Old European Cut Diamond Weight

The Old European Cut Diamond Weight calculator computes the approximate carat weight of a Old European cut diamond based on the average diameter, depth and girdle thickness factor.

INSTRUCTIONS: Choose units and enter the following:

• (V) Vertical Length
• (H) Horizontal Width
• (D) Depth
• (T) Girdle Thickness Factor

Old European Diamond Carat Weight (Wt): The calculator returns weight of the Old European Cut diamond in carats.  However, this can be automatically converted to grams or other weight units via the pull-down menu.  Note: Both the vertical and horizontal are entered to compute the average diameter in case the diamond face isn't precisely symmetrical.

The Math / Science

The formula to estimate the carat weight of an Old European Cut diamond is:

  Wt = vLENGTH * hWIDTH * DEPTH * 0.0064 * wc

where:

• Wt = Carat Weight of an Old English Diamond
• vLength = Vertical Length of face
• hWidth = Horizontal Width of face
• Depth =  Depth of side (see diagram)
• wc = Diamond Weight Correction, which is between 1.00 and 1.08 depending on the girdle thickness and mean diameter.  
  • Mean Diameter = (WIDTH + LENGTH)/2

Diamond Carat Weight Calculator

This jewelers suite of calculators includes carat weight estimations of diamonds based on the cut diamonds shape and size that can be measured while still within a setting. This enables the jeweler to estimate the carat weigh of the diamond without damaging the setting.

The diamond weight formulas contain carat weight equations that are specific to diamonds and diamond cuts:

• Compute carat weight of Round Brilliant diamond 
• Compute carat weight of Oval Brilliant diamond
• Compute carat weight of Heart Shaped diamond
• Compute carat weight of Emerald Cut diamond 
• Compute carat weight of Baguette diamond
• Compute carat weight of Princess Cut diamond
• Compute carat weight of Triangular Brilliant diamond 
• Compute carat weight of Marquise Brilliant diamond
• Compute carat weight of Pear Shaped Brilliant (Teardrop) diamond 
• Compute carat weight of Tapered Baguette diamond
• Compute carat weight of Old European cut diamond
• Compute carat weight of Cushion diamond

ACCURACY COMPARISON

The carat weight equations and data used in vCalc's jewelry library and calculator were reviewed by a certified gemologist.   The equations are based on industry recognized formulas and data.  The table below shows a comparison of computations between vCalc and an industry accepted application (Quantum Leap).

The length, width and depth are in millimeters (mm), and the Quantum Leap and vCalc measurements are in carats (cwt).

The largest variance, an oval faceted alexandrite, which can be seen in the last row above, has been double checked against several source equations which tend to support vCalc's accuracy.