

Proportion Insight

Elongated silhouette that visually lengthens the finger while appearing roughly 10%–15% larger face-up than a round diamond of matching weight.

Oval Proportion Matrix Standard Size 6 (16.5 mm) reference diameter

Carat Weight	Dimensions (L × W)	Surface Area	Finger Coverage	Recommended Setting
0.50 ct	6.0 × 4.0 mm	18.8 mm²	36%	Delicate 4-Prong Solitaire
0.75 ct	6.8 × 4.8 mm	25.6 mm²	41%	Pavé Petite Whisper Band
1.00 ct	7.7 × 5.7 mm	34.5 mm²	47%	Hidden Halo Solitaire
1.25 ct	8.3 × 6.0 mm	39.1 mm²	50%	East-West Bezel or Solitaire
1.50 ct	8.8 × 6.3 mm	43.5 mm²	53%	Six-Prong Platinum Crown
1.75 ct	9.2 × 6.6 mm	47.7 mm²	56%	Three-Stone Pear Side Mounts
2.00 ct	9.9 × 7.0 mm	54.4 mm²	60%	Cathedral Knife-Edge Shank
2.50 ct	10.6 × 7.5 mm	62.4 mm²	64%	Signature Atelier Setting
3.00 ct	11.3 × 8.0 mm	71.0 mm²	68%	Bespoke Half-Moon Side Mount
4.00 ct	12.4 × 8.8 mm	85.7 mm²	75%	Haute Joaillerie Statement Band
5.00 ct	13.3 × 9.5 mm	99.2 mm²	81%	Museum Collection Atelier Mount

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Shape & Faceting Emerald Step Cut with Chiseled Corners

Ideal L/W Ratio 1.30 – 1.50 Step Cut Hall of Mirrors

Proportion Insight

Architectural lines and open facets create mesmerizing flashes of clarity. Emphasizes stone transparency, depth, and vintage Art Deco sophistication.

Emerald Proportion Matrix Standard Size 6 (16.5 mm) reference diameter

Carat Weight	Dimensions (L × W)	Surface Area	Finger Coverage	Recommended Setting
0.50 ct	5.5 × 3.8 mm	20.9 mm²	33%	Minimalist Solitaire
0.75 ct	6.2 × 4.3 mm	26.7 mm²	38%	Classic Bezel Setting
1.00 ct	7.0 × 5.0 mm	35.0 mm²	42%	Tapered Baguette Three-Stone
1.25 ct	7.5 × 5.3 mm	39.8 mm²	45%	Double Claw Corner Prongs
1.50 ct	8.0 × 5.5 mm	44.0 mm²	48%	Art Deco Geometric Crown
1.75 ct	8.4 × 5.8 mm	48.7 mm²	51%	East-West Platinum Bezel
2.00 ct	8.8 × 6.2 mm	54.6 mm²	53%	Double-Prong Cathedral Band
2.50 ct	9.5 × 6.7 mm	63.7 mm²	58%	Trapezoid Side Stone Mount
3.00 ct	10.1 × 7.1 mm	71.7 mm²	61%	High Maison Atelier Architecture
4.00 ct	11.0 × 7.8 mm	85.8 mm²	67%	Bespoke Solid Platinum Vitrine
5.00 ct	11.8 × 8.4 mm	99.1 mm²	72%	Heritage Master Collector Mount

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Shape & Faceting Princess Square Modified Brilliant

Ideal L/W Ratio 1.00 – 1.05 Sharp Contemporary Fire

Proportion Insight

Combines the brilliance of a round cut with crisp 90-degree geometric lines. Features protected V-prong corners in bespoke settings.

