Crown height: Height from the top of the girdle to the table.Pavilion depth: Height from culet to bottom of the girdle.Total depth: Height of a diamond from culet to table.Culet: Size of the culet (bottom tip of a diamond).Lower girdle length: Width of the lower girdle-from the culet to where the facet connects to the girdle.

Girdle thickness: Height of girdle (belt that divides the crown from the pavillion).Star length: Length of the angled facets adjacent to the table.

Table size: Length and width of a diamond’s table (top surface area).

Here are the 10 main components that impact diamond proportion: How well a diamond interacts with light is affected by the size, shape and angle of each facet. There are several factors that impact a diamond’s proportions, including the table size and total depth.

A diamond with too high of a depth percentage loses light out the bottom of the diamond, making it appear dull.

A diamond with a lower depth percentage usually appears larger due to its increased width, but often creates a dark appearance as the diamond doesn’t reflect light as well.

For example, if a diamond measures 3mm in depth and 4mm in width, the depth percentage is 75%. For instance, if a diamond has a length of 5mm and a width of 3mm, the length to width ratio is 1.67.ĭepth percentage is calculated by dividing the depth of the diamond (its height) by its width.

Length to width ratio is calculated by dividing the length of the diamond by its width.

Width is primarily used to determine the length to width ratio which denotes how proportionate the diamond is for its intended shape (i.e.

Width is calculated by measuring from one end of the girdle (the diameter at its widest point) to the opposite end of the girdle.

If the table percentage is too high, light doesn’t reflect off of the diamond’s crown angles and facets-leaving the diamond looking dull.

If the table percentage is too low, light gets trapped inside the diamond and leaks out the sides of the diamond (instead of reflecting back through the table).

For example, if the table facet is 3mm wide and the diameter is 5mm, the table percentage is 60%. Table percentage is calculated by dividing the table width (top surface area) by the diameter. The formulas for each specific component of a diamond’s proportions are listed below. These aspects are universally measured in millimeters (mm) and/or percentages. Each calculation describes the angles and ratios of the diamond’s precise cut. Learn More.ĭiamond proportion is calculated using the dimensions of the table size, crown height and pavilion depth in relation to the diamond’s diameter. We get commissions for purchases made from our affiliates through links in this article.

Diamond dimensions 1