Moissanite MM to Carat Chart — All 14 Shapes, Melee to 10 ct

Short answer: a 1.5 mm round moissanite melee weighs about 0.014 ct (≈ 70 stones per carat); a 2 mm round about 0.03 ct (≈ 35 per carat); a 3 mm round about 0.10 ct (≈ 10 per carat). For fancy shapes the tables below convert every size Caratura stocks — 14 shapes, melee to 10 ct — from millimetres to carats and back. Moissanite is about 9% lighter than diamond at the same size (specific gravity 3.21 vs 3.52), so a moissanite that looks like a 1 ct diamond weighs roughly 0.91 ct.

Size & price chart (107 sizes) · Round melee mm→ct explained · Halo stone counts · Tennis bracelet & eternity counts · ±0.1 mm guarantee

Why we sell by the millimetre, not the carat

A seat is cut to a diameter, not a weight. Two "0.03 ct" stones can be 1.9 mm and 2.1 mm and only one of them fits. That is why every Caratura melee size is listed, sorted and guaranteed in millimetres (±0.1 mm), and why this page exists at all: you will still meet carat figures on invoices, appraisals and customer briefs, and you need a reliable way to translate between the two.

Jump to a shape: Round · Oval · Pear · Marquise · Princess · Cushion · Radiant · Emerald · Asscher · Baguette · Trapezoid · Heart · Trillion · Triangle

Round — mm to carat

Round melee is sold by the calibrated 1-carat bag, so the weight per stone is simply one carat divided by the bag count. Counts are what we actually pack, not a formula.

Size Stones per 1 ct Weight per stone Order
0.7 mm ≈ 595 ≈ 0.002 ct 1-ct bag
0.8 mm ≈ 340 ≈ 0.003 ct 1-ct bag
0.9 mm ≈ 290 ≈ 0.003 ct 1-ct bag
1 mm ≈ 200 ≈ 0.005 ct 1-ct bag
1.1 mm ≈ 170 ≈ 0.006 ct 1-ct bag
1.2 mm ≈ 125 ≈ 0.008 ct 1-ct bag
1.3 mm ≈ 100 ≈ 0.010 ct 1-ct bag
1.4 mm ≈ 85 ≈ 0.012 ct 1-ct bag
1.5 mm ≈ 70 ≈ 0.014 ct 1-ct bag
1.6 mm ≈ 60 ≈ 0.017 ct 1-ct bag
1.7 mm ≈ 50 ≈ 0.020 ct 1-ct bag
1.8 mm ≈ 40 ≈ 0.025 ct 1-ct bag
1.9 mm ≈ 37 ≈ 0.027 ct 1-ct bag
2 mm ≈ 35 ≈ 0.029 ct 1-ct bag
2.1 mm ≈ 30 ≈ 0.033 ct 1-ct bag
2.2 mm ≈ 25 ≈ 0.040 ct 1-ct bag
2.3 mm ≈ 22 ≈ 0.045 ct 1-ct bag
2.4 mm ≈ 20 ≈ 0.050 ct 1-ct bag
2.5 mm ≈ 17 ≈ 0.059 ct 1-ct bag
2.6 mm ≈ 16 ≈ 0.062 ct 1-ct bag
2.7 mm ≈ 15 ≈ 0.067 ct 1-ct bag
2.8 mm ≈ 12 ≈ 0.083 ct 1-ct bag
2.9 mm ≈ 11 ≈ 0.091 ct 1-ct bag
3 mm ≈ 10 ≈ 0.10 ct 1-ct bag

Larger round stones (0.5 ct and up) are listed by carat with the millimetre size we cut them to:

Carat Size (mm) Order
0.5 ct 5.0 mm $13
0.6 ct 5.5 mm $15.6
0.8 ct 6.0 mm $20.8
1 ct 6.5 mm $26
1.5 ct 7.0 mm $39
2 ct 8.0 mm $52
2.5 ct 8.5 mm $65
3 ct 9.0 mm $78
3.5 ct 9.5 mm $91
4 ct 10 mm $104

↑ All shapes

Oval — mm to carat

Oval melee is sold by the stone and calibrated by the millimetre. Weights below are estimates from the standard cutter's formula (see the method note at the end), not weighed lots.

