Mass and Weight · Unit Converter

Convert Grain to Ounce

Convert grains to ounces instantly. 1 grain = 0.0022857139 ounce — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Ounce 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.

Avoirdupois

Ounce

What is a ounce?

The (avoirdupois) ounce (oz) equals one-sixteenth of a pound, about 28.35 grams.

Origin of the ounce

From Latin 'uncia', meaning a twelfth part.

Where it is used

US food portions, postal weights, and boxing weight classes.

When and where it was developed

Standardized as 1/16 of the international pound from 1959.

Grain to Ounce conversion formula

The relationship between grains and ounces:

1 gr = 0.0022857139 oz
1 oz = 437.5000671308 gr

To convert grains to ounces, multiply the value in grains by 0.0022857139. To reverse, multiply ounces by 437.5000671308.

How to use this converter

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

Step-by-step: convert grains to ounces

  1. Write down the value in grains (gr).
  2. Multiply that value by the factor 0.0022857139.
  3. The product is the equivalent value in ounces (oz).
  4. To reverse, multiply the ounce value by 437.5000671308.

Worked examples

Example 1 — Convert 1 gr to oz:
1 × 0.0022857139 = 0.0022857139 oz

Example 2 — Convert 100 gr to oz:
100 × 0.0022857139 = 0.2285713935 oz

Real-world example — Plastic film and laminate thickness

A 500-grain sheet is a typical spec for ID-card laminates and film overlays. Converting to ounces aligns the value with the unit most CAD systems and material datasheets prefer.

500 gr × 0.0022857139 = 1.1428569675 oz

Real-world example — Packaging gauge

A 4-grain plastic bag thickness is a common spec for grocery and freezer bags. Converting from grains to ounces is what packaging buyers do whenever they bridge US and metric supplier quotes.

4 gr × 0.0022857139 = 0.0091428557 oz

Grain to Ounce conversion table

Standard reference values for converting grains to ounces:

Grain [gr]Ounce [oz]
0.012.285714e-5
0.10.0002285714
10.0022857139
20.0045714279
30.0068571418
40.0091428557
50.0114285697
100.0228571393
200.0457142787
300.068571418
400.0914285574
500.1142856967
1000.2285713935
5001.1428569675
10002.285713935

Frequently asked questions

How many ounces is 1 grain?
1 grain equals 0.0022857139 ounce.
How do I convert grains to ounces?
Multiply the value in grains by 0.0022857139 to get ounces.
How do I convert ounces back to grains?
Multiply the value in ounces by 437.5000671308, or use the Ounce to Grain converter.
How many ounces is 100 grains?
100 grains equals 0.2285713935 ounces, because 100 × 0.0022857139 = 0.2285713935.

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 = 0.0022857139 oz) verified against the following authoritative sources:

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