Carats: Gemstone Calculator

Your care and good judgment matter with every stone. Thank you for using Carats. Estimate gemstone weight, organize inventory and prepare clear quotes with tools for jewelers, gem dealers, collectors and lapidary artists.

GEMSTONE WEIGHT ESTIMATES

- Estimate carat weight from measurements in millimeters.
- Find diamond, ruby, sapphire, emerald and other gemstone references.
- Choose a cut factor and review specific gravity.
- Account for girdle thickness, pavilion bulge and outline.
- Explore brilliant, step, cushion and cabochon shapes.

ADVANCED GEM AND CUSTOM CUTS

- Measure above, through and below the girdle separately.
- Set upper and lower profiles independently.
- Enter table, culet and cushion corner measurements.
- Add custom materials, species and density.
- Use measured outline area, custom factors or measured volume.

INVENTORY WITH CARATS PRO

Give each stone a record you can return to between calculations.

- Assign stock IDs and add actual photographs.
- Attach gemstone certificates as images or PDFs.
- Record suppliers, purchase costs and storage locations.
- See available, reserved and sold stock.
- Keep estimated and measured weights separate, with dates and methods.
- Choose which saved weight a customer quote uses.
- Manage parcels, matched pairs and individual stones.
- Track partial sales, physical returns and remaining quantities.

STONE COSTS AND PROFIT WITH PRO

- Include purchase, cutting, setting and shipping costs.
- Add selling fees and seller-paid commissions.
- Compare profit, markup and margin before tax.
- Keep commission income separate from selling expenses.
- Record cost corrections while keeping original sale history.

CUSTOMER QUOTES AND RECEIPTS WITH PRO

- Select several stones for one quote.
- Include photos, dimensions and the selected weight basis.
- Price by stone, carat or the whole selection.
- Add business details, a logo and quote acceptance deadlines.
- Record deposits, payments, refunds and balances.
- Share quote and receipt PDFs with internal costs kept private.
- Keep issued documents when stock details change.

CONVERSIONS AND REFERENCE

- Convert carats, grams, points and milligrams.
- Compare wire gauge sizes in inches and millimeters.
- Convert distance, area and volume units.
- Work with US gallons, Imperial gallons and liters.
- Browse gemstone density and cut factor charts.

SAVE AND REVIEW YOUR WORK

- Save reusable density and profile presets.
- Import CSV files with column mapping and a preview.
- Review row errors and duplicate stock before importing.
- Back up your workspace with photographs and saved PDFs.
- Review saved gemstone and sales statistics.
- Keep customer details and commission payment history together.
- Link stock with saved calculations and sales.
- Duplicate measurements without replacing the original record.
- Keep receipt PDFs with customer payment history.

APPLE WATCH TOOLS

- Convert weight and gauge sizes at your wrist.
- Browse guides, gemstone references and calculator graphs.
- Share results from the separate Watch app.
- Use Watch tools without a usage limit or subscription.

On iPhone and iPad, try five free calculations per day for five consecutive calendar days, up to 25 total. Your first free Calculate request starts day one. Inactive days count; unused daily calculations do not roll over. Pro adds unlimited live calculations, interactive calculator graphs and the record, inventory, document and import tools described above. Choose monthly or lifetime access. Monthly renews automatically until canceled. Existing records remain viewable, shareable and exportable without Pro.


For monthly subscriptions:
Monthly Pro is a 1-month auto-renewable subscription.
Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Gemstone weights are estimates based on measurements, density and cut. Use a scale for actual weight.