Mass and Weight · Unit Converter

Convert Dram (avoirdupois) to Dram (apothecary/troy)

Convert drams (avoirdupois) to drams (apothecary/troy) instantly. 1 dram (avoirdupois) = 0.4557291679 dram (apothecary/troy) — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Dram (apothecary/troy) to Dram (avoirdupois) 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

Avoirdupois

Dram (avoirdupois)

What is a dram (avoirdupois)?

The avoirdupois dram (dr) equals one-sixteenth of an ounce, about 1.77 grams.

Origin of the dram (avoirdupois)

From Greek 'drachma' through Latin 'dragma'.

Where it is used

Historically pharmacy; today occasional cooking and firearms (powder) use.

When and where it was developed

Defined as 1/256 of the avoirdupois pound.

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.

Dram (avoirdupois) to Dram (apothecary/troy) conversion formula

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

1 dr = 0.4557291679 dr ap
1 dr ap = 2.1942857085 dr

To convert drams (avoirdupois) to drams (apothecary/troy), multiply the value in drams (avoirdupois) by 0.4557291679. To reverse, multiply drams (apothecary/troy) by 2.1942857085.

How to use this converter

Type a value into the calculator. The result in drams (apothecary/troy) updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Dram (apothecary/troy) to Dram (avoirdupois) converter for the reverse direction.

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

  1. Write down the value in drams (avoirdupois) (dr).
  2. Multiply that value by the factor 0.4557291679.
  3. The product is the equivalent value in drams (apothecary/troy) (dr ap).
  4. To reverse, multiply the dram (apothecary/troy) value by 2.1942857085.

Worked examples

Example 1 — Convert 1 dr to dr ap:
1 × 0.4557291679 = 0.4557291679 dr ap

Example 2 — Convert 100 dr to dr ap:
100 × 0.4557291679 = 45.5729167872 dr ap

Real-world example — Ruler-scale measurements

A 30-dram (avoirdupois) school ruler converts cleanly to drams (apothecary/troy) — useful when buying a desk accessory from a retailer whose product specs use a different unit.

30 dr × 0.4557291679 = 13.6718750362 dr ap

Real-world example — Hardware-scale dimensions

A 10-dram (avoirdupois) fastener or component is about as long as a thumbnail. Mechanics and DIY enthusiasts convert between drams (avoirdupois) and drams (apothecary/troy) daily when mixing metric and imperial tools.

10 dr × 0.4557291679 = 4.5572916787 dr ap

Real-world example — Postcard and small-object dimensions

A postcard is about 5 drams (avoirdupois) wide. Converting to drams (apothecary/troy) is essential for international postal addressing forms that ask for dimensions in different units across countries.

5 dr × 0.4557291679 = 2.2786458394 dr ap

Dram (avoirdupois) to Dram (apothecary/troy) conversion table

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

Dram (avoirdupois) [dr]Dram (apothecary/troy) [dr ap]
0.010.0045572917
0.10.0455729168
10.4557291679
20.9114583357
31.3671875036
41.8229166715
52.2786458394
104.5572916787
209.1145833574
3013.6718750362
4018.2291667149
5022.7864583936
10045.5729167872
500227.8645839362
1000455.7291678723

Frequently asked questions

How many drams (apothecary/troy) is 1 dram (avoirdupois)?
1 dram (avoirdupois) equals 0.4557291679 dram (apothecary/troy).
How do I convert drams (avoirdupois) to drams (apothecary/troy)?
Multiply the value in drams (avoirdupois) by 0.4557291679 to get drams (apothecary/troy).
How do I convert drams (apothecary/troy) back to drams (avoirdupois)?
Multiply the value in drams (apothecary/troy) by 2.1942857085, or use the Dram (apothecary/troy) to Dram (avoirdupois) converter.
How many drams (apothecary/troy) is 100 drams (avoirdupois)?
100 drams (avoirdupois) equals 45.5729167872 drams (apothecary/troy), because 100 × 0.4557291679 = 45.5729167872.