Princess Proportion Matrix Standard Size 6 (16.5 mm) reference diameter

Carat Weight	Dimensions (L × W)	Surface Area	Finger Coverage	Recommended Setting
0.50 ct	4.4 × 4.4 mm	19.4 mm²	27%	V-Prong Solitaire
0.75 ct	5.0 × 5.0 mm	25.0 mm²	30%	Channel-Set Diamond Band
1.00 ct	5.5 × 5.5 mm	30.3 mm²	33%	Square Halo Atelier Mount
1.25 ct	6.0 × 6.0 mm	36.0 mm²	36%	Pavé Bridge Cathedral
1.50 ct	6.4 × 6.4 mm	41.0 mm²	39%	Trillion Side Stone Trilogy
1.75 ct	6.7 × 6.7 mm	44.9 mm²	41%	Beveled Platinum Knife-Edge
2.00 ct	7.0 × 7.0 mm	49.0 mm²	42%	Modern Flush Bezel
2.50 ct	7.6 × 7.6 mm	57.8 mm²	46%	Heavy Platinum V-Prong
3.00 ct	8.1 × 8.1 mm	65.6 mm²	49%	Architectural Modernist Setting
4.00 ct	8.9 × 8.9 mm	79.2 mm²	54%	Master Jeweller Custom Cast
5.00 ct	9.6 × 9.6 mm	92.2 mm²	58%	Grand Statement Atelier Mount

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Shape & Faceting Cushion Modified Cushion Brilliant

Ideal L/W Ratio 1.00 – 1.15 Romantic Pillow Cut

Proportion Insight

Rounded corners and larger facet patterns produce antique fire and romantic scintillation. Available in both classic square and elongated ratios.

Cushion Proportion Matrix Standard Size 6 (16.5 mm) reference diameter

Carat Weight	Dimensions (L × W)	Surface Area	Finger Coverage	Recommended Setting
0.50 ct	4.8 × 4.5 mm	21.6 mm²	29%	Four-Prong Wire Basket
0.75 ct	5.4 × 5.1 mm	27.5 mm²	33%	Vintage Milgrain Pavé
1.00 ct	6.0 × 5.6 mm	33.6 mm²	36%	Soft Cushion Halo
1.25 ct	6.5 × 6.0 mm	39.0 mm²	39%	Double Claw Prong Solitaire
1.50 ct	6.9 × 6.4 mm	44.2 mm²	42%	Cadillac Side Stone Mount
1.75 ct	7.2 × 6.7 mm	48.2 mm²	44%	Hidden Halo Pavé Gallery
2.00 ct	7.5 × 7.0 mm	52.5 mm²	45%	Classic Cathedral Trilogy
2.50 ct	8.1 × 7.5 mm	60.8 mm²	49%	Antique Reproduction Solitaire
3.00 ct	8.6 × 8.0 mm	68.8 mm²	52%	High Atelier Platinum Basket
4.00 ct	9.4 × 8.8 mm	82.7 mm²	57%	Custom Hand-Forged Mount
5.00 ct	10.1 × 9.5 mm	96.0 mm²	61%	Museum Solitaire Crown

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Shape & Faceting Radiant Brilliant Cut with Cut Corners

Ideal L/W Ratio 1.20 – 1.40 Vibrant Ice Fire

Proportion Insight

Combines the emerald silhouette with a 70-facet crushed-ice brilliant faceting style for unmatched sparkle in elongated shapes.

Radiant Proportion Matrix Standard Size 6 (16.5 mm) reference diameter

Carat Weight	Dimensions (L × W)	Surface Area	Finger Coverage	Recommended Setting
0.50 ct	5.0 × 4.0 mm	20.0 mm²	30%	Corner-Claw Solitaire
0.75 ct	5.7 × 4.6 mm	26.2 mm²	35%	Petite Pavé Band
1.00 ct	6.4 × 5.1 mm	32.6 mm²	39%	Hidden Halo Atelier Crown
1.25 ct	6.9 × 5.5 mm	38.0 mm²	42%	Trillion Diamond Three-Stone
1.50 ct	7.3 × 5.9 mm	43.1 mm²	44%	Four Double-Claw Cathedral
1.75 ct	7.7 × 6.2 mm	47.7 mm²	47%	Trapezoid Side Stone Mount
2.00 ct	8.0 × 6.5 mm	52.0 mm²	48%	High Platinum Solitaire
2.50 ct	8.7 × 7.0 mm	60.9 mm²	53%	Signature Maison Radiant Mount
3.00 ct	9.2 × 7.5 mm	69.0 mm²	56%	Bespoke Tapered Baguette Trilogy
4.00 ct	10.1 × 8.2 mm	82.8 mm²	61%	Haute Joaillerie Statement
5.00 ct	10.9 × 8.8 mm	95.9 mm²	66%	Atelier Collector Masterpiece

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Shape & Faceting Pear Teardrop Modified Brilliant

Ideal L/W Ratio 1.50 – 1.75 Graceful Teardrop

Proportion Insight

An asymmetrical teardrop silhouette uniting round fire and marquise length. Highly flattering on the hand when worn point towards the nail.

