Mass and Weight · Unit Converter

Convert Dram (apothecary/troy) to Attogram

Convert drams (apothecary/troy) to attograms instantly. 1 dram (apothecary/troy) = 3.887935e+18 attogram — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Attogram to Dram (apothecary/troy) 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

Troy & Apothecary

Dram (apothecary/troy)

What is a dram (apothecary/troy)?

The apothecary (troy) dram equals one-eighth of a troy ounce, about 3.888 grams.

Origin of the dram (apothecary/troy)

From the apothecaries' system rooted in the Greek 'drachma'.

Where it is used

Historical pharmacy and medicine compounding.

When and where it was developed

Part of the apothecaries' system of weights used through the 19th century.

Metric / SI

Attogram

What is a attogram?

An attogram (ag) equals 10^-21 kilogram.

Origin of the attogram

From the SI prefix 'atto-' (from Danish 'atten', eighteen).

Where it is used

Frontier nanoscience and single-molecule mass detection.

When and where it was developed

The atto- prefix was adopted by the CGPM in 1975.

Dram (apothecary/troy) to Attogram conversion formula

The relationship between drams (apothecary/troy) and attograms:

1 dr ap = 3.887935e+18 ag
1 ag = 2.57206e-19 dr ap

To convert drams (apothecary/troy) to attograms, multiply the value in drams (apothecary/troy) by 3.887935e+18. To reverse, multiply attograms by 2.57206e-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 (apothecary/troy) converter for the reverse direction.

Step-by-step: convert drams (apothecary/troy) to attograms

  1. Write down the value in drams (apothecary/troy) (dr ap).
  2. Multiply that value by the factor 3.887935e+18.
  3. The product is the equivalent value in attograms (ag).
  4. To reverse, multiply the attogram value by 2.57206e-19.

Worked examples

Example 1 — Convert 1 dr ap to ag:
1 × 3.887935e+18 = 3.887935e+18 ag

Example 2 — Convert 100 dr ap to ag:
100 × 3.887935e+18 = 3.887935e+20 ag

Real-world example — Centimeter to wavelength scale

One dram (apothecary/troy) equals 10 million attograms. Physics curricula use this kind of conversion to relate everyday measurements to atomic and optical scales.

1 dr ap × 3.887935e+18 = 3.887935e+18 ag

Real-world example — Small-scale to atomic-scale

One dram (apothecary/troy) equals 10 million attograms — useful for physics curricula that relate everyday measurements to atomic and optical scales.

1 dr ap × 3.887935e+18 = 3.887935e+18 ag

Dram (apothecary/troy) to Attogram conversion table

Standard reference values for converting drams (apothecary/troy) to attograms:

Dram (apothecary/troy) [dr ap]Attogram [ag]
0.013.887935e+16
0.13.887935e+17
13.887935e+18
27.775869e+18
31.16638e+19
41.555174e+19
51.943967e+19
103.887935e+19
207.775869e+19
301.16638e+20
401.555174e+20
501.943967e+20
1003.887935e+20
5001.943967e+21
10003.887935e+21

Frequently asked questions

How many attograms is 1 dram (apothecary/troy)?
1 dram (apothecary/troy) equals 3.887935e+18 attogram.
How do I convert drams (apothecary/troy) to attograms?
Multiply the value in drams (apothecary/troy) by 3.887935e+18 to get attograms.
How do I convert attograms back to drams (apothecary/troy)?
Multiply the value in attograms by 2.57206e-19, or use the Attogram to Dram (apothecary/troy) converter.
How many attograms is 100 drams (apothecary/troy)?
100 drams (apothecary/troy) equals 3.887935e+20 attograms, because 100 × 3.887935e+18 = 3.887935e+20.

