Tools
Diamond
Quick, approximate tools for everyday questions — estimate a round brilliant’s weight from its measurements, or gauge a value from a price per carat. For anything official, rely on a DGI report.
Weight estimator
Round brilliant
mm
mm
—
Estimate for a standard round brilliant, using diameter² × depth × 0.0061. Fancy shapes and unusual proportions will vary.
Value estimator
Price per carat
ct
USD
—
A rough guide only. Actual prices depend on the full 4C grade, fluorescence, cut quality and the market. Not an official appraisal.
These calculators are provided for guidance and give approximate figures. A DGI certificate records the measured weight and full grade; an appraisal, when requested, gives an estimated replacement value based on the current Rapaport price list.