Size (L × W) Est. weight per stone Stones per carat Order
2×3 mm ≈ 0.042 ct ≈ 24 1 stone $4
4×2 mm ≈ 0.056 ct ≈ 18 1 stone $5
2.5×3.5 mm ≈ 0.077 ct ≈ 13 1 stone $6
4×3 mm ≈ 0.13 ct ≈ 8 1 stone $8
5×3 mm ≈ 0.16 ct ≈ 6 1 stone $10

Larger oval stones (0.5 ct and up) are listed by carat with the millimetre size we cut them to:

Carat Size (mm) Order
0.5 ct 6×4 mm $13
1 ct 7×5 mm $26
2 ct 9×7 mm $52
3 ct 10×8 mm $78
4 ct 11×9 mm $104

↑ All shapes

Pear — mm to carat

Pear melee is sold by the stone and calibrated by the millimetre. Weights below are estimates from the standard cutter's formula (see the method note at the end), not weighed lots.

Size (L × W) Est. weight per stone Stones per carat Order
2.5×1.5 mm ≈ 0.019 ct ≈ 53 1 stone $2
3×1.5 mm ≈ 0.023 ct ≈ 44 1 stone $3
3×2 mm ≈ 0.040 ct ≈ 25 1 stone $4
3.5×2.5 mm ≈ 0.073 ct ≈ 14 1 stone $4.5
4×2 mm ≈ 0.053 ct ≈ 19 1 stone $5
4×2.5 mm ≈ 0.083 ct ≈ 12 1 stone $6
4×3 mm ≈ 0.12 ct ≈ 8 1 stone $8
5×3 mm ≈ 0.15 ct ≈ 7 1 stone $10

Larger pear stones (0.5 ct and up) are listed by carat with the millimetre size we cut them to:

Carat Size (mm) Order
0.5 ct 6×4 mm $13
1 ct 8×5 mm $26
2 ct 10×7 mm $52
3 ct 11×8 mm $78
4 ct 12×9 mm $104

↑ All shapes

Marquise — mm to carat

Marquise melee is sold by the stone and calibrated by the millimetre. Weights below are estimates from the standard cutter's formula (see the method note at the end), not weighed lots.

Size (L × W) Est. weight per stone Stones per carat Order
3×1.5 mm ≈ 0.022 ct ≈ 45 1 stone $3
4×2 mm ≈ 0.052 ct ≈ 19 1 stone $5
5×2.5 mm ≈ 0.10 ct ≈ 10 1 stone $7
6×3 mm ≈ 0.18 ct ≈ 6 1 stone $9
7×3.5 mm ≈ 0.28 ct ≈ 4 1 stone $11

↑ All shapes

Princess — mm to carat

Princess melee is sold by the stone and calibrated by the millimetre. Weights below are estimates from the standard cutter's formula (see the method note at the end), not weighed lots.

Size (L × W) Est. weight per stone Stones per carat Order
1.5×1.5 mm ≈ 0.018 ct ≈ 56 1 stone $1.5
2×2 mm ≈ 0.042 ct ≈ 24 1 stone $3
2.5×2.5 mm ≈ 0.083 ct ≈ 12 1 stone $5
3×3 mm ≈ 0.14 ct ≈ 7 1 stone $7
3.5×3.5 mm ≈ 0.23 ct ≈ 4 1 stone $9
4×4 mm ≈ 0.34 ct ≈ 3 1 stone $11

Larger princess stones (0.5 ct and up) are listed by carat with the millimetre size we cut them to:

Carat Size (mm) Order
0.5 ct 5×5 mm $13
1 ct 5.5×5.5 mm $26
2 ct 7×7 mm $52
3 ct 8×8 mm $78
4 ct 9×9 mm $104

↑ All shapes

Cushion — mm to carat

Cushion melee is sold by the stone and calibrated by the millimetre. Weights below are estimates from the standard cutter's formula (see the method note at the end), not weighed lots.