Pear Proportion Matrix Standard Size 6 (16.5 mm) reference diameter

Carat Weight	Dimensions (L × W)	Surface Area	Finger Coverage	Recommended Setting
0.50 ct	6.5 × 4.2 mm	21.4 mm²	39%	V-Tip Protected Solitaire
0.75 ct	7.5 × 4.8 mm	28.3 mm²	45%	Whisper Pavé Teardrop
1.00 ct	8.5 × 5.5 mm	36.7 mm²	52%	Hidden Halo Pear Crown
1.25 ct	9.1 × 5.9 mm	42.2 mm²	55%	East-West Modern Setting
1.50 ct	9.7 × 6.3 mm	47.9 mm²	59%	Five-Prong with V-Cap Solitaire
1.75 ct	10.2 × 6.6 mm	52.9 mm²	62%	Tapered Diamond Shank
2.00 ct	10.7 × 7.0 mm	58.8 mm²	65%	Round Brilliant Shoulder Stones
2.50 ct	11.5 × 7.5 mm	67.7 mm²	70%	Signature Atelier Teardrop Mount
3.00 ct	12.2 × 8.0 mm	76.6 mm²	74%	High Jewellery Split-Shank
4.00 ct	13.4 × 8.8 mm	92.6 mm²	81%	Custom Handcrafted Platinum Crown
5.00 ct	14.4 × 9.5 mm	107.4 mm²	87%	Grand Atelier Exhibition Ring

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Shape & Faceting Marquise Boat-Shaped Navette Brilliant

Ideal L/W Ratio 1.75 – 2.15 Maximized Surface Spread

Proportion Insight

Offers the highest face-up surface area of any diamond cut per carat weight. Creates a dramatically elongated, royal silhouette.

Marquise Proportion Matrix Standard Size 6 (16.5 mm) reference diameter

Carat Weight	Dimensions (L × W)	Surface Area	Finger Coverage	Recommended Setting
0.50 ct	7.5 × 4.0 mm	23.6 mm²	45%	V-Tip Dual End Prongs
0.75 ct	8.7 × 4.5 mm	30.7 mm²	53%	Six-Prong Atelier Band
1.00 ct	10.0 × 5.0 mm	39.3 mm²	61%	East-West Modern Bezel
1.25 ct	10.8 × 5.4 mm	45.8 mm²	65%	Hidden Halo Navette Mount
1.50 ct	11.5 × 5.8 mm	52.4 mm²	70%	Cathedral Solitaire with V-Tips
1.75 ct	12.1 × 6.1 mm	57.9 mm²	73%	Tapered Baguette Side Stones
2.00 ct	12.7 × 6.4 mm	63.8 mm²	77%	High-Profile Platinum 6-Prong
2.50 ct	13.7 × 6.9 mm	74.2 mm²	83%	Signature Navette Atelier Setting
3.00 ct	14.5 × 7.3 mm	83.1 mm²	88%	High Maison Statement Mount
4.00 ct	16.0 × 8.0 mm	100.5 mm²	97%	Handcrafted Royal Crown
5.00 ct	17.2 × 8.6 mm	116.2 mm²	104%	Bespoke Masterpiece Mount

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Shape & Faceting Asscher Square Step Cut with Deep Pavilion

Ideal L/W Ratio 1.00 – 1.05 Octagonal Step Cut

Proportion Insight

Royal vintage cut with high crown, smaller table, and large step facets creating an extraordinary hypnotic windmill optical reflection pattern.

