Aisha K.
Mar 12, 2026
Clean layout and the results update instantly. Exactly what I needed for a quick planning check.
Unit Converters
Atomic Mass Units to Grams Converter
grams = u × 1.66053906660 × 10⁻²⁴. (1 u = 1.66053906660 × 10⁻²⁷ kg.)
Daltons (u) are how chemists weigh atoms. Carbon-12 is defined as 12 u. The gram is 6.022 × 10²³ of those, which is why a mole of carbon is 12 g. This page is for lab sheets, not grocery bags.
Atomic mass units
u → g
1.9926e-23 g
12 u (carbon-12 atom) ≈ 1.993 × 10⁻²³ g. Water 18 u ≈ 2.989 × 10⁻²³ g per molecule.
- You typed
- 12 u
- One g is
- 6.0221e23 u
- How it’s calculated
- grams = u × 1.66053906660 × 10⁻²⁴. (1 u = 1.66053906660 × 10⁻²⁷ kg.)
Plain-English guide
Terms & how it works
Confused by a field? Read the short definitions here while you use the tool.
Atomic mass units
The “Atomic mass units” value used in this tool’s formula. Adjust it to see results update live.
How this calculator works
Daltons (u) are how chemists weigh atoms. Carbon-12 is defined as 12 u. The gram is 6.022 × 10²³ of those, which is why a mole of carbon is 12 g. This page is for lab sheets, not grocery bags. grams = u × 1.66053906660 × 10⁻²⁴. (1 u = 1.66053906660 × 10⁻²⁷ kg.) Example: 12 u (carbon-12 atom) ≈ 1.993 × 10⁻²³ g. Water 18 u ≈ 2.989 × 10⁻²³ g per molecule.
grams = u × 1.66053906660 × 10⁻²⁴. (1 u = 1.66053906660 × 10⁻²⁷ kg.)
Example: 12 u (carbon-12 atom) ≈ 1.993 × 10⁻²³ g. Water 18 u ≈ 2.989 × 10⁻²³ g per molecule.
When to use this Atomic Mass Units to Grams
Common use cases
- Daltons (u) are how chemists weigh atoms. Carbon-12 is defined as 12 u. The gram is 6.022 × 10²³ of those, which is why a mole of carbon is 12 g. This page is for lab sheets, not grocery bags.
- Sanity-check with this case: 12 u (carbon-12 atom) ≈ 1.993 × 10⁻²³ g. Water 18 u ≈ 2.989 × 10⁻²³ g per molecule.
- The relationship is: grams = u × 1.66053906660 × 10⁻²⁴. (1 u = 1.66053906660 × 10⁻²⁷ kg.)
Localized examples
- Unit Converters: the example on this page uses the same formula as the widget.
What you get
- Fields: Atomic mass units
- grams = u × 1.66053906660 × 10⁻²⁴. (1 u = 1.66053906660 × 10⁻²⁷ kg.)
- Example on the page: 12 u (carbon-12 atom) ≈ 1.993 × 10⁻²³ g. Water 18 u ≈ 2.989 × 10⁻²³ g per molecule.
How to Convert Atomic Mass Units to Grams Step-by-Step
- 1Enter Atomic mass units. Use the values you have, not a catalog average, unless that is all you know.
- 2grams = u × 1.66053906660 × 10⁻²⁴. (1 u = 1.66053906660 × 10⁻²⁷ kg.)
- 3Worked case: 12 u (carbon-12 atom) ≈ 1.993 × 10⁻²³ g. Water 18 u ≈ 2.989 × 10⁻²³ g per molecule.
- 4Check which dictionary the other person is using — US or UK, decimal or 1,024 — then trust the number.
Governing formula
grams = u × 1.66053906660 × 10⁻²⁴. (1 u = 1.66053906660 × 10⁻²⁷ kg.)
12 u (carbon-12 atom) ≈ 1.993 × 10⁻²³ g. Water 18 u ≈ 2.989 × 10⁻²³ g per molecule.
Example: set Atomic mass units = 12, then read the result.
Variable definitions
- value
Atomic mass units
The “Atomic mass units” field. Default 12; typical range 0–1000000000.
- The conversion (grams = u × 1.66053906660 × 10⁻²⁴. (1 u = 1.66053906660 × 10⁻²⁷ kg.)) does not pick US vs UK gallons, SI vs binary megabytes, or Mach at altitude for you. Read the footnote on the page.
- Nothing here is uploaded for the calculation itself.
Frequently Asked Questions
Dalton and unified atomic mass unit are treated as the same here.
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4.8
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4 reviews
Daniel R.
Feb 28, 2026
Very usable on mobile. Would love a save/export option later, but the math feels solid.
Priya S.
Feb 3, 2026
The FAQ section answered my questions before I even had to search. Smooth dark mode too.
Marcus L.
Jan 19, 2026
Simple inputs, clear outputs. This replaced three bookmarks I used to juggle.
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