Convert Dram (avoirdupois) to Attogram
Convert drams (avoirdupois) to attograms instantly. 1 dram (avoirdupois) = 1.771845e+18 attogram — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Attogram to Dram (avoirdupois) converter for the reverse conversion.
Units explained
Dram (avoirdupois)
The avoirdupois dram (dr) equals one-sixteenth of an ounce, about 1.77 grams.
From Greek 'drachma' through Latin 'dragma'.
Historically pharmacy; today occasional cooking and firearms (powder) use.
Defined as 1/256 of the avoirdupois pound.
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.
Dram (avoirdupois) to Attogram conversion formula
The relationship between drams (avoirdupois) and attograms:
To convert drams (avoirdupois) to attograms, multiply the value in drams (avoirdupois) by 1.771845e+18. To reverse, multiply attograms by 5.643834e-19.
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 Dram (avoirdupois) converter for the reverse direction.
Step-by-step: convert drams (avoirdupois) to attograms
- Write down the value in drams (avoirdupois) (dr).
- Multiply that value by the factor 1.771845e+18.
- The product is the equivalent value in attograms (ag).
- To reverse, multiply the attogram value by 5.643834e-19.
Worked examples
Example 1 — Convert 1 dr to ag:
1 × 1.771845e+18 = 1.771845e+18 ag
Example 2 — Convert 100 dr to ag:
100 × 1.771845e+18 = 1.771845e+20 ag
Real-world example — Centimeter to wavelength scale
One dram (avoirdupois) equals 10 million attograms. Physics curricula use this kind of conversion to relate everyday measurements to atomic and optical scales.
1 dr × 1.771845e+18 = 1.771845e+18 ag
Real-world example — Small-scale to atomic-scale
One dram (avoirdupois) equals 10 million attograms — useful for physics curricula that relate everyday measurements to atomic and optical scales.
1 dr × 1.771845e+18 = 1.771845e+18 ag
Dram (avoirdupois) to Attogram conversion table
Standard reference values for converting drams (avoirdupois) to attograms:
| Dram (avoirdupois) [dr] | Attogram [ag] |
|---|---|
| 0.01 | 1.771845e+16 |
| 0.1 | 1.771845e+17 |
| 1 | 1.771845e+18 |
| 2 | 3.54369e+18 |
| 3 | 5.315536e+18 |
| 4 | 7.087381e+18 |
| 5 | 8.859226e+18 |
| 10 | 1.771845e+19 |
| 20 | 3.54369e+19 |
| 30 | 5.315536e+19 |
| 40 | 7.087381e+19 |
| 50 | 8.859226e+19 |
| 100 | 1.771845e+20 |
| 500 | 8.859226e+20 |
| 1000 | 1.771845e+21 |
Frequently asked questions
How many attograms is 1 dram (avoirdupois)?
How do I convert drams (avoirdupois) to attograms?
How do I convert attograms back to drams (avoirdupois)?
How many attograms is 100 drams (avoirdupois)?
Popular weight unit conversions
Convert Dram (avoirdupois) to other weight units
Show all Dram (avoirdupois) conversions
Metric / SI (18 units)
Avoirdupois (14 units)
Troy & Apothecary (10 units)
Indian / South Asian (6 units)
Scientific / Atomic (9 units)
Astronomical (4 units)
Biblical / Ancient (14 units)
Sources & references
Conversion factor (1 dr = 1.771845e+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.