Size (L × W) Est. weight per stone Stones per carat Order
2.5×3.5 mm ≈ 0.11 ct ≈ 9 1 stone $6
3.5×3.5 mm ≈ 0.22 ct ≈ 5 1 stone $9
4×4 mm ≈ 0.32 ct ≈ 3 1 stone $11

Larger cushion stones (0.5 ct and up) are listed by carat with the millimetre size we cut them to:

Carat Size (mm) Order
0.5 ct 5×5 mm $13
1 ct 6×6 mm $26
2 ct 7×7 mm $52
3 ct 8×8 mm $78
4 ct 9×9 mm $104

↑ All shapes

Radiant — mm to carat

Radiant melee is sold by the stone and calibrated by the millimetre. Weights below are estimates from the standard cutter's formula (see the method note at the end), not weighed lots.

Size (L × W) Est. weight per stone Stones per carat Order
2.5×3.5 mm ≈ 0.11 ct ≈ 9 1 stone $6
2×4 mm ≈ 0.082 ct ≈ 12 1 stone $7
3×4 mm ≈ 0.19 ct ≈ 5 1 stone $9
3×5 mm ≈ 0.23 ct ≈ 4 1 stone $10

Larger radiant stones (0.5 ct and up) are listed by carat with the millimetre size we cut them to:

Carat Size (mm) Order
0.5 ct 6×4 mm $13
1 ct 7×5 mm $26
2 ct 8×6 mm $52
3 ct 9×7 mm $78
4 ct 10×8 mm $104

↑ All shapes

Emerald — mm to carat

Emerald melee is sold by the stone and calibrated by the millimetre. Weights below are estimates from the standard cutter's formula (see the method note at the end), not weighed lots.

Size (L × W) Est. weight per stone Stones per carat Order
3×2 mm ≈ 0.062 ct ≈ 16 1 stone $6
4×2 mm ≈ 0.082 ct ≈ 12 1 stone $7
4×2.5 mm ≈ 0.13 ct ≈ 8 1 stone $8
4×3 mm ≈ 0.19 ct ≈ 5 1 stone $9
5×3 mm ≈ 0.23 ct ≈ 4 1 stone $10

Larger emerald stones (0.5 ct and up) are listed by carat with the millimetre size we cut them to:

Carat Size (mm) Order
0.5 ct 6×4 mm $13
1 ct 7×5 mm $26
2 ct 8×6 mm $52
3 ct 9×7 mm $78
4 ct 10×8 mm $104

↑ All shapes

Asscher — mm to carat

Asscher melee is sold by the stone and calibrated by the millimetre. Weights below are estimates from the standard cutter's formula (see the method note at the end), not weighed lots.

Size (L × W) Est. weight per stone Stones per carat Order
2×2 mm ≈ 0.041 ct ≈ 24 1 stone $3
2.5×2.5 mm ≈ 0.080 ct ≈ 12 1 stone $5
3×3 mm ≈ 0.14 ct ≈ 7 1 stone $7
3.5×3.5 mm ≈ 0.22 ct ≈ 5 1 stone $9
4×4 mm ≈ 0.33 ct ≈ 3 1 stone $11

Larger asscher stones (0.5 ct and up) are listed by carat with the millimetre size we cut them to:

Carat Size (mm) Order
0.5 ct 5×5 mm $13
1 ct 6×6 mm $26
2 ct 7×7 mm $52
3 ct 8×8 mm $78
4 ct 9×9 mm $104

↑ All shapes

Baguette — mm to carat

Baguette melee is sold by the stone and calibrated by the millimetre. Weights below are estimates from the standard cutter's formula (see the method note at the end), not weighed lots.

