Mass and Weight · Unit Converter

Convert Dram (apothecary/troy) to Ounce

Convert drams (apothecary/troy) to ounces instantly. 1 dram (apothecary/troy) = 0.1371428573 ounce — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Ounce 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.

Avoirdupois

Ounce

What is a ounce?

The (avoirdupois) ounce (oz) equals one-sixteenth of a pound, about 28.35 grams.

Origin of the ounce

From Latin 'uncia', meaning a twelfth part.

Where it is used

US food portions, postal weights, and boxing weight classes.

When and where it was developed

Standardized as 1/16 of the international pound from 1959.

Dram (apothecary/troy) to Ounce conversion formula

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

1 dr ap = 0.1371428573 oz
1 oz = 7.2916666602 dr ap

To convert drams (apothecary/troy) to ounces, multiply the value in drams (apothecary/troy) by 0.1371428573. To reverse, multiply ounces by 7.2916666602.

How to use this converter

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

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

  1. Write down the value in drams (apothecary/troy) (dr ap).
  2. Multiply that value by the factor 0.1371428573.
  3. The product is the equivalent value in ounces (oz).
  4. To reverse, multiply the ounce value by 7.2916666602.

Worked examples

Example 1 — Convert 1 dr ap to oz:
1 × 0.1371428573 = 0.1371428573 oz

Example 2 — Convert 100 dr ap to oz:
100 × 0.1371428573 = 13.7142857264 oz

Real-world example — Ruler-scale measurements

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

30 dr ap × 0.1371428573 = 4.1142857179 oz

Real-world example — Hardware-scale dimensions

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

10 dr ap × 0.1371428573 = 1.3714285726 oz

Real-world example — Postcard and small-object dimensions

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

5 dr ap × 0.1371428573 = 0.6857142863 oz

Dram (apothecary/troy) to Ounce conversion table

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

Dram (apothecary/troy) [dr ap]Ounce [oz]
0.010.0013714286
0.10.0137142857
10.1371428573
20.2742857145
30.4114285718
40.5485714291
50.6857142863
101.3714285726
202.7428571453
304.1142857179
405.4857142906
506.8571428632
10013.7142857264
50068.5714286319
1000137.1428572638

Frequently asked questions

How many ounces is 1 dram (apothecary/troy)?
1 dram (apothecary/troy) equals 0.1371428573 ounce.
How do I convert drams (apothecary/troy) to ounces?
Multiply the value in drams (apothecary/troy) by 0.1371428573 to get ounces.
How do I convert ounces back to drams (apothecary/troy)?
Multiply the value in ounces by 7.2916666602, or use the Ounce to Dram (apothecary/troy) converter.
How many ounces is 100 drams (apothecary/troy)?
100 drams (apothecary/troy) equals 13.7142857264 ounces, because 100 × 0.1371428573 = 13.7142857264.

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 = 0.1371428573 oz) verified against the following authoritative sources:

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