Mass and Weight · Unit Converter

Convert Atomic Mass Unit to Gram

Convert atomic mass unit to grams instantly. 1 atomic mass unit = 1.66054e-24 gram — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Gram to Atomic Mass Unit 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

Scientific / Atomic

Atomic Mass Unit

What is a atomic mass unit?

One unified atomic mass unit (u) is defined as 1/12 the mass of a carbon-12 atom, about 1.6605E-27 kg.

Origin of the atomic mass unit

Introduced to give atomic and molecular masses convenient numerical values.

Where it is used

Atomic, molecular, and nuclear physics and chemistry.

When and where it was developed

The unified (carbon-12) scale was adopted by IUPAC and IUPAP in 1960-1961.

Metric / SI

Gram

What is a gram?

The gram (g) equals one-thousandth of a kilogram.

Origin of the gram

From Late Latin 'gramma', a small weight or scruple.

Where it is used

The everyday metric unit for food, medicine, and small objects.

When and where it was developed

Defined in 1795 as the mass of one cubic centimeter of water at melting point.

Atomic Mass Unit to Gram conversion formula

The relationship between atomic mass unit and grams:

1 u = 1.66054e-24 g
1 g = 6.022137e+23 u

To convert atomic mass unit to grams, multiply the value in atomic mass unit by 1.66054e-24. To reverse, multiply grams by 6.022137e+23.

How to use this converter

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

Step-by-step: convert atomic mass unit to grams

  1. Write down the value in atomic mass unit (u).
  2. Multiply that value by the factor 1.66054e-24.
  3. The product is the equivalent value in grams (g).
  4. To reverse, multiply the gram value by 6.022137e+23.

Worked examples

Example 1 — Convert 1 u to g:
1 × 1.66054e-24 = 1.66054e-24 g

Example 2 — Convert 100 u to g:
100 × 1.66054e-24 = 1.66054e-22 g

Real-world example — Sub-micron to millimeter

500,000 atomic mass unit converts to a small everyday quantity in grams — useful when relating optical-wavelength specifications to physical mounting hardware.

500000 u × 1.66054e-24 = 8.302701e-19 g

Real-world example — From wavelengths to millimeter-scale objects

A value of one million atomic mass unit sounds vast at the atomic scale but converts to a small everyday quantity in grams — useful when relating optical-wavelength specifications to physical mounting hardware.

1000000 u × 1.66054e-24 = 1.66054e-18 g

Atomic Mass Unit to Gram conversion table

Standard reference values for converting atomic mass unit to grams:

Atomic Mass Unit [u]Gram [g]
0.011.66054e-26
0.11.66054e-25
11.66054e-24
23.32108e-24
34.981621e-24
46.642161e-24
58.302701e-24
101.66054e-23
203.32108e-23
304.981621e-23
406.642161e-23
508.302701e-23
1001.66054e-22
5008.302701e-22
10001.66054e-21

Frequently asked questions

How many grams is 1 atomic mass unit?
1 atomic mass unit equals 1.66054e-24 gram.
How do I convert atomic mass unit to grams?
Multiply the value in atomic mass unit by 1.66054e-24 to get grams.
How do I convert grams back to atomic mass unit?
Multiply the value in grams by 6.022137e+23, or use the Gram to Atomic Mass Unit converter.
How many grams is 100 atomic mass unit?
100 atomic mass unit equals 1.66054e-22 grams, because 100 × 1.66054e-24 = 1.66054e-22.