Size (L × W) Est. weight per stone Stones per carat Order
1×2 mm ≈ 0.010 ct ≈ 97 1 stone $1
1.5×2.5 mm ≈ 0.029 ct ≈ 35 1 stone $2
1.5×3 mm ≈ 0.035 ct ≈ 29 1 stone $3
1.5×3.5 mm ≈ 0.041 ct ≈ 25 1 stone $4
2×3 mm ≈ 0.062 ct ≈ 16 1 stone $5
2×3.5 mm ≈ 0.072 ct ≈ 14 1 stone $6
2×4 mm ≈ 0.082 ct ≈ 12 1 stone $7
3×4 mm ≈ 0.19 ct ≈ 5 1 stone $8
2.5×5 mm ≈ 0.16 ct ≈ 6 1 stone $9
3×5 mm ≈ 0.23 ct ≈ 4 1 stone $11
3.5×5 mm ≈ 0.32 ct ≈ 3 1 stone $12
3×6 mm ≈ 0.28 ct ≈ 4 1 stone $13

↑ All shapes

Trapezoid — mm to carat

Trapezoid melee is sold by the stone and calibrated by the millimetre. Weights below are estimates from the standard cutter's formula (see the method note at the end), not weighed lots.

Size (short base × long base × height) Est. weight per stone Stones per carat Order
1.5×2.5×3.5 mm ≈ 0.072 ct ≈ 14 1 stone $7
1.5×2.5×5 mm ≈ 0.10 ct ≈ 10 1 stone $9
2×3×4 mm ≈ 0.13 ct ≈ 8 1 stone $9.5
2×3×4.5 mm ≈ 0.14 ct ≈ 7 1 stone $10
3×5×2.5 mm ≈ 0.13 ct ≈ 8 1 stone $10
3×4×3 mm ≈ 0.16 ct ≈ 6 1 stone $10
3.5×2.5×5 mm ≈ 0.23 ct ≈ 4 1 stone $10
2×3×5 mm ≈ 0.16 ct ≈ 6 1 stone $12
1.7×2.5×6.5 mm ≈ 0.15 ct ≈ 7 1 stone $12
3×4×5 mm ≈ 0.32 ct ≈ 3 1 stone $17
3×4.5×5 mm ≈ 0.36 ct ≈ 3 1 stone $17
3×5×4 mm ≈ 0.33 ct ≈ 3 1 stone $17
3×4×6 mm ≈ 0.38 ct ≈ 3 1 stone $20
4×7×4 mm ≈ 0.45 ct ≈ 2 1 stone $20
3.1×5.3×5.4 mm ≈ 0.49 ct ≈ 2 1 stone $20
1.8×3×7.5 mm ≈ 0.22 ct ≈ 4 1 stone $20
3.8×5.8×4.2 mm ≈ 0.44 ct ≈ 2 1 stone $25
3.5×5×6.5 mm ≈ 0.60 ct ≈ 2 1 stone $32

↑ All shapes

Heart — mm to carat

Heart melee is sold by the stone and calibrated by the millimetre. Weights below are estimates from the standard cutter's formula (see the method note at the end), not weighed lots.

Size (L × W) Est. weight per stone Stones per carat Order
3×3 mm ≈ 0.090 ct ≈ 11 1 stone $7
3.5×3.5 mm ≈ 0.14 ct ≈ 7 1 stone $9
4×4 mm ≈ 0.21 ct ≈ 5 1 stone $11
4.5×4.5 mm ≈ 0.30 ct ≈ 3 1 stone $12

Larger heart stones (0.5 ct and up) are listed by carat with the millimetre size we cut them to:

Carat Size (mm) Order
0.5 ct 5×5 mm $13
1 ct 6.5×6.5 mm $26
2 ct 8×8 mm $52
3 ct 9×9 mm $78
4 ct 10×10 mm $104

↑ All shapes

Trillion — mm to carat

Trillion melee is sold by the stone and calibrated by the millimetre. Weights below are estimates from the standard cutter's formula (see the method note at the end), not weighed lots.

