The Definitive Guide to Troy Ounce to Kilogram (troy oz to kg) Conversion
Converting troy ounces (oz t / ozt) to kilograms (kg) is an indispensable mathematical calculation in institutional bullion banking, central bank sovereign gold reserve accounting, London Bullion Market Association (LBMA) vault logistics, COMEX/NYMEX precious metals futures delivery settlement, and precious metals refinery refining. Under the 1959 International Yard and Pound Agreement codified by the National Institute of Standards and Technology (NIST), one international troy ounce is defined as exactly 31.1034768 grams ($0.0311034768\text{ kg}$). Because one kilogram contains exactly 32.1507465686 troy ounces, converting between spot market troy ounce quotations and physical refinery kilogram scale weights requires exact mathematical precision.
At ConverterGuru, our calculation engine operates 100% locally in your browser with zero latency. You can explore our Weight Converter Hub for multi-unit mass calculations, check our Troy Ounce to Gram Tool for jewelry scale readouts, or visit our Length Converter for vault ingot dimensions. This comprehensive guide covers exact legal metrology definitions, LBMA Good Delivery bar specifications, COMEX contract settlement rules, and central bank sovereign reserve math.
Understanding the 0.0311034768-Kilogram Troy Ounce Metrological Standard
Under international legal metrology, the troy ounce is defined as 480 grains, which equals exactly 31.1034768 grams or 0.0311034768 kilograms:
Reverse Formula: Troy Ounces = Kilograms × 32.1507466 (e.g. 1.00 kg × 32.1507466 = 32.1507 oz t)
The "Multiply by 31.1, Then Divide by 1,000" Mental Shortcut
Because 1 troy ounce is approx. 31.1 grams, multiply your troy ounce number by 31.1, then divide by 1,000 for kilograms:
- 1 oz t: 1 × 31.1035 ÷ 1,000 = 0.0311 kg (31.10 g)
- 10 oz t: 10 × 31.1035 ÷ 1,000 = 0.3110 kg (311.03 g)
- 32.15 oz t: 32.1507 × 31.1035 ÷ 1,000 = 1.0000 kg (1 Kilo bar)
- 100 oz t: 100 × 31.1035 ÷ 1,000 = 3.1103 kg (COMEX gold bar)
- 400 oz t: 400 × 31.1035 ÷ 1,000 = 12.4414 kg (LBMA Good Delivery bar)
Troy Ounces to Kilograms Quick-Lookup Reference Tables
Use these verified reference charts for instant lookups across physical bullion coin weights, commercial cast bars, and institutional gold delivery vaults:
Standard Troy Ounce to Kilogram Reference Lookup Table
| Troy Ounces (oz t) | Kilograms (kg) | Grams (g) | Avoirdupois Pounds (lbs) | Bullion & Vault Benchmark |
|---|---|---|---|---|
| 1.00 oz t | 0.0311 kg | 31.10 g | 0.0686 lbs | 1 oz American Gold Eagle / Maple Leaf bullion coin |
| 5.00 oz t | 0.1555 kg | 155.52 g | 0.3429 lbs | 5 oz poured gold / silver collector bar |
| 10.00 oz t | 0.3110 kg | 311.03 g | 0.6857 lbs | 10 oz minted investment silver bar |
| 32.15 oz t | 1.0000 kg | 1,000.00 g | 2.2046 lbs | Standard 1 Kilogram fine gold investment bar |
| 50.00 oz t | 1.5552 kg | 1,555.17 g | 3.4286 lbs | 50 oz silver ingot / foundry cast |
| 100.00 oz t | 3.1103 kg | 3,110.35 g | 6.8571 lbs | COMEX standard gold futures deliverable bar |
| 400.00 oz t | 12.4414 kg | 12,441.39 g | 27.4286 lbs | LBMA standard Good Delivery gold vault bar |
| 1,000.00 oz t | 31.1035 kg | 31,103.48 g | 68.5714 lbs | LBMA / COMEX institutional silver vault bar |
