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Calculate glaze batch weight from unity formula and raw material analysis. Scale recipes to any batch size for consistent studio pottery glazing.
Create kiln firing schedules with ramp rates, hold times, and cone temperatures. Plan bisque and glaze firings for electric and gas pottery kilns.
Calculate clay shrinkage percentage from wet, dry, and fired dimensions. Plan pottery sizes accurately for clay bodies from leather-hard through glaze firing.
The classic round diamond estimation uses diameter squared times depth with an adjustment factor for girdle and pavilion proportions.
Carats ≈ D² × depth (mm) × 0.0061 (standard round factor)Oval, pear, emerald, and marquise cuts use length × width × depth multiplied by a shape-specific factor derived from average proportions and specific gravity.
Carats ≈ L × W × D × shape factor × SG adjustmentStandard formulas assume diamond SG 3.52. For other gems, multiply by (gem SG / 3.52) — sapphire ~4.0, quartz ~2.65, emerald ~2.72.
Adjusted weight = estimated weight × (gem SG / reference SG)Updated: July 2026
6.5 mm diameter × 3.9 mm depth: 6.5² × 3.9 × 0.0061 ≈ 1.00 ct. Verify on a carat scale before quoting in a setting.
8 × 6 × 4 mm oval blue sapphire (SG 4.0): base estimate ~1.2 ct × (4.0/3.52) ≈ 1.36 ct. Useful for ordering rough or matching pairs.
14 × 10 × 5 mm oval cab (SG 2.6): volume-based estimate ~3.5 ct after SG correction. Cabochons vary in dome height — measure at thickest point.
All standard carat formulas use millimeters. Convert inches × 25.4 before applying — failure to convert produces errors of 15× or more.
A 6 mm round sapphire weighs more than a 6 mm diamond. Adjust for specific gravity or use gem-specific factors for meaningful estimates.
Gemstone weight in carats can be estimated from dimensions and cut style before unset stones are weighed. This calculator applies industry-standard formulas for common gem shapes using specific gravity and measurement-based volume estimates.