Asscher Proportion Matrix Standard Size 6 (16.5 mm) reference diameter

Carat Weight	Dimensions (L × W)	Surface Area	Finger Coverage	Recommended Setting
0.50 ct	4.4 × 4.4 mm	19.4 mm²	27%	Corner-Claw Vintage Mount
0.75 ct	5.0 × 5.0 mm	25.0 mm²	30%	Art Deco Milgrain Pavé
1.00 ct	5.5 × 5.5 mm	30.3 mm²	33%	Classic 4-Prong Cathedral
1.25 ct	6.0 × 6.0 mm	36.0 mm²	36%	Octagonal Flush Bezel
1.50 ct	6.4 × 6.4 mm	41.0 mm²	39%	Double Claw Corner Solitaire
1.75 ct	6.7 × 6.7 mm	44.9 mm²	41%	Baguette Diamond Trilogy
2.00 ct	7.0 × 7.0 mm	49.0 mm²	42%	Platinum Antique Reproduction
2.50 ct	7.6 × 7.6 mm	57.8 mm²	46%	Signature Asscher Atelier Mount
3.00 ct	8.1 × 8.1 mm	65.6 mm²	49%	High Maison Art Deco Setting
4.00 ct	8.9 × 8.9 mm	79.2 mm²	54%	Custom Hand-Forged Platinum
5.00 ct	9.6 × 9.6 mm	92.2 mm²	58%	Heritage Master Collector Crown

Ready to explore certified lab-grown Asscher diamonds in your ideal carat weight?

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Shape & Faceting Heart Heart Modified Brilliant

Ideal L/W Ratio 1.00 – 1.05 Romantic Precision Symmetry

Proportion Insight

The quintessential symbol of eternal affection. Requires master precision cutting to maintain distinct clefts, even lobes, and fiery brilliance.

Heart Proportion Matrix Standard Size 6 (16.5 mm) reference diameter

Carat Weight	Dimensions (L × W)	Surface Area	Finger Coverage	Recommended Setting
0.50 ct	5.0 × 5.0 mm	19.6 mm²	30%	Three-Prong V-Tip Solitaire
0.75 ct	5.8 × 5.8 mm	26.4 mm²	35%	Petite Pavé Band Mount
1.00 ct	6.5 × 6.5 mm	33.2 mm²	39%	Heart Outline Hidden Halo
1.25 ct	7.0 × 7.0 mm	38.5 mm²	42%	Modern Bezel Solitaire
1.50 ct	7.4 × 7.4 mm	43.0 mm²	45%	Five-Prong Atelier Crown
1.75 ct	7.8 × 7.8 mm	47.8 mm²	47%	Tapered Platinum Shank
2.00 ct	8.2 × 8.2 mm	52.8 mm²	50%	Cathedral Solitaire Setting
2.50 ct	8.8 × 8.8 mm	60.8 mm²	53%	Signature Heart Atelier Setting
3.00 ct	9.4 × 9.4 mm	69.4 mm²	57%	High Maison Romantic Trilogy
4.00 ct	10.3 × 10.3 mm	83.3 mm²	62%	Custom Handcrafted Platinum
5.00 ct	11.1 × 11.1 mm	96.8 mm²	67%	Museum Collection Masterpiece

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Carat Weight vs Physical Millimeters

Carat is strictly a measurement of weight (1.00 ct = 0.20 grams). Two diamonds of identical carat weight can have markedly different surface diameters depending on how deeply the stone was cut by the master cutter.

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The Optical Elongation Advantage

Fancy elongated shapes like Oval, Marquise, Emerald, and Pear distribute their mass across a longer surface axis, creating a visual footprint that appears 12% to 18% larger on the hand than an equivalent round brilliant.

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Cut Quality Maximizes Spread

An Ideal or Excellent cut grade ensures weight is not hidden in an overly deep pavilion or thick girdle. This delivers maximum face-up millimeter spread and intense brilliance across all lighting conditions.

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Crafted For Your Moment

The Fine Jewellery Edit

Certified & conflict-free

Crafted For Your Moment

The Fine Jewellery Edit

Diamond Size & Finger Coverage Chart

Diamond Size Chart: Carat to MM Matrix

Carat Weight vs Physical Millimeters

The Optical Elongation Advantage

Cut Quality Maximizes Spread

Good to know