Mass and Weight · Unit Converter

Convert Ton (assay) (US) to Milligram

Convert tons (assay) (us) to milligrams instantly. 1 ton (assay) (us) = 29166.67 milligram — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Milligram to Ton (assay) (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 June 10, 2026 Last reviewed June 10, 2026 Updated June 10, 2026

Units explained

Force / Engineering

Ton (assay) (US)

What is a ton (assay) (us)?

The assay ton (US) equals about 29.167 grams, a mining-assay convenience unit.

Origin of the ton (assay) (us)

Devised so an assay sample's metal in milligrams reads as troy ounces per short ton.

Where it is used

Ore assaying and metallurgy.

When and where it was developed

Adopted in assay laboratories to simplify ore-grade calculation.

Metric / SI

Milligram

What is a milligram?

A milligram (mg) equals one-millionth of a kilogram, or 0.001 gram.

Origin of the milligram

From the SI prefix 'milli-' (from Latin 'mille', thousand).

Where it is used

Standard for medicine dosing, nutrition labels, and fine jewelry.

When and where it was developed

Part of the original metric system of 1795.

Ton (assay) (US) to Milligram conversion formula

The relationship between tons (assay) (us) and milligrams:

1 AT = 29166.67 mg

1 mg = 3.428571e-5 AT

To convert tons (assay) (us) to milligrams, multiply the value in tons (assay) (us) by 29166.67. To reverse, multiply milligrams by 3.428571e-5.

How to use this converter

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

Step-by-step: convert tons (assay) (us) to milligrams

Write down the value in tons (assay) (us) (AT).
Multiply that value by the factor 29166.67.
The product is the equivalent value in milligrams (mg).
To reverse, multiply the milligram value by 3.428571e-5.

Worked examples

Example 1 — Convert 1 AT to mg:
1 × 29166.67 = 29166.67 mg

Example 2 — Convert 100 AT to mg:
100 × 29166.67 = 2916667 mg

Real-world example — Adjacent small-scale precision

One ton (assay) (us) equals 1,000 milligrams — the standard sub-millimeter precision conversion that materials engineers use whenever they switch between bulk material thickness specs (larger unit) and surface-finish characteristics (smaller unit).

1 AT × 29166.67 = 29166.67 mg

Real-world example — Adjacent metric sub-units

One ton (assay) (us) equals 1,000 milligrams. Engineers move between these scales constantly: PCB feature sizes in the larger unit, wire-bond diameters in the smaller.

1 AT × 29166.67 = 29166.67 mg

Ton (assay) (US) to Milligram conversion table

Standard reference values for converting tons (assay) (us) to milligrams:

Ton (assay) (US) [AT]	Milligram [mg]
0.01	291.6667
0.1	2916.667
1	29166.67
2	58333.34
3	87500.01
4	116666.68
5	145833.35
10	291666.7
20	583333.3999999999
30	875000.1
40	1166666.7999999998
50	1458333.5
100	2916667
500	1.458334e+7
1000	2.916667e+7

Frequently asked questions

How many milligrams is 1 ton (assay) (us)?

1 ton (assay) (us) equals 29166.67 milligram.

How do I convert tons (assay) (us) to milligrams?

Multiply the value in tons (assay) (us) by 29166.67 to get milligrams.

How do I convert milligrams back to tons (assay) (us)?

Multiply the value in milligrams by 3.428571e-5, or use the Milligram to Ton (assay) (US) converter.

How many milligrams is 100 tons (assay) (us)?

100 tons (assay) (us) equals 2916667 milligrams, because 100 × 29166.67 = 2916667.

Convert Ton (assay) (US) to other weight units

Show all Ton (assay) (US) conversions

Metric / SI (18 units)

Avoirdupois (15 units)

Troy & Apothecary (10 units)

Ton (assay) (US) to Point (1/100 carat) (pt) Ton (assay) (US) to Carat (metric) (ct) Ton (assay) (US) to Scruple (apothecary) (s ap) Ton (assay) (US) to Pennyweight (dwt) Ton (assay) (US) to Momme (mom) Ton (assay) (US) to Mace (mace) Ton (assay) (US) to Dram (apothecary/troy) (dr ap) Ton (assay) (US) to Troy Ounce (oz t) Ton (assay) (US) to Tael (tael) Ton (assay) (US) to Pound (troy/apothecary) (lb t)

Indian / South Asian (6 units)

Ton (assay) (US) to Ratti (ratti) Ton (assay) (US) to Masha (masha) Ton (assay) (US) to Tola (tola) Ton (assay) (US) to Chittack (Chatank) (chittack) Ton (assay) (US) to Seer (Ser) (seer) Ton (assay) (US) to Maund (Mann) (maund)

Scientific / Atomic (9 units)

Ton (assay) (US) to Electron Mass (rest) (me) Ton (assay) (US) to MeV/c2 (MeV/c²) Ton (assay) (US) to Muon Mass (mµ) Ton (assay) (US) to Atomic Mass Unit (u) Ton (assay) (US) to Proton Mass (mp) Ton (assay) (US) to Neutron Mass (mn) Ton (assay) (US) to Deuteron Mass (md) Ton (assay) (US) to Carbon-12 Atom Mass (C-12) Ton (assay) (US) to Planck Mass (mP)

Astronomical (4 units)

Ton (assay) (US) to Lunar Mass (Moon) (M☾) Ton (assay) (US) to Earth's Mass (M⊕) Ton (assay) (US) to Jupiter Mass (MJ) Ton (assay) (US) to Sun's Mass (M☉)

Biblical / Ancient (14 units)

Force / Engineering (4 units)

Ton (assay) (US) to Poundal (pdl) Ton (assay) (US) to Ton (assay) (UK) (AT) Ton (assay) (US) to Kilogram-force square second/meter (hyl) Ton (assay) (US) to Slug (slug)

Sources & references

Conversion factor (1 AT = 29166.67 mg) 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.

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