Gold Weight Calculator
Calculate pure gold weight and alloy content from total weight and karat purity. Free online gold weight calculator with interactive charts and breakdowns.
About This Calculator
The Gold Weight Calculator helps you determine the exact amount of pure gold in any gold item based on its total weight and karat purity. Whether you are buying gold jewelry, investing in gold coins and bars, or evaluating scrap gold, this calculator provides accurate measurements of pure gold content, alloy metal content, and purity percentage. It can also estimate the market value when you enter the current gold price per gram in your local currency.
Gold purity is measured in karats (K), with 24K being 99.9% pure gold. The formula used is: Pure Gold = Total Weight × (Karat / 24). For example, a 20-gram 22K gold item contains 18.33 grams of pure gold. The alloy metals (typically copper, silver, nickel, or zinc) make up the remaining weight and give the jewelry strength and durability. In India, 22K is the standard for jewelry; in the US, 14K and 18K are most common; and in the UK, hallmark fineness stamps like 375, 585, 750, and 916 indicate purity.
The calculator supports five common purity levels: 24K (99.9% — investment grade bullion and coins), 22K (91.7% — standard Indian jewelry), 18K (75% — international jewelry standard), 14K (58.5% — common US jewelry), and 10K (41.7% — minimum karat for gold in the US). You can also enter the current gold market price per gram to instantly see the estimated value of the pure gold content.
Regional Notes
India: Gold prices are typically quoted per 10 grams in INR. The standard for jewelry is 22K (916 hallmark). Gold is a culturally significant investment and gifting metal, with prices regulated by the Indian Bullion and Jewellers Association (IBJA).
United States: Gold is typically priced per troy ounce (31.1 g) in USD. Common jewelry purities are 14K and 18K. The gold spot price fluctuates throughout the trading day on COMEX. For accurate valuation, use the current spot price per gram.
United Kingdom: Gold is priced per troy ounce in GBP, with hallmark purity stamps like 375 (9K), 585 (14K), 750 (18K), and 999 (24K). The London Bullion Market Association (LBMA) sets the global gold benchmark price twice daily.
Frequently Asked Questions
How do I calculate the pure gold content of an item?
To calculate the pure gold content, multiply the total weight of the item by the karat value divided by 24. For example, a 20-gram 22K gold item contains 20 × (22/24) = 18.33 grams of pure gold. The remaining 1.67 grams are alloy metals like copper, silver, or zinc added for durability.
What is the difference between karat and carat?
Karat (K) measures gold purity on a scale of 1 to 24, with 24K being pure gold. Carat (ct) is a unit of mass used for gemstones and pearls. They are completely different measurements despite similar spelling and pronunciation.
What is the purest form of gold available?
24K gold (99.9% pure) is the purest form commonly available. It is too soft for most jewelry and is primarily used for investment products like gold bars and coins. For jewelry, 22K (91.7%) and 18K (75%) are more common as they include alloy metals for strength.
How is gold purity measured in different countries?
In India, gold purity is commonly measured in karats with 22K being the standard for jewelry. The US also uses the karat system but also marks fineness (e.g., 750 for 18K). The UK uses the hallmark system with fineness stamps like 375 (9K), 585 (14K), 750 (18K), 916 (22K), and 999 (24K).
How does gold purity affect the value of jewelry?
The value of gold jewelry depends on both its weight and purity. Higher karat gold (22K, 24K) contains more pure gold and is therefore more valuable per gram. However, lower karat gold (14K, 18K) is more durable due to the alloy metals, making it better suited for everyday jewelry like rings and bracelets.
Can I use this calculator for gold investments?
Yes, the gold weight calculator helps investors determine the pure gold content of gold bars, coins, and other bullion. Enter the total weight and purity (typically 24K for investment gold) along with the current market price per gram to estimate the market value of your gold holdings.
What are the common gold purity standards worldwide?
Common gold purity standards include 24K (99.9% pure — investment grade), 22K (91.7% — Indian jewelry standard), 18K (75% — international jewelry standard), 14K (58.5% — US jewelry standard), and 10K (41.7% — minimum karat for gold in the US). Each standard strikes a different balance between purity and durability.
How much gold is in a 22K gold coin weighing 10 grams?
A 10-gram 22K gold coin contains 10 × (22/24) = 9.17 grams of pure gold. The remaining 0.83 grams consist of alloy metals, typically copper and silver, which give the coin durability while maintaining its golden color.