Convert Troy Ounce to Dram (avoirdupois)
Convert troy ounces to drams (avoirdupois) instantly. 1 troy ounce = 17.5542856678 dram (avoirdupois) — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Dram (avoirdupois) to Troy Ounce converter for the reverse conversion.
Units explained
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 (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.
Troy Ounce to Dram (avoirdupois) conversion formula
The relationship between troy ounces and drams (avoirdupois):
To convert troy ounces to drams (avoirdupois), multiply the value in troy ounces by 17.5542856678. To reverse, multiply drams (avoirdupois) by 0.056966146.
How to use this converter
Type a value into the calculator. The result in drams (avoirdupois) 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 (avoirdupois) to Troy Ounce converter for the reverse direction.
Step-by-step: convert troy ounces to drams (avoirdupois)
- Write down the value in troy ounces (oz t).
- Multiply that value by the factor 17.5542856678.
- The product is the equivalent value in drams (avoirdupois) (dr).
- To reverse, multiply the dram (avoirdupois) value by 0.056966146.
Worked examples
Example 1 — Convert 1 oz t to dr:
1 × 17.5542856678 = 17.5542856678 dr
Example 2 — Convert 100 oz t to dr:
100 × 17.5542856678 = 1755.4285667845 dr
Real-world example — Ruler-scale measurements
A 30-troy ounce school ruler converts cleanly to drams (avoirdupois) — useful when buying a desk accessory from a retailer whose product specs use a different unit.
30 oz t × 17.5542856678 = 526.6285700354 dr
Real-world example — Hardware-scale dimensions
A 10-troy ounce fastener or component is about as long as a thumbnail. Mechanics and DIY enthusiasts convert between troy ounces and drams (avoirdupois) daily when mixing metric and imperial tools.
10 oz t × 17.5542856678 = 175.5428566785 dr
Real-world example — Postcard and small-object dimensions
A postcard is about 5 troy ounces wide. Converting to drams (avoirdupois) is essential for international postal addressing forms that ask for dimensions in different units across countries.
5 oz t × 17.5542856678 = 87.7714283392 dr
Troy Ounce to Dram (avoirdupois) conversion table
Standard reference values for converting troy ounces to drams (avoirdupois):
| Troy Ounce [oz t] | Dram (avoirdupois) [dr] |
|---|---|
| 0.01 | 0.1755428567 |
| 0.1 | 1.7554285668 |
| 1 | 17.5542856678 |
| 2 | 35.1085713357 |
| 3 | 52.6628570035 |
| 4 | 70.2171426714 |
| 5 | 87.7714283392 |
| 10 | 175.5428566785 |
| 20 | 351.0857133569 |
| 30 | 526.6285700354 |
| 40 | 702.1714267138 |
| 50 | 877.7142833923 |
| 100 | 1755.4285667845 |
| 500 | 8777.1428339225 |
| 1000 | 17554.285667845 |
Frequently asked questions
How many drams (avoirdupois) is 1 troy ounce?
How do I convert troy ounces to drams (avoirdupois)?
How do I convert drams (avoirdupois) back to troy ounces?
How many drams (avoirdupois) is 100 troy ounces?
Popular weight unit conversions
Convert Troy Ounce to other weight units
Show all Troy Ounce 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 oz t = 17.5542856678 dr) 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.