Gold Weight Guide: Grams, Troy Ounces & Pennyweights Explained
Understanding gold weight units is essential for getting a fair price when buying or selling gold. This guide covers every unit you need to know, with conversion tables and practical advice for weighing gold in the UK.
Whether you are selling gold jewellery, buying bullion coins, or simply curious about what your gold is worth, understanding weight units is the first step. Gold is measured differently from everyday items — the industry uses troy ounces, pennyweights, and grams rather than the standard ounces you see on kitchen scales.
Getting the units wrong can cost you real money. A troy ounce is roughly 10% heavier than a regular ounce, and some unscrupulous dealers have been known to exploit this confusion. Read on to make sure you know exactly how gold weight works before you visit a gold dealer.
Gold Weight Units Explained
There are six weight units you may encounter when dealing with gold. Here is what each one means and where it is used.
Gram
Abbreviation: g
= 1.0000g
The metric base unit for measuring gold weight. Most commonly used in the UK retail market and for smaller quantities.
Commonly used for: UK jewellery trade, scrap gold, small bars
Troy Ounce
Abbreviation: toz
= 31.1035g
The international standard for trading precious metals. All spot prices are quoted per troy ounce.
Commonly used for: International trading, bullion, spot prices
Avoirdupois Ounce
Abbreviation: oz
= 28.3495g
The common ounce used for everyday weighing. Not used for gold trading, but often confused with troy ounces.
Commonly used for: Everyday items (NOT gold)
Pennyweight
Abbreviation: dwt
= 1.5552g
A traditional jewellers' unit equal to 1/20th of a troy ounce. Still widely used by UK and US jewellers.
Commonly used for: Jewellers, gold buyers, trade pricing
Kilogram
Abbreviation: kg
= 1,000.00g
Used for large-scale trading and standard gold bars. A London Good Delivery bar weighs approximately 12.4 kg.
Commonly used for: Wholesale trading, central banks, large bars
Tola
Abbreviation: tola
= 11.6638g
A traditional South Asian unit of weight. Commonly used in India, Pakistan, and the Middle East for gold trading.
Commonly used for: South Asian jewellery markets
Why Gold Uses Troy Ounces, Not Regular Ounces
Key fact: 1 troy ounce = 31.1035g. 1 regular (avoirdupois) ounce = 28.3495g. A troy ounce is approximately 10% heavier than a standard ounce. If a dealer quotes you a price “per ounce” without specifying troy, always clarify which ounce they mean.
The troy weight system dates back to the Middle Ages and is named after Troyes, France, a major trading hub. Merchants needed a standardised system for precious metals, and the troy system became the international standard.
The London Bullion Market Association (LBMA), which sets the global gold price benchmark, quotes all prices in US dollars per troy ounce. This has been the case for centuries and remains the standard today.
| Measure | Troy | Avoirdupois |
|---|---|---|
| 1 Ounce | 31.1035g | 28.3495g |
| 1 Pound | 373.24g (12 oz) | 453.59g (16 oz) |
| Used for | Precious metals | Everything else |
Watch out: A troy pound (12 troy ounces = 373g) is actually lighter than a regular pound (16 ounces = 454g), even though a troy ounce is heavier than a regular ounce. This confuses many people.
Gold Weight Conversion Table
Use this table to convert between all the common gold weight units. Bookmark this page for quick reference whenever you need to check a conversion.
| Unit | Grams (g) | Troy Oz (toz) | Pennyweight (dwt) | Av. Oz (oz) |
|---|---|---|---|---|
| 1 Gram | 1.0000 | 0.03215 | 0.6430 | 0.03527 |
| 1 Troy Ounce | 31.1035 | 1.0000 | 20.0000 | 1.09714 |
| 1 Pennyweight | 1.5552 | 0.05000 | 1.0000 | 0.05486 |
| 1 Avoirdupois Oz | 28.3495 | 0.91146 | 18.2292 | 1.0000 |
| 1 Kilogram | 1,000.00 | 32.1507 | 643.015 | 35.2740 |
| 1 Tola | 11.6638 | 0.37500 | 7.5000 | 0.41143 |
Quick Conversions to Remember
- Grams to troy ounces: divide by 31.1035
- Troy ounces to grams: multiply by 31.1035
- Pennyweights to grams: multiply by 1.5552
- Grams to pennyweights: divide by 1.5552
- Tolas to grams: multiply by 11.6638
How to Weigh Gold at Home
Knowing the weight of your gold before visiting a dealer puts you in a stronger position. Here is how to get an accurate reading at home.