LBMA & COMEX Standard Precious Metal Bar Matrix
| Market Contract / Bar Type | Nominal Weight (Troy Oz) | Metric Mass (Kilograms) | Minimum Purity (Fineness) |
|---|---|---|---|
| 1 Kilo Gold Bullion Bar | 32.1507 oz t | 1.0000 kg | 99.99% (999.9 fine) |
| COMEX Gold Contract Bar | 100.000 oz t | 3.1103 kg | 99.50% (995.0 fine) |
| LBMA Good Delivery Gold Bar | 350 oz t to 430 oz t (nominal 400 oz t) | 10.88 kg to 13.37 kg (nominal 12.44 kg) | 99.50% (995.0 fine) |
| LBMA Good Delivery Silver Bar | 750 oz t to 1,100 oz t (nominal 1,000 oz t) | 23.33 kg to 34.21 kg (nominal 31.10 kg) | 99.90% (999.0 fine) |
| NYMEX Platinum Contract Bar | 50.000 oz t | 1.5552 kg | 99.95% (999.5 fine) |
Troy vs Avoirdupois System Comparison in Kilograms
| Unit Name | Mass in Grams (g) | Mass in Kilograms (kg) | Ounces per Kilogram | Primary Global Application |
|---|---|---|---|---|
| Avoirdupois Ounce (oz) | 28.3495 g | 0.02835 kg | 35.2740 oz/kg | Food, postal freight, and industrial base metals (copper) |
| Troy Ounce (oz t) | 31.1035 g | 0.03110 kg | 32.1507 oz t/kg | Gold, silver, platinum, and palladium spot trading |
Cross-Industry Applications and Practical Scenarios
LBMA Good Delivery Gold Bar Vault Operations
Under LBMA Good Delivery Rules, institutional central bank vault bars are traded with a nominal weight of 400 troy ounces. When commercial security carriers transport physical gold pallets, vault managers multiply the certified gross weight of each bar in troy ounces by 0.0311034768 to calculate total pallet kilogram payload limits.
COMEX Futures Contract Physical Settlement
Under CME Group COMEX Gold Futures Rules, one gold contract represents 100 troy ounces of 0.995 fine gold. When physical delivery warrants are issued, refinery scales confirm that the delivered bar contains at least 3.1103 kg of gross weight multiplied by certified millesimal fineness.
Central Bank Sovereign Gold Reserve Accounting
Under World Gold Council (WGC) reporting standards, national central banks report sovereign gold reserves interchangeably in metric tonnes and millions of fine troy ounces. Converting 1 metric tonne (1,000 kg) yields exactly 32,150.75 fine troy ounces.
Frequently Asked Questions About Troy Ounces and Kilograms
How many kilograms are in 1 troy ounce?
There are exactly 0.0311034768 kilograms in 1 troy ounce (1 oz t = 31.1034768 grams = 0.0311035 kg).
How many troy ounces are in a 1 kilogram gold bar?
There are exactly 32.1507465686 troy ounces in a 1 kilogram (1,000 g) gold bar.
How heavy is a 400 oz LBMA Good Delivery gold bar in kilograms?
A standard 400 troy ounce LBMA Good Delivery gold bar weighs approximately 12.4414 kilograms (about 27.43 avoirdupois pounds).
How do you convert troy ounces to kilograms manually?
Multiply the troy ounce value by 0.0311034768 (or multiply by 31.1035 to get grams, then divide by 1,000). For example, 100 oz t × 0.0311034768 = 3.11035 kg.
What is the difference between a troy ounce and a regular ounce in kg?
A troy ounce weighs 0.0311035 kg (31.1035 g), while a regular avoirdupois ounce weighs 0.0283495 kg (28.3495 g). A troy ounce is approx. 9.71% heavier than a regular ounce.
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