Convert Grain to Exagram
Convert grains to exagrams instantly. 1 grain = 6.47989e-20 exagram — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Exagram 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.
Exagram
An exagram (Eg) equals 10^15 kilograms, or one quintillion grams.
From the SI prefix 'exa-' (from Greek 'hex', six, denoting the sixth power of 1000).
Confined to planetary- and atmospheric-scale mass discussions; never used in daily measurement.
The exa- prefix was adopted by the General Conference on Weights and Measures (CGPM) in 1975.
Grain to Exagram conversion formula
The relationship between grains and exagrams:
To convert grains to exagrams, multiply the value in grains by 6.47989e-20. To reverse, multiply exagrams by 1.543236e+19.
How to use this converter
Type a value into the calculator. The result in exagrams updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Exagram to Grain converter for the reverse direction.
Step-by-step: convert grains to exagrams
- Write down the value in grains (gr).
- Multiply that value by the factor 6.47989e-20.
- The product is the equivalent value in exagrams (Eg).
- To reverse, multiply the exagram value by 1.543236e+19.
Worked examples
Example 1 — Convert 1 gr to Eg:
1 × 6.47989e-20 = 6.47989e-20 Eg
Example 2 — Convert 100 gr to Eg:
100 × 6.47989e-20 = 6.47989e-18 Eg
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 exagrams for direct comparison across supplier datasheets.
70 gr × 6.47989e-20 = 4.535923e-18 Eg
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 × 6.47989e-20 = 1.943967e-19 Eg
Real-world example — Plastic-film thickness alternates
A 150-grain plastic film converts cleanly to exagrams — useful for packaging buyers reconciling supplier datasheets across metric and US measurement systems.
150 gr × 6.47989e-20 = 9.719835e-18 Eg
Grain to Exagram conversion table
Standard reference values for converting grains to exagrams:
| Grain [gr] | Exagram [Eg] |
|---|---|
| 0.01 | 6.47989e-22 |
| 0.1 | 6.47989e-21 |
| 1 | 6.47989e-20 |
| 2 | 1.295978e-19 |
| 3 | 1.943967e-19 |
| 4 | 2.591956e-19 |
| 5 | 3.239945e-19 |
| 10 | 6.47989e-19 |
| 20 | 1.295978e-18 |
| 30 | 1.943967e-18 |
| 40 | 2.591956e-18 |
| 50 | 3.239945e-18 |
| 100 | 6.47989e-18 |
| 500 | 3.239945e-17 |
| 1000 | 6.47989e-17 |
Frequently asked questions
How many exagrams is 1 grain?
How do I convert grains to exagrams?
How do I convert exagrams back to grains?
How many exagrams is 100 grains?
Popular weight unit conversions
Convert Grain to other weight units
Show all Grain conversions
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 = 6.47989e-20 Eg) 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.