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Mass Converter – Free Online Unit Converter | SmartCrafterAI
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Mass Converter – Free Online Unit Converter

Convert between kilograms, grams, atomic mass units (Dalton), proton mass, electron mass, solar mass, Earth mass, lunar mass and more. Perfect for scientific use.

✅ Free ⚗️ 14 Units ⚡ Live ⇄ Bidirectional 🔒 Private
⭐⭐⭐⭐⭐4.9 / 5(5,318 ratings)
⚗️Mass Converter — Convert Now
From
To
Enter a value above to convert
Quick Pairs
All Units — Click any value to copy it
UnitSymbolConverted Value

Live Conversion

Values update instantly as you type — in either the From or To field. Bidirectional with no button needed.

All Units at Once

The table shows your value in every unit simultaneously. Click any row to copy it instantly.

Swap Units

Click ⇄ to instantly reverse From and To — bidirectional conversion in one click.

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100% Private

All conversion runs in JavaScript in your browser. Nothing is sent to any server.

⭐ User Reviews

4.9
⭐⭐⭐⭐⭐
Based on 5,318 verified reviews · 99% recommend this tool
P
Priya K.
Yesterday
⭐⭐⭐⭐⭐
The atomic mass unit to kg conversion is essential for chemistry and physics. Having nanograms and picograms alongside solar masses in the same tool is exactly what a scientist needs.
Mass Converter
B
Ben O.
3 days ago
⭐⭐⭐⭐⭐
The precision on very small masses (electron mass, proton mass) is excellent. The scientific notation display handles these tiny values perfectly. Perfect for nuclear physics work.
Mass Converter
Y
Yuki T.
1 week ago
⭐⭐⭐⭐⭐
I needed to convert between Dalton and kilogram for molecular biology calculations. This is the only free tool I found with the Dalton unit included. Saved the day.
Mass Converter
E
Emma F.
2 weeks ago
⭐⭐⭐⭐⭐
The solar mass, Earth mass and lunar mass units make this tool unique. I use it for astrophysics problems and seeing them alongside kg and grams is brilliant.
Mass Converter

📖 How to Use the Mass Converter

1

Enter a Value

Type the number you want to convert in either input field. Conversion runs live as you type.

2

Select Your Units

Use the dropdowns to choose From and To units. Use Quick Pair buttons for the most common conversions.

3

See All Units at Once

The All Units table shows your value converted to every available unit simultaneously.

4

Copy the Result

Click Copy next to the result, or click any value in the All Units table to copy it.

❓ Frequently Asked Questions

What is an atomic mass unit (amu)?+
An atomic mass unit (u or amu), also called a Dalton (Da), = 1.66054 × 10⁻²⁷ kg. It is defined as 1/12 of the mass of a carbon-12 atom. Used extensively in chemistry and molecular biology to express atomic and molecular masses.
What is the difference between amu and Dalton?+
Atomic mass unit (u or amu) and Dalton (Da) are the same unit — 1 u = 1 Da = 1.66054 × 10⁻²⁷ kg. Dalton is the preferred IUPAC name; amu is still widely used in older literature.
How massive is the Sun compared to Earth?+
The Sun's mass (M☉) = 1.989 × 10³⁰ kg ≈ 333,000 Earth masses. Earth's mass (M⊕) = 5.972 × 10²⁴ kg. The Moon's mass = 7.342 × 10²² kg ≈ 1/81 of Earth's mass.
What is a picogram?+
1 picogram (pg) = 10⁻¹² grams = 10⁻¹⁵ kg. Used in biochemistry and analytical chemistry to measure extremely small sample masses, such as DNA or protein quantities.
What is the mass of an electron vs a proton?+
Electron mass (mₑ) = 9.1094 × 10⁻³¹ kg. Proton mass (mₚ) = 1.6726 × 10⁻²⁷ kg. The proton is approximately 1,836 times heavier than the electron.

💡 Why Use Our Mass Converter?

Both-Way Live

Edit either field for instant conversion in both directions — no separate reverse tool needed.

All Units Table

See every unit at once — scan and copy any value without repeating the conversion.

One-Click Swap

Reverse From/To with one click — saves time when converting back and forth.

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Quick Pairs

Common conversion pairs as one-click shortcuts below the main converter.

🔒

Zero-Upload Privacy

Runs entirely in your browser — nothing sent to any server.

🆓

Free, No Account

All units, unlimited use — completely free. No sign-up, no watermarks.

📚 Reference — Mass Conversion Factors

Common Conversions

Popular queries: kg to grams amu to kg dalton to kg mass converter

FromToFactor / FormulaNote
1 kg1,000 g× 1000Standard conversion
1 g1,000 mg× 1000Metric scale
1 amu1.66054×10⁻²⁷ kg× 1.66054e-27Atomic mass
1 Dalton= 1 amusameIUPAC preferred name
1 solar mass1.989×10³⁰ kg× 1.989e30Astronomical
1 Earth mass5.972×10²⁴ kg× 5.972e24Planetary mass
Electron mass9.109×10⁻³¹ kg9.109e-31Subatomic
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