Mass and Weight · Unit Converter

Convert Grain to Attogram

Convert grains to attograms instantly. 1 grain = 6.47989e+16 attogram — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Attogram to Grain converter for the reverse conversion.

Written by Sunith Babu L, Ph.D., Lead Engineer Reviewed by Dr. Ashok Kumar K, Ph.D.
Mass and Weight category 2 min read Published Last reviewed Updated

Units explained

Avoirdupois

Grain

What is a grain?

The grain (gr) equals 1/7000 of an avoirdupois pound, about 64.8 milligrams.

Origin of the grain

Based on the nominal mass of a single barley grain.

Where it is used

Ammunition and bullet mass, archery, and historical pharmacy.

When and where it was developed

Standardized through the English avoirdupois system and retained in 1959.

Metric / SI

Attogram

What is a attogram?

An attogram (ag) equals 10^-21 kilogram.

Origin of the attogram

From the SI prefix 'atto-' (from Danish 'atten', eighteen).

Where it is used

Frontier nanoscience and single-molecule mass detection.

When and where it was developed

The atto- prefix was adopted by the CGPM in 1975.

Grain to Attogram conversion formula

The relationship between grains and attograms:

1 gr = 6.47989e+16 ag
1 ag = 1.543236e-17 gr

To convert grains to attograms, multiply the value in grains by 6.47989e+16. To reverse, multiply attograms by 1.543236e-17.

How to use this converter

Type a value into the calculator. The result in attograms updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Attogram to Grain converter for the reverse direction.

Step-by-step: convert grains to attograms

  1. Write down the value in grains (gr).
  2. Multiply that value by the factor 6.47989e+16.
  3. The product is the equivalent value in attograms (ag).
  4. To reverse, multiply the attogram value by 1.543236e-17.

Worked examples

Example 1 — Convert 1 gr to ag:
1 × 6.47989e+16 = 6.47989e+16 ag

Example 2 — Convert 100 gr to ag:
100 × 6.47989e+16 = 6.47989e+18 ag

Real-world example — From microns to sub-micron features

One grain equals one thousand attograms — the conversion semiconductor designers do constantly when comparing mask feature dimensions to actual transistor gate lengths.

1 gr × 6.47989e+16 = 6.47989e+16 ag

Real-world example — Infrared to visible-spectrum mapping

A 10-grain thermal infrared wavelength corresponds to a much larger number in attograms, the unit favoured for ultraviolet and visible-light specifications.

10 gr × 6.47989e+16 = 6.47989e+17 ag

Real-world example — Mid-micron to nanometer

3 grains equals 3,000 attograms — useful when relating mid-infrared wavelengths (typically quoted in microns) to nanometer-scale visible-light wavelength tables.

3 gr × 6.47989e+16 = 1.943967e+17 ag

Grain to Attogram conversion table

Standard reference values for converting grains to attograms:

Grain [gr]Attogram [ag]
0.016.47989e+14
0.16.47989e+15
16.47989e+16
21.295978e+17
31.943967e+17
42.591956e+17
53.239945e+17
106.47989e+17
201.295978e+18
301.943967e+18
402.591956e+18
503.239945e+18
1006.47989e+18
5003.239945e+19
10006.47989e+19

Frequently asked questions

How many attograms is 1 grain?
1 grain equals 6.47989e+16 attogram.
How do I convert grains to attograms?
Multiply the value in grains by 6.47989e+16 to get attograms.
How do I convert attograms back to grains?
Multiply the value in attograms by 1.543236e-17, or use the Attogram to Grain converter.
How many attograms is 100 grains?
100 grains equals 6.47989e+18 attograms, because 100 × 6.47989e+16 = 6.47989e+18.

Convert Grain to other weight units

Show all Grain conversions
Metric / SI (18 units)
Grain to Attogram (ag) Grain to Femtogram (fg) Grain to Picogram (pg) Grain to Nanogram (ng) Grain to Microgram (µg) Grain to Milligram (mg) Grain to Centigram (cg) Grain to Decigram (dg) Grain to Gram (g) Grain to Dekagram (dag) Grain to Hectogram (hg) Grain to Kilogram (kg) Grain to Quintal (metric) (q) Grain to Metric Ton (t) Grain to Gigagram (Gg) Grain to Teragram (Tg) Grain to Petagram (Pg) Grain to Exagram (Eg)
Avoirdupois (14 units)
Grain to Dram (avoirdupois) (dr) Grain to Ounce (oz) Grain to Pound (lb) Grain to Clove (clove) Grain to Stone (US) (st) Grain to Stone (UK) (st) Grain to Quarter (US) (qr) Grain to Quarter (UK) (qr) Grain to Hundredweight (US) (cwt) Grain to Hundredweight (UK) (cwt) Grain to Wey (wey) Grain to Kilopound (kip) (kip) Grain to Ton (short, US) (sh tn) Grain to Ton (long, UK) (long tn)
Troy & Apothecary (10 units)
Grain to Point (1/100 carat) (pt) Grain to Carat (metric) (ct) Grain to Scruple (apothecary) (s ap) Grain to Pennyweight (dwt) Grain to Momme (mom) Grain to Mace (mace) Grain to Dram (apothecary/troy) (dr ap) Grain to Troy Ounce (oz t) Grain to Tael (tael) Grain to Pound (troy/apothecary) (lb t)
Indian / South Asian (6 units)
Grain to Ratti (ratti) Grain to Masha (masha) Grain to Tola (tola) Grain to Chittack (Chatank) (chittack) Grain to Seer (Ser) (seer) Grain to Maund (Mann) (maund)
Scientific / Atomic (9 units)
Grain to Electron Mass (rest) (me) Grain to MeV/c2 (MeV/c²) Grain to Muon Mass (mµ) Grain to Atomic Mass Unit (u) Grain to Proton Mass (mp) Grain to Neutron Mass (mn) Grain to Deuteron Mass (md) Grain to Carbon-12 Atom Mass (C-12) Grain to Planck Mass (mP)
Astronomical (4 units)
Grain to Lunar Mass (Moon) (M☾) Grain to Earth's Mass (M⊕) Grain to Jupiter Mass (MJ) Grain to Sun's Mass (M☉)
Biblical / Ancient (14 units)
Grain to Lepton (Biblical Roman) (lepton) Grain to Quadrans (Biblical Roman) (quadrans) Grain to Assarion (Biblical Roman) (assarion) Grain to Gerah (Biblical Hebrew) (gerah) Grain to Drachma (Biblical Greek) (drachma) Grain to Denarius (Biblical Roman) (denarius) Grain to Bekan (Biblical Hebrew) (bekah) Grain to Didrachma (Biblical Greek) (didrachma) Grain to Shekel (Biblical Hebrew) (shekel) Grain to Tetradrachma (Biblical Greek) (tetra) Grain to Mina (Biblical Greek) (mina) Grain to Mina (Biblical Hebrew) (mina) Grain to Talent (Biblical Greek) (talent) Grain to Talent (Biblical Hebrew) (talent)
Force / Engineering (5 units)
Grain to Poundal (pdl) Grain to Ton (assay) (US) (AT) Grain to Ton (assay) (UK) (AT) Grain to Kilogram-force square second/meter (hyl) Grain to Slug (slug)

Sources & references

Conversion factor (1 gr = 6.47989e+16 ag) verified against the following authoritative sources:

Results are provided for general reference. Verify critical measurements against an authoritative standard.