Convert Dram (avoirdupois) to other weight units

Show all Dram (avoirdupois) conversions
Metric / SI (18 units)
Dram (avoirdupois) to Attogram (ag) Dram (avoirdupois) to Femtogram (fg) Dram (avoirdupois) to Picogram (pg) Dram (avoirdupois) to Nanogram (ng) Dram (avoirdupois) to Microgram (µg) Dram (avoirdupois) to Milligram (mg) Dram (avoirdupois) to Centigram (cg) Dram (avoirdupois) to Decigram (dg) Dram (avoirdupois) to Gram (g) Dram (avoirdupois) to Dekagram (dag) Dram (avoirdupois) to Hectogram (hg) Dram (avoirdupois) to Kilogram (kg) Dram (avoirdupois) to Quintal (metric) (q) Dram (avoirdupois) to Metric Ton (t) Dram (avoirdupois) to Gigagram (Gg) Dram (avoirdupois) to Teragram (Tg) Dram (avoirdupois) to Petagram (Pg) Dram (avoirdupois) to Exagram (Eg)
Avoirdupois (14 units)
Dram (avoirdupois) to Grain (gr) Dram (avoirdupois) to Ounce (oz) Dram (avoirdupois) to Pound (lb) Dram (avoirdupois) to Clove (clove) Dram (avoirdupois) to Stone (US) (st) Dram (avoirdupois) to Stone (UK) (st) Dram (avoirdupois) to Quarter (US) (qr) Dram (avoirdupois) to Quarter (UK) (qr) Dram (avoirdupois) to Hundredweight (US) (cwt) Dram (avoirdupois) to Hundredweight (UK) (cwt) Dram (avoirdupois) to Wey (wey) Dram (avoirdupois) to Kilopound (kip) (kip) Dram (avoirdupois) to Ton (short, US) (sh tn) Dram (avoirdupois) to Ton (long, UK) (long tn)
Troy & Apothecary (10 units)
Dram (avoirdupois) to Point (1/100 carat) (pt) Dram (avoirdupois) to Carat (metric) (ct) Dram (avoirdupois) to Scruple (apothecary) (s ap) Dram (avoirdupois) to Pennyweight (dwt) Dram (avoirdupois) to Momme (mom) Dram (avoirdupois) to Mace (mace) Dram (avoirdupois) to Dram (apothecary/troy) (dr ap) Dram (avoirdupois) to Troy Ounce (oz t) Dram (avoirdupois) to Tael (tael) Dram (avoirdupois) to Pound (troy/apothecary) (lb t)
Indian / South Asian (6 units)
Dram (avoirdupois) to Ratti (ratti) Dram (avoirdupois) to Masha (masha) Dram (avoirdupois) to Tola (tola) Dram (avoirdupois) to Chittack (Chatank) (chittack) Dram (avoirdupois) to Seer (Ser) (seer) Dram (avoirdupois) to Maund (Mann) (maund)
Scientific / Atomic (9 units)
Dram (avoirdupois) to Electron Mass (rest) (me) Dram (avoirdupois) to MeV/c2 (MeV/c²) Dram (avoirdupois) to Muon Mass (mµ) Dram (avoirdupois) to Atomic Mass Unit (u) Dram (avoirdupois) to Proton Mass (mp) Dram (avoirdupois) to Neutron Mass (mn) Dram (avoirdupois) to Deuteron Mass (md) Dram (avoirdupois) to Carbon-12 Atom Mass (C-12) Dram (avoirdupois) to Planck Mass (mP)
Astronomical (4 units)
Dram (avoirdupois) to Lunar Mass (Moon) (M☾) Dram (avoirdupois) to Earth's Mass (M⊕) Dram (avoirdupois) to Jupiter Mass (MJ) Dram (avoirdupois) to Sun's Mass (M☉)
Biblical / Ancient (14 units)
Dram (avoirdupois) to Lepton (Biblical Roman) (lepton) Dram (avoirdupois) to Quadrans (Biblical Roman) (quadrans) Dram (avoirdupois) to Assarion (Biblical Roman) (assarion) Dram (avoirdupois) to Gerah (Biblical Hebrew) (gerah) Dram (avoirdupois) to Drachma (Biblical Greek) (drachma) Dram (avoirdupois) to Denarius (Biblical Roman) (denarius) Dram (avoirdupois) to Bekan (Biblical Hebrew) (bekah) Dram (avoirdupois) to Didrachma (Biblical Greek) (didrachma) Dram (avoirdupois) to Shekel (Biblical Hebrew) (shekel) Dram (avoirdupois) to Tetradrachma (Biblical Greek) (tetra) Dram (avoirdupois) to Mina (Biblical Greek) (mina) Dram (avoirdupois) to Mina (Biblical Hebrew) (mina) Dram (avoirdupois) to Talent (Biblical Greek) (talent) Dram (avoirdupois) to Talent (Biblical Hebrew) (talent)
Force / Engineering (5 units)
Dram (avoirdupois) to Poundal (pdl) Dram (avoirdupois) to Ton (assay) (US) (AT) Dram (avoirdupois) to Ton (assay) (UK) (AT) Dram (avoirdupois) to Kilogram-force square second/meter (hyl) Dram (avoirdupois) to Slug (slug)

Sources & references

Conversion factor (1 dr = 0.4557291679 dr ap) verified against the following authoritative sources:

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