Unit Conversions

Convert between carats, grams, millimeters, inches, Celsius, and Fahrenheit.

Convert between carats, grams, and milligrams

Enter a value in any field to convert between weight units.

1 carat = 0.2 grams = 200 milligrams

Carats(ct)

Grams(g)

Milligrams(mg)

Common weights:

• 1 carat engagement diamond ≈ 0.2g

• 5 carat sapphire ≈ 1.0g

• Melee diamonds are typically 0.01-0.20 ct (2-40 mg)

Convert between millimeters and inches

Enter a value in either field to convert between length units.

1 inch = 25.4 mm

Millimeters(mm)

Inches(in)

Common stone sizes:

• 6.5mm round ≈ 1 carat diamond

• 7mm round ≈ 1.25 carat diamond

• 8mm round ≈ 2 carat diamond

• Ring sizes typically 16-20mm diameter

Convert between Celsius and Fahrenheit

Enter a value in either field to convert between temperature units.

Formula: °F = (°C × 9/5) + 32

Celsius(°C)

Fahrenheit(°F)

• Corundum: 1200-1800°C (2192-3272°F)

• Tanzanite: 550-700°C (1022-1292°F)

• Aquamarine: 400-450°C (752-842°F)

• Citrine (from amethyst): 470-560°C (878-1040°F)

• Zircon: 900-1000°C (1652-1832°F)

Note: Heat treatment temperatures are approximate and depend on specific conditions including atmosphere, duration, and starting material.