Length-to-width adjustments (LWA) for weight estimation formula.
L/W ratio LWA
1.25/1.00 .00615
1.50/1.00 .00600
1.66/1.00 .00590
2.00/1.00 .00575
Pear Shape Formula: Length x Width x Depth x LWA x GTA
#1 Example of formula in use:
Length measurement: 7.35 mm
Width measurement: 5.20 mm
Depth measurement: 3.05 mm
Girdle: Thick
High shoulders: 1.02
L/W ratio: 7.35 divided by 5.20 = 1.413
Formula will read:
7.35 x 4.89 x 3.25 x .0060 (LWA) x 1.03 (GTA) x 1.02 shape adjustment (high shoulders) = 0.736
Rounded down to 0.73 ct.
#2 Example of formula in use:
Length measurement: 9.73 mm
Width measurement: 7.26 mm
Depth measurement: 5.01 mm
Girdle: Very Thick
High shoulders: 1.02
L/W ratio: 9.73 divided by 7.26 = 1.34
Formula will read:
9.73 x 7.26 x 5.01 x .0061 (LWA) x 1.045 (GTA) x 1.02 (shape adjustment, high shoulders) = 2.301
Rounded to 2.30 ct.
