Mass and Weight · Unit Converter

Convert Stone (US) to Grain

Convert stones (us) to grains instantly. 1 stone (us) = 87500.0135033157 grain — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Grain to Stone (US) 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

Stone (US)

What is a stone (us)?

A less common US definition of the stone, about 5.67 kilograms.

Origin of the stone (us)

A variant stone weight used in some historical US trade.

Where it is used

Rare; appears mainly in historical or specialized contexts.

When and where it was developed

Derived from older English stone weights that varied by commodity.

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.

Stone (US) to Grain conversion formula

The relationship between stones (us) and grains:

1 st = 87500.0135033157 gr
1 gr = 1.142857e-5 st

To convert stones (us) to grains, multiply the value in stones (us) by 87500.0135033157. To reverse, multiply grains by 1.142857e-5.

How to use this converter

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

Step-by-step: convert stones (us) to grains

  1. Write down the value in stones (us) (st).
  2. Multiply that value by the factor 87500.0135033157.
  3. The product is the equivalent value in grains (gr).
  4. To reverse, multiply the grain value by 1.142857e-5.

Worked examples

Example 1 — Convert 1 st to gr:
1 × 87500.0135033157 = 87500.0135033157 gr

Example 2 — Convert 100 st to gr:
100 × 87500.0135033157 = 8750001.3503315654 gr

Real-world example — Sub-meter precision

A 0.001-stone (us) (1 mm) tolerance equals 1,000 grains — useful for surface-finish specs, where macro-scale dimensions are given in the larger unit but feature roughness in the smaller.

0.001 st × 87500.0135033157 = 87.5000135033 gr

Real-world example — Macro-to-micro scale comparison

2 stones (us) of measurement converts to a very large number in grains — useful in materials science when comparing bulk-sample dimensions to feature-level surface specs.

2 st × 87500.0135033157 = 175000.0270066313 gr

Real-world example — Macroscopic to microscopic

One stone (us) equals a million grains. Optical engineers calculating coherence length compare macro-scale path lengths with micro-scale wavelength differences using exactly this conversion.

1 st × 87500.0135033157 = 87500.0135033157 gr

Stone (US) to Grain conversion table

Standard reference values for converting stones (us) to grains:

Stone (US) [st]Grain [gr]
0.01875.0001350332
0.18750.0013503316
187500.0135033157
2175000.0270066313
3262500.040509947
4350000.0540132626
5437500.0675165782
10875000.1350331565
201750000.270066313
302625000.4050994697
403500000.540132626
504375000.6751657827
1008750001.3503315654
5004.375001e+7
10008.750001e+7

Frequently asked questions

How many grains is 1 stone (us)?
1 stone (us) equals 87500.0135033157 grain.
How do I convert stones (us) to grains?
Multiply the value in stones (us) by 87500.0135033157 to get grains.
How do I convert grains back to stones (us)?
Multiply the value in grains by 1.142857e-5, or use the Grain to Stone (US) converter.
How many grains is 100 stones (us)?
100 stones (us) equals 8750001.3503315654 grains, because 100 × 87500.0135033157 = 8750001.3503315654.

Convert Stone (US) to other weight units

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

Sources & references

Conversion factor (1 st = 87500.0135033157 gr) verified against the following authoritative sources:

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