Gold Weight Calculator
Calculate weight, volume, and cost of gold objects based on dimensions and purity
Gold Properties & Shape
Gold Properties
Dimensions
Cost Calculation (Optional)
Calculation Results
Example Calculation
18k Gold Wedding Ring
Shape: Ring (torus)
Outer diameter: 20 mm
Inner diameter: 16 mm
Thickness: 2 mm
Gold standard: 18k (75% purity, 15.58 g/cm³)
Calculation Results
1. Ring volume = 2π²R·r²·t = 2π²(9mm)(2mm)²(2mm) ≈ 1,421 mm³
2. Volume in cm³ = 1,421 ÷ 1,000 = 1.42 cm³
3. Total weight = 1.42 cm³ × 15.58 g/cm³ = 2.21 g
4. Pure gold content = 2.21 g × 75% = 1.66 g
5. Result: Ring weighs 2.21 g with 1.66 g of pure gold
Gold Standards
Understanding Gold Purity
Karat System
Parts of pure gold per 24 parts total
Formula: K = 24 × (M_gold / M_total)
Fineness
Parts of pure gold per 1000 parts total
18k = 750 fineness (750/1000)
Supported Shapes
Quick Tips
Higher karat = more pure gold = higher value
24k is pure gold, softer and more expensive
18k and 14k are popular for jewelry
Consider wastage for fabrication costs
Density decreases with lower purity
Understanding Gold Weight Calculations
Gold Purity Systems
Gold purity is measured using two main systems: the karat system and fineness. The karat system divides gold into 24 parts, where 24k represents pure gold. Fineness measures purity in parts per thousand, where 999 represents the highest purity available commercially.
Density and Weight Relationship
Gold alloys have different densities depending on their purity and the metals used for alloying. Pure gold has a density of 19.30 g/cm³, but this decreases as other metals are added. Common alloying metals include copper, silver, zinc, and nickel, each affecting the final density.
Applications by Weight
- •0.1-1g: Earrings, small pendants, delicate chains
- •1-5g: Rings, medium pendants, thin bracelets
- •5-20g: Wedding bands, necklaces, chunky rings
- •20g+: Statement pieces, chains, investment items
Weight Calculation Formula
Basic Formula
Weight = Volume × Density
Where density depends on gold purity and alloy composition
Karat to Density:
ρ = ρ_pure × (purity/100) + ρ_alloy × (1-purity/100)
Pure Gold Content:
Pure Gold = Total Weight × (Purity/100)
ρ: Density of gold alloy (g/cm³)
Volume: Calculated from shape dimensions
Purity: Percentage of pure gold in alloy
Cost Consideration: Account for material wastage during fabrication. Typical wastage ranges from 2-10% depending on the complexity of the work and craftsmanship method used.