Carat (Weight) – How carat affects the size and price of a diamond
Carat is one of the most well-known terms in diamonds – but it’s often misunderstood. Many people think that carat automatically means size, but it’s actually a weight number. Here you’ll find out what carat really means, how it affects appearance and price, and what to consider when choosing the carat weight for your diamond.
What is a carat – and where does the term come from?
The word carat comes from the Greek “keration”, which means carob seed. These seeds were historically used as a unit of weight due to their uniform weight. Since 1907, 1.00 carat has been defined as 0.20 grams.
Today, carat is used as the standard measurement for diamonds worldwide.
Visual size vs carat
Carat measures weight – not visual size. Two diamonds with the same carat weight can appear different sizes depending on:
- Cut shape – for example, oval or marquise can look larger than round
- Proportions – too deep grinding can reduce visual diameter
- Measurements in millimeters – determine what the eye actually perceives
All our diamonds have precise measurements and 360° views . Read more about proportions and ratios .
Approximate diameter for round brilliant cut (approx. in mm)
| Carat | Diameter |
|---|---|
| 0.25 ct | 4.1mm |
| 0.50 ct | 5.1mm |
| 0.75 ct | 5.8mm |
| 1.00 ct | 6.4 mm |
| 1.50 ct | 7.4 mm |
| 2.00 ct | 8.2 mm |
| 3.00 ct | 9.3 mm |
| 4.00 ct | 10.2mm |
| 5.00 ct | 11.1 mm |
Carat and price – what determines?
The price increases with carat – but not linearly. Some weight limits give price jumps (e.g. 0.50 ct, 0.70 ct, 1.00 ct, 2.00 ct). Even small differences can affect the price, e.g. 0.98 ct vs 1.00 ct.
Filter by carat range:
Recommendations by weight
- 0.30–0.49 ct: Elegant and discreet – works well in a halo or thin band
- 0.50–0.69 ct: Balanced expression – fits perfectly in solitaire rings
- 0.70–0.99 ct: Good value – looks big without costing like 1.00 ct
- 1.00–1.99 ct: Statement size – especially popular for engagement rings
- 2.00–5.00 ct: Luxurious, powerful expression
- 5.00 ct and up: Exceptionally exclusive – also available as lab grown
Natural or lab-grown – does it affect the choice of carat?
No – 1.00 ct always weighs the same. However, with lab-grown diamonds you often get more size for your money.
All our diamonds are certified by IGI or GIA .
Our help when choosing carat
- Filtering by carat, color, clarity and cut
- Exact dimensions in millimeters
- 360° video view of each stone
- Personal advice via chat or booked appointment