Kitchen Scales (Not Recommended)
- - Typically accurate to 1g or 2g only
- - A 2g error on a 10g gold ring could mean a 20% price difference
- - Fine for approximate estimates, not for selling
Digital Jeweller's Scales (Recommended)
- - Accurate to 0.01g or 0.1g
- - Available online from around GBP 10-20
- - Compact and easy to use
- - Often include a calibration weight
- 1.Calibrate first — use the included calibration weight or a coin of known weight
- 2.Flat, stable surface — avoid carpets, uneven tables, or areas with vibration
- 3.No draughts — air currents can affect sensitive scales
- 4.Clean items — remove dirt or debris that could add weight
- 5.Take multiple readings — weigh each item two or three times and use the average
- 6.Remove non-gold parts — gemstones, clasps, and non-gold attachments add weight but not gold value
Common Gold Item Weights
These typical weights can help you estimate your gold's value before weighing. Remember that actual weights vary significantly depending on size, design, and carat. Use our gold calculator with your item's exact weight for an accurate valuation.
| Item | Typical Weight | Notes |
|---|---|---|
| Thin wedding band | 2 - 4g | 9ct or 18ct, depends on width and size |
| Standard wedding ring | 4 - 8g | Wider bands and men's rings weigh more |
| Signet ring | 5 - 12g | Heavier due to solid head; 9ct most common |
| Light chain necklace | 5 - 15g | Thin curb or rope chains |
| Heavy chain necklace | 20 - 50g+ | Thick Cuban, belcher, or figaro chains |
| Bracelet (standard) | 8 - 30g | Link bracelets, bangles vary widely |
| Sovereign (full) | 7.98g | 22ct, 7.3224g fine gold content |
| Half sovereign | 3.99g | 22ct, 3.6612g fine gold content |
| Krugerrand (1oz) | 33.93g | 22ct, contains exactly 1 toz fine gold |
| Britannia (1oz) | 31.21g | 24ct (999.9 fine) since 2013 |
| Small gold bar (1g) | 1.00g | 24ct, common investment bar |
| Gold bar (1oz) | 31.10g | 24ct, standard bullion bar |
How Gold Dealers Weigh Gold
When you take gold to a verified dealer, here is what should happen during the weighing process.
- 1.Calibrated scales — dealers use professional scales certified to trading standards, typically accurate to 0.01g
- 2.Weighing in your presence — items should be weighed in front of you, on a visible display
- 3.Sorted by carat — items of different purities should be weighed and priced separately
- 4.Weight recorded — the dealer should provide a written breakdown showing weight and price per gram
- !Hidden scales — you cannot see the display or the weighing process
- !Quoting per “ounce” without specifying troy — they may be using the lighter avoirdupois ounce
- !Weighing all items together — different carats should always be separated
- !Refusing to show the weight — you have every right to see exactly what your gold weighs
- !No written breakdown — always get a written receipt showing individual weights and prices
Your Rights as a Seller
Under UK consumer protection law, you have the right to see your gold being weighed, to receive a clear explanation of the price offered, and to walk away without selling. A reputable dealer will always weigh gold in front of you and provide a transparent breakdown. Use our dealer directory to find verified gold buyers in your area.
Calculate Your Gold's Value
Once you know the weight of your gold, calculating its value is straightforward:
Gold Value = Weight (g) x Purity (%) x Spot Price per Gram
For example: 10g of 18ct gold at a spot price of GBP 65/g = 10 x 0.75 x GBP 65 = GBP 487.50
Step 1: Weigh your gold in grams using an accurate scale.
