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.

Carat Weight	Dimensions (L × W)	Surface Area	Finger Coverage (Size 6)	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.

Carat Weight	Dimensions (L × W)	Surface Area	Finger Coverage (Size 6)	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

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

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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.

Carat Weight	Dimensions (L × W)	Surface Area	Finger Coverage (Size 6)	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

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

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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.

Carat Weight	Dimensions (L × W)	Surface Area	Finger Coverage (Size 6)	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

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

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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.

Carat Weight	Dimensions (L × W)	Surface Area	Finger Coverage (Size 6)	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

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

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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.

Carat Weight	Dimensions (L × W)	Surface Area	Finger Coverage (Size 6)	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

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

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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.

Carat Weight	Dimensions (L × W)	Surface Area	Finger Coverage (Size 6)	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

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

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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.

Carat Weight	Dimensions (L × W)	Surface Area	Finger Coverage (Size 6)	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

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

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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.

Carat Weight	Dimensions (L × W)	Surface Area	Finger Coverage (Size 6)	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.

Carat Weight	Dimensions (L × W)	Surface Area	Finger Coverage (Size 6)	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

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

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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

Save 30% on Lab Diamonds

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