Convert Grain to UK Ton (grton (UK))

The grain is the smallest traditional weight unit, used in pharmaceutical compounding, ammunition, and arrow tips.

6.378 × 10^-8
1 gr6.378 × 10^-8 ton (UK)NIST · BIPM accuracy

Grain to UK Ton Conversion Table

10 common values
GrainUK Ton
1 gr6.378 × 10^-8 ton (UK)
5 gr3.189e-7 ton (UK)
10 gr6.378e-7 ton (UK)
25 gr0.000001594 ton (UK)
50 gr0.000003189 ton (UK)
100 gr0.000006378 ton (UK)
250 gr0.00001594 ton (UK)
500 gr0.00003189 ton (UK)
1,000 gr0.00006378 ton (UK)
5,000 gr0.000319 ton (UK)

How to Convert Grain to UK Ton Manually

Step by Step

Converting grains to UK 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 6.378 × 10^-8
    The conversion factor from gr to ton (UK) is 6.378 × 10^-8. Multiply your value by this number.
  3. 3
    Read the result in UK tons
    The result is your value in UK tons (ton (UK)).
Practical Examples
1 gr
equals
6.378 × 10^-8 ton (UK)
5 gr
equals
3.189e-7 ton (UK)
10 gr
equals
6.378e-7 ton (UK)
25 gr
equals
0.000001594 ton (UK)
100 gr
equals
0.000006378 ton (UK)

Formula

Multiply the value in grains by 6.378 × 10^-8. For the reverse direction, multiply by 15,680,000.

Forwardton (UK) = gr × 6.378 × 10^-8
Reversegr = ton (UK) × 15,680,000
Example: 10 gr × 6.378 × 10^-8 = 6.378e-7 ton (UK)

Tips

Use these in everyday conversions
  • 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.

Common Mistakes

Avoid these
  • 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).

About Grain and UK Ton

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
Real-world examples

A 9 mm bullet typically weighs 115–124 grains (7.45–8.03 g). Aspirin grain dosing: "5 grain aspirin" = 325 mg.

What is the UK Ton?

The UK long ton equals exactly 2,240 pounds or 1,016.0469088 kilograms, and was historically the standard weight unit in the British Empire and remains in use in shipping, mining, and engineering throughout the United Kingdom and Commonwealth countries. The long ton is closer in size to the metric ton (only 1.6% lighter), which is why it has resisted complete replacement. Shipping displacement, especially of older and military vessels, is often quoted in long tons (the British Royal Navy historically used long tons for ship tonnage). It relates to the hundredweight (20 cwt = 1 long ton), the pound (2,240 lb = 1 long ton), and the metric ton (1 long ton ≈ 1.016 t). The long ton's name reflects its larger size compared to the US short ton (2,000 lb).

  • Older UK shipping and commodity contracts
  • British naval displacement tonnage (ships)
  • Historical coal and steel production data
Real-world examples

Pre-1971 British ship displacements were given in long tons. UK steel output before EU harmonisation used long tons.

Learn About Both Units

⚖️ Reference

What is the Grain?

Read the unit page →
⚖️ Reference

What is the UK Ton?

Read the unit page →

Grain to UK Ton FAQ

5 questions
How many UK tons in a grain?
One grain equals 6.378 × 10^-8 UK tons.
How do I convert grains to UK tons?
Multiply the grain value by 6.378 × 10^-8 to get the equivalent in UK tons.
What is 100 grains in UK tons?
100 grains equals 0.000006378 UK tons.
Is a grain bigger than a uk ton?
No. 1 grain equals 6.378 × 10^-8 UK tons, so one grain is smaller.
How to convert grains to UK tons without a calculator?
Multiply by 0 for a quick estimate; use a calculator for precise results.

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