Carat is the unit of measurement of diamond weight. One diamond carat is divided into 100 points. One carat is equivalent to 0.20 grams (or 1 gram contains 5 carats). Carat is often confused with size, whereas it is actually a measure of weight. The chart below shows the relative comparison of Carat Weight and its Size:
Large and big size diamonds with higher quality grade (colour, clarity and cut) are rare and expensive. The price bracket jumps as the carat weight reaches 1.00 ct mark. This is also why the price of a 1ct diamond is not twice the price of a 0.50ct diamond.
What Carat Size to choose?
To choose the right carat weight of the diamond for engagement and wedding rings, you need to consider your budget, ring style (or setting), shape of diamond and overall quality of diamond. The one carat round brilliant or princess cut is ideal for those who are looking for quality and finest expression of their feelings.
With budget constraints, a relative smaller size to 1 ct diamond (like 0.90 or 0.85 ct) will show similar appearance like 1ct diamond, because there is minor difference on mm sizes when view from top and that is how diamonds are presented to us when set into a ring.