Convert Gram to Attogram
Convert grams to attograms instantly. 1 gram = 1e+18 attogram — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Attogram to Gram converter for the reverse conversion.
Units explained
Gram
The gram (g) equals one-thousandth of a kilogram.
From Late Latin 'gramma', a small weight or scruple.
The everyday metric unit for food, medicine, and small objects.
Defined in 1795 as the mass of one cubic centimeter of water at melting point.
Attogram
An attogram (ag) equals 10^-21 kilogram.
From the SI prefix 'atto-' (from Danish 'atten', eighteen).
Frontier nanoscience and single-molecule mass detection.
The atto- prefix was adopted by the CGPM in 1975.
Gram to Attogram conversion formula
The relationship between grams and attograms:
To convert grams to attograms, multiply the value in grams by 1e+18. To reverse, multiply attograms by 1e-18.
How to use this converter
Type a value into the calculator. The result in attograms updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Attogram to Gram converter for the reverse direction.
Step-by-step: convert grams to attograms
- Write down the value in grams (g).
- Multiply that value by the factor 1e+18.
- The product is the equivalent value in attograms (ag).
- To reverse, multiply the attogram value by 1e-18.
Worked examples
Example 1 — Convert 1 g to ag:
1 × 1e+18 = 1e+18 ag
Example 2 — Convert 100 g to ag:
100 × 1e+18 = 1e+20 ag
Real-world example — Centimeter to wavelength scale
One gram equals 10 million attograms. Physics curricula use this kind of conversion to relate everyday measurements to atomic and optical scales.
1 g × 1e+18 = 1e+18 ag
Real-world example — Small-scale to atomic-scale
One gram equals 10 million attograms — useful for physics curricula that relate everyday measurements to atomic and optical scales.
1 g × 1e+18 = 1e+18 ag
Gram to Attogram conversion table
Standard reference values for converting grams to attograms:
| Gram [g] | Attogram [ag] |
|---|---|
| 0.01 | 1e+16 |
| 0.1 | 1e+17 |
| 1 | 1e+18 |
| 2 | 2e+18 |
| 3 | 3e+18 |
| 4 | 4e+18 |
| 5 | 5e+18 |
| 10 | 1e+19 |
| 20 | 2e+19 |
| 30 | 3e+19 |
| 40 | 4e+19 |
| 50 | 5e+19 |
| 100 | 1e+20 |
| 500 | 5e+20 |
| 1000 | 1e+21 |
Frequently asked questions
How many attograms is 1 gram?
How do I convert grams to attograms?
How do I convert attograms back to grams?
How many attograms is 100 grams?
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Metric / SI (17 units)
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Indian / South Asian (6 units)
Scientific / Atomic (9 units)
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Biblical / Ancient (14 units)
Sources & references
Conversion factor (1 g = 1e+18 ag) 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 Hydrographic Organization — Resolution on the Nautical Mile
International authority that standardised the nautical mile at exactly 1852 m in 1929 — the value adopted worldwide for sea and air navigation.