Ruby Price Calculator

Ruby Price Calculator – How The Formulas Work

Ruby prices in the real world are built from several pieces: carat weight, price per carat, discounts or markups and fixed extra costs such as setting and certification. The Ruby Price Calculator turns these ideas into clear formulas so you can see how each piece contributes to the final estimate.

This tool does not try to guess the correct price per carat for you. Instead, you enter the per-carat figure based on current quotes, price guides or dealer offers. The calculator then handles the arithmetic, showing a transparent price breakdown in your chosen currency.

Step 1: Ruby Carat Weight And Price Per Carat

Ruby prices are usually quoted in price per carat. If the ruby weighs C carats and the agreed price per carat is P, the base value of the stone before any discounts or extras is:

Example: a 1.20 carat ruby priced at 1,500 per carat has a base value:

In the calculator, you enter C as the “Ruby Weight (carats)” and P as “Price Per Carat”. The base stone value is computed directly from this formula.

Step 2: Carats To Grams And Milligrams

Although the trade uses carats, sometimes it is useful to see weight in grams or milligrams. The conversion is based on the fixed relationship:

If C is the ruby carat weight, the gram weight G is:

Because 1 gram equals 1,000 milligrams, the same ruby in milligrams is:

For example, a 0.75 carat ruby weighs:

The calculator uses these relationships to show carats, grams and milligrams side by side so you can work in the unit that is most convenient.

Step 3: Discount Or Markup Formula

Negotiations around ruby prices often involve discounts from a price list or markups over a base cost. The Ruby Price Calculator lets you model either a discount or a markup using the same base stone value.

Let B be the base stone value from the carat calculation and let d be the discount or markup rate expressed as a percentage. The adjustment factor depends on whether you are applying a discount or a markup.

If you select a discount, the adjusted stone value is:

If you select a markup instead, the formula is:

If you choose “No Discount/Markup”, the adjusted stone value is simply equal to B.

Example: suppose the base stone value is 1,800 and the agreed discount is 10%. The adjusted value becomes:

Step 4: Extra Fixed Costs

Beyond the stone itself, there are usually fixed extra costs in a ruby purchase. Common examples include:

• Setting cost for mounting the ruby in a ring or pendant
• Certification or lab report fees
• Other charges such as design, engraving or shipping

If S is the setting cost, L is the lab or certification cost and O is other extra costs, the total extra cost E is:

The calculator adds these values directly from the three extra cost fields you enter.

Step 5: Final Estimated Ruby Price

The final estimated price combines the adjusted stone value and the total extra costs. Let A be the adjusted stone value from the discount or markup formula, and E be the total extras. The final estimated price F is:

This is the figure that appears as the “Final Estimated Price” in the results grid. It is expressed in your chosen currency symbol.

Effective Price Per Carat And Per Gram

To compare ruby prices fairly, it can be helpful to express the final cost as a price per carat or per gram that already includes extras. If the ruby weight is C carats and the final price is F, the effective price per carat is:

Similarly, if the ruby gram weight is G = C × 0.2, the effective price per gram is:

These values let you compare different ruby offers or upgrade options on a consistent per-unit basis.

Worked Example With All Steps

Consider this scenario:

• Ruby weight C = 1.30 carats
• Price per carat P = 2,200
• Discount of 5%
• Setting cost S = 300
• Certification cost L = 120
• Other extra costs O = 80

The steps are:

The effective prices then become:

These are exactly the kinds of numbers the Ruby Price Calculator produces automatically once you fill in the inputs.

How To Use The Ruby Price Calculator

• Measure or look up the ruby’s carat weight and enter it in the “Ruby Weight (carats)” field.
• Enter a price per carat based on dealer quotes or a price guide.
• Choose your currency symbol so the output is easy to read.
• Select whether you are applying a discount, a markup or neither, and enter the percentage rate if relevant.
• Add setting, certification and other extra costs if they apply to your situation.
• Choose how many decimal places of precision you want in the results.
• Click “Calculate Ruby Price” to see the full price breakdown and effective per-unit costs.

Limitations And Good Practices

Ruby pricing is nuanced. Factors such as hue, saturation, tone, clarity, cut quality, origin and treatment status can change price per carat by multiples. The Ruby Price Calculator focuses on the arithmetic around a price per carat; it does not determine what that price per carat should be.

Use this tool to:

• Compare different ruby options at similar carat weights
• See how discounts or markups change overall value
• Understand the impact of setting and certification costs
• Translate carat-based prices into per-gram figures for analysis

For buying, selling or insuring higher value rubies, combine the calculator’s output with professional gemological advice and up-to-date market data.