What it is
A reproducible estimate generated at 0.1 carat intervals from 1.0 through 3.0 carats.
Open reference data
The millimeters behind carat weight, in a file you can actually use.
Eighty-four approximate face-up size rows for round, oval, emerald, and Dutch Marquise diamonds. Download them, cite them, build with them, or inspect every value here.
How it works
Each one-carat length and width anchor is scaled by the cube root of carat weight.
What it is not
It is not a survey of individual stones or a substitute for grading-report measurements.
Inspect the rows
Face-up size explorer
| Shape | Carat | Approx. length | Approx. width | Check |
|---|
Loading the local JSON dataset.
Suggested citation
Stienhardt. Facet Approximate Diamond Face-Up Size Reference, version 1.0.0, 2026. https://jacobiusmakes.github.io/facet-diamond-tool/dataset.htmlData is licensed under CC BY 4.0. Code is MIT licensed. A machine-readable citation file is included in the source repository.