Rapaport Diamond Price Calculator
Estimate a stone’s value using color, clarity, shape, carat weight, and your expected market discount or premium.
What Is a Rapaport Diamond Calculator?
A Rapaport diamond calculator is a quick way to estimate a diamond’s market value using the same core logic many dealers start with: list price per carat, then a discount or premium based on real trading conditions. Think of it as a pricing framework, not a final invoice.
In wholesale trading, buyers and sellers commonly quote values as “Rap minus” or “Rap plus.” For example, “Rap -25” means 25% below the relevant list benchmark. This calculator helps translate that language into a usable number.
How This Calculator Works
1) Base Price by Color and Clarity
The tool starts with a model price-per-carat grid organized by color (D–M) and clarity (IF–I1). Better grades generally command higher prices.
2) Carat Bracket Multiplier
Price per carat is not linear. Larger stones usually receive higher per-carat pricing, so the calculator applies a size bracket multiplier.
3) Shape Adjustment
Round brilliants often trade differently from fancy shapes. The calculator includes shape factors to reflect broad market tendencies.
4) Discount/Premium and Market Adjustments
You can add a discount, premium, or other market adjustment percentage to better mirror current demand and inventory conditions.
Inputs You Should Understand Before Pricing
- Carat: Weight drives value heavily, especially at milestone sizes (1.00 ct, 1.50 ct, 2.00 ct, etc.).
- Color: D is colorless and usually higher priced than lower color grades.
- Clarity: Fewer inclusions generally mean higher market value.
- Shape: Round often trades at different levels compared with oval, cushion, emerald, and others.
- Discount/Premium: Real-world transactions almost always deviate from any benchmark list.
Example Use Case
Suppose you are reviewing a 1.20 ct, G/VS2 round stone. If your market intelligence suggests similar goods are trading around Rap -18, you can input that directly and get an estimated total stone value. Then add optional costs such as logistics or certification to approximate your landed cost.
Practical Buying and Selling Tips
- Always confirm grading report details (lab, cut, polish, symmetry, fluorescence).
- Use this estimate as a negotiation baseline, not an absolute valuation.
- Compare at least 3–5 similar listings before making an offer.
- For high-value stones, request an independent appraisal and verify inscription numbers.
Important Limitations
No calculator can fully capture the nuances of diamond pricing. Two stones with the same 4Cs can trade at very different prices due to cut precision, visual performance, brand positioning, and local market velocity. Use this page for directional guidance and deal preparation.