Understanding Troy Ounces to Grains Conversion
The troy ounce (ozt) is the precious-metals mass unit of about 31.10 grams, and the grain (gr) is the smallest traditional unit in the troy and apothecaries systems, equal to 64.79891 milligrams. By definition one troy ounce contains exactly 480 grains, so this is an exact conversion. Grains remain common in ammunition (bullet and powder weights) and in historic coinage specifications.
Conversion Formula
To convert Troy Ounces to Grains, multiply by this factor:
Step-by-Step Example
Convert 25 Troy Ounces to Grains.
How to Convert Troy Ounces to Grains
The troy ounce is defined as exactly 480 grains, making this conversion precise.
- Identify the input: Take the troy-ounce value you want to convert (ozt).
- Multiply by the factor: Multiply by 480, the exact number of grains in one troy ounce.
- Read the result: The product is the mass in grains (gr).
- Worked example: For 25 troy ounces: 25 x 480 = 12000 gr.
Troy Ounces to Grains conversion table
| Troy Ounces (ozt) | Grains (gr) |
|---|---|
| 0 | 0 |
| 1 | 480 |
| 2 | 960 |
| 3 | 1440 |
| 4 | 1920 |
| 5 | 2400 |
| 6 | 2880 |
| 7 | 3360 |
| 8 | 3840 |
| 9 | 4320 |
| 10 | 4800 |
| 15 | 7200 |
| 20 | 9600 |
| 25 | 12000 |
| 30 | 14400 |
| 40 | 19200 |
| 50 | 24000 |
| 60 | 28800 |
| 70 | 33600 |
| 80 | 38400 |
| 90 | 43200 |
| 100 | 48000 |
| 150 | 72000 |
| 200 | 96000 |
| 250 | 120000 |
| 300 | 144000 |
| 400 | 192000 |
| 500 | 240000 |
| 600 | 288000 |
| 700 | 336000 |
| 800 | 384000 |
| 900 | 432000 |
| 1000 | 480000 |
| 2000 | 960000 |
| 3000 | 1440000 |
| 4000 | 1920000 |
| 5000 | 2400000 |
| 10000 | 4800000 |
| 25000 | 12000000 |
| 50000 | 24000000 |
| 100000 | 48000000 |
| 250000 | 120000000 |
| 500000 | 240000000 |
| 1000000 | 480000000 |
What is the Troy Ounce?
The troy ounce is a unit of mass used almost exclusively for precious metals such as gold, silver, platinum, and palladium. It is the standard weight quoted on global bullion markets.
Definition
The troy ounce is defined as exactly 480 grains, which equals 31.1034768 grams:
By definition, 1 troy ounce = 480 grains = 31.1034768 g exactly, and 12 troy ounces make one troy pound (≈373.242 g). Note that the troy ounce is heavier than the more familiar avoirdupois ounce (≈28.3495 g).
Origin and History
The troy system takes its name from the French market town of Troyes, a major medieval trading hub. It descends from the Roman monetary system and was standardized in England for coinage and precious metals, later adopted across Europe and the English-speaking world.
Law and Notable Facts
The troy ounce remains the legal basis for bullion trading and coinage weights; in the United States it is codified for precious-metal transactions. A curious consequence is that a pound of gold (troy, ~373 g) actually weighs less than a pound of feathers (avoirdupois, ~454 g).
Real-World Examples and Conversions
A standard Good Delivery gold bar weighs about 400 troy ounces (≈12.4 kg). A 1 oz American Gold Eagle contains one troy ounce (31.1 g) of gold. When gold is quoted at "$2,000 per ounce," that means per troy ounce, not the avoirdupois ounce.
What is the Grain?
The grain is a small unit of mass in the avoirdupois, troy, and apothecaries' systems. Today it is used mainly for bullets, gunpowder, arrows, and some medications.
Definition
The grain is defined as exactly 1/7000 of an avoirdupois pound:
Precisely, 1 grain = 64.79891 mg exactly. There are 7000 grains in an avoirdupois pound and 480 grains in a troy ounce, making the grain the common link between the troy, avoirdupois, and apothecaries' systems.
Origin and History
The grain originally referred to the mass of a single seed of a cereal grain such as wheat or barley. It is one of the oldest units of mass in the English-speaking world and long served as the base unit from which pounds and ounces were built.
Law and Notable Facts
The grain is the only mass unit shared identically across the troy, avoirdupois, and apothecaries' systems. In firearms, ammunition is still specified in grains—for both projectile mass and powder charge.
Real-World Examples and Conversions
A common 9mm bullet weighs about 115 grains (≈7.45 g). A standard aspirin tablet of 325 mg is roughly 5 grains. One gram equals about 15.43 grains.
Frequently Asked Questions
How many grains are in a troy ounce?
Exactly 480 grains, since the troy ounce is defined as 480 grains by convention.
Is this conversion exact?
Yes. Both units share the grain as their base, so 1 ozt = 480 gr with no rounding.
How do I convert grains back to troy ounces?
Divide by 480, or multiply by 0.002083333. So 240 gr equals 0.5 troy ounces.
Why do reloaders care about grains?
Bullet and powder charges are specified in grains; knowing a bullet weighs, say, 240 gr shows it is exactly half a troy ounce.
People also convert
Complete Troy Ounces conversion table
| Unit | Result |
|---|---|
| Micrograms (mcg) | 31103480 mcg |
| Milligrams (mg) | 31103.48 mg |
| Grams (g) | 31.10348 g |
| Kilograms (kg) | 0.03110348 kg |
| Metric Tonnes (mt) | 0.00003110348 mt |
| Carats (ct) | 155.5174 ct |
| Ounces (oz) | 1.097143 oz |
| Pounds (lb) | 0.06857143 lb |
| Stones (st) | 0.004897959 st |
| Tons (t) | 0.00003428571 t |
| Long Tons (long-ton) | 0.00003061224 long-ton |
| Grains (gr) | 480 gr |
| US Hundredweights (cwt-us) | 0.0006857143 cwt-us |
| UK Hundredweights (cwt-uk) | 0.0006122449 cwt-uk |
| Slugs (slug) | 0.002131265 slug |