Size (L × W) Est. weight per stone Stones per carat Order
3×3 mm ≈ 0.063 ct ≈ 16 1 stone $7
4×4 mm ≈ 0.15 ct ≈ 7 1 stone $11
5×5 mm ≈ 0.29 ct ≈ 3 1 stone $13

↑ All shapes

Triangle — mm to carat

Triangle melee is sold by the stone and calibrated by the millimetre. Weights below are estimates from the standard cutter's formula (see the method note at the end), not weighed lots.

Size (L × W) Est. weight per stone Stones per carat Order
3×3 mm ≈ 0.063 ct ≈ 16 1 stone $7
4×4 mm ≈ 0.15 ct ≈ 7 1 stone $11
4.5×4.5 mm ≈ 0.21 ct ≈ 5 1 stone $12
5×5 mm ≈ 0.29 ct ≈ 3 1 stone $13
6.5×6.5 mm ≈ 0.64 ct ≈ 2 1 stone $26

↑ All shapes

How the weights on this page are calculated

Round melee — not calculated. Each bag is a real 1-carat lot and the stone count is what we pack (e.g. 1.5 mm ≈ 70 stones), so weight per stone = 1 ÷ count.

Larger stones (0.5 ct and up) — the carat and millimetre figures are the sizes each stone is listed under on its product page.

Fancy-shape melee — estimated with the standard cutter's formula: length × width × depth × shape constant, then × 0.912 for moissanite's lower density. Constants and depth assumptions used: round 0.0061 (depth 60% of diameter); oval 0.0062, pear and heart 0.0059, marquise 0.0058 (depth 62% of width); princess 0.0083 (70%); cushion 0.0081, radiant, emerald, asscher, baguette 0.0083 (68%); trillion and triangle 0.0057 (45%). For trapezoids the area is (short base + long base) ÷ 2 × height. Real stones vary with how deep they are cut, so treat these as ±15%. If you need a weighed figure for a parcel, ask — we weigh every lot before it ships.

Frequently asked questions

How many carats is a 2 mm moissanite?

A 2 mm round moissanite melee weighs about 0.03 ct — Caratura packs roughly 35 stones of 2.0 mm to a 1-carat bag. A 2×2 mm princess is about 0.04 ct.

How many carats is a 3 mm moissanite?

A 3 mm round is about 0.10 ct (roughly 10 stones per carat). A 3×3 mm trillion is about 0.06 ct and a 3×3 mm heart about 0.09 ct, because those cuts are shallower.

What size is a 1 carat moissanite in mm?

At Caratura a 1 ct round is 6.5 mm; a 1 ct oval, emerald or radiant is 7×5 mm; a 1 ct pear is 8×5 mm; a 1 ct cushion or asscher is 6×6 mm; a 1 ct princess is 5.5×5.5 mm; a 1 ct heart is 6.5×6.5 mm.

Does moissanite weigh the same as diamond at the same mm size?

No. Moissanite's specific gravity is 3.21 against diamond's 3.52, so a moissanite of the same dimensions weighs about 9% less. A stone the size of a 1 ct diamond weighs about 0.91 ct as moissanite, which is why moissanite is sold and specified by millimetre size rather than by weight.

How many 1.5 mm moissanite stones are in a carat?

About 70. Caratura's 1.5 mm round melee is packed in 1-carat bags of roughly 70 stones, calibrated to ±0.1 mm.

Can I order fancy-shape melee by carat weight?

Fancy shapes are sold by the stone and by millimetre size, from one stone with no minimum. If you need to hit a carat total for a design, use the estimated weights in the tables above to work out the count, then add 10–15% spares.

Order calibrated moissanite by the millimetre

Round melee 0.7–3.0 mm is $28 per calibrated 1-ct bag; the 13 fancy shapes are sold by the stone from $1. Every parcel is hand-inspected and filmed before dispatch; anything outside ±0.1 mm, reported within 14 days, is replaced free or refunded. Not sure which size a design needs? Send Leilei the setting on WhatsApp — she replies the same day.