Step 2: Identify the carat (check the hallmark). The purity percentage is: 9ct = 37.5%, 14ct = 58.5%, 18ct = 75%, 22ct = 91.6%, 24ct = 99.9%.
Step 3: Check today's live gold price per gram.
Step 4: Multiply weight x purity x price per gram to get your gold's melt value.
Scrap Gold vs Spot Price
Dealers typically pay 70-90% of the spot gold price for scrap jewellery. This discount covers refining costs, overheads, and profit margin. Investment coins like Sovereigns and Krugerrands often trade closer to (or above) spot price due to their collectability and recognised standard weights.
Frequently Asked Questions
What is the difference between a troy ounce and a regular ounce?
A troy ounce weighs 31.1035 grams, while a regular (avoirdupois) ounce weighs 28.3495 grams. This means a troy ounce is approximately 10% heavier than a standard ounce. Gold is always traded in troy ounces, so this distinction is critical when buying or selling. If someone offers you a price “per ounce”, always confirm they mean troy ounces.
How many grams are in a troy ounce of gold?
One troy ounce of gold equals exactly 31.1035 grams. This is the standard unit used for trading gold worldwide, including on the London Bullion Market. When you see gold prices quoted in the news, they are always per troy ounce.
What is a pennyweight and how is it used for gold?
A pennyweight (abbreviated dwt) equals 1.55517 grams or 1/20th of a troy ounce. It is commonly used by jewellers in the UK and the United States to weigh gold jewellery. The abbreviation “dwt” comes from the Latin denarius weight, referring to the Roman penny. If a jeweller quotes you a price per pennyweight, multiply by 0.6430 to convert to a price per gram for easier comparison.
How can I accurately weigh gold at home?
Use a digital scale accurate to at least 0.1 grams (0.01g is better). Standard kitchen scales are generally not precise enough for gold. Calibrate your scale before use, weigh items on a flat surface away from draughts, and take multiple readings to confirm accuracy. Digital jeweller's scales can be purchased online for around GBP 10-20 and are well worth the investment if you are selling gold.
How much does a gold sovereign weigh?
A full gold sovereign weighs 7.98 grams (containing 7.3224 grams of pure gold at 22 carat / 916.7 fineness). A half sovereign weighs 3.99 grams. Sovereigns are one of the most popular gold coins in the UK and are exempt from Capital Gains Tax for UK residents. See our sovereign price page for today's values.
Ready to Value Your Gold?
Now you understand gold weight units, use our calculator to find out exactly what your gold is worth today
Related Guides
Learn how to read hallmarks, identify purity marks (375, 585, 750, 916, 999), and understand assay office symbols.
Read Guide →Understand gold purity, what the carat numbers mean, and how alloys affect colour, durability, and value.
Read Guide →Discover the value of popular gold coins including Sovereigns, Britannias, and Krugerrands with live prices.
Read Guide →Step-by-step guide to selling your gold jewellery for the best price, from preparation to payment.
Read Guide →Sources and References
Troy weight system information sourced from the London Bullion Market Association (LBMA).
Sovereign and coin specifications from the Royal Mint.
Trading standards and consumer rights information from Office for Product Safety and Standards.
Last updated: February 2026
Founder & Market Researcher
Taro has been actively investing in precious metals and financial markets for over 15 years. Frustrated by the lack of transparent, accurate gold pricing information in the UK, he built London Gold Exchange as a data-driven resource for fellow investors. The site combines real-time market data, verified dealer information from 242+ UK businesses, and insights drawn from years of hands-on experience in the gold market.
- ✓15+ years investing in precious metals & equities
- ✓Built verified database of 242+ UK gold dealers
- ✓Daily market data analysis and price tracking
Disclaimer: This guide provides general information about gold weight units and measurements. Actual gold values depend on current market prices, purity, and dealer margins. Always weigh gold on calibrated scales and obtain quotes from multiple dealers before selling. Information current as of February 2026.