Troy Ounces to Long Tons (oz t to ton (UK))

1 troy ounce equals 0.0000306122449 long tons (rounded).

1 troy ounce = 0.0000306122449 long tons

How to convert troy ounces to long tons

To convert troy ounces to long tons, multiply the number of troy ounces by 0.0000306122449. The factor is rounded to 10 significant digits. To go the other way, multiply long tons by 32,666.66667 (rounded).

long tons = troy ounces × 0.0000306122449

Example: 10 troy ounces = 0.000306122449 long tons.

About these units

Troy Ounce (oz t)

Troy & apothecaries'Current unit

Exactly 31.1034768 g (480 grains). The standard unit for precious metals; gold and silver prices are quoted per troy ounce.

Nobody is certain where troy weight got its name. The usual explanation is the fairs of Troyes in France, where English merchants traded by the early 9th century, and the word troy appears in English in 1390. An alternative theory ties it to a word for weighing by balance, though it is unsourced. Troy weights were first used in England in the 15th century and made official for gold and silver in 1527. The British Imperial troy ounce was adopted in 1824 and became the basis for US coinage through an act of Congress in 1828.

The troy ounce is exactly 31.1034768 g, or 480 grains, about 9.7 percent heavier than the ordinary avoirdupois ounce. A troy pound has only 12 ounces and is lighter than the avoirdupois pound, a mismatch that catches many first-time bullion buyers. Troy ounces remain the standard in precious-metal markets, even in countries that otherwise use SI, so gold, silver and platinum prices are all quoted per troy ounce. In the UK it is the only troy unit still permitted in trade, and only for precious metals.

1 troy ounce = 0.0311034768 kilograms (exactly).

Sources: Wikipedia: Troy ounce; Wikipedia: Ounce; NIST Guide to the SI, Appendix B.8 (mass conversions)

Long Ton (ton (UK))

Imperial (British)Current unit

2,240 pounds (1,016.05 kg), the imperial or UK ton. Also used for ship displacement.

Before the 15th century an English ton was 2,160 pounds, twenty hundredweight of 108 pounds. Nineteenth-century British definitions included 2,240, 2,352 and 2,400 pounds, though the legal ton was usually 2,240 lb, which is twenty hundredweight of 112 lb. Industry bent the rules: in the 17th and 18th century iron trade, workers were given a 2,240 lb ton of raw material but were expected to return a 2,400 lb ton of processed iron, allowing for waste, and some coal mines delivered long tons but paid miners for a shorter one, which the miners saw as unfair.

The long ton, about 1,016 kg, is within 2 percent of the metric tonne, which makes the two easy to mistake for each other. It is used in the UK, Ireland and most Commonwealth countries that followed the imperial system, although the tonne is now the legal trade unit in the UK, Canada and Australia. Ship displacement has traditionally been quoted in long tons, because a ship cannot be put on a scale and is instead measured by the weight of water it pushes aside. The 2,240 lb figure became the standard for ship design.

1 long ton = 1,016.046909 kilograms (approximately).

Sources: Wikipedia: Ton; NIST Guide to the SI, Appendix B.8 (mass conversions)

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