Convert Dram (apothecary/troy) to Troy Ounce
Convert drams (apothecary/troy) to troy ounces instantly. 1 dram (apothecary/troy) = 0.125 troy ounce — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Troy Ounce to Dram (apothecary/troy) converter for the reverse conversion.
Units explained
Dram (apothecary/troy)
The apothecary (troy) dram equals one-eighth of a troy ounce, about 3.888 grams.
From the apothecaries' system rooted in the Greek 'drachma'.
Historical pharmacy and medicine compounding.
Part of the apothecaries' system of weights used through the 19th century.
Troy Ounce
The troy ounce (ozt) equals about 31.103 grams, one-twelfth of a troy pound.
From the Troy system of weights associated with Troyes, France.
The global standard for pricing gold, silver, platinum, and palladium.
Established in the medieval Troy system and retained for precious metals.
Dram (apothecary/troy) to Troy Ounce conversion formula
The relationship between drams (apothecary/troy) and troy ounces:
To convert drams (apothecary/troy) to troy ounces, multiply the value in drams (apothecary/troy) by 0.125. To reverse, multiply troy ounces by 8.
How to use this converter
Type a value into the calculator. The result in troy 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 Troy Ounce to Dram (apothecary/troy) converter for the reverse direction.
Step-by-step: convert drams (apothecary/troy) to troy ounces
- Write down the value in drams (apothecary/troy) (dr ap).
- Multiply that value by the factor 0.125.
- The product is the equivalent value in troy ounces (oz t).
- To reverse, multiply the troy ounce value by 8.
Worked examples
Example 1 — Convert 1 dr ap to oz t:
1 × 0.125 = 0.125 oz t
Example 2 — Convert 100 dr ap to oz t:
100 × 0.125 = 12.5 oz t
Real-world example — Ruler-scale measurements
A 30-dram (apothecary/troy) school ruler converts cleanly to troy ounces — useful when buying a desk accessory from a retailer whose product specs use a different unit.
30 dr ap × 0.125 = 3.75 oz t
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 troy ounces daily when mixing metric and imperial tools.
10 dr ap × 0.125 = 1.25 oz t
Real-world example — Postcard and small-object dimensions
A postcard is about 5 drams (apothecary/troy) wide. Converting to troy ounces is essential for international postal addressing forms that ask for dimensions in different units across countries.
5 dr ap × 0.125 = 0.625 oz t
Dram (apothecary/troy) to Troy Ounce conversion table
Standard reference values for converting drams (apothecary/troy) to troy ounces:
| Dram (apothecary/troy) [dr ap] | Troy Ounce [oz t] |
|---|---|
| 0.01 | 0.00125 |
| 0.1 | 0.0125 |
| 1 | 0.125 |
| 2 | 0.25 |
| 3 | 0.375 |
| 4 | 0.5 |
| 5 | 0.625 |
| 10 | 1.25 |
| 20 | 2.5 |
| 30 | 3.75 |
| 40 | 5 |
| 50 | 6.25 |
| 100 | 12.5 |
| 500 | 62.5 |
| 1000 | 125 |
Frequently asked questions
How many troy ounces is 1 dram (apothecary/troy)?
How do I convert drams (apothecary/troy) to troy ounces?
How do I convert troy ounces back to drams (apothecary/troy)?
How many troy ounces is 100 drams (apothecary/troy)?
Popular weight unit conversions
Convert Dram (apothecary/troy) to other weight units
Show all Dram (apothecary/troy) conversions
Metric / SI (18 units)
Avoirdupois (15 units)
Troy & Apothecary (9 units)
Indian / South Asian (6 units)
Scientific / Atomic (9 units)
Astronomical (4 units)
Biblical / Ancient (14 units)
Sources & references
Conversion factor (1 dr ap = 0.125 oz t) 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.