Convert Grain to US Ton (gr → ton (US))

Converting grains to US tons is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.

1. 1
   Take your value in grains

   Start with the number of grains (gr) you want to convert.
2. 2
   Multiply by 7.143 × 10^-8

   The conversion factor from gr to ton (US) is 7.143 × 10^-8. Multiply your value by this number.
3. 3
   Read the result in US tons

   The result is your value in US tons (ton (US)).

Multiply the value in grains by 7.143 × 10^-8. For the reverse direction, multiply by 14,000,000.

• ✓1 grain = 64.79891 mg exactly. 7000 grains = 1 pound.
• ✓Ballistics is one of the few modern contexts where grains are essential.
• ✓Some older pharmacology dosing survives in grain units — 5 gr ≈ 325 mg.

• ✗Confusing the grain (mass) with the troy grain in older precious-metal contexts — they are identical (64.8 mg).
• ✗Assuming "grain" refers to an amount of cereal — in firearms it is always a weight.
• ✗Reading "5 gr" as 5 grams — it is 5 grains (324 mg).

What is the Grain?

The grain equals exactly 64.79891 milligrams (0.06479891 g) and is the smallest unit in the traditional avoirdupois weight system. Originally based on the average mass of a single grain of wheat or barley, the unit was standardized to its current value with the 1959 international yard and pound agreement. The grain is still used in pharmaceutical compounding (some older drug formulations specify grains, especially aspirin and codeine), arrow tips and ammunition (bullet weights are commonly given in grains — a 9 mm bullet is around 115 grains), and precious-metal weighing (one troy ounce = 480 grains). It relates to the ounce (437.5 grains = 1 oz avoirdupois), the pound (7,000 grains = 1 lb), and the milligram (1 grain ≈ 64.8 mg). The unit reflects medieval agriculture's role in shaping early measurement systems.

• Bullet and gunpowder mass in ballistics
• Older pharmaceutical dosing in Anglo-Saxon countries
• Arrow shaft and archery equipment weights

What is the US Ton?

The US short ton equals exactly 2,000 pounds or 907.18474 kilograms, and is the standard weight unit for American freight, mining, construction, and waste management. Its name distinguishes it from the longer UK long ton (2,240 lb). The short ton emerged in the United States during the 19th century to simplify calculations: 2,000 is a rounder number than 2,240. Today it dominates American industry — coal mining quotes production in short tons, dump trucks are rated by short-ton capacity, and the EPA tracks emissions in short tons. Imperial-to-metric confusion can be costly: in 1999, the Mars Climate Orbiter spacecraft was lost partly due to a units mismatch involving pounds and newtons. The short ton relates to the pound (2,000 lb = 1 ton), the metric ton (1 short ton ≈ 0.907 t), and the long ton (1 long ton = 1.12 short tons).

• US freight and trucking weight limits
• US coal and mining production
• US shipbuilding and heavy industry