Convert Grain to Wey
Convert grains to weys instantly. 1 grain = 5.668933e-7 wey — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Wey to Grain converter for the reverse conversion.
Units explained
Grain
The grain (gr) equals 1/7000 of an avoirdupois pound, about 64.8 milligrams.
Based on the nominal mass of a single barley grain.
Ammunition and bullet mass, archery, and historical pharmacy.
Standardized through the English avoirdupois system and retained in 1959.
Wey
The wey was an English bulk weight, here taken as 252 pounds (about 114.3 kg).
From Old English 'waege', a weighing or balance.
Obsolete English unit for wool, cheese, and salt.
Used in medieval and early-modern English trade.
Grain to Wey conversion formula
Note: this conversion uses a generally accepted modern value. Historical and regional definitions of this unit varied across times and places.
The relationship between grains and weys:
To convert grains to weys, multiply the value in grains by 5.668933e-7. To reverse, multiply weys by 1764000.2722268435.
How to use this converter
Type a value into the calculator. The result in weys updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Wey to Grain converter for the reverse direction.
Step-by-step: convert grains to weys
- Write down the value in grains (gr).
- Multiply that value by the factor 5.668933e-7.
- The product is the equivalent value in weys (wey).
- To reverse, multiply the wey value by 1764000.2722268435.
Worked examples
Example 1 — Convert 1 gr to wey:
1 × 5.668933e-7 = 5.668933e-7 wey
Example 2 — Convert 100 gr to wey:
100 × 5.668933e-7 = 5.668933e-5 wey
Real-world example — Plastic-film thickness alternates
A 150-grain plastic film converts cleanly to weys — useful for packaging buyers reconciling supplier datasheets across metric and US measurement systems.
150 gr × 5.668933e-7 = 8.5034e-5 wey
Real-world example — Hair-width scale measurements
A 70-grain measurement (about the diameter of a human hair) is the kind of value materials engineers regularly express in adjacent micro-scale units like weys for direct comparison across supplier datasheets.
70 gr × 5.668933e-7 = 3.968253e-5 wey
Real-world example — Paper and film thicknesses
At the thickness of office paper (roughly 3 grains), converting between sub-millimeter units is routine for packaging and printing buyers comparing quotes from metric and US suppliers.
3 gr × 5.668933e-7 = 1.70068e-6 wey
Grain to Wey conversion table
Standard reference values for converting grains to weys:
| Grain [gr] | Wey [wey] |
|---|---|
| 0.01 | 5.668933e-9 |
| 0.1 | 5.668933e-8 |
| 1 | 5.668933e-7 |
| 2 | 1.133787e-6 |
| 3 | 1.70068e-6 |
| 4 | 2.267573e-6 |
| 5 | 2.834467e-6 |
| 10 | 5.668933e-6 |
| 20 | 1.133787e-5 |
| 30 | 1.70068e-5 |
| 40 | 2.267573e-5 |
| 50 | 2.834467e-5 |
| 100 | 5.668933e-5 |
| 500 | 0.0002834467 |
| 1000 | 0.0005668933 |
Frequently asked questions
How many weys is 1 grain?
How do I convert grains to weys?
How do I convert weys back to grains?
How many weys is 100 grains?
Popular weight unit conversions
Convert Grain to other weight units
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Metric / SI (18 units)
Avoirdupois (14 units)
Troy & Apothecary (10 units)
Indian / South Asian (6 units)
Scientific / Atomic (9 units)
Astronomical (4 units)
Biblical / Ancient (14 units)
Sources & references
Conversion factor (1 gr = 5.668933e-7 wey) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Astronomical Union — System of Astronomical Constants
The IAU defines astronomical units including the AU (149597870700 m exactly) light-year and parsec used in astronomy and astrophysics.