Convert Atomic Mass Unit to other weight units

Show all Atomic Mass Unit conversions
Metric / SI (18 units)
Atomic Mass Unit to Attogram (ag) Atomic Mass Unit to Femtogram (fg) Atomic Mass Unit to Picogram (pg) Atomic Mass Unit to Nanogram (ng) Atomic Mass Unit to Microgram (µg) Atomic Mass Unit to Milligram (mg) Atomic Mass Unit to Centigram (cg) Atomic Mass Unit to Decigram (dg) Atomic Mass Unit to Gram (g) Atomic Mass Unit to Dekagram (dag) Atomic Mass Unit to Hectogram (hg) Atomic Mass Unit to Kilogram (kg) Atomic Mass Unit to Quintal (metric) (q) Atomic Mass Unit to Metric Ton (t) Atomic Mass Unit to Gigagram (Gg) Atomic Mass Unit to Teragram (Tg) Atomic Mass Unit to Petagram (Pg) Atomic Mass Unit to Exagram (Eg)
Avoirdupois (15 units)
Atomic Mass Unit to Grain (gr) Atomic Mass Unit to Dram (avoirdupois) (dr) Atomic Mass Unit to Ounce (oz) Atomic Mass Unit to Pound (lb) Atomic Mass Unit to Clove (clove) Atomic Mass Unit to Stone (US) (st) Atomic Mass Unit to Stone (UK) (st) Atomic Mass Unit to Quarter (US) (qr) Atomic Mass Unit to Quarter (UK) (qr) Atomic Mass Unit to Hundredweight (US) (cwt) Atomic Mass Unit to Hundredweight (UK) (cwt) Atomic Mass Unit to Wey (wey) Atomic Mass Unit to Kilopound (kip) (kip) Atomic Mass Unit to Ton (short, US) (sh tn) Atomic Mass Unit to Ton (long, UK) (long tn)
Troy & Apothecary (10 units)
Atomic Mass Unit to Point (1/100 carat) (pt) Atomic Mass Unit to Carat (metric) (ct) Atomic Mass Unit to Scruple (apothecary) (s ap) Atomic Mass Unit to Pennyweight (dwt) Atomic Mass Unit to Momme (mom) Atomic Mass Unit to Mace (mace) Atomic Mass Unit to Dram (apothecary/troy) (dr ap) Atomic Mass Unit to Troy Ounce (oz t) Atomic Mass Unit to Tael (tael) Atomic Mass Unit to Pound (troy/apothecary) (lb t)
Indian / South Asian (6 units)
Atomic Mass Unit to Ratti (ratti) Atomic Mass Unit to Masha (masha) Atomic Mass Unit to Tola (tola) Atomic Mass Unit to Chittack (Chatank) (chittack) Atomic Mass Unit to Seer (Ser) (seer) Atomic Mass Unit to Maund (Mann) (maund)
Scientific / Atomic (8 units)
Atomic Mass Unit to Electron Mass (rest) (me) Atomic Mass Unit to MeV/c2 (MeV/c²) Atomic Mass Unit to Muon Mass (mµ) Atomic Mass Unit to Proton Mass (mp) Atomic Mass Unit to Neutron Mass (mn) Atomic Mass Unit to Deuteron Mass (md) Atomic Mass Unit to Carbon-12 Atom Mass (C-12) Atomic Mass Unit to Planck Mass (mP)
Astronomical (4 units)
Atomic Mass Unit to Lunar Mass (Moon) (M☾) Atomic Mass Unit to Earth's Mass (M⊕) Atomic Mass Unit to Jupiter Mass (MJ) Atomic Mass Unit to Sun's Mass (M☉)
Biblical / Ancient (14 units)
Atomic Mass Unit to Lepton (Biblical Roman) (lepton) Atomic Mass Unit to Quadrans (Biblical Roman) (quadrans) Atomic Mass Unit to Assarion (Biblical Roman) (assarion) Atomic Mass Unit to Gerah (Biblical Hebrew) (gerah) Atomic Mass Unit to Drachma (Biblical Greek) (drachma) Atomic Mass Unit to Denarius (Biblical Roman) (denarius) Atomic Mass Unit to Bekan (Biblical Hebrew) (bekah) Atomic Mass Unit to Didrachma (Biblical Greek) (didrachma) Atomic Mass Unit to Shekel (Biblical Hebrew) (shekel) Atomic Mass Unit to Tetradrachma (Biblical Greek) (tetra) Atomic Mass Unit to Mina (Biblical Greek) (mina) Atomic Mass Unit to Mina (Biblical Hebrew) (mina) Atomic Mass Unit to Talent (Biblical Greek) (talent) Atomic Mass Unit to Talent (Biblical Hebrew) (talent)
Force / Engineering (5 units)
Atomic Mass Unit to Poundal (pdl) Atomic Mass Unit to Ton (assay) (US) (AT) Atomic Mass Unit to Ton (assay) (UK) (AT) Atomic Mass Unit to Kilogram-force square second/meter (hyl) Atomic Mass Unit to Slug (slug)

Sources & references

Conversion factor (1 u = 1.66054e-24 g) verified against the following authoritative sources:

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