Ring Weight Calculator - Gold, Silver, Platinum

How ring weight is calculated:

A ring is essentially a hollow cylinder. Its weight depends on the ring’s dimensions (inner diameter, width, thickness) and the density of the metal.

The formula:

Volume = π × Width × Thickness × (Inner Diameter + Thickness)

Weight (grams) = Volume (cm³) × Metal density (g/cm³)

This formula models a simple band ring. Wider and thicker bands use a lot more metal, and not in proportion. Doubling the thickness more than doubles the weight, because the outer surface grows along with it.

Metal densities (g/cm³):

Worked example:

US size 7 ring (inner diameter 17.35 mm = 1.735 cm), 6 mm wide, 1.5 mm thick, 14K gold:

• Volume = 3.14159 × 0.6 × 0.15 × (1.735 + 0.15) = 0.533 cm³
• Weight = 0.533 × 13.07 = 6.97 grams of 14K gold

Ring size to inner diameter (US sizes):

• Size 5: 15.70 mm
• Size 6: 16.51 mm
• Size 7: 17.35 mm
• Size 8: 18.19 mm
• Size 9: 18.95 mm
• Size 10: 19.84 mm

A US size is worth about 0.8 mm of inner diameter, so a whole size up on a 6 mm band adds roughly 3% to the weight. That is small enough to ignore on a silver band and large enough to matter when you are quoting platinum.

Cost estimation tip: Multiply weight by the current per-gram price of your metal. For 14K gold, the metal value is 58.3% of pure gold price per gram (14/24 = 0.583).

Troy, not avoirdupois. Precious metal is weighed in troy ounces: 31.103 grams, against 28.35 for the ordinary ounce you weigh flour in. That is a 9% difference, so quoting a gold ring in the wrong ounce is a real pricing error rather than a rounding one. The result panel reports troy.