Pennyweights to Metric Tons (dwt to t)

1 pennyweight equals 0.00000155517384 metric tons exactly.

1 pennyweight = 0.00000155517384 metric tons

How to convert pennyweights to metric tons

To convert pennyweights to metric tons, multiply the number of pennyweights by 0.00000155517384. This factor is exact. To go the other way, multiply metric tons by 643,014.9314 (rounded).

metric tons = pennyweights × 0.00000155517384

Example: 10 pennyweights = 0.0000155517384 metric tons.

About these units

Pennyweight (dwt)

Troy & apothecaries'Traditional unit (still used in some regions)

One twentieth of a troy ounce (1.5552 g), originally the weight of a silver penny. Still used by jewelers.

Silver pennies gave this unit its name. In the Middle Ages an English penny weighed one twentieth of an ounce and one 240th of a pound of sterling silver, so its weight and its face value agreed. The abbreviation dwt keeps the d from denarius, the Roman coin that stood behind the old British penny.

The size changed over time. Under the medieval Tower pound a pennyweight was 32 Tower grains. When troy weights replaced Tower weights in 1527, it became 24 troy grains, which is exactly 1.55517384 grams.

Twenty pennyweights make a troy ounce, and 240 make a troy pound. Jewellers still use it to work out the precious metal content of jewellery, and dental labs have used it for gold in crowns and inlays. In parts of England, gooseberry growers also record prize fruit in pennyweights and grains.

1 pennyweight = 0.00155517384 kilograms (exactly).

Sources: Wikipedia: Pennyweight; Wikipedia: Troy weight; NIST SP 811, Appendix B.8

Metric Ton (t)

Metric (SI)Current unit

1,000 kilograms (about 2,204.6 lb), also spelled tonne. Used for cargo, grain and vehicle weights outside the US.

Barrels gave the tonne its name. The word goes back to a Germanic root for a large cask, the tun, and a full tun could easily weigh around a tonne. In English this became ton; the spelling tonne has been used in France since 1842, where it replaced the older tonneau, and pre-metric French tonnes were 2,000 livres, about 979 kg. Once the metric system took hold, the tonne was fixed at 1,000 kilograms, which is the mass of roughly a cubic metre of water.

The unit is accepted for use with the SI, and its symbol is a lowercase t with no period. Because it sits close to the old English ton, the two get confused: the short ton used in the US is about 10 percent lighter than a tonne, while the long ton differs by less than 2 percent. NIST calls the unit the metric ton, and the spelling tonne is rare in the US. Very large quantities are stated in prefixed forms such as the megatonne, which equals a teragram. In explosives, a tonne of TNT is taken as about 4.2 gigajoules.

1 metric ton = 1,000 kilograms (exactly).

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

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