Online Gold Purity Calculator – Assess Your Gold’s Value

Gold purity describes how much pure gold is present in a given item relative to its total weight. It is most commonly expressed in karats or as a percentage. Pure gold is rated at 24 karats, which equals 100% gold content. Common jewellery grades include 22 karat (91.67% pure), 18 karat (75% pure), 14 karat (58.33% pure), and 10 karat (41.67% pure). The higher the karat, the more gold is present — but also the softer and more malleable the metal, which is why lower-karat alloys are often preferred for everyday jewellery that needs to withstand regular wear.

Our Gold Purity Calculator takes the guesswork out of this entirely. Whether you’re a jeweller verifying a piece, an investor assessing gold bars, or simply curious about what your jewellery is actually worth, this free online tool gives you instant, accurate results with no sign-up or payment required.

Karat vs. Percentage – What’s the Difference?

Karat is the traditional unit used to measure gold purity, particularly in jewellery. It works on a scale of 24, where 24 karats represents pure gold. Percentage expresses the same information as a proportion out of 100. The two formats are directly interchangeable — for example, 18 karat gold is 18 divided by 24, which equals 75%. This calculator accepts both formats so you can work with whichever figure is printed on your item or listed by your supplier.

Who Should Use This Calculator

Jewellers

Verify the purity of pieces before buying or selling, and ensure you’re pricing items accurately based on their actual gold content.

Investors

Quickly assess the pure gold content and estimated value of bars or coins without needing complex formulas.

Everyday Users

If you want to understand what your jewellery is actually worth or compare pieces before making a purchase, this tool gives you clear and reliable answers with zero guesswork.

How to Use the Gold Purity Calculator

Getting your results takes less than a minute. Just follow these steps.

Step 1: Enter the Total Weight

Input the weight of your gold item and select your preferred unit — grams, troy ounces, or kilograms.

Step 2: Choose the Purity Format

Enter purity either as a karat value (e.g., 18 or 22) or as a percentage (e.g., 75% or 91.67%), depending on what information you have available.

Step 3: Add a Market Price (Optional)

If you want to estimate the monetary value of your gold, enter the current gold price per gram in your local currency. This step is optional but highly useful for buyers, sellers, and investors.

Step 4: Click Calculate

The tool instantly processes your inputs and displays a full breakdown of results.

Step 5: Review Your Results

You’ll see gold purity in both percentage and karat, the weight of pure gold within your item, the estimated monetary value (if a market price was entered), a detailed results table, and a visual progress bar showing purity level at a glance.

What the Calculator Tells You

Once you hit calculate, the tool delivers a thorough breakdown including total item weight (converted to grams automatically), gold purity in both karat and percentage form, the actual weight of pure gold in the item, and the estimated market value based on the price per gram you entered. All figures are displayed in a clean summary table alongside a purity visualization bar, making it easy to interpret your results instantly.

Why This Tool Stands Out

Unlike basic karat converters, this calculator handles multiple weight units, supports both karat and percentage purity inputs, and factors in live or custom market pricing to give you a real-world value estimate. There’s no sign-up, no fee, and no complicated process. It works on any device and delivers accurate results using standard gold purity formulas trusted across the jewellery and investment industries.

A Note on Market Price

Gold prices fluctuate daily based on global markets. For the most accurate value estimate, check a reliable financial source for the current gold spot price per gram before entering it into the calculator. The value this tool returns is an estimate based on pure gold content — it does not account for craftsmanship, brand value, gemstones, or collector premiums that may affect the actual resale price of a jewellery piece.