Convert Dram (apothecary/troy) to other weight units

Show all Dram (apothecary/troy) conversions
Metric / SI (18 units)
Dram (apothecary/troy) to Attogram (ag) Dram (apothecary/troy) to Femtogram (fg) Dram (apothecary/troy) to Picogram (pg) Dram (apothecary/troy) to Nanogram (ng) Dram (apothecary/troy) to Microgram (µg) Dram (apothecary/troy) to Milligram (mg) Dram (apothecary/troy) to Centigram (cg) Dram (apothecary/troy) to Decigram (dg) Dram (apothecary/troy) to Gram (g) Dram (apothecary/troy) to Dekagram (dag) Dram (apothecary/troy) to Hectogram (hg) Dram (apothecary/troy) to Kilogram (kg) Dram (apothecary/troy) to Quintal (metric) (q) Dram (apothecary/troy) to Metric Ton (t) Dram (apothecary/troy) to Gigagram (Gg) Dram (apothecary/troy) to Teragram (Tg) Dram (apothecary/troy) to Petagram (Pg) Dram (apothecary/troy) to Exagram (Eg)
Avoirdupois (15 units)
Dram (apothecary/troy) to Grain (gr) Dram (apothecary/troy) to Dram (avoirdupois) (dr) Dram (apothecary/troy) to Ounce (oz) Dram (apothecary/troy) to Pound (lb) Dram (apothecary/troy) to Clove (clove) Dram (apothecary/troy) to Stone (US) (st) Dram (apothecary/troy) to Stone (UK) (st) Dram (apothecary/troy) to Quarter (US) (qr) Dram (apothecary/troy) to Quarter (UK) (qr) Dram (apothecary/troy) to Hundredweight (US) (cwt) Dram (apothecary/troy) to Hundredweight (UK) (cwt) Dram (apothecary/troy) to Wey (wey) Dram (apothecary/troy) to Kilopound (kip) (kip) Dram (apothecary/troy) to Ton (short, US) (sh tn) Dram (apothecary/troy) to Ton (long, UK) (long tn)
Troy & Apothecary (9 units)
Dram (apothecary/troy) to Point (1/100 carat) (pt) Dram (apothecary/troy) to Carat (metric) (ct) Dram (apothecary/troy) to Scruple (apothecary) (s ap) Dram (apothecary/troy) to Pennyweight (dwt) Dram (apothecary/troy) to Momme (mom) Dram (apothecary/troy) to Mace (mace) Dram (apothecary/troy) to Troy Ounce (oz t) Dram (apothecary/troy) to Tael (tael) Dram (apothecary/troy) to Pound (troy/apothecary) (lb t)
Indian / South Asian (6 units)
Dram (apothecary/troy) to Ratti (ratti) Dram (apothecary/troy) to Masha (masha) Dram (apothecary/troy) to Tola (tola) Dram (apothecary/troy) to Chittack (Chatank) (chittack) Dram (apothecary/troy) to Seer (Ser) (seer) Dram (apothecary/troy) to Maund (Mann) (maund)
Scientific / Atomic (9 units)
Dram (apothecary/troy) to Electron Mass (rest) (me) Dram (apothecary/troy) to MeV/c2 (MeV/c²) Dram (apothecary/troy) to Muon Mass (mµ) Dram (apothecary/troy) to Atomic Mass Unit (u) Dram (apothecary/troy) to Proton Mass (mp) Dram (apothecary/troy) to Neutron Mass (mn) Dram (apothecary/troy) to Deuteron Mass (md) Dram (apothecary/troy) to Carbon-12 Atom Mass (C-12) Dram (apothecary/troy) to Planck Mass (mP)
Astronomical (4 units)
Dram (apothecary/troy) to Lunar Mass (Moon) (M☾) Dram (apothecary/troy) to Earth's Mass (M⊕) Dram (apothecary/troy) to Jupiter Mass (MJ) Dram (apothecary/troy) to Sun's Mass (M☉)
Biblical / Ancient (14 units)
Dram (apothecary/troy) to Lepton (Biblical Roman) (lepton) Dram (apothecary/troy) to Quadrans (Biblical Roman) (quadrans) Dram (apothecary/troy) to Assarion (Biblical Roman) (assarion) Dram (apothecary/troy) to Gerah (Biblical Hebrew) (gerah) Dram (apothecary/troy) to Drachma (Biblical Greek) (drachma) Dram (apothecary/troy) to Denarius (Biblical Roman) (denarius) Dram (apothecary/troy) to Bekan (Biblical Hebrew) (bekah) Dram (apothecary/troy) to Didrachma (Biblical Greek) (didrachma) Dram (apothecary/troy) to Shekel (Biblical Hebrew) (shekel) Dram (apothecary/troy) to Tetradrachma (Biblical Greek) (tetra) Dram (apothecary/troy) to Mina (Biblical Greek) (mina) Dram (apothecary/troy) to Mina (Biblical Hebrew) (mina) Dram (apothecary/troy) to Talent (Biblical Greek) (talent) Dram (apothecary/troy) to Talent (Biblical Hebrew) (talent)
Force / Engineering (5 units)
Dram (apothecary/troy) to Poundal (pdl) Dram (apothecary/troy) to Ton (assay) (US) (AT) Dram (apothecary/troy) to Ton (assay) (UK) (AT) Dram (apothecary/troy) to Kilogram-force square second/meter (hyl) Dram (apothecary/troy) to Slug (slug)

Sources & references

Conversion factor (1 dr ap = 3.887935e+18 ag) verified against the following